CIP Annual Report 1973

8/9/2019 CIP Annual Report 1973

1/87

IlfTIBI TIOK L

POT TO

INTERN CION L

D L P P


2/87

nnu l

report

973

CENTRO INTERNACIONAL DE

LA

PA PA

APARTADO

5969 LIMA PERU

CA

B

LES.

CI

P

APA


3/87

The

Internat iona

l otato

Center CI

P i s a

scient i f ic

ins t i tut

ion,

autonomous a nd non- profit

making

,

estab

l i

sh

e d by

mea

n s of an agreement w

ith

the Gov ernment of

P er-6 with the

purpo se

of deve lopin g a n d

dissemina

t ing

knowledge

for

grea te r

uti l iz

a

t ion

of

th

e

potato

as

a

bas ic

food .

Int

e

rnat ional

f

unclin

g

sources

for

technical

ass i s t

ance

in ag r i cul tur e a r e fina ncing the Cente r .

11

orta dor de

Papa

11

-

4th

Century A . D . Nazca Culture


4/87


5/87

Board of

Trustees

Staffing

ONTENTS

Forward- Origin of CIP

Objectives

The Potato-Historical

Location of

CIP

CIP - Toluca

General Program

in

RHiearcJli

Thrusts:

System::ttl.cs

Utilization

Control- Ftnlgi

Eact@riai

Viruses

Nem.atode.s

d a p ~ : t i . f J n t


6/87

CIP

BOARD

O F

TRUSTEES

DR. MARIANO SEGURA

Direc tor of

Research

Minis t ry of Agricul ture

La Molina

Lima

Peru

MR. JACK RIGNEY

Dean

of Internat ional Programs ,

North Carol ina

State

Universi ty

l

Pat te r son

Hall

Raleigh

North Carol ina 27607

U.S.

A

DR.

GERRIT DE

BAKKER

Genera l Direc tor

of

Agric .

Resea rch

Minis t ry

of

Agricu l ture

:

Fisher ies ,

l e

v.

d.

Boschs t raa t

4

The Hague

The

Nether lands

DR. B l>RGE JACOBSEN

Superintendent of

the

Improvement

Station

of the

Danish

Fa rme r s Potato

Breeding

Foundation in

Vandel

LKF Foraedl ings

stat ionen

DK-7184 Vandel

Denmark


7/87

DR. ERNS I K ~ L L R

Professor

of

Plant Breeding a t the

Federa l Technical Universi ty,

Eidg. Technische Hoshschule

Zlirich,

Universi t l : l ts trasse

2

8006

Z\irich,

Switzerland

DR. ATMARAM BHAIRAV JOSHI

Direc tor

Indian Agricul tura l Research Inst i tute ,

New Delh i 110012,

India

DR. COLIN

MC CLUNG

Associa te

Director ,

Agricul tural

Sciences,

The Rockefel ler Foundation,

111

West SOth Street,

New York,

New York 10020,

U.

S.

A.

DR.

JOSE

V L L E ~

RlESTRA

Dil ec tor-

Proyecc ion

de

Servicios ,

Univers idad Nacional Agrar ia

Apartado 45 6

La Molina, Lin1a,

Pe ru

DR. RICHARD .L.

SAWYER

Director

General ,

Internat ional Potato Center ,

Apartado 5 969,

Lima,

Pe ru


8/87

S T F F IN G

Decemher-.-' ' 197'3)

i;'lcipal and

Suppo " ing Scientis ts

PhD

Richard Sawyer

Director

General

PhD

Orvil le T. Page

Director of Research

Ing.

Agr.Car los Bohl

P . Executive Officer

PhD

Edward French Head of Depar tment

PhD

Roger

Rowe

Head

of Depar tment

PhD

John

Niederhauser Associa te

Head

PhD

Richard

Wurs te r

Acting Head

PhD Julia

Guzman

N. Pathologist

PhD Nelson Est rada

Breeder

PhD

Raymond Meyer

Agronomist

MS

James

Bryan Seed Production

Special is t

MS Carlos Ochoa Taxonomist

PhD Michael Twomey

Economis t

PhD

Kenneth

Sayre

Physiologis t

PhD

Rolf Scha fer

Nematologist

CPC

Oscar Gil Y. Control ler

Mrl. l

Guil lermo R omero

Accountant

PhD Rainer

Zachmann

Mycologist

PhD Marra

de Scur rah

Nematologis t /

Breeder

Ph

Ana M. Hinostroza Virologis t

PhD

Roger

Jones

Virologis t

PhD

Marco

Soto Superintendent-

Huanca

yo

PhD

Will iam Roca

P:tiysiologist


9/87

MS

Luis

Salazar

MS

Manuel Villareal

MS Oscar Hidalgo

Ing.

Ag r. Juan Aguilar

BS Carmen

de

o d e s t ~

Ing. Agr. Luis

Valencia

Ing.Ag:r. David Baumann

Ing.

Agr.

Lis

de Ocampo

BS Rosa

Mendez

T.

MS Stephanie

Tribble

PhD

Fernando Ezeta

PhD Humberto Mendoza

BS

Norma

Gonzalez

PhD

Pen

Hsiang, Li

PhD Kenneth .Evans

PhD Kenneth

Proudfoot

PhD

John C.

Vessey

MS

Michael

Jackson.

Ing.Agr.

Javie:i;: Franco

MS

Zosimo Huaman

PhD

Lodewijk

Turkensteen

PhD

arviz Jata la

PhD

.Robert

Llischer

Virologist

Regional

Training Officer

Regional

Training

Officer

Agronomist

Librar ian

Entomologist

Field Supervisor

Assis tant

Plant

Pathologist

Laboratory

Technician

Geneticist

Physiologist

Breeder

Laboratory Technician

Physiologist

Nematologist

Pathologist

Pathologist

Taxonomist

Nematologist .

Breeder

Mycologist

Nematologist

Breeder


10/87

FOREWORD

ORIGIN

O F

CIP

El

Centro Internacional de la Papa

is

relat ively new

inst i tut ion. On

January 20

1971 an

organizat ional

agreement

was signed with the Government of Peru

marking

the establ ishment of

CIP as an autonomous

institution.c

The

f i rs t funding for

program act ivi t ies

was received in 1972 but due

to

the la te ass ignment

of

money

most expendi tures and staff

addit ions

were

not

made until the las t

pa r t of that

year . Since then CIP

has made

rapid

progress

in

the development of faci l i t ies

the staffing

of posi t ions and the

initiation

of

program ac-

t ivities.

CIP is

single.-:

crop inst i tute devoted to the tuber

bear ing Solanum species the

white

or I r i sh potato. Peru

has

had

strong potato

research

progra m for

some

years ass i s t ed original ly by North Carol ina State Uni

vers i ty under gran t . f rom

U.S.

AID. This

gave

the

ini t ial impetus

to

the es tabl ishment

of

CIP.

Through

r e sea rch

cont rac ts

ClP has

also

l inked

with

advanced

potato improvement work

a t

other North Amer ican and

European

institutions.

This combination

has

had

the

effect of

providing

CIP

with ready ongoing projects

so

that init ial progress

has been much

more rapid

than

could otherwise

have been real ized.


11/87


12/87


13/87


14/87


15/87

-

-

3J

SAN

RAMQ_T i

(

8

00

m

- - - - -

..

MAX:-

25

2

-.---...

oc.

MEAN.

-----,.----.._________

------------------

~ . MIN.

isr

~

_

_ L

. l

..J

____ _.J. _ _

....J.._._.

__...J_,____

..

___

J_

- -

..

I

..

- J

'

5j-

HUANCA

YO

3380 m)

----

AX.

l -

l

__ /

-

- - - - - - - - - - - -

zor

I

'

oi-

I

I-

I

oc:

st...

I

O

r

-- -

_

i

5

I -

- - - - - - ~ - - - - -

MEAN.

- - - - - - ~ . : : . _ = . - M I ~ T ~

- -

I _ .

. .L___

L ~ ~ L . I I t., ..._ ... L ....... 1

3 0 ~

2st

_:(.A_J\'.LOLINA (

238

m)

zJ ----;--

~

c.

1 5 ~

.

ioL

.

.

F

M

A

MAX./

/

__/

MEAN.

MIN.

_

....

------

- - - - - - - - .

----------

. __ . .L . .L . . . I .L...... _ .J

M

J

JY A S 0 N D

Monthly Average Tempera tures (1968-72


16/87

-

12

-

cult ivated

potato,

the Peruvian facil i t ies of CIP

are

also

stra tegical ly posi t ioned to provide a range of environ

menta l s t resses . Experimental

field

plots are

located

between 11

and 12

south lati tude,

within a

north- south

dis tance of less than 60

miles ,

which

provides essen

t ially uniform shor t -day

condit ions

at

al l

sites.

CIP

plots near

the

coast

a t La Molina are in

one of

the

world s

dr ies t deser ts with

an average

annual

precipi ta

t ion of l e ss than

O

5 inches . A t

Huancayo, f ros t is

predictable

through April

to September

in

the

high

alt i

tude

plots

10,

000

feet) while low

1 5

inches)

to high

12 inches)

seasonal

monthly

rainfal l

and high dayt ime

t emperatures ,

character i s t ic of hot humid

t ropical

jun

gle,

prevai l

a t the

San Ramon

station. Thus

extremes

of heat, cold,

drought ,

and

precipitat ion, as

well as -

vorable

cl imat ic condit ions for potato production, a re

a t

hand

for l arge- scale s t ress s tudies .

Choices

of sea

son and

site

combination permi t

year

round evaluation

of the

adaptabili ty

of

clones

to

specific

cl imat ic

varia

bles l ikely

to be encountered in growing potatoes in de

veloping

countr ies located

in

t ropical

and

sub-tropical

regions.

The centra l headquar te rs of CIP

in the La Molina

dis

t r ic t

of

Lima are

adjacent

to the Estacion

Experimen

ta l

Agricola,

Minister io de Agricul tura ,

and

to

the

Univers idad Nacional

Agrar ia

of

Peru.

The proximity

of these ins t i tut ions permi t s

ready access

to

excel lent

l ib ra ry

facil i t ies, as

well as

an agreeable environment

for the

interchange of ideas

and

t raining of

personnel

in

all

aspec ts of potato research .

The main headquar te rs

building

is

a

modern t vo s tory

concrete s t ructure having a total

floor area

of 1,

230

m2

s i tuated on

approximately three-

quar te r

hectare

of land

scaped grounds. Offices for

Administ rat ive staff

and a

number of

Research

staff,

a Conference

room,

and com

municat ion

and duplicat ing

facil i t ies

occupy the lower

f loor; l ibrary , resea rch staff offices and well-equipped

labo-


17/87

- 13 -

r a to r i e s a re located

on

the upper

f loor.

Screenhouses

and at tached l abora tory faci l i t ies having a to tal a r e a of

approxirr1ately

1 5

00

m2,

a

spacious

br ick

and

concre te

storage-

work

building

and a

smal l ca re - t ake r s home

a re convenient ly

located close

to the

headquar t e rs

build-'

ing.

During the year , four

r e sea rch

l abora tor ies and a prep

ara t ion ro o m w e re furnished and serv ices ins tal led.

In keeping

with the

in tegra ted

r e sea rch phi losophy of

GIP,

the

l abora to r i e s

have been

designed

for

f lexible,

mult i -purpose use . Ini t ial purchases

of

microscopes ,

balances , re f r igera tors ,

incubators ,

cold

s torage units ,

t r ans fer

hoods, an autoclave ,

glassware ,

and genera l

chemica l

and

media

supplies

were made . Such rna jor

equipment

as an ul t ra -

centr i fuge ,

a

re f r igera ted cen

t r i fuge, a record ing spectrophotorneter ,

and

a

f reeze

d ry e r w er e

a l so purchased . Despite minor inconven

i ences normal ly as soc ia ted

with the

development

of

labo

ra tory

facil i t ies ,

l abora tory r e sea rch

was commenced

dur ing

November -

December ,

1973.

A l a rge

port ion

of a

f ive-hectare

si te a t Santa Ana

(Huan

cayo)

was p lan ted to

se lec t ge rm p lasm mate r i a l during

October . ,

At th is

location,

which

was granted

to

GIP by

the

Minis ter io de Agricul tura , a permanen t l abora tory ,

s torage ,

and

personne l housing complex

is

to

be

erec ted ,

according

to

plans

developed during

1973. The t empora ry

use

of land

for field exper iments

was also granted a t

San Lorenzo and on the Exper imenta l

Station, both s i tes

located in the

Mantaro

Valley. Extensive bl ight

t es t

plots

were planted

in San Lorenzo while plots devoted

to

taxo

nomic

s tudies w er e

planted

a t

the

Mantaro

Station.

A

modes t car pool was operat ive dur ing the year

to

t r ans

por t

personnel between

La

Molina, Huancayo and

San Ra

mon

as

well

as

to

provid '

essent ia l

local

se rv i ces

a t

all

si tes .


18/87


19/87


20/87

16

GIP-TOLUCA

In

addit ion

to

Central

resea rch

labora tor ies

located

in

Peru

in 1972 CIP assumed control and

responsibil i ty

for

facil i t ies

and

programs relat ing

pr imar i ly to

la te

blight

test ing previously supported

by

the

Rockefel ler Founda

tion. The

facil i t ies located

a t the CIMMYT

Exper imen

tal Station

in the Toluca Valley Mexico

consis t

of four

hectares of

tes t plots office and

work area a

gre:en

house seed storage and a

t raining c lassroom.

Exposure in the

field

a t Toluca provides a screen for la te

blight

field

res i s tance perhaps unequalled elsewhere

in

the world.

During

the past 20 years over

160 000

seed

lings and selections

have

been tes ted for

blight res is t -

ance a t Toluca for potato breeding programs

in

29

coun

t r ies . Under

the auspices

of CIP the Internat ional

Pota

to Blight Te sting Program

is

being continued. During

the

past

year

and

in

1972

potato

breeding

programs

in

the United States Canada

England

Holland

West Ger

many

Sweden

and Japan have

made use of the Toluca

tes t

sponsored

by CIP. n addition to per forming a val

uable

blight

tes t ing service of internat ional scope the

Toluca facil i t ies

are

also used for tes t ing and maintain

ing selected blight res is tan t

l ines

for the CIP Outreach

program. As

par t

of the

Outreach

objectives

in

Central

America

training

programs are also

regular ly

conduct

ed

at GIP-Toluca.


21/87

1 7 .

GENERAL

PROGRAM

IN

RESEARCH

1973

The

Research

rog ram

of

CIP

has

two

basic

components:

A.

Research

conducted a t CIP facili t ies

B.

Research

contracted

at

selected institutions

Through this

inter-locking

approach CIP has been able to

initiate ro jec ts very quickly par t icular ly Contract ro -

jects where facili t ies

and

expert ise

already

exis t

for solv

ing

problems.

Projec ts

conducted a t CIP as well as Contract

Projec ts

are

formally outlined with respect to title leaders

and

assis t -

ants justification

detai led

objectives presen t

state

of

knowledge and

detailed methods mater ia ls and

facili-

t ies

required. These

Projects

are

the

units

of

research

designed

to

fulfill the

following

designated

Thrus t objec

tives:

THRUSTS

L Systematic collection classif ication maintenance

and

distribution

of

all

tuber- bearing

Solanum

species .

2. Utilization of

the tuber-

bearing Solanums to provide

bet ter adapted potatoes

for

developing countr ies .

3.

Control of selected

fungal

pathogens.

4. Control

of

selected bacterial

pathogens.

5. Control

of

selected viruses and insect vectors .

6. Control of

selected

nematode pests .


22/87

18

7. Development of potatoes with wider adaptation to en

vironmental

s t ress

and insect

pests .

8. .

Improvement

of general

nutri t ional

quality, protein

yield, and

carbohydrate-protein

balance in potatoes;

the

development of economical , scale-neutral methods of

storage

and processing for developing countries.

9.

Seed

production

technology

for

developing

countries;

t issue

culture

for

disease elimination,

rapid

multiplica

tion

and distribution.

of

new

clones.

10.

Outreach

Program and

affiliated

Socio-Economic

Projects)

concerned

with tr:tining

personnel , the adapta

tion of research and the efficient distr ibution and

utili.za

tion of

the

potato in

developing

countries.

SYSTEMATICS

During

1973

CIP

conducted

two

field

expeditions in

Peru

that collected 714 accessions in the Departments of An

cash

and La

Libertad

in

May

and

an additional 330 ac

cessions from the Department of Lima during the

favor

able

collect ing period of June and July.

The

strategic

location of

CIP

close to the center of origin, diversity,

and

ear ly

cult ivation

of

the potato

has

great ly

facil i tated

the organization

of

collecting expeditions. Five expedi

tions, including a Dutch- Brit ish collecting party, a re

planned

for 1974.

A

vigorous s tar t has

been

made

in classifying

accessions;

approximately

566

taxonomic determinations as well as

287

chromosome counts

hav.e

been com pleted.

Eighty hybrid clones

o

potential breeding value

were

in

t roduced f rom Europe and Mexico; 600 a.ccessions have

been donated f rom Chile, Colombia

and Sturgeon

Bay,

Wisconsin. At

present , CIP

has

more than 5, 000 tuber

bering Solanum accessions. A measure of the poten-


23/87

- 19

t ial

value and in teres t

in the

collection

is

the fact

that

approximately 8, 000 samples were dis tr ibuted

for tes t

ing to

31

scientis ts

around

the

world

in

1973.

Basic studies into the

origin and taxonomy

of

t r iploid

po

ta toes in

native cultivations in

Peru a re

being studied

through

controlled diploid-tetraploid

crosses .

Success

ful crosses

have been achieved with

an

unexpected

high

f requency of t r iploid

progeny indicative

of a potential for

t r iploids to act as bridges

in

gene-flow between diploids

and

tet raploids .

Some

evidence

has

been obtained that Solanum ajanhuir i

could

ar i se between

the

cult ivated species , ..

stenoto

mum, and the

wild

species,

S.

megistacrolobum. The

th ree species overlap

in

their geographical

dis tr ibut ion

and

ecology

along

the

Andes

of southern P eru and Bol i

via.

S. ajanhuir i is a frost - resistant species and

i t

seems

l ikely that i t

might

inher i t

this character is t ic

f rom

the highly

frost-resistant ..

megis tacrolobum.

Many

morphological

characters appear to

be

in termedi

ate

between.. s tenotomum

and__.

megis tacrolobum.

Although.. ajanhuir i has been repor ted to be a

male

s ter i le

species ,

severa l l ines of evidence dete rmined

a t

CIP do

not

support

this

report . Pollen s tainabi l ity ranged

from 13-30 . In crosses using S. ajanhuir i as a

male parent

the

ber ry

set

was

10%

with an

average

of

11

seeds per ber ry

and 16%

parthenocarpic ber r i es .

These

resul ts indicate

low pollen

fert i l i ty ra ther than male

s te

r i l i ty. However, since there are a greater number of

successful

crosses when S. ajanhuir i is

used

as

a

female

parent , ber ry se t

approximately 50 ,it is apparent that

this

species

can be

best

util ized in breeding

as a

female

parent .

Intraspecif ic

crosses

involving

nine

clones

of

S.

ajanhuir i

have been

made.

A

ber ry set of 43 , with

6- 18

seeds per ber ry was ob

tained in reciprocal

c rosses between

. s tenotomum

and


24/87

20

S.

megis tacrolobum. Althogh many ovules

s eem

to be

fer t i l ized

they

do

not

mature

beyong

the formation

of

seed coats indicative of some fundamental bar r i e r s in

the format ion

of

viable seed. Some seeds

burs t

before

reaching

matur i ty and

relat ively

few

seeds develop

com

pletely.

In ear ly November near ly 4 000 clones 15 tubers of

each when possible

w ere planted for

observat ion and

maintenance a t

Santa

Ana

Huancayo.

In addition 750

cul t ivars w ere increased

a t La Molina for dist r ibut ion

in ear ly 1974; 70 clones of wild

species

were grown

for

observation

in

screenhouses .

Open pollinated

seed

was

collected f rom plants

grown

ear l ie r

in:

the year a t Huan

cayo. In keeping with the

policy to convert

cer ta in

l ines

to t rue seed seed f rom 2 200 clones is now

avai lable

for

long t e rm

storage.

.

Pfanning Conference

on

Germ-Plasm-Explora t ion and

Taxonomy of

Potatoes

In

January 1973 a Planning Conference

was held

in La

Molina to examine pr ior i t ies

and

recommend an action

p r o g r a m for the next

five

years

on germ p l a sm

explora

t ion

and

taxonomic

research . A repor t was prepared

in

which

discussions

and

recommendat ions

w ere

summa

r ized pointing out pr ior i t ies and indicating the individ

uals

and

organizat ions f rom whom

cooperat ion might

be

sought

in

addition

to the

resea rch envisaged a t

CIP

headquar ters .

In

the

Introduction to

the

Repor t

i t

was

stated:

breeders a re

turning

to

the

use

of

wild

species

and

pr imi t ive

cultivated

forms to

solve

prob lems of disease res i s tance

and

ad

aptat ion to a wide range of environmental con

ditions.


25/87

- 21 -

Unfortunately, this r ~ s e r v o i r of genetic

variabili ty, which Un.til a

few years

ago had

been taken so much for g r ~ n t e d ,

is now

di

minishing at an alarming rate. The old high

ly

complex

pat tern of diversi ty is , paradoxi

cally,

being replciced

by the newly bred cul

t ivar

s which

are

themselves

derived

f rom

i t

Such an

erosion of

genetic diversi ty is

a

proc

ess that must be halted, i f breeders are to

continue

the production of

new variet ies now

and in the

future

11

It was agreed that

the firs t task of the

Planning Confer

ence should

be

to examine the prior i t ies for exploration,

country by country, for wild and cultivated

species

Prior i t ies were

established,

A, .B or C in descending

order ,

A being the most important, .

under

the

following

headings:

I

Genetic

erosion

in

progress

or

threatened.

II Plant

breeding needs based

on knowledge

of

the species and/ or

areas

concerned.

III

Lack

of living

material , in

comparison with

known distribution area.

Taxonomic in ter-

est .

Wild

Cultivated

I

III

I 1I

III

Venezuela

B c

A

B

? A

Colombia

A c B

A

B

C?*

Ecuador

?

c

A A

B

A

Peru

B

B

A

E ~ ~

A A

Bolivia

c B B A B B

Argentina c

B

c

A-E

c

A

Chile

c

c

B N

c

N***

Uru- ,

Para - Brazi l C?

G?

B

N N

N

Mex-,

USA, Guat.

c A-B A-B

E c

C?

Central Am.

c c B

N N

N

*

Needs further

assessment

Emergency


26/87

- 22

The 18 taxonomic

ser i es

into which

the

tuber-bear ing

species of

the

genus Solanum have been divided,

w er e

each d iscussed

by

the

par t ic ipants

a t

the

Planning

Conference.

Pr ior i t i es

A to C were as s igned

for

taxo-

nomic research . It was recommended tha t the

highest

pr ior i ty (

1

A

) be given to taxonomic r e s e a r c h on the fol-

lowing

se r i e s :

Conicibaccata ;

Piurana;

Tuberosa wild

spec ies f rom Ecuador , P e r u and

Bolivia;

Tuberosa

cul t ivated

species)

f rom

all

Andean countr ies . In view

of

the i r impor tance in plant breeding, i t was r e c o m m e n d

ed

that

specia l emphas is

should

be placed

on

taxonomic

r e s e a r c h in th is

group.

Ser ies

recommended to be ass igned a B

pr ior i ty

were:

Acaul ia , Demis sa, Megis tacro loba .

Pr io r i t y

C

se

r i e s were Morel l i formia ,

Bulbocastana ,

Pinnat isec ta ,

Commerson iana ,

Circaefo l ia ,

Longipedicel la ta ,

Polya-

denia, Cuneolata, Ingaefol ia and Olmosiana .

The

high-

es t p r ior i ty r e s e a r c h

is

to be

n

the cul t ivated m e m b e r s

of the se r i e s Tuberosa ;

no

pr ior i ty in te res t was indica t

ed for m e m b e r s of the

se r i e s Juglandifolia

and

Etube-

rosa .

The deve lopment of an In te rna tiona l B oard for

Plan t

Genetic

Resources i s

being

fol lowed

with

in te res t by CIP

personnel respons ib le

for

sys temat ica l ly collect ing,

class i fying and maintaining an ever - inc reas ing number

of

Solanum

access ions .

UTILIZATION

The in te r locking

of

CIP

p;:oojects and Contrac t projec ts

is

exempl i f ied by in tegra ted

r e sea rch

designed

to

mo s t

ef-

fect ively ut i l ize

Andean

cul t ivated diploid species and

cul-

t ivated

andigena

te t rap lo id species .

CIP Headquar te r s - La MoHr,,,,


27/87


28/87


29/87

- 25 -

Selections f rom

adapted

populations

in North

Carol ina

were grown in both highland and lowland t ropics of

P eru

in 1973.

Selections

represent ing

43 families frorn N. C.

State were super ior in performance to the native clones

at the jungle

locat ion

at

San

Ramon.

Thir teen

selected

clones

were produced. t is recommended that a growing

season,

September to

January, might put

more

s t ress

on populations than

the

June-September

se ason employed

in

1973

a t San Ramon.

2.

The

Utilization

of

Solanum

tuberosum

spp.

andigena

G e r m P l a s m

in

Potato Improvement

and

Adaptat ion

Cornel l

Cont rac t Project .

Advanced Population (Sixth Cycle)

Seed

Production: - The sixth cycle of

this

andigena ge rm

plasrn

mater ia l

was f i rs t grown

in

the field in

1972

as

single-

spaced

hil ls

and

selected

for

tuber appearance and yield. All hil ls

of family

N-503

were re ta ined based on superior blight res i s t ance record-

ed a t Toluca.

All clones

f rom

other

families and

88

of

the N 503 clones were

planted

in the greenhouse during

the

winter 1972- 73) and pollinated with bulk sets of andi

gena pollen-

one for

res i s tance to late blight,

one for

e

l i te appearance

sets ,

one

for PVY

res i s tance

and

one

for

res i s tance

to

root

knot

nematodes ,

Seeds

w ere

pro-

duced

on

264 of 402 clones. During the

summer

of 1973,

open

poll inated

seeds

were harves ted f rom an additional

175 clones, including several N 503 clones. Over 145,000

seeds

were

col lected from N 503

clones alone.

Disease e s i s t a n c e ~ - Greenhouse t es t s under control-

led temperature

and humidity

yielding

515

clones

with res i s tance

to Phytophthora blight,

When tes ted

in

Toluca

al l

clones res i s tant in

I thaca

to

races O

l

4; and

l 2,

3, 4 had

les ions

in Mexico, al

though

74

had intermediate general res i s t ance

and

50

clones had

high

levels

of resis tance. Clones N 503-128

and N 503-129 were outstanding

for

res i s tance being


30/87

26

ra ted

1

on

a 0-5

scale. Three field

tes ts

of

47 andigena

clones

and

13

tuberosum clones

with

general

res is tance

and

10 suscept ible check varie t ies were made

a t

two lo

cations

in

New York State

and one in

West

Virginia.

The

general res is tance

of

the andigena clones was outstand

ingly

superior to the tuberosum

res is tance .

Root knot reaction for 357

clones

was determined in

a

greenhous-e during the summer

1973.

A range in res is t -

ance f rom 1 to 10 was

observed

among clones

o f

individ

ual

families.

Thirty-two

clones which

ra ted

1-2

were

considered

res i s tan t

to

a

mixed

population

of

Meloido

incognita

M. hapla M. javanica M. aeranar ia

and M. incognita acr i ta

A

total of

385 clones

were

inoculated

with PVX in

the

field while 587 Clones were exposed to natural infection

by

PVY. Tubers f rom PVX plots

will

be sprouted and

the

foliage

rubbed

on

Gomphrena

globosa to

indicate in

fection;

this wil l be

completed

by spring

197

4. Plants

f rom tubers harves ted f rom PVY plots will

be tes ted a

gainst seedling 41956

or

2 demissum in

the

greenhouse

during

the

winter . Pre l iminary

evidence

is that a single

locus is involved

in

PVY res i s tance

Insect

Resis tance:

Results of

evaluating

tes t plots

of

various

andigena

clones for

res i s t -

ance to

leafhopper

aphids ta rn ished plant bug and the

Colorado potato

beet le

were equivocal.

Within

each fam

i ly

represen ted by more

than

4 clones populations of

insec ts

and rat ings

of

damage ranged widely.

Clones

within

a

family

were

nei ther

al l res is tant nor al l

suscep

tible nor

consis tent ly

a t

a

level in between. Although the

resul ts

indicate some

res is tance

in

andigena

germ plasm

Katahdin

controls

p.resumably

genetical ly al ike also

showed wide

variat ions in

insec t populations and damage.


31/87

-

27

-

Tuberizat ion under Warrn

Temperatures : -

Pre l iminary

exper iments

were

car r ied

out

in

control led

growth

chambers

to

deter -

mine

whether these

might

be used

to

simulate environ

mental di fferences between high and low alt i tudes

in the

tropics.

Four, cycle

-.5

andigena clones

previous ly

screened

for

heat tolerance

a t

Rio Piedras Puer to Rico,.

were grown under

12-hour l ight

at ei ther

70

or 80

F; 2 ~

hour

dark temp era tures were l0F

cooler .

The

andigena

clones and

a

Katahdin control

produced

longer haulm inter-

nodes

and smal le r leaves

under an

80-day, 70 -night

cycle. There was also

a

reduction in tuber

yield

under

this regime.

Clone N

55

8-36 which appeared

to be the most to lerant to high tempera ture

in

the

growth

chamber also

yielded

relat ively

well

in

Puer to Rico.

Second

Cycle

Population

Tuber Production:

-

Seedling tubers of this generat ion

were

produced

in the greenhouse in

1972 and were planted in the field in New York in May,

1973.

Under

temperate zone conditions

only

539 of 807

access ions

produced

clones with tubers

in

a

population

23, 531

hills . A

base

for

second cycle

consis ts

of

1615

clones f rom 539 access ions

which

tuber ized.

The

origin

of the access ions to be planted

for

study in 1974

is as

follows:

Origin

No

of

accessions

N of clones

Argentina

81

298

Bolivia

56

136

Chile

10

52

Colombia

61

180

Costa

Rica 5

Ecuador

10

21

Mexico 20

71

P e r u

176 416

CPC

80

IR-

I

crosses


32/87


33/87

. . 29 -

Resis tance to

cys t

nematode:

-

This

pa r t

of the Cornel l

program has

been

broad

ened

to

include

30

new

introductions added

to

the diploid

spec ies

a l ready

being studied

Solanum mult id i ssec tum,

sanctae- rosae

S.

f i l @ Z i n i J : and_. vernei) as

well

as 57 introductions of 20

additional

diploid

spec ies

of

Solanum. Greenhouse

and field

increases of these

in

troductions

resul ted in

approximately 900

clones which

tu

ber ized successful ly;

these

will be screened

for

res i s t

ance

to race

A of Heterodera ros tochiens is and concur

rent ly

increased

for CIP

t r ials .

Nearly 3,000 clones

resul t ing f rom

interspecif ic

crosses

of diploid

Solanum clones with res i s tance to r ace A with

zero

cys ts

per root ball)

were screened in 1973. Crosses

involving_.

sanctae-

rosae gave the highest

percentage

of

res i s t an t

progeny,

general ly

90 or higher . Fie ld

in

creases of 2,081 entr ies

a re

intended

for

CIP coopera

t ive

t r ia ls .

CONTROL- FUNGI

Late Blight Phytophthora

infestans)

Late blight of potato

is

one of the

mos t de

s truct ive

diseases of this

basic

food

crop s ince the dis

ease

was discovered

in the 1840

1

s. It

is

among the mos t

impor tant of al l plant diseases

and

has

received

a grea t

deal

of attention

through

research and extension.

In

spite of advanced knowledge concerning la te blight,

t

is

st i l l a major problem

and

can

be

a

l imit ing factor

in po

ta to product ion in

developing

countr ies .

The

causal

fungus,

Phytophthora

infestans

Mont. ) de

Bary,

is

biologically adapted

to thr ive in most

environ

ments

where the

potato

is

cultured.

It

is

well adapted


34/87

30

for widespread

disseminat ion through the

a i r

or through

i-r1ovement

of

infected

tubers .

Infected

tubers

a re

the

major source of surv iva l in

developed

countr ies ;

the

des t ruc t ion of such inoculum foci i s

an

essent ia l

ele

ment in control .

The

protec t ion

of foliage by fungicides

has

been develop

ed to a high sta te of

technology

in

many

count r ies w here

inodern fungicidal chemica ls

and

expensive ,

sophist icat

ed

1nachinery

permi t s

effective control . However , in

many

developing

nat ions

there i s

re la t ively l i t t le

use

of

fungicides.

Although

hand sprayers a re

used by some

smal l

growers

control is

genera l ly

unsa t i s fac tory in

the

ra iny seasons when

the potato is commonly grown in

t ropical

countr ies .

More important ly , the

subs is tence

fa rn ier se ldom has money

to

purchase sprayers and fun

gicides , evei1

i

avai lable .

The

grea tes t promise

for

control

of

pota to

la te

blight in

developing countr ies re l i es upon the

in t roduct ion

of re

s i s tan t

var ie t ies .

The knowledge that adequate res i s t

ance to

the

pathogen is avai lable gives

confidence

that

th is

promise

can

become

a

real i ty . This

is par t icular ly

t rue when res i s tance is control led by a ser i es of mult i

p le

genes

which appear

to

be addi t ive in effect

and

inher

i ted in a

polygenic

fashion. This has been t e r m e d

' field

resis tance {

and

is apparent ly s table

in the

face

of the var

iable

pathogen.

t consists of a complex of factors in

cluding res i s tance to

en t rance

of the fungus and res i s t

ance

to growth and sporulat ion of the paras i te ;

addit ional

fac tors

may

also

play a ro le .

Fie ld

res is tance is

race

non-

specif ic and

i s apparent ly not

subject

to being

over

corne by

pathogenic

recombinants

of the blight

fungus.

Fie ld

res i s tance

offers a posi t ive method of providing

in ternat ional control

of

potato

blight.

Accordingly, CIP

is utilizing f ie ld- res is tant clones developed through the

breeding

program

sponsored by

the

Rockefel ler

Founda

t ion

a t

Toluca, Mexico.

Approximately two- th i rds

of


35/87

31

1200 clones having varying levels of field res i s tance

were

sc reened

in

1973

by

CIP

s ince assuming

respons ib i l i ty

for

the

Toluca

program.

Fur ther

sc reening to reduce

the

presen t inventory of bl ight - res i s tan t clones a t

Toluca

i s p ro jec ted for

1974.

t is ant ic ipated tha t se lec ted

bl ight - res i s tan t clones f rom Toluca, sc reened

for

other

agronomic

at t r ibu tes

will be used to fulfill ea r ly obl iga

t ions of the Outreach P r o g r a m of CIP. A

total

of 2

700

clones

submi t ted by

eight breeding ins t i tu t ions were

under t r ia l a t Toluca

in

1973 as par t of the CIP- In ter

nat ional Pota to Blight Test ing Program.

Procedures

for

en t ry

to

the

CIP IPBT p ro g ra m a t Toluca have

been

formal ized .

The

pedigree of all clones submi t ted for

t es t mu s t be prov ided and

CIP r e se rves

the r igh t

to uti l

ize any

clones to help developing

countr ies the

naming

of

var ie t i es is

not a

CIP

objective,

so

tha t no

clone

could

be

se lec ted

for

var i e t a l re l ease

by

CIP).

An

aggress ive

program

for

the

select ion

and

breeding

of

clones

with high levels of re s i s t ance to la te

blight

was

in i t ia ted

a t

CIP- P e r u

in

1973. Approximately

2,

780 g e r m

p l a sm access ions

were planted in March in

non- sp rayed

blight plots in

Huancayo. The development of a severe

bl ight epidemic

permi t t ed

the select ion of

973

andigenum

clones with useful l eve ls of field res i s tance . A plant ing

a t La Molina of 816 se lec t ions f rom Huancayo resu l ted in

a

fur ther

se lec t ion

of

135

clones

with

combined bl ight

re

s is tance and ea r ly matur i ty . These were

re .planted in

San

Lorenzo

in

December , 1973,

together

with

al l

addi

t ional

clones

1,295) of Solanumandigenum,

S. phure ja

_

s tenotomum and_. goniocalyx belonging

to

the g e r m

p l a sm

collect ion,

as well a s 318 clones obtained

frorn

se lec t ion

f rom Mexico w i th high l eve ls

of blight

r e s i s t

ance. In accordance with recommendat ions

ar i s ing

f rom

the Late

Blight

Pro jec t Planning

Conference

Repor t

11

Late Blight Stra tegy

11

.

a s tandard

set

of 16 different ial

hos ts were a lso

planted

a t the blight plots in San Lorenzo.


36/87

3 2

Segregat ing

populat ions of diploid

clones

were tes ted

in cooperat ion

with the

North

Carol ina

Contrac t

Projec t .

Eighty-five

res i s tan t

clones,

having other desi rab le a

gronomic charac te r i s t i cs

were se lected

f rom 945 acces

s ions p lanted a t La

Molina.

Four teen different ia l R- gene hos ts were

inoculated

with

spores

of

i so la tes of P. infes tans col lected

f rom Caja

: rnarca,

Huancayo,

Porcon Canta a 1d La

Molina. Only

r aces 0 and 2, 4 were

detected.

The

l imi ted number of

r aces

detected was probably

due

to

the

genera l absence

cf race- inducing

d emis s u m

crosses . Because of

the

po

tent ia l pathogenic

adaptat ion

of P . infestans

when

main

ta ined on a specif ic suscept ible var ie ty and because of

the

known loss of pathogenici ty when this fungus

i s

cul

tu red

on

ar t i f ic ia l

medium,

f re sh spores col lec ted

in

the

f ield f rom a wide spec t rum of bl ighted clones offers an

opt imum range

of

pathogenic var iab i l i ty for sc reening of

seedl ings in

the

sc reenhouse .

The

successful

cul tur ing

of Phytophthora on tuber

s l ices

m a y be useful

in

mainta in

ing

pathogenic

heterogenei ty;

this

technique wil l be fur ther

evaluated .

Late Blight Stra tegy

A Planning Conference sponsored

by

CIP was held a t

CIMMY

El Ba tan, Mexico

during

August

22- 27, 1973.

A

pos i t ion paper p re p a re d

by

Dr. Vilhelm Umaerus

se rved

as

a background for wide ranging

discuss ions

by 14

Conference

par t ic ipants f rom

8 countr ies . A

comprehen

s ive Repor t of the

Conference edi ted

by Dr.

E.

R. French

Head, CIP

Pathology

Depar tment , has

been

publ ished.

Stra tegy

recommended for

the

development , moni tor ing,

and

rnain tenance

of sources of re s i s t ance to

blight

a re

de

ta.Hed in

the Report .

Wart

(Synchi t r ium

endobiot icum)

Wart o r

Verruga

was f i r s t

descr ibed in

Europe

in

1896.

Since

tha t

t ime i t

has been in t roduced f rom Europe into

.

.


37/87

33

North

America , India,

South Africa and ~ w Zealand.

The disease

is

probably indigenous

to

the

Andes

and

has

been reported from Peru, Bolivia, and Chile. Wart

is

favored

by temperatures below 18C during the growing

season and by an annual

rainfall of

at least 700 mm; the

greates t incidence

in the

Sier ras

occurs between 3,000

and

4,

000

meters .

Since the 1940' s

races of

Synchitrium have

been ident i

fied in

Germany, Newfoundland, Russia

and India. The

number

of

races reported as

occurring

in these locations

var ies but

some

16 have

been

claimed

for

Russia. It

is

essent ia l

that CIP

develop a screening procedure to de

termine whether

races of

the fungus occur in Peru and

also

to

evaluate immunity and

field

res is tance to races

l ikely

to be

encountered in

developing

countr ies .

Trial plantings of variet ies used to differentiate races

in

Europe

were

made

a t

Casa

Blanca and Cuzco. The

plants

developed poorly

with

only a

few

tubers

being

produced

under

the

short-day conditions in Peru.

f

European

dif

ferentials are

to

be used in

race

determinations in Peru

i t is apparent that growing conditions must be modified

to

enhance tuberization.

Alternatively,

a new se t

of

dif

ferentials

which tuberize

under

Peruvian conditions

might

be

developed,

or

resistance to

races of

Synchi t r ium eval

uated

elsewhere.

Using accessions in the germ

plasm

collection

which

were immune

or

field

res is tant

in previous tes ts a t Ca

sa

Blanca, a cross ing program

has

been init iated to

com

bine

wart res is tance

with

la te

blight and

nematode

(Hete

rodera) resistance. In addition, in tercrosses between

wart- res is tan t

clones were also made.

$ome 150 cross

es

were

successful

and

seed

are

to

be

planted in

1974

at

GIP

and

also in Newfoundland

for screening against

the

wart races occurring there.


38/87


39/87


40/87

36

th ree i so la tes of

P.

so lanacearum sugges t

that this

spe

cies

of

potato

might

contain

sources

of

re s i s t ance

to

all

known s t ra ins of the pathogen. Genetic studies indicate

that wil t res i s tance

is inher i ted

through

a

ser i es

of

dom

inant genes

tha t

a r e

eas i ly

t ransfer red. To facil i tate ge

net ic s tudies through a mo re

rap id

screening

procedure

a technique for the root inoculation of seedl ings has

been

developed.

The Development of Potato

clones

with Resis tance

to

Bac

t e r ia l

Wilt

Pseudomonas solanacearum)

Wisconsin

Con

t rac t Projec t .

Resis tance to i solates

K60 and

Sl23 of r ace l

is

controlled

by th ree dominant and independent genes

in

_. phure-

.i:.

In order

to determine

the

mode of

inheri tance

to

a

race

3 i sola te ,

six

parenta l

clones

and 16 hybr id

fami

l ies of .:

phure ja

have been

tes ted by

stem

inoculat ion

with

isolate

S

206.

A

high

level of re s i s t ance was demons t ra ted by four of

the parenta l clones, 1386. 12,-15, -22 and -26. One clone

1388.

30 exhibited an in termedia te level of

res i s tance

and

clone 13 3 9. 28

was

complete ly suscept ible ,

Dist r ibut ion of disease

index

ra t ings among segregat ing

progeny in

the

16

hybr id fam i l ies

t e s ted were general ly

bimodal , L e.

mo s t

individuals tended to be

ei ther very

res i s tan t or very suscept ible . Resis tance

in

phure ja

to

the race 3 isolate S

206

was

not

inher i ted in the same

manner a s res i s tance to r ace 1

i so la tes

The low

inci

dence of res i s tan t individuals in

both

R x R and R x S

hybr id famil ies despi te the high

level

of

res i s tance

ex

hibi ted

by

parenta l clones , suggest tha t mo re than 3

genes

a r e involved,

t

i s apparent that re s i s t ance to r ace

3

of

so lanacearum

evolved

independently

of

res i s tance

to r ace

i so la tes .


41/87

37

Work

completed

in 1972 indicated

that the concentrat ion

of a par t ia l ly

purif ied bacter ia l inhibitor

f rom tubeTs of

five

clones of

S.

:phureja

.and

tuberosum

was not re la t

ed to levels

of

res i s t ance to

P . solanacea:rum. However

inhibition

by crude ext racts was corre la ted to

res i s tance

levels

in

the same Solanum

clones.

Research

is

continu

ing in

an

at tempt to

determine

whether m o r e than one in

hibi tory

compound is

present

in

crude ext racts . Based

on NMR

and mass

spect ra l

data a cycl ic te rpencid has

been proposed as one of the inhibitors. A knowledge of

the

specif ic

inhibi tors

involved

would

be

ext remely use

ful in guiding a breeding program

for

res is tance to

bac

te r ia l wilt.

A

seedl ing

inoculation

tes t has

been

developed to select

wil t - res is tant clones

f rom

la rge seedling populations.

F r o m progenies of

crosses

of wilt res is tant x

late

blight

res i s tan t paren t s

selected by

seedling inoculation 11

clones out

of

90

had su:eerior

res i s tance

in

the f ield

in

Costa

Rica

in 1973. Tests

a t C3.rtago

C . R .

included

plantings for late

blight

exposure a t 3 200 m

and

sam

pling of bacter ia l wilt res i s tance a t

1 400

m . Field

tes ts

a t l

400

m gave

the

highest late

blight

incidence

and

ad

equate

tes ts

levels of bacter ia l wilt. Eight clones that

combined res i s tance to

blight

and bacter ia l wil t were se

lected

in the field.

Three

clones

MSIE- 7 MSl 8 4

and MS35-22

had

adequate

combined

res is tance

good

tuber type and acceptable yields. These and severa l

other clones a re

being increased

a t high elevat ions for

additional tes ts . In Peru clones that have high l evels

of

bacter ia l wilt

have

been increased

for

broad scale

tes t ing

for adaptat ion

pr ior to

re lease .

In all 12 coun

t r ies

are now

known to

be using the phureja

source

of

res i s tance.


42/87

- 38 -

CONTROL

- VIRUSES

One of

the mos t

immedia te object ives of

CIP

vi rus re

search i s

to

f ree selected clones

of

viruses , insofar as

th is is :feasible. Late in

1973

a p r o g r a m was in i t ia ted to

produce vi rus- f ree

m e r i s t e m cul tures , under the con

dit ions

of

l imi ted equipment then available.

Meris tems

were cul tured in solid media (Morel

and

Mulle r

modifi

cation)

supplemented

with

gibberel l ic acid.

n pre l imi

nary

t r i a l s mer i s t ems

w e re

successful ly cul tured

and

af ter

8

weeks contaminat ion l eve ls

were

relat ively low

15 ).

The use

of

mer i s t em

culture techniques,

with

and

without

heat t r ea tments pr io r

to

m e r i s t e m excision,

w:i 11

be

one of

the principal

methods

used in producing

cert i f ied seed

stock.

The

indexing

of

selected

clones

for virus and the mult ipl i

cation

of virus-ree

11

mater ia l

is an

impor tant function

re la t ive

to

the

dis tr ibut ion of seed s tock by Outreach. In

December , severa l Peruvian cul t ivars f rom basic

seed

w e re planted

ready for indexing and v i rus - f r ee

s tock of

the

Peruv ian

var ie ty Ccompis ( f reed f rom vi ruses by m e r

i s t em- t ip cul ture) is

being

multiplied. Tubers in s torage

await ing indexing include

Synchi t r ium -

and

Phytophthora

res i s t an t l ines

impor ted f rom Germany. CIP a lso has

v i rus - f r ee

tubers of severa l v ar ie t ies f rom

Scotland

which give

a

character i s t ic

reac t ions

to

so i l- borne v i ruses ;

the,se

a r e

await ing

mult ipl ica t ion.

Init ial

work is well

in

hand on a number

of

specif ic potato

vi ruses

including: potato spindle tuber virus

(PSTV);

and

ean

potato

la tent

vi rus

(APLV);

potato

leaf - rol l

v i rus

(PL

RV); potato vi rus X (PVX); potato vi rus Y

(PVY);

potato

virus

S

(PVS), as

well

as

a

new vi rus , SB-4.

PSTV Although hard ly

any

potato

plants with spindle

tuber- l ike symptoms

have been

seen

in recent v is i ts

to

the Sier ra of Peru ,

symptoms of th is

virus

in

po-


43/87


44/87

40

tato

vines are

often

obscure. Some tuber mater ia l

that may be infected

with

PSTV

has

been

collected

and

two

i sola tes

mild

and

severe)

of

PSTV have

been

obtained

f rom North America) to

use for

compar i

son

with any andean i so la tes we

may

obtain in the

future.

Upon receipt of seed of the best indicator

species Scopolia s inensis

screenhouse

work w il l be

init iated.

APLV An isolate

which

appears to

be

APLV has

been

obtained

f rom

the Cuzco

region

of

Peru .

Chenopo

dium

amarant ico lor

is to be tes ted

as an

indicator

hos t for APLV.

PLRV

Symptoms

are well known

in potato

plantings on

the

coas t

of P eru and

reach

their highest incidence

in the region of

Tacna

where Solanum

tuberosum is

grown.

PLRV-l ike symptoms

somet imes occur in

the

Sierra par t icular ly

in

varie t ies

such

as

Ticahua

si .

PLRV has been t ransmi t ted f rom Ticahuasi

plants grown f rom tubers

collected

in the Sier ra to

Physal is f loridana using aphids this requi res con

firmati?n). Other

exper iments

are in progress .

In recent

visi ts to

the impor tant

potato seed grow

ing a rea of Huasahuas i

in the

Sier ra

leaf

and tuber

samples

were eol lected f rom plants with leaf

rol l -

l ike symptoms. A few clones w ere

seen with

PLRV

l ike

symptoms in

a par t of the CIP

germ p l a sm

col

lection;

tubers

of

these

have

been

requested.

Some mater ia l with PLRV res i s t ance has been

received f rom Germany which will be evaluated un

der Peruv ian

condit ions.

PVX About

2,500

clones f rom CIF

germ plasm were

evaluated by

indicator hosts

and serology to detect

.


45/87

- 41

infectien by these twe viruses.

PVX

were found in

1

ca.

60

ef

the

clenes

ancl

PVY

in

68%.

The PVY

free clones were planted in a ield in Arequipa

to

:record field

t ransmissien. Only

500

PVX-free

clones

were

plante


46/87

-

4

-

PVS

and SB-4

Isolates f rom different

samples

of potato plants

showing

symptoms of virus Shave been collected

fr,om

different localit ies. in the

Sierra

Tubers of

some plants

f rom

the

germ pl.asm

collection

show

ing symptoms of virus S,

have

been requested.

New

isola tes of SB-4 were

obtained

f rom

the

varie ty

Antarki

growing

in

Huasahua.si. Their host

range

was studied

5 t imes

in different

weather

con

dHions of

the

year .

Species

in

the family Legumi

nosae,

Chenopodiaceae,

Solanaceae and Amaran

thaeceae

were

local and sys temat icaUy infected.

New deterrn.inations of

physical

proper t ies gave

the

following resul ts :

Dilution- end point:

Thermal

inactivation

point:

Longevity

in vi tro:

1

o

3

to

1

o

4

65 - 70C

3-4

weeks

Corre la t ions

made by testing fiel j. samples show

that

the

main symptom

SB-4

cau ; es is yellowing and

smal l necrot ic spots on

the

leaves.

Elec t ron micrograph s

obtained

by

Dr.

B. D.

Harr i son (Scott ish Hort icul tural Research Institute)

and in

the Hospita l

del Rimac, Lima, show isodia

me tr ic p ar t ic les ca.

30 mm in diameter .

These

vi ruses resemble

those of the NEPOVI

RUSES group but"serological t es t s in agar o r

l iquid

failed to show any relat ionship.

There

are

s tudies under

way to

as se s s

the

pos

s ible vi ra l

origin

of "cork

diseasen

of

potato.

At

tempts

a t

isola t ion

of

.v i rus

directly f rom c.ork

affected tubers

and

f rom the roots of weeds

col lected


47/87

43

f rom cork- infes ted

land,

have so

far

met with l i t t le

success .

However, a vi rus

which

resembled in

some proper t ies

RNA isolat.es of tobacco ra t t le

vi rus

(TRV) was i sola ted

f rom plants

grown f rom

cork-af fected- tubers , but not from plants grown

f rom normal-looking

ones of several local varie-

t ies . There appears to be a direct correla t ion be

tween occur rence of

cork disease

in a field and pres -

ence

of Tr:i.chodorus, the

vector

of

TRV. Also

when

maize o r wheat precede

potatoes in

infested f ields

the

incidence

of

cork disease is

very

high,

which

could be because

maize and wheat are

very

good

hosts of Trichodorus.

Potato mop-top virus (PMTV) is another

possi -

ble causal agent of

cork disease in

addit ion

to TR V.

So far, PMTV has been i sola ted

f rom

l ea f / tuber

mater i a l

f rom

Junin, Apurimac and

Cuzco,

In the

zone

a t

Huasahuasi where

cork-infes ted

land

occurs

PMTV was found in the soil (7 /9 of the f ields tes ted)

and PMTV symptoms were common in

the

potato

plants

(in one ins tance 25 ). However, not al l cork

infested fields

a re

infested with PMTV.

At the present , 2 field experiments are in pro-

gr0ss l t Cuzco

and many soi l

and

tuber

samples

have

been

accumulated f rom

different

local i t ies

in the Sie

r r a ready

for

screenhouse tests .

CONTROL NEMATODES

Cyst Nem atodes

(Heterodera

rostochiensis ;

H.

pallida)

During

a

6

month

per iod

over

200

collections

were

made

0 which

115

we:r_e c;:yst-positive. Sorne 50-60 posi t ive

collections are to be

evaluated a t Rotharnsted'.,

England

relat ive to population

composit ion

with different degrees


48/87

-

Damage

to

potato

roots by

Nacobbus upper) arid

Meloidogy:ne

species of nematodes

.


49/87

- 45 -

of geographical

isolation. :J;n

the field,

i

the crop

is

of

the

correc t

maturi ty ,

i t

has

been

possible

to

distinguish

between the two species of Heterodera. Throughout Peru,

north

of .Lake Titipaca

(and probably

Ecuador and

Colombia) H.

pallida

is the

dominant cyst nematode.

There are

sporadic

occurrences

of: .

rostochiensis

-

2

fields in

Colombia,

some fields

near

Arequipa

and

sev-

era l fields south of Puno near

Lake

Titicaca. To

the

south

of the

Lake,

there

are la rger

numbers of H.

rosto-

chiensis,

although

H.

pallida

stil l

appears

to

pre.domi-

nate.

Since

approximately two

thirds

of all European in-

festations a re _ :h rostochiensis, the predominance of

H.

pallida in

areas

of eru and Bolivia

that

have

been

sur-

veyed is an interesting contrast.

A Canonical

Variate

analysis of morphometr ic data on 3

pathotypes f rom the

two

cyst

species was

run on the

R-

thamsted computer in Decem ber . This showed that the

best character is t ics for separating rostochiensis

f rom

pallida were stylet lengths of adult males

and

females;

and,

stylet

length, head width

and length,

and

tai l

width

at

the anus of larvae

(with

female

.stylet

length the best).

A smal l m orphometr ics study

of

four

CIP

tes t

populations

and two populations representat ive

of

Brit ish

11

A

11

and

11

E"

pathotypes was carr ied out using

only

the best character-

is t ics

selected by C. V. analysis.

Two groups

were iden-

tified:

Puno grouped

with Britiish "A'

1

(H. rostochiensis)

and

the

others grouped

with

British.

11

E'

1

:H. pallida).

H o w e ~ ~ r

there was some v a r i ~ t : i . G J l

f;etween

populations,

e .g . the

stylet

l ~ p g t h Puno

lar'\taefW.a,s 1.

62 l . grea ter

than that

oCBrH:is:h.

: A and the ct:i. tetehce between Bri t -

ish

"A" and

11

E" p a t h o t y p ~ . s ~ a s only 3J:> 6

Jl

In a

pre-

l iminary electrophoretic.st;ittq:y 9 t ~ A r a t e ~ soluble protein

band

patterns ... a

B r i t i s h ~

i ? a n i ~ . p o p l l . l a t i o n produced

different protefo

pat terns

than

two.

Peruvian

H.

pallida

populations. the two Peru".ian P'opulatioAs,

one

f rom

Otuzco

and the

other from Huancayo,

produced

different

electrophoret ic patterns from e a ~ other.


50/87

- 46 -

During

1973

in two

t es t s

900 clones were screened

against

four

cyst nematode

populat ions. One clone

of...:. raphani-

fol ium 2n=24); 3 clones of S . acaule 2n=48); and l clone

of

S.

spars ipi lum

2n=24) have

res i s tance

against

the

four

Andean pathotypes of potato cyst nematodes tes ted.

Following

a

fur ther conf i rmatory t es t these species will

be used

in c rosses

with cultivated species .

Studies have

also

been made on the role of to le rance

as

dist inct

f rom res i s tance

to

potato cys t nematodes .

In

spite

of

nematode

attack, 90 clones, which were planted

in

12

hil l

plots in

a

heavily infes ted

field

a t

Chocon

Jau

ja), outyielded

Renacimiento

by as much as 5-fold. In

the absence of nematodes ,

Renacirniento, would normal ly

outyield

these

selections).

Access ions

G- 0171

G-1330,

and G-2115 showed outstanding tolerance to natural

levels

of cys t nematode

infestat ion.

Root-

Knot

Nematodes

Meloidogyne sp.)

In

a pre l iminary taxonomic

identification

made

in

Novem

ber

a t La

Molina,

M. incognita and M.

hapla

were

found

in a 4: l

ratio,

respect ively.

A

planting a t San Ramon of

57 clones showed

only

very minimal and sporadic galling

in 9

clones.

This was probably due to the

high

soil

mois

ture

a t this

jungle

si te

which

inhibited

penetra t ion

of root-

knot

nematodes .

A study has

been

init iated

to

determine the impor tance of

the false root- kpot nematode Nacobbus sp. ) to potato cul

tu re in

Peru . These nematodes

have

a wide host range-

_

onion, l ima bean,

corn,

oats , peas , etc . ; i t is not

known

whether the species which

at tack

potatoes

also at tack

other c rops .

Microscopic examinat ion

of Nacobbus

col

lec ted

near Puno

indicate

that

the specimens

are morpho

logically different

f rom

N.

dorsal is

and

N.

aber rans

the

two valid species

of th is

genus.


51/87


52/87

48

Max ;

Planck Insti tute

Dr. Hans

Ross

Botanical

seed

of

12

families

which

were

second and

third

backcrosses to Solanum

oplocense

which

has

res is tance

to H.

pall ida

were

sent

to GIP

f rom

the

Institute.

Tubers

were

obtained f rom

seedlings and

these

were screened

in

Huancayo

in January-M arch, against nematodes f rom

Huancayo.

Only two families

showed

res is tance

in

two

tes ts

These will be

re tes ted

in January, 1974,

with dif-

ferent

populations of nematodes and

if

res is tant they

will

be

incorporated

into

breeding

programs.

U.S. D. A. Breeding Program Dr. R. Webb

33 2 tubers were

obtained

belonging

to

four

famil ies de

r ived r o m ~ vernei . These were tes ted in October,

1972,

a t

La

Molina and

the resis tant select ion again

tes t -

ed in

August,

1973,

a t

La

Molina.

Fif teen

clones have

given resis tant

readings

during two consecutive years

These will be

re tes ted

with different populations of

nema

todes

and

those clones showing continued res is tance will

be incorpora ted into breeding programs.

ADAPTATION TO STRESS

Although

the potato is wl.dely grown

in

t ropical and sub

t ropical regions,

the

absolute

l imi ts

of environmental

s t ress

under

which

an economical crop

of

potatoes

can be

grown are unknown. Some

environmental factors

which

m y cause

destruct ive physiological s t r ess

in potatoes

include

st i l l undefined

l imits of

cold,

heat,

drought,

tox

ic

soi l

conditions,

altitude

re:

ultraviolet tolerance, z

tension) and

. insect predation.

The

f i rs t

and

las t

of

these

f c ~ o r s

have

been

selected

for

special

study by

GIP.


53/87

49 -

Cold

Hardiness

Fros t is a

major

factor l imit ing pGtato prodtiction in the

Andean region

of

South America

and norther.n

India.

Since

a number of

Solanum

species exhibit marked cold

tolerance a project

was

initiate.cl

by

CIP

in

1973

to

breed

plants having incre.ased cold tolera.hce

along

with sever:eratur.e bath Two sample

leaflets

were

placed

in

each chilled

tes t

tube

and

held.at

0C

for at leas t one

hourbefore

lowering the

bath tem

pera ture to -0. 5C. Thirtyminutes.a.fter the bath

tem

perature had

reached

-0. 5 C, leaflets were inoculated

by

touching

with

a very

smal l

pieceof wetcheesecloth.

Each

tube

was held for

a t least 30 .minutes;at a given

freezing temperatures The freezing temperature pro

'.ile

of. a

c,lone

.was

determined

by

exposing

a

ser ies

of

lea,flets of the clone to a temperature range of -

2.

0 to

-6

..0C at.., O. 5 Gincrements. Follewing

rewarming a t

0C for

a t least ' one

hour\ leaflets were t ransfer red in

dividually

into

f lasks contaming

H>O t.nl

:of

dist i l led deion

ized

water

fo.r

collect ing

electrolytes.


54/87

- 50 -

Elect ro ly tes w ere col lected by shaking

f lasks for

one

hour

a t

room tempera ture .

After

removal

of

a

leaflet ,

the

conductance of

electrolytes

was measured

by

a

con

ductivity bridge. Subsequently leafle ts were completely

ki l led

by

placing t hem

on

a block of

dry ice or

in a

deep

f reeze

for a t leas t

one hour and,

again,

the electrolytes

were

collected

in

their

corresponding

f lasks. The

con

ductance was determined aga in

af ter

removal

of

the dead

leaflet .

Percent

leaching,

that

is :

Conductance of leachate af ter freezing

Conductance of leachate

af ter

killing

x

100

was a quanti tat ive index of f reezing injury. Norm ally an

index of 5 0 is indicative of a killing temperature .

Pr io r

to

quanti tat ive

measurements

of

kill ing

tempera

tures pre l iminary

exper iments

were

conducted

to detet

rnine the influence of

water

s t ress

on cold hardiness .

Month-old plants. of several variet ies of

potato

were

s t ressed

by withholding water

until

wilting

of

lower

leaves

was apparent . No effect

of

water

s t ress

on the level

of

cold

tolerance

was

observed

in

compar ison with water -

s t ressed

and control leaves of

the

varie t ies tested. In

another

ser ies

of

exper iments

t

was

a h o

determined

that the:,:'e was

no

significant difference in cold hardiness

in

compar isons of young

and

old leaves.

Potato plants of two

var ie t ies were

grown at three con

t ras t ing field si tes to determine the effect of location on

cold hardiness.

At

the Chicala field ai r

t emperatures

ranged

between 10-l5C during the

day and

4-7C dur-

ing the night. In

contras t , a t

La Molina,

during

the grow

ing season day

t emperatures

ranged between 20-24 C and

night

t emperatures

11- 15 C. The temperature range a t

Matucana was interm.ediate. Despite the .variables o r ~

mally

encountered in such

fiel.d exper iments , the

survival


55/87

5

Yield of

single

plants

of four

andigena

clones and

Katahdin in

gr;owth

chambers , 12-hour days

: ;


56/87

- 5 2 -

tempera ture of Antarki and Ranrahi rca l eaves was above

-3. 5C a t

al l three

locations.

Survival

Tempera tu res of Some Commonly Grown

Pota to

Varie t ies in Pe r u

Tempera tu re

( C)

Varie ty Leaching

- 2. 0

25.

9

-

3.

0

Mariva 56.

1

-

4.

0

100.0

- 2. 5

1

o

8

>;c

- 3.5

Huagalina

17.8

-

4.

5

(89.1%Hz0)

61.

2

- 4. 0

22.3

> C

-

4. 5

Ccompis 21. 5

-5.0

(90. 4%

HzO)

71.

1

-

4.

0 35 9

- 5. 0

Rucki

37. 1

-

6.

0

54. 6

;

Survival

t empera tu re

of specific

var ie t ies Rucki is

a

11

bit ter

11

potato

varie ty.

The native people in the Andes have selected a long t ime

ago

the papas amargas

to make chufio. These potatoes

a re

frost

res is tan t and have originated f rom

pr imi t ive

spec ies

:

a janhui r i

(2n:-=24),

. i zepczukii

(2n=36) ,

S.

curt i lobum

(Zn=

60).

Selections

of

mor e

res is tan t

clones

a re

being used

in

crosses

to diploid and tet raploid

clones .


57/87

53

Initial t r ia ls to

select

potato

genotypes

adaptable to

hot

humid

t ropical

conditions have been conducted

a t

San

Ramon, Of

56 clones evaluated

N503-93

gave

super ior

yield

710 grams/hi l l .

Entomology

An act ive entomology

program was s tar ted

in 1973,

aimed

ini t ial ly

a t

obtaining an

inventory of

insects destruct ive

to potatoes in

Peru . An

extensive collection

of

potato

insects has been

made. The

Andean weevil, Premno-

t rypes sutur ical lus , and leafhoppers are potential ly very

ser ious pes ts in experimental

field

plots a t Huancayo and

San Ramon, respect ively.

Attention

has also

been directed

while

making f ield

sweeps a t collecting and

identifying

natural ly occurr ing

paras i tes

and

predators .

The following

numbers

of

six

species

have been collected a t Huancayo and Casa B l a n c a ~

Winthemia sp.

Prosopochaeta se tosa

Incamyia sp. I

Incamyia sp. II

Eriops is

connexa

Blenmies

sp.

45

18

16

21

8

Huancayo

Casa Blanca

Huancayo

The

aphid, Myzus

pers icae , an

impor tant vector of

PVY,

PVS, and

potato leaf roll,

a lso

frequents plants other

than

potato, which serve as al ternate

hosts .

Surveys

have

been

made

to determine the species

of plants

serv-

ing

as al ternate hosts of M. pers icae as

well

as other

potato infest ing aphids

in

the Mantaro

Valley.

At presen t

388 sl ides of a t leas t 20 different species of aphids

have

been prepared and are

being

identified. P res sed speci

mens of

host

plants are

being

identified in col laborat ion

with

the

Agrar ian Univers i ty of Peru.


58/87


59/87

55

Research

was ini t iated in the screenhouse a t

La

Molina,

in November,

1973,

to

assess

the

interrelat ionships

be

tween

the

physiological state

of

the

potato plant and popu

lat ions

of M.

pers icae relat ive to

cold,

drought, soil

sal ini ty and disease s t resses on the host.

Apterous

forms

of M.

pers icae

are

being

used.

PROTEIN YIELD

The potato is one

of the

most important food crops in

the

world. Per hectare i t possesses greater food value

than

the

cereal

crops. In the production

of

dry matter

content,

per

hectare ,

i t is superior

to

legumes an

Documents

CIP Annual Report 1973