Evaluation of resistance in wheat against Rhopalosiphum padi (L.) (Homoptera: Aphididae)

Noreen Moin

05-arid-345

PMAS-Arid Agriculture University Rawalpindi

CONTENTS

IntroductionMaterials and methods

Seedling bulk testAntibiosis testTolerance test

Results Seedling bulk testAntibiosis testTolerance test

Conclusion Recommendation

INTRODUCTION

Aphids are consider as serious pests of crops (Wheat, Barely, Maize etc)

Transmit virus (MMSV, BYDV)

Persist through out the wheat season

Reproduce Sexually

Asexually

INTRODUCTION continue…

Some important species of aphids in Pakistan

Bird cherry oat aphid (Rhopalosiphum padi (L))Wheat grain aphid (Sitobion avenae) Grain aphid (Sitobion miscanthi)

Corn leaf aphid (Rhopalosiphum maidis)

Control strategies Insect pest management

Benefits of IPMEnvironmentally sound method Economic

OBJECTIVES

Evaluation of resistant varieties of National Uniform Wheat Yeild Trials (NUWYT) Rain Fed (RF) against Bird cherry oat aphid by applying following tests

Seedling bulk test

Antibiosis test

Tolerance test

MATERIALS AND METHODS

Host was wheat 11 varieties of (NUWYT) Rain Fed (R.F) of year 2004-05.

Experiments were conducted under controlled environment

28+2 oC, 40-70% RH and photoperiod of 16:8h

Mass rearing was done in NARC by establishing the culture of Rhopalosiphum padi (L)

Resistance was evaluated by Seedling bulk test

Antibiosis test

Tolerance test

SEEDLING BULK TESTMetal trays measuring(51x35x9 cm)Eight rows of one cm depth25 seeds per genotype was sownTen aphids were released at seedling height of 5-6 cmDamage rating was recorded after 10-15 days

ANTIBIOSIS TEST

Two seeds were sown in 7 cm diameter potAt height of 5-6 cm, each variety was thinned to one One adult aphid was released Covered with plastic cage having two side ventilation holes, 6 cm diameter and 30 cm height One nymph was allowed to grow until it becomes sexually mature Nymphs reproduced daily were removed and counted for each seedling

TOELRANCE TEST

Seeds were sown as described in antibiosis testSeedlings were infested by aphids at the height of 5-6 cmTen adults were maintained

RESULTS Seedling bulk test

Varieties NUWYT (RF) No. of seedlings Damage rating (DR)

Nature of resistance

PR-87 21 4 MR

NR-241 17 4 MR

SN-128 20 5 MR

V-00BT004 16 5 MR

V-00055 18 6 MR

V-5 20 3 R

NRL-2017 22 7 S

NR-234 15 5 MR

RESULTS Seedling bulk test CONTI….

Varieties NUWYT (RF)

No. of seedlings Damage rating (DR) Nature of resistance

V-002467 15 4 MR

DN-44 18 4 MR

PR-83 25 5 MR

Chakwal-97 14 7 S

R = Resistant varieties with damage rating = 3MR = Moderately Resistant varieties with damage rating = 4-6S = Susceptible varieties with damage rating =7-9

RESULTSANTIBIOSIS TESTVarieties NUWYT (RF) Average no. of nymphs Remarks

PR-87 1.3 MF

NR-241 1.3 MF

SN-128 1.5 HF

V-00BT004 1.3 MF

V-00055 1.2 MF

V-5 1.0 MF

NRL-2017 0.9 MF

NR-234 1.1 MF

Varieties NUWYT (RF) Average no. of nymphs Remarks

V-002467 0.5 LF

DN-44 1.2 MF

PR-83 0.7 LF

Chakwal-97 1.6 HF

Wafaq-2001 1.3 MF

RESULTSANTIBIOSIS TEST CONTI..

LF = Least Fecund MF = Moderately Fecund HF = Highly Fecund

RESULTSTOLERANCE TESTVarieties NUWYT (RF) Average DR Remarks

PR-87 3.8 MT

NR-241 3.6 HT

SN-128 3.6 HT

V-00BT004 6.2 LT

V-00055 4.4 MT

V-5 3.6 HT

NRL-2017 4.4 MT

NR-234 5.4 MT

RESULTSTOLERANCE TEST CONTI..

Varieties NUWYT (RF) Average DR Remarks

V-002467 5.2 MT

DN-44 4.6 MT

PR-83 3.6 HT

Chakwal-97 4.2 MT

Wafaq-2001 4.6 MT

HT = Highly Tolerant MT = Moderately Tolerant LT = Least Tolerant

3.83.6 3.6

6.2

4.4

3.6

4.4

5.45.2

4.6

3.6

4.2

4.6

0

1

2

3

4

5

6

7

Wheat varieties NUWYT (RF) 2004-05 along with Wafaq 2001

Av

g D

am

ag

e R

ati

ng

PR-87

NR-241

SN-128

V-00BT004

V-00055

V-5

NRL-2017

NR-234

V-002467

DN-44

PR-83

Chakwal-97

Wafaq-2001

RECOMANDATIONS

The use of resistant varieties will remain the most logical and economical way of reducing damage of pests in wheat germplasm

CONCLUSIONS

In seedling bulk test V-5 was highly resistantIn antibiosis test least fecund line was PR-83In tolerance test four lines NR-241, SN-128, V-5 and PR-83 was found to be tolerant to aphid R.padi