Wheat production in Algeria is threatened by several biotic stresses. Diseases like Stripe rust (Puccinia striiformis)

and leaf rust (Puccinia recondita), Septoria tritici leaf blotch, Tan spot (helminthosporium tritici repentis) and

Fusrium or Take all are among the most prevalent diseases that occured this year mostly all over the Northern part

of the country. Intensive cropping of high yielding varieties is rapidly replacing the traditional lower yielding

landraces. At a breeding level in the National Wheat improvement Program, and since 2005, we had to go for a

large screening of all cereal collections. As a result we could identify wheat lines that carry simultaneously adult

plant resistance (APR) to leaf rust, yellow rust, Septoria leaf blotch and Tan spot in the favorable site and tan spot,

septoria leaf blotch, stripe rust on bread wheat; take all is more present in durum wheat varieties in the semi arid

site.

Key words: Wheat, biotic stresses, screening, APR adult plant resistance, fleaf rust, stripe rust, septoria, tan spot,

yield losses, breeding for disease resistance, Algeria .

ABSTRACT

Acknowledgements: The authors acknowledge all the help given by CIMMYT and

ICARDA .

INTRODUCTION

In Algeria, wheat is grown on approximately 2.5 million ha, though yields

are low due to abiotic and biotic constraints. Cereal production in Algeria (3

million tons on average) is facing several abiotic (drought, cold and salinity)

and biotic (diseases and insects) constraints. During the best seasons

where the abiotic stresses are hindered, diseases and insects are

widespread and are the most damaging in all cereal growing areas of

Algeria. Yield losses of 30 to 80% (epidemic situation) have been recorded

almost annually.

Breeding efforts concentrate on achieving maximum yield potentials

under highly favorable environments, in addition to breeding for tolerance

to major biotic and abiotic stresses. In low rainfall areas, priority is given to

drought tolerance and resistance to stresses such as cold and frost.

However, biotic stresses such as leaf rust (occurring in the sub-littoral

regions), stripe rust, Septoria leaf blotch, and Tan spot are destructive in all

winter wheat regions and are considered the most important wheat

diseases in Algeria. Such diseases are therefore also a focus for breeders.

Annual surveys were undertaken to assess the prevalence, incidence

and severity of cereal diseases across the Northern part of the country in

order to draw maps that are very useful tool to tailor breeding objectives.

The survey allows also the collection of pathogen samples for

determination of genetic diversity and virulence phenotyping. Durum and

bread wheat fields were evaluated for their reaction at the adult stage for

the most prevailing diseases in different North East Algeria cereal growing

area. On station work was mainly concentrating in screening for different

pests and breeding for resistance.

Results of the surveys show that Durum wheat fields seem to be

more affected this last season by take all or fusarium, they are

also slightly affected by leaf rust but not by yellow rust; in the

bread wheat fields there is more susceptiblity to septoria tritici,

and both leaf and yellow rusts. In general, all Northern area has a

particular disease incidence.

The severity is more apparent in the coastal and interior plains

than in the high plateau.

Septoria like diseases (50 to 65% incidence), leaf rust and, to

some extent, yellow rust were prevaling. Powdery mildew, root rot

Fusarium or take all are becoming more present in wheat fields.

Widespread stripe rust epidemics occurred in 2003 and 2004,

and localized (eastern) in multiple years. Yield losses were as

high as 60 percent in susceptible varieties, but in recent years,

major yield losses were prevented by widespread and timely

applications of fungicides, based on accurate monitoring and the

prediction of disease epidemics.

References: Benbelkacem. A. (1991). Les céréales d’hiver. In Céréaliculture 25. ITGC.

Caron. D. (1993). Maladies des blés et des orges. ITCF. Céréales de France. pp 43-53.

Eyal. Z, Scharen. A. L, Prescott. J. M et Van Ginkel. M. (1987). The Septoria diseases of wheat:

concepts and methods of disease management. CIMMYT, Mexico. pp 45.

Saari, EE & JM.Prescott, 1975. A scale for appraising the foliar intensity of wheat diseases.

Plant Disease report. 59: 377-380.

Zillinsky F.J. (1983). Maladies commune des céréales à paille : Guide d’identification. CIMMYT,

Mexico. 141p.

Results & discussion:

P.N.A.B

Breeding for resistance to wheat diseases in Algeria

A.Benbelkacem1* and C.Djenadi² 1INRAA/URC Station ITGC, 25100 Algeria

2INRAA CRP M.Boualem Algiers

benbelkacem@mail.com

Wheat for Food Security in Africa

October 8 - 12, 2012, Addis Ababa, Ethiopia

Material & Methods: Diseases survey are one of the important ways to get acquainted of the

pests situation in a region. North Eastern Algeria is mostly affected during

each year by different pathogens. The survey is performed in the coastal,

interior plains and high plateau areas. All wheat fields of the region are

inspected in samples under natural conditions representing favorable and

semi arid regions; diseases are naturally expressed each year under field

conditions. Severities and reaction types for the rusts and pycnidial

coverage for leaf blight diseases were recorded using the Saari & Prescott

scale (1975).

Nurseries developed through our breeding programs and new

introductions from CIMMYT & ICARDA were screened in hot spot sites

and selection was done at adult plant stage.

Studies of wheat cultivars have also identified sources of genetic resistance to stripe

rust. Durable resistance has been linked to genes such as Yr18, and some very effective

major genes such as Yr9, Yr27, and Yr1 (which were associated with good parental lines

and hence extensively used in Algeria’s breeding program) have effectively reduced the

impact of yellow rust for over a decade.

Recent virulence on Yr27 has been detected in rust nurseries. The potential of wheat rust

epidemics from new emerging virulent rust races remains a real threat to most wheat

producing areas. New material selected during the yellow rust epidemic of 2004 has

shown potential for resistance; four new cultivars (Tiddis, Boumerzoug, Akhamokh, and

Massine) have been released in the past two last seasons and are being dispatched to

selected farmers for seed production. In collaboration with CIMMYT and ICARDA, the

program is also releasing a new wheat cultivar (Yacine) with high resistance to Ug99.

Conclusion

Biotic stresses are important in different wheat growing areas of Algeria; septoria like

diseases (septoria tritici, septoria nodorum and tan spot) and the main rusts (leaf and stripe

rust) are the most prevailing ones. The existing wheat collections comprising, old land races,

modern and new varieties have relatively low resistant rates (28% for bread wheat and 43% in

the durums). This studies gave a picture of the adult plant reaction to the different diseases

and permitted to select for the multiple resistant ones that can of use in the new wheat

improvement program. Durable adult plant resistance sources are being increasingly used as

parents in breeding programs. Creating and disseminating cultivars with continually improved

resistance needs to be a focus of African NARS, and the extension of modern technological

packages, such as integrated pest management (IPM), is needed.