Mesut Keser

Improved winter wheat genotypes for Central and West Asia

High grain yield and resistance to stripe (yellow) rust are the most important traits for successful adoption of winter wheat varieties in Central and West Asia. This study was conducted to determine the stripe rust response and agronomic performance of a set of breeding lines recently developed by the International Winter Wheat Improvement Program (IWWIP). Replicated field studies were conducted in 2010 and 2011 using 38 experimental lines, one regional check (Konya) and one local check. Stripe rust scores were recorded at Karshi, Uzbekistan, and Karaj and Mashhad, Iran, in 2010. Grain yield was recorded at two sites each in Uzbekistan (Karshi and Kibray) and Iran (Karaj and Mashhad) and one site in Turkey (Eskisehir). The test lines showed variation for stripe rust severity, grain yield, 1,000-kernel weight, days to heading and plant height. Several stripe rust resistant genotypes were either higher yielding or equal to the local checks at different sites. Based on stripe rust resistance and yield performance in 2010, a set of 16 genotypes was selected and evaluated in 2011. All 16 were resistant at Almaty, Kazakhstan, and Dushanbe, Tajikistan, in 2011, whereas 9 of the 16 were resistant at Terter, Azerbaijan. The genotypes ‘TCI-02-138, ‘Solh’, ‘CMSS97M00541S’, ‘TCI -2-88(A)’ and ‘TCI-02-88(C)’ were consistently resistant to stripe across all sites in both years. Several lines showed high grain yields and superior agronomic performance across four sites in Uzbekistan and one site in Tajikistan. One genotype has been released in Uzbekistan and another in Tajikistan.

The international breeding strategy for the incorporation of resistance in bread wheat against the soil borne pathogens (Dryland Root Rot and cyst and lesion Cereal Nematodes) using conventional and molecular tools.

Soil borne pathogens (SBPs) including the Dryland Root Rots and Cereal Nematodes are causing economic yield loss in many parts of the world where cereals dominate the cropping system and sub-optimal growing conditions or cultural practices are common. One of the most effective control measures of these SBPs is the use of host resistance, whereby the inoculum level of these pathogens can be reduced to below economically damaging thresholds. CIMMYT International in collaboration with The Turkish Ministry of Agriculture and Rural Affairs have established an International field and laboratory screening program for identifying spring and winter wheat accessions with resistance to SBPs. Several screening protocols for assessing resistance to both cereal root rots and nematodes have been modified and optimized. Known resistance sources to SBPs from other regions of the world have been tested against Turkish isolates of SBPs and several of these have been shown to be effective in the region. In addition new sources of resistance with genetic variability have been identified against the prevalent SBPs. These diverse genes for resistance are being pyramided into both spring and winter bread wheat backgrounds using both conventional and molecular tools where feasible

High-yielding winter synthetic hexaploid wheats resistant to multiple diseases and pests

Development of winter wheat ( Triticum aestivum ) synthetics started at CIMMYT-Mexico in 2004, when winter durum wheat ( Triticum turgidum ) germplasm from Ukraine and Romania was crossed with Aegilops tauschii accessions from the Caspian Sea region. Chromosomes were doubled after pollination and embryo rescue, but chromosome number and cytological validation was not performed. F 2 populations were grown in Mexico and were shipped to Turkey in 2008. During 2009–2015, these populations were subjected to rigorous pedigree selection under dry, cold, disease-affected environments of the Central Anatolian Plateau. The wide segregation and partial sterility observed in 2009 gradually decreased and, by 2016, most of the F 8 single spike progenies demonstrated good fertility and agronomic performance. Since 2013, lines have been selected from synthetic populations and evaluated at multiple sites. Superior lines were characterized for resistance to leaf, stripe and stem rust, plant height, and reaction to common bunt and soil-borne pathogens. Thousand kernel weight of many lines exceeded 50 g, compared with the check varieties that barely reached 40 g. Threshability of synthetic lines varied from 0 to 95%, demonstrating genetic variation for this important domestication trait. Screening against Hessian fly, sunny pest and Russian wheat aphid identified several resistant genotypes. Both durum and Aegilops parents affected synthetic wheat traits. Several studies are underway to reveal the genetic diversity of synthetic lines and the basis of resistance to diseases and insects. This synthetic germplasm represents a new winter bread wheat parental pool. It is available upon request to interested breeding/research programmes.

MEASURING THE IMPACT OF AGRICULTURAL RESEARCH: THE CASE OF NEW WHEAT VARIETIES IN TURKEY

SUMMARY This paper summarizes a study initiated by the Turkish General Directorate of Agricultural Research and ICARDA/CIMMYT Wheat Improvement Program on the adoption of five new winter and spring wheat varieties developed and released by the Turkish national breeding program and through international collaboration in the past 10 years. The study results are based on a survey of 781 households selected randomly in the Adana, Ankara, Diyarbakir, Edirne, and Konya provinces of Turkey. The five new wheat varieties are compared to old improved varieties released prior to 1995 that are also still grown by farmers. Technical and biological indicators of impacts including crop productivity are measured to determine the impact of these varieties. Yield stability is assessed by comparing average yields in normal, good and dry years and by comparing the coefficients of variation of yields by variety. Profitability is measured by the gross margin generated per unit of land. Household income from wheat and for all economic activities are estimated and compared between adopters and non-adopters. Adopters of the new varieties have higher per-capita income than non-adopters as compared to the same group using old varieties. However, the overall impact of the improved varieties is generally low, mainly due to their low adoption levels. Farmers’ knowledge and perception of certain variety characteristics and unavailability of adequate and timely seed are the main reasons. Increasing adoption has the potential to improve household income and this requires revising wheat impact pathway to achieve the expected impact.

Yield gain due to fungicide application in varieties of winter wheat (Triticum aestivum) resistant and susceptible to leaf rust

Abstract. In three independent experiments in Turkey and Kazakhstan, winter wheat germplasm with variable degrees of resistance to leaf rust was subjected to fungicide protection. The yield loss of genotypes susceptible to leaf rust varied from 30% to 60% depending on the environment and severity of infection. Genotypes completely or moderately resistant to leaf rust also responded positively to fungicide protection, with average yield increases in the range 10–30%. This increase was observed even in one season without leaf rust infection. The main character affected by fungicide was 1000-kernel weight. There was stable expression of the magnitude of yield gain in resistant genotypes in different seasons, confirming genetic variation for this trait. Possible mechanisms of yield gain from fungicide protection in resistant genotypes are related to a positive physiological effect of the chemical used as well as a possible ‘cost of resistance’ to wheat plants. The magnitude of yield gain by resistant germplasm justifies its capture in breeding programs to develop varieties resistant to diseases and with greater benefits from the fungicide protection.