Climate change has generated unpredictability in the timing and amount of rain, as well as extreme heat and cold spells that have affected grain yields worldwide and threaten food security. Sources of specific adaptation related to drought and heat, as well as associated breeding of genetic traits, will contribute to maintaining grain yields in dry and warm years. Increased crop photosynthesis and biomass have been achieved particularly through disease resistance and healthy leaves. Similarly, sources of drought and heat adaptation through extended photosynthesis and increased biomass would also greatly benefit crop improvement. Wheat landraces have been cultivated for thousands of years under the most extreme environmental conditions. They have also been cultivated in lower input farming systems for which adaptation traits, particularly those that increase the duration of photosynthesis, have been conserved. Landraces are a valuable source of genetic diversity and specific adaptation to local environmental conditions according to their place of origin. Evidence supports the hypothesis that landraces can provide sources of increased biomass and thousand kernel weight, both important traits for adaptation to tolerate drought and heat. Evaluation of wheat landraces stored in gene banks with highly beneficial untapped diversity and sources of stress adaptation, once characterized, should also be used for wheat improvement. Unified development of databases and promotion of data sharing among physiologists, pathologists, wheat quality scientists, national programmes, and breeders will greatly benefit wheat improvement for adaptation to climate change worldwide.

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. F2 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 F8 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.

The normalized difference vegetation index (NDVI) continues to provide easy and fast methodologies to characterize wheat genetic resources in response to abiotic stresses. This study identifies ways to maximize green leaf area duration during grain filling and develops NDVI models to predict physiological maturity and different stay-green parameters to increase grain yield of rainfed winter wheat under terminal drought. Three wheat populations were evaluated: one containing 240 landraces from Afghanistan, the second with 250 modern lines and varieties, tested for two years under low rainfall conditions in Turkey, and the third with 291 landraces from Central and Western Asia (grown for one year in the same location). The onset of senescence, maximum "greenness", rate of senescence and residual "greenness" at physiological maturity were estimated using sequential measurements of NDVI and have shown significant correlations with grain yield under low rainfall rainfed conditions. Trade-offs were identified among the different stay-green attributes, e.g. delayed onset of senescence and high maximum "greenness" resulted in accelerated rates of senescence and highest yields and were most evident in the landrace populations. It is concluded, that the use of rate of senescence to select for staygreen must be coupled with other stay-green components, e.g. onset of senescence or maximum "greenness" to avoid the effects of the trade-offs on final grain yield. The NDVI decay curves (using the last three NDVI measurements up to maturity) were used to estimate days to maturity using the NDVI decay during the senescence period and days to heading. A training and testing set (20 and 80% of each population, respectively) were used for calibrations allowing for correlations between predicted and observed maturity of up to r=+0.85 (P<0.0001). This procedure will facilitate large-scale wheat phenotyping in the future.

From 2009 to 2014 a nationwide effort was made to document, collect, conserve, and characterize wheat landraces grown by Turkish farmers. Spike samples were collected from more than 1600 farmers from 59 provinces, planted as single‐spike progenies, and classified into species, subspecies, and botanical varieties (or morphotypes). Altogether, 95 morphotypes were identified representing three species and six subspecies: einkorn wheat (Triticum monococcum L.), emmer wheat [T. turgidum subsp. dicoccon (Schrank) Thell.], cone wheat (T. turgidum subsp. turgidum), durum wheat [T. turgidum subsp. durum (Desf.) Husn.], bread wheat (T. aestivum L. subsp. aestivum), and club wheat [T. aestivum subsp. compactum (Host) Mackey]. Compared with a nationwide survey in 1920, these findings represent a loss of 50 to 70% of the diversity found in 1920, though in four provinces, little if any loss occurred. Based on the Shannon diversity index (H′) and number of morphotypes, the highest diversity for bread wheat was observed in Manisa, Konya, Iğdır, Diyarbakır, and Tokat provinces and for durum wheat in Adana, Diyarbakır, and Hatay provinces. Socioeconomic data indicated that landrace farmers are found mostly in remote mountainous subsistence communities with very little grain trade, small areas planted to wheat, and relatively simple production technologies. The key reasons famers continue to grow landraces are their grain qualities and adaptation to abiotic stresses. In situ conservation should be targeted at provinces with the highest morphotype diversity, with the rarest landraces, and with the highest share of farmers growing landraces.

Kazakhstan is the fourteenth largest wheat producer in the world. Despite this fact, there has not been a comprehensive survey of wheat root and crown rot. A quantitative survey was conducted for the purpose of establishing the distribution of fungi associated with root and crown rot on wheat (Triticum spp.). During the 2019 growing season, samples were taken from the affected plants’ roots and stem bases. A total of 1221 fungal isolates were acquired from 65 sites across the central (Karagandy region), eastern (East Kazakhstan region), and southeastern (Almaty region) parts of the country and identified using morphological and molecular tools. The internal transcribed spacer (ITS), translation elongation factor 1-alpha (EF1-α), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) sequences were successfully used to identify the species of fungal isolates. It was found that Bipolaris sorokiniana (44.80%) and Fusarium acuminatum (20.39%) were the most predominant fungal species isolated, which were present in 86.15 and 66.15% of the fields surveyed, respectively, followed by F. equiseti (10.16%), Curvularia spicifera (7.62%), F. culmorum (4.75%), F. oxysporum (4.10%), F. redolens (2.38%), Rhizoctonia solani AG2-1 (1.06%), Nigrospora oryzae (0.98%), C. inaequalis (0.90%), F. pseudograminearum (0.74%), F. flocciferum (0.74%), Macrophomina phaseolina (0.66%), F. cf. incarnatum (0.33%), Fusarium sp. (0.25%), and F. torulosum (0.16%). A total of 74 isolates representing 16 species were tested via inoculation tests on the susceptible Triticum aestivum cv. Seri 82 and the results revealed that F. culmorum and F. pseudograminearum, B. sorokiniana, Fusarium sp., R. solani, F. redolens, C. spicifera, C. inaequalis, and N. oryzae were virulent, whereas others were non-pathogenic. The findings of this investigation demonstrate the presence of a diverse spectrum of pathogenic fungal species relevant to wheat crown and root rot in Kazakhstan. To the best of our knowledge, this is the first report of F. pseudograminearum, Fusarium sp., C. spicifera, and C. inaequalis as pathogens on wheat in Kazakhstan.