Genome-wide association study was performed in a Tunisian durum wheat collection. The collection was genotyped with the wheat 90K Illumina array and phenotyped for seportia tritici blotch.
A core collection of 235 durum wheat accessions consisting mainly of landraces was genotyped and evaluated for its genetic diversity and population structure. The same collection was phenotyped for the fungal pathogen Pyrenophora triciti-repentis (cause of tan spot disease of wheat) in Tunisia to perform genome-wide association analyses. The results highlight the significance of chromosomes, 2B, 3B, 5B, and 6A as genomic regions associated with tan spot resistance.
Interspecific hybrids can be formed through allopolyploidization. Synthetic hexaploid wheats (SHW) have been created in breeding programs through the intentional crossing of tetraploid and diploid species. In this study, quantitative genetics tools developed to predict cross performance within a species were applied to predict the phenotypes of SHW for four major quantitatively inherited diseases using the data contained in this dataset. The results of the analysis are presented in the accompanying article.
Lower yield of wheat in eastern India can be attributed to several input factors i.e., inappropriate crop management practices including other social and environmental factors. Among them, sub-optimal irrigation is one of the important factors. Recommended number of irrigations for optimal wheat harvest is 4-5 depending upon crop growth stages and availability of water. Observations by the project team and a recent survey conducted by CSISA at a landscape-level found that majority of farmers in this part of India apply 2-3 irrigations. Moreover, several studies have suggested to apply irrigation to wheat at its grain filling stage to protect the crop from terminal heat stress thereby safeguarding yield. To validate the effect of number of irrigations and irrigation at the grain-filling stage of wheat, multi-location on-farm trials were conducted continuously over six years starting from 2016-17. Krishi Vigyan Kendras, district-level extension center of national agriculture research and extension system were involved in this process. Ten districts were selected in a way that all agro-climatic zones of this area are covered. The treatment in this trial was application of additional irrigation at maturity/grain-filling stage of wheat crop against general farmer practice. Number of irrigations with farmers vary from 1 to 4, so our treatments included 1+1, 2+1, 3+1, and 4+1 irrigations. We applied these treatments in two sets of wheat crop establishment i.e., zero-tillage and conventional tillage methods. There is asymmetry in distribution of samples within treatments and over years. That happened as trial was in farmer’s participatory mode and numbers were dependent completely on willingness of farmers to participate. Altogether, the trial was conducted at 1810 sites, and we captured 63 variables including yield and yield attributing traits.
CIMMYT annually distributes improved germplasm developed by its researchers and partners in international nurseries trials and experiments. The High Temperature Wheat Yield Trial (HTWYT) is a replicated yield trial that contains spring bread wheat (Triticum aestivum) germplasm adapted to Mega-environment 1 (ME1) which represents high temperature areas.
CIMMYT annually distributes improved germplasm developed by its researchers and partners in international nurseries trials and experiments. The High Rainfall Wheat Yield Trial (HRWYT) contains very top-yielding advance lines of spring bread wheat (Triticum aestivum) germplasm adapted to high rainfall, Wheat Mega-environment 2 (ME2HR).
The Elite Spring Wheat Yield Trial (ESWYT) is a replicated yield trial that contains spring bread wheat (Triticum aestivum) germplasm adapted to Mega-environment 1 (ME1) which represents the optimally irrigated, low rainfall areas. Major stresses include leaf, stem and yellow rusts, Karnal bunt, and lodging. Representative areas include the Gangetic Valley (India), the Indus Valley (Pakistan), the Nile Valley (Egypt), irrigated river valleys in parts of China (e.g. Chengdu), and the Yaqui Valley (Mexico). This ME encompasses 36 million hectares spread primarily over Asia and Africa between 350S -350N latitudes. White (amber)-grained types are preferred by consumers of wheat in the vast majority of the areas. It is distributed to upto 200 locations and contains 50 entries.
DArTAG panel 2 validation data on 1454 CIMMYT spring bread wheat elite lines included in the 53, 54 and 55IWBWSN and 38, 39 and 40 SAWSN. DArTAG panel 2 consists of 3897 selected SNPs.
The list includes wheat genotypes that have been evaluated for wheat blast resistance with data available publicly (database links are provided). The list is to be updated regularly