Accelerating HEAT Tolerant Wheat Breeding for Climate Change Adaptation and FOOD Security in Bangladesh.

 

Wheat, the second most important cereal crop in Bangladesh, is normally subjected to multiple environmental stresses including extreme heat. Terminal heat during grain fill is the most common abiotic stress and reduces wheat yield by 0.2 to 0.5 t ha^-1 with each one degree Celsius increase in temperature. Most of the wheat in Bangladesh encounters heat stress at grain filling, and to sustain yield it is extremely important to develop heat tolerant varieties. With this objective, 16SABWGPYT nurseries were planted in Bangladesh to perform association mapping to identify heat tolerant QTLs, development of molecular markers, and selecting candidate genotypes for use in the development to heat tolerant varieties. Six hundred advanced breeding lines from CIMMYT and USAID Feed the Future Innovation Lab were evaluated and screened using augmented incomplete block design with two replications. Data were recorded for NDVI, canopy temperature, heading, maturity, grains per spike, thousand grain weight, and yield using handheld high throughput phenotyping platform. All 600 lines have been genotyped using genotyping-by-sequencing. The genotypic and phenotypic data will be used for association mapping for heat tolerance. Moreover, the data will be analyzed to calculate Genomic Estimated Breeding Values (GEBVs) that will accelerate the selection of candidate wheat lines. These candidate lines will be used in developing and released as superior varieties.

Key words: Wheat, HTP, GBS, GWAS, QTL, GEBVs, crop breeding.