Wheat genotypes showed location-specific heat tolerance and genetic diversity

What the study found: The study found that heat tolerance in 25 wheat genotypes varied by location, and that some genotypes were consistently tolerant or susceptible across both test sites. It also found a range of genetic similarity among the genotypes based on SSR (simple sequence repeat) and STS (sequence-tagged site) markers.

Why the authors say this matters: The authors conclude that genetic diversity is important for plant breeding, because it provides breeders with genetic resources that may be used to develop improved varieties with stress-resistant traits.

What the researchers tested: The researchers evaluated 25 wheat genotypes during the Rabi season of 2020-21 under four environmental conditions: timely sowing and late sowing at two sites, in Jalandhar, Punjab, and Karnal, Haryana. They used an Alpha Lattice Design with two replications, assessed heat susceptibility with the Heat Susceptibility Index (HSI), and analyzed diversity with STS and SSR markers.

What worked and what didn't: At Jalandhar, DBW187, HD3298, HI1612, DBW303, PBW644, NIAW3170, HD3086, HD3118, and DBW88 were classified as tolerant, while DBW222, WB-2, DBW173, DBW90, PBW771, HD3043, HI1605, and HD3249 were susceptible. At Karnal, DBW222, HD3086, DBW173, WB-2, DBW90, HI1605, DBW88, PBW771, HD3043, NIAW3170, and HD3249 were tolerant, while DBW303, DBW187, HD3298, PBW644, HD3118, and HI1612 were susceptible; across both locations, HD2967, WH1142, HD3171, and WH1270 were consistently tolerant, while DBW71, K1317, WH1105, and HI1628 were consistently susceptible. Genetic similarity ranged from 0.61 to 0.94, with an average of 0.77, and the highest similarity was reported for several genotype pairs including DBW187/WH1270 and HD3086/WH1142.

What to keep in mind: The abstract does not describe broader limitations beyond the two sites, the single season, and the specific set of 25 genotypes studied.

Key points

• Heat tolerance differed by genotype and by location in the 25 wheat genotypes tested.
• HD2967, WH1142, HD3171, and WH1270 were consistently tolerant across both locations.
• DBW71, K1317, WH1105, and HI1628 were consistently susceptible across both locations.
• SSR and STS marker analysis showed genetic similarity values ranging from 0.61 to 0.94, with an average of 0.77.
• The authors state that genetic diversity can support breeding for stress-resistant wheat varieties.