To accelerate genetic gains in breeding, physiological trait (PT) characterization of candidate parents can help make more strategic crosses, increasing the probability of accumulating favorable alleles compared to crossing relatively uncharacterized lines. In this study, crosses were designed to complement

Kumar et al. GWAS for Multiple Rust Resistance genome-wide association for identification of a large number of favorable alleles for leaf, stripe, and stem rust resistance for broadening the genetic base. Quick conversion of these QTL into user-friendly markers will accelerate the deployment of these resistance loci in wheat breeding programs.

Relationship of canopy temperature (CT) with grain yield and its components were evaluated under terminal heat stress conditions, in Central India, during 2010-2013 growth season, in which 102 durum wheat genotypes were tested under late and very late sown conditions. The genotypes in late sown conditions showed higher grain yield/plant, biomass/plant, harvest index and test grain weight compared to very late sown conditions. The mean grain yield/plant and biomass yield/plant were 18.8 and 55.9 g, respectively, under late sown conditions, compared to 15.1 and 48.9 g under very late sown conditions. Genotypes MACS 3125, HI 8627, HI 8638, HI 8498, WH 896 and HI 8691 showed stable performance under both late and very late sown conditions over the years and hence exhibited high degree of tolerance to terminal heat. CT ranged from 21.0 to 24.7 and 20.2 to 24.9°C under late and very late sown conditions, respectively. CT showed significant and negative correlation with grain yield/plant and biomass/plant under late and very late conditions and number of grains/spike and 1000 grain weight under very late sown conditions and hence can be successfully used as an important selection parameter in breeding programme at field. The study suggests that CT can be used as one of the important criteria for the selection of stable genotypes under late heat and very late heat stress conditions and can help in improving production and productivity of durum wheat under terminal heat stress conditions.

Farmers in northwestern and central India have been exploring to sow their wheat much earlier (October) than normal (November) to sustain productivity by escaping terminal heat stress and to utilize the available soil moisture after the harvesting of rice crop. However, current popular varieties are poorly adapted to early sowing due to the exposure of juvenile plants to the warmer temperatures in the month of October and early November. Therefore, a study was undertaken to identify wheat genotypes suited to October sowing under warmer temperatures in India. A diverse collection of 3322 bread wheat varieties and elite lines was prepared in CIMMYT, Mexico, and planted in the 3rd week of October during the crop season 2012–2013 in six locations (Ludhiana, Karnal, New Delhi, Indore, Pune and Dharwad) spread over northwestern plains zone (NWPZ) and central and Peninsular zone (CZ and PZ; designated as CPZ) of India. Agronomic traits data from the seedling stage to maturity were recorded. Results indicated substantial diversity for yield and yield-associated traits, with some lines showing indications of higher yields under October sowing. Based on agronomic performance and disease resistance, the top 48 lines (and two local checks) were identified and planted in the next crop season (2013–2014) in a replicated trial in all six locations under October sowing (third week). High yielding lines that could tolerate higher temperature in October sowing were identified for both zones; however, performance for grain yield was more promising in the NWPZ. Hence, a new trial of 30 lines was planted only in NWPZ under October sowing. Lines showing significantly superior yield over the best check and the most popular cultivars in the zone were identified. The study suggested that agronomically superior wheat varieties with early heat tolerance can be obtained that can provide yield up to 8 t/ha by planting in the third to fourth week of October.

The original article was corrected. Author Muhammad Kundi should instead read: Muhammad Sohail.