Detection of QTLs for Heat Tolerance and Other Quantitative Traits in Cowpea.

Cowpea is a popular food crop in Texas and other Southern States of USA, and it is a good source of protein, minerals, vitamins, and antioxidants providing good nutrition as well as health benefits. The cultivation of cowpea in the State is declining due to numerous production constraints including drought, heat, and pests. Therefore, a systematic program has initiated to develop improved cowpea varieties with tolerance to heat and drought, and resistance to aphid. A total of 41 cowpea varieties were planted at College Station on June 12, 2011. The temperature in July and August covering the reproductive phase of cowpea was above 100⁰F. This temperature range provided excellent opportunity to screen cowpea varieties for heat tolerance, and the results showed significant genetic variability in the germplasm for heat tolerance. IT98K-476-8 (susceptible) and GEC (tolerant genotypes) parents were used to develop a bi-parental population of 171 RILs in order to locate the QTLs responsible for heat tolerance and other agronomical traits. Flowering date, pods/plant, plant height, and seed weight/plant were significantly difference at significance level 0.05. Flowering date ranged from 22 to 61 days after planting, pods/plant ranged from 0 to 35, plant height ranged from 8 to 34 cm, and seed weight/plant ranged from 0 to 37 g/plant. QTLs will be identified using SNPs genotypic data for all documented traits.