GHS101 and GHSP26 improves boll retention in upland cotton grown under high temperature of semi-arid subtropical climate

Abstract Background Cotton is a natural fibre producing crop grown worldwide where agro climatic conditions match with its growth and reproduction. High temperature is a major environmental factor affecting cotton production due to climate change. Only way to cope with high temperature is to breed for the tolerance. High temperature tolerance is a complex mechanism that includes many genes by which cotton responds to stress. Genes conferring heat stress can be best studied in segregating population like F2 grown under stressed environment. Results Based on contrasting traits (boll retention percentage), two cotton cultivars i.e. FH-Lalazar (High temperature susceptible) and CRIS-9 (High temperature tolerant) were evaluated for eight heat stress related genes. Out of eight, two genes (i.e. GHS101 and GHSP26) were present only in tolerant genotype i.e. CRIS-9 and these two were selected for further analyses. After development of F2, the morphological and yield data from parental as well as F2 population was recorded under natural high temperature conditions. The data for boll retention percentage under high temperature was recorded as an indicator of high temperature tolerance. These two genes were surveyed in 129 plants of F2 population. Most of the plants, containing both genes showed up to 81% boll retention, but some exceptions were there. Most of the phenotypic traits showed skewed variation on histogram depicting metric nature of genes. Conclusion Results demonstrated that co-segregation of boll retention property along with heat tolerant genes in F2 population is important in reproductive development of cotton under high temperature conditions. Thus, it is necessary to identify, and pyramid other genes related to high temperature tolerance at reproductive stage.