Abstract
Fifty accessions of Gossypium hirsutum L., were evaluated for heat tolerance based on relative cell injury level (RCIL %) and stomatal conductance. Accessions showed highly significant differences for both the parameters and ranged in relative cell injury level between 44.8 to 74.9% and from 58.1 mu ms(-1) to 120.6 mu ms(-1) in stomatal conductance. The breeding material (NIAB 111/2 followed by MNH 553) showing the least mean Relative cell injury level also showed the highest stomatal conductance and both these traits showed negative correlation (r= -0.70). The data on the basis of both the above mentioned criteria were used to sort out heat tolerant and sensitive cotton accessions for further breeding program.