Screening for high-temperature tolerent cotton (Gossypium Spp.) by using some physio-morphological leaf treats

Abstract

One hundred sixty cotton genotypes obtained from genetic stocks were evaluated for high temper- ature tolerance based on some physio-morphological leaf traits under field conditions and controlled con- dition. Genotypes showed differences for all investi- gated traits. In the study, stomal density ranged from 83.49-128.35 stomata. (mm2)-1, stomatal conduct- ance ranged from 140.77-394.90 mmol.m-2.s-1, sto- mal width ranged from 92.39-154.01 µm, stomatal rate of width/length ranged from 0.42-0.58, canopy temperature ranged from 20.24-52.00 oC, leaf area ranged from 67.50-173.05 cm2, leaf SPAD value ranged from 31.80-63.73, and leaf photosynthesis yield ranged from 12.72-33.05 µmol.m-2s-1. The re- sults showed that high temperature stress did not in- fluence stoma numbers, whereas it decreased sto- matal conductance, stomatal width, stomatal width/length, leaf area, leaf SPAD and leaf photo- synthesis yield; and that it increased canopy temper- ature values. The Fantom was determined to be tol- erant with respect to stomatal conductance trait and the Tropikal-225 genotype with respect to stoma width and width/length traits.