Responses of Gossypium hirsutum L. varieties / lines to NaCl salinity at seedling

Abstract

Responses of fifty varieties/lines of Gossypium hirsutum L. to three NaCl salinity levels i.e., control, 10 dS/m and 20 dS/m, were compared at seedling stage. The results revealed that increase in NaCl salinity, after 30 days growth, considerably affected the root and shoot lengths, but the effect was more pronounced on roots. Based upon absolute salt tolerance and relative salt tolerance, using root length and shoot length data, three varieties/lines i.e., NIAB 78, B 557 and MNH 522 were found to be salt tolerant, and by contrast Qalandri, MNH 147 and BP52NC63 were found to be salt sensitive. In order to confirm the selection of the tolerant and sensitive varieties/lines, it was considered to study substrate salt tolerance of the selected varieties, the uptake of Na+ and K+ in the leaves, and then K+ /Na+ ratio. The estimates of broadsense heritability of root length was high, suggesting that improvement in salinity tolerance in Gossypium hirsutum L. is possible exploiting the existing variation through selection and breeding.