Discrimination of Salt Tolerant and Susceptible Cotton Genotypes at Seedling Stage using Selection Index.

This research work was planned to screen a part of cotton germplasm to find out their salt tolerance potential at seedling stage measuring root length, shoot length, root fresh weight, root dry weight, root dry weight and shoot dry weight. A control and two levels of NaCl (10 & 20 dS m-1) and 50 cotton genotypes in completely randomized design were used. Data indicated that there was significant reduction in all seedling traits. It was also observed that 24 genotypes could not show even emergence at 20 dS m-1 salinity level. Moderate to high genetic variability was observed in all traits at all levels of salinity except at relative salinity of 10 dS m-1. High heritability and high genetic advance was also found for most of the traits. Some genotypes were ranked top on the basis of root length, while others performed well on the basis of shoot dry weight. Thus, to get rid of this complication, selection index was performed by giving an equal weight to all the seedling traits studied. As a result, top 6 genotypes (NIAB-999, CIM-707, NIAB-78, MNH-93, CIM-446 & CIM-443) performing well at 20 dS m-1 were declared salt tolerant. [ABSTRACT FROM AUTHOR]