Adaptation population genetics and fruit quality characteristics of Morus alba L from trans Himalayan Ladakh region India

Abstract

Ten quantitative morphological characters were studied in 56 Morus alba L trees representing three natural populations from the trans Himalayan Ladakh region The altitude of collection sites ranged from 2815 to 3177 m asl Coefficient of variation CV showed high phenotypic variation in M alba populations from the transHimalaya Phenotypic plasticity measured using phenotypic plasticity index revealed significant contribution of phenotypic plasticity towards phenotypic variation Linear regression analysis revealed that size of leaf and fruit characters decreases with increase in altitude High CV was observed for leaf length 2665 percent leaf width 2621 percent petiole length 3221 percent leaf area 5034 percent internodal distance 3811 percent number of nodes 4601 percent bud length 2358 percent fruit length 1314 percent fruit width 2152 percent and fruit weight 4414 percent Similarly high phenotypic plasticity was observed for bud length 032 leaf length 05 leaf width 05 petiole length 061 leaf area 073 and internodal distance 051 number of nodes 06 fruit length 025 fruit width 031 and fruit weight 066 For every 100 m increase in altitude leaf length leaf width and leaf area decreased by 1 cm 08 cm and 166 cm2 respectively Analysis of covariance showed a predominant altitudinal effect on the morphological characters in comparison to the population effect A small change in altitude caused significant change in plant morphological characters The present investigation represents to our knowledge the first study addressing phenotypic variation in mulberry along altitudinal gradient