Analysis of genetic variability and agronomic performance of Indian lettuce (Lactuca indica L.)

Abstract

Lactuca indica L. is an undomesticated medicinal crop in the Asteraceae family. The study was carried out to identify elite genotypes for lettuce cultivation and breeding improvement. Data was recorded for 19 morphological and developmental traits across 38 accessions (Acc). The genotypic mean square variance was significant for all characters. The higher extent of genotypic and phenotypic coefficient of variation were obtained for basal branch, leaf blade width, and node number. The broad-sense heritability (H2B) ranged from 45.85% (seed length) to 98.59% (node number), whereas genetic advance as a percentage of the mean (GAM%) ranged from 9.33 to 191. Vegetative characters such as node number, plant height, basal branches were conjugated with high H2B and high GAM% indicating additive gene effect and selection of these traits based on phenotypic observation is effective for better gain. Reproductive traits, including bolting duration, flowering duration, and seed weight were linked with high H2B, and moderate GAM% revealing that these traits are amenable to genetic improvement, these traits also showed a significant and high positive correlation. Acc 55 and 8 showed the best performance for the majority of the attributes could be good material for further research and breeding. In the Wards’ phylogenetic tree of morphological traits, accessions were clustered based on their phenotypic characters rather than the geographic origin.