Genetic variability, heritability and genetic advance of growth, flowering and yield traits in lisianthus (Eustoma grandiflorum Shinn.) under protected cultivations

Lisianthus (Eustoma grandiflorum Shinn.) is an important cut flower cultivated under protected conditions, where consistency in growth, flower quality and yield is critical for commercial success. The present study was conducted during Rabi 2024-25 in a naturally ventilated polyhouse at University of Agricultural and Horticultural Sciences, Shivamogga, Karnataka, to assess genetic variability, heritability and genetic advance among twelve Lisianthus genotypes. The experiment was laid out in a randomized complete block design with three replications, and observations were recorded on growth, flowering, flower quality and yield traits. Analysis of variance revealed significant differences among genotypes for all characters studied. Phenotypic coefficients of variation were marginally higher than genotypic coefficients of variation for most traits, indicating limited environmental influence. High genotypic variability was observed for leaf area (GCV 25.30%; range 1001.02-2669.78 cm² plant^–1), number of branches per plant (GCV 38.42%; range 1.22-3.56) and internodal length (GCV 41.80%; range 4.22-12.53 cm). These traits exhibited high heritability (93.22-97.06%) and high genetic advance as per cent of mean (49.91-84.27%), indicating predominance of additive gene action. Quality traits such as number of buds per stalk (h² 97.12%; GAM 74.07%) and stalk girth (h² 98.47%; GAM 86.60%), along with yield traits including number of spikes per plant (h² 91.24%; GAM 35.98%) and per square metre (h² 89.18%; GAM 34.40%), also showed strong genetic control. In contrast, duration of flowering exhibited low heritability (3.91%) and genetic advance (0.46%). The identified traits offer reliable selection indices for Lisianthus improvement under protected cultivation.