Morphological and Phytochemical Variation in Photo-Insensitive Lablab Bean (Lablab purpureus L.) Genotypes

Lablab bean (Lablab purpureus L.) is a widely grown winter crop in Bangladesh. The photo-insensitive lablab beans are also suitable for the summer season. This study analyses six photo-insensitive genotypes of lablab bean for their morphological traits and bioactive compounds. The study was conducted at Sylhet Agricultural University, and a completely randomized block design was employed, with the treatment repeated three times. The six genotypes analyzed are Sikribi sheem-1, Sikribi sheem-2, IPSA sheem-1, IPSA sheem-2, SB-003, and SB-011. Key morphological and yield parameters, including plant height, branches per plant, days to flower, days to harvest, and pod yield per plant, were measured. In the phytochemical analyses of the pods, total phenol and flavonoid contents, along with antioxidant activity, were quantified. IPSA sheem-2 showed strong growth, reaching 253.33 cm in height, followed by IPSA sheem-1 (226.67 cm) at 30 days after sowing. IPSA sheem-2 and Sikribi sheem-1 had approximately 4 branches plant-1 and 3 branches plant-1 at 30 days after sowing, respectively. Sikribi sheem-1 excelled in pod production with 216.67 pods/plant, the highest individual pod weight (4.21 g), and the maximum pod yield (36 kg decimal-1). IPSA sheem-2 had the highest dry matter (13.06%), whereas IPSA sheem-1 had the highest fibre content (1.35%). In terms of phytochemical attributes, Sikribi sheem-1 had the highest total flavonoid content (4.5 µg/mg quercetin equivalent). IPSA sheem-2 exhibited the highest dry matter (%) and moderate yield. Sikribi sheem-1 excelled in terms of number of pods plant-1, total flavonoid content, and pod yield. Therefore, Sikribi sheem-1 and IPSA sheem-1 can be recommended for commercial cultivation during the summer season.