Genetic variability and correlation studies of physiological and yield attributing traits in clusterbean [Cyamopsis tetragonoloba (L.) Taub.] under arid rainfed condition of Jaisalmer

Abstract

Clusterbean [Cyamopsis tetragonoloba (L.)Taub.], also known as guar, is a drought hardy leguminous crop cultivated mainly in arid and semi- arid region of India. It is one of the most important and potential vegetable cum industrial crop grown for vegetable and for endospermic gum. Assessment of variation among diverse genotypes helps in identification of parents for hybridization program. Twenty-one clusterbean genotypes were assessed for genetic divergence and correlation study of different morpho-physiological and yield attributing traits at ICAR-CAZRI Regional Research Station, Jaisalmer under arid rainfed condition during the kharif season of 2015. The experiment was laid out in randomized complete block design with three replications. Wide range of variability for plant height (39.5-64.6 cm), days to flower initiation (24-33 days), leaf area (190.6 – 400.9 cm2) and other yield attributing trait i.e., number of branches per plant (0.6-5.3), cluster per plant (5.8-14.9), pod per cluster (2.3-5.0), seed per pod (5.3-7.5), total dry matter (14.7-28.7g plant-1), 100 seed weight (2.09-3.79g) was observed. Physiological traits known to be related to crop performance under arid conditions like relative leaf water (RLWC) (70.5- 96.6%) and membrane stability index (3.8-47.1) also showed variation along with contents of different metabolites like total sugar (77.5- 159.5 mg/g fresh weight) and total phenol content (15.5 – 26.7 mg/g fresh wt.). In addition, high genotypic coefficient of variation (GCV) was recorded for RLWC (90.2), cluster per plant (78.8), number of branches per plant (70.4), phenol content (62.9), total plant dry wt.(61.6), plant height (85.2) and seed yield (53.7). High phenotypic coefficient of variation (PCV) was also recorded for these characters. High heritability was recorded in pod per cluster (55.3), cluster per plant (42.2), phenol (41.7), 100 seed weight (40.0), number of branches per plant (38.3), total plant dry weight (36.0) and seed yield (36.5). Significant positive correlation of plant dry weight (0.865 * *), cluster/plant (0.811 * *), pod/cluster(0.694 * *) and metabolite sugar (0.619 * *) and total phenol(0.659 * *) with seed yield further clearly identifies these parameters which could be used for future improvement programs of clusterbean.