Genetic Variability and Divergence studies in Prosopis juliflora DC

Abstract

Variability in morphometric traits of thirty seed sources of Prosopis juliflora were collected from different agroclimatic zones of Tamilnadu state, India were assessed. There were significant differences among different growth parameters both at nursery level and in the field for plant height, collar diameter and number of branches and also for secondary parameters viz., Sturdiness quotient and volume index. Superiority in terms of growth parameters were recorded in four seed sources viz., Ramnad, Rameshwaram, Madurai and Keezhakarai. However, consistent performance in growth characters were depicted by two seed sources viz., Ramnad and Rameshwaram, throughout the study at nursery and field conditions. In general, phenotypic coefficient of variation was higher than the genotypic coefficient of variation indicating the predominant role of environment. High heritability was recorded for plant heightand volume index respectively (89.00% and 73.00%) and genetic gain as percentage of mean was high for volume index (65.50 %) followed by plant height (32.69%) indicating the additive gene action. Volume index had positive correlation and intercorrelation with plant height, collar diameter and number of branches. Path analysis indicated that collar diameter and plant height had positive effect on Volume index. Hence, these two parameters can be used as selection index for biomass production in Prosopis juliflora. On the basis of hierarchical Euclidian cluster analysis, two major clusters were obtained with highest number of sources falling under cluster A. These clusters were further branched into four sub clusters. The highest Euclidean distance was recorded between the sources of Pudukkottai and Tuticorin (30.33) followed by Pudukkottai and Pollachi of 29.95. The lowest genetic distance of 2.207 was observed between Virudhunagar and Tirupathur. Thus genetic divergence studies using biometric approach revealed similarity with geographic distribution of seed sources.