Character association and path coefficient analysis for improved traits in rambutan

Abstract

Variable types of rambutan collected from the natural diversity existing in the homesteads of Kerala were characterized and correlations among both qualitative and quantitative traits were studied by using Spearman and Pearson coefficient, respectively. The loading plot was drawn with principal components. The direct and indirect effects of component characters on fruit weight were also studied by path coefficient analysis. The collections having soft textured aril exhibited very strong adherence of aril to seed, whereas the collections having crispy aril were of free stone aril. The taste sweetness was found to tend towards soft textured and creamy white aril, but moved away from free seed aril. The loading plot revealed significant positive correlations between rachis length and leaflet width; leaflet width and leaflet length and between tree age and number of leaflets per leaf and a negative correlation between petiole length and leaflet width. Strong positive associations were observed between TSS and sugar content and among yield, fruit weight, fruit diameter, rind weight, aril weight and aril thickness whereas, a significant negative correlation between titrable acidity and TSS. The highest positive direct effect of aril weight and fruit weight on fruit yield reveals the true relationship between them and direct selection for this trait will be rewarding for yield improvement. The association of various characters provided information on the nature and relationship among various traits and it can certainly serve as an effective tool for the exploitation of a particular trait towards crop improvement.