Morpho-phenological diversity and performance of Palmyrah (Borassus flabellifer L.) accessions

Abstract

A comprehensive morpho-phenological evaluation was conducted on thirteen Palmyrah (Borassus flabellifer L.) accessions planted in 2003 at the Horticultural Research Station (HRS), Pandirimamidi, Andhra Pradesh, India, to assess phenotypic diversity and identify superior genotypes for improvement and conservation. Significant variability was observed across vegetative and reproductive traits, indicating substantial heterogeneity within the germplasm. Correlation analysis revealed strong positive associations among palm height, total leaves, and total leaf length, while fruit weight showed positive relationships with fruit circumference, reflecting coordinated growth and yield attributes. Principal Component Analysis (PCA) extracted four principal components explaining 82.41% of the total variation. The first principal component (PC1) accounted for 27.61% of the variation and was predominantly influenced by fruit and reproductive traits, whereas the second component (PC2), explaining 16.82%, was mainly associated with vegetative growth parameters. Cluster analysis grouped the accessions into four distinct clusters, reflecting divergence driven by both vegetative and fruit traits. Path coefficient analysis indicated that fruit circumference exerted a strong direct positive effect on fruit weight, underscoring its importance in yield improvement. Accessions IC 0630888 (ACC-2), IC 0630892 (ACC-6), and IC 0630895 (ACC-9) were identified as superior for fruit yield and quality, while IC 0630890 (ACC-4) and IC 0630894 (ACC-8) exhibited robust vegetative vigor. The observed diversity is likely influenced by the dioecious nature of Palmyrah, local adaptation, and cumulative selection pressure. These findings highlight the importance of systematic germplasm evaluation for effective conservation and targeted improvement of Palmyrah under changing climatic conditions.