Selecting superior genotypes to enhance yield and fruit quality in Australian passion fruit

Abstract

Passion fruit (Passiflora edulis) holds significant economic value due to its distinct flavour, aroma, rich nutritional composition, and notable medicinal benefits. Despite its economic importance, the passion fruit industry is constrained by the limited availability of improved cultivars, which adversely affects yield, fruit quality, and profitability. Breeding efforts aimed at improving passion fruit are complex due to the polygenic nature of yield and quality traits, as well as the genetic correlations among them. This study evaluated nine agronomic traits (fruit weight and number, pulp weight and content, fruit length and diameter, soluble solids, skin thickness and yield) across 10 genotypes to estimate heritability and genetic correlations and to identify promising candidates for yield and quality improvement. Heritability estimates ranged from 0.58 for fruit number to 0.95 for pulp weight. Strong and positive genetic correlations were observed among traits related to fruit size and weight, ranging from 0.94 (fruit length–fruit diameter) to 0.97 (fruit weight–fruit diameter). Based on the predicted genetic values of nine fruit traits, different genotype rankings were obtained. The top 20 % of genotypes (PF102 and PF115) were identified using a selection index for fruit yield and soluble solids, achieving gains of 59.11 % and 6.68 %, respectively. Additionally, the study assessed weight loss and storage quality, revealing that PF101 had the longest shelf life, lasting 40 days. These findings provide valuable insights for selecting genotypes in passion fruit breeding programs aimed at improving yield, quality, and post-harvest performance.