Biometeorological regulation of male and female fertility traits in banana (Musa spp.) across contrasting flowering environments

The reproductive competence of banana (Musa spp.) is governed by genetic constitution, with its expression being modulated by environmental conditions prevailing during flowering, which is not well explored. The present investigation evaluated genotypic and environmental modulation of pollen count (PC), pollen viability (PV), pollen germination (PG), and stigma receptivity duration (SR) in fifteen banana genotypes across four flowering phases: FP1 (April-May, 2024), FP2 (July-August, 2024), FP3 (September-November, 2024), and FP4 (January-March, 2025). Substantial genotypic differences were evident, with the diploid genotype ‘Calcutta 4, AA’ consistently expressing maximal PC (24,051.4 ± 3349.66) and PV (71.73 ± 9.05%), whereas negligible to extremely poor pollen production was observed in ‘Banana-02/22, BB’ and ‘Alpan, AAB’. Reproductive performance peaked during FP1, characterized by elevated PC (8201.5 ± 1352.66), PV (56.24 ± 3.97%), and PG (45.9 ± 4.60%), and declined markedly under FP4, coinciding with reduced thermal accumulation. Diploid genotypes, notably ‘cv. Rose, AA’ and ‘Calcutta 4, AA’ exhibited consistently superior PG (≥ 60%), in contrast to triploids, which remained largely sterile. Correlation analysis indicated positive associations of PC, PV, and PG with biothermal indices, especially photothermal units, while SR exhibited a weak negative relationship, with maximum duration recorded during cooler flowering phases. These findings underscore the utility of integrating biometeorological cues with genotype-specific fertility attributes to optimize hybridization strategies under variable environmental regimes.