Imbalanced expression of stay-green 1 alleles in banana AAB/ABB cultivars prevents high-temperature-induced green ripening as in AAA Cavendish fruit

•Unlike green-ripening of AAA banana, AAB/ABB fruit yellows faster at 30 °C than 20 °C•SGR1 was repressed at 30 °C in AAA fruit, while it was induced in AAB/ABB fruit•A conserved polymorphism code differentiates A- and B-SGR1 from AAB/ABB fruit•Imbalanced expression of A/B-SGR1, favouring B-SGR1, was found in AAB/ABB fruit•B-SGR1 was induced at 30 °C and showed stronger chlorophyll degradation than A-SGR1