ABSTRACT

Yield in cherimoya (Annona cherimola Mill.) is affected by various factors reducing fertilization and fruit production such as: the protogynous dichogamy of the flowers, deficient natural pollination, and low pollen quality. The objective of this study was to determine in vitro the differences in pollen quality of nine ecotypes and one cultivar of A. cherimola from pollen samples collected at the female and male phenological stages of flowering. The percentage of pollen germination and the length of pollen tubes was evaluated in vitro at 2 and 24 hours after incubation at 21°C, in two phenological stages of the flowers during bloom in 2018 and 2019 seasons. The germination medium contained: 10% sucrose, 1% agar, 0.005% boric acid, and 0.025% calcium nitrate. Fabulosa and Austro ecotypes and the Fino de Jete cultivar had the highest pollen germination in the male phenological stage, after 2 and 24 hours in both seasons. Fabulosa had the highest percentage of germination in the female stage in both seasons. The ideal phenological stage for pollen collection was at anther dehiscence. Austro and Fabulosa ecotypes had the longest pollen tubes after 2 and 24 hours, in both phenological stages for both seasons. Fabulosa and Austro ecotypes, and Fino de Jete cultivar, showed promising pollen characteristics for hand pollination of cherimoya.

摘要

番荔枝 ( Annona cherimola Mill.) 的产量受多种因素的影响，这些因素会降低受精和果实产量，例如：花朵的雌雄同体、自然授粉不足和花粉质量低下。本研究的目的是从开花的雌性和雄性物候阶段收集的花粉样本，在体外确定九种生态型和一种A. cherimola栽培品种的花粉质量差异。花粉萌发率和花粉管长度的体外评价在 21°C 下孵化后 2 小时和 24 小时，在 2018 和 2019 季节开花期间的两个物候阶段。发芽培养基含有：10%蔗糖、1%琼脂、0.005%硼酸和0.025%硝酸钙。Fabulosa 和 Austro 生态型以及 Fino de Jete 品种在雄性物候阶段的花粉萌发率最高，在两个季节的 2 小时和 24 小时之后。Fabulosa 在两个季节的雌性阶段发芽率最高。花粉收集的理想物候阶段是花药开裂。在两个季节的两个物候阶段，Austro 和 Fabulosa 生态型在 2 小时和 24 小时后具有最长的花粉管。Fabulosa 和 Austro 生态型，以及 Fino de Jete 栽培品种，显示出对 cherimoya 进行人工授粉的有希望的花粉特征。