Characterization of cultivars and low-temperature pollen grain storage in amaryllis (Hippeastrum sp.)

ABSTRACT The determination of viability and the preservation of pollen grains are useful tools for breeding of ornamentals, especially when the synchronization of flowering between species or cultivars does not occur naturally. Thus, the objective of this study was to characterize the flowering and to evaluate the preservation and maintenance of the viability of pollen grains in cultivars of amaryllis (Hippeastrum sp.) subjected to three storage temperatures. Anthers of five cultivars of amaryllis were collected from 12 to 24 hours after anthesis. One part of the anthers was immediately used for germination tests using in vitro germination in culture medium and the other part was stored at temperatures of 25, 8 and -20 °C. Pollen grains were germinated in culture medium at 0, 20, 75, 125, 165, 205 and 245 days after storage. All cultivars of amaryllis showed an accelerated loss of viability at 25 °C storage temperature. The 'Bull' cultivar showed higher recalcitrance to cold-storage, while 'Intokazie' and 'Pink Panther' cultivars showed higher longevity and higher percentage of germination along storage. The temperature of -20 °C resulted in the best responses for the maintenance of the integrity and preservation of the viability of pollen grains of different cultivars of amaryllis.

摘要：花粉粒活力测定与保存是观赏植物育种的重要手段，尤其当物种或品种间的开花同步性无法自然达成时。本研究以经25℃、8℃及-20℃三种储存温度处理的朱顶红（amaryllis, Hippeastrum sp.）品种为材料，旨在表征其开花特性，并评估花粉粒活力的保存与维持效果。研究于开花后12至24小时采集5个朱顶红品种的花药，其中部分花药立即用于培养基离体萌发试验，剩余花药分别置于上述三种温度下储存。分别于储存后0、20、75、125、165、205及245天，对花粉粒进行萌发检测。结果表明，所有供试朱顶红品种在25℃储存条件下均出现活力快速丧失的现象。其中‘Bull’品种对低温储存的顽拗性更强，而‘Intokazie’与‘Pink Panther’品种的花粉寿命更长，储存过程中的发芽百分率也更高。-20℃储存条件可最有效地维持朱顶红不同品种花粉粒的结构完整性与活力。