百香果花不同发育阶段花粉活力、柱头可授性及其对坐果的影响

Pollen viability,stigma receptivity and their effect on fruit set of passionfruit at different flower developmental stages

【目的】探讨百香果花不同发育阶段花粉活力、柱头可授性变化及有效授粉期,为百香果生产及杂交育种提供理论依据。【方法】于百香果花不同发育阶段测定花粉的萌发率、柱头可授性及对花粉、柱头的电镜观察并进行人工授粉,统计坐果率及分析果实特性。【结果】百香果在花前5h时的花粉就具有一定的活力,随后花粉活力不断升高,开花后3h达到高峰,9h后花粉活力仅为10.63%,20h后为0。柱头可授性与花粉活力呈极显著正相关,相关系数为0.711,表明百香果花为雌雄蕊同熟。花前3h授粉的坐果率最高,开花时及花后1h次之,此后随着时间延长不断降低,花后9h的坐果率为0。扫描电镜观察表明花前后不同时间的花粉在外观上无明显变化,柱头在花后7h乳突细胞表面皱缩增多,20h后柱头皱缩明显。说明可通过观察柱头的乳突细胞外观来判断柱头的可授性,而花粉却不能通过外观判断其活性。花粉活力及柱头可授性与坐果率显著相关,但与单果质量、果实横径、果实纵径、可食率等无显著的相关性,表明花粉活力及柱头可授性只影响坐果率,但对果实特性不产生影响。【结论】百香果花粉及柱头属于雌雄蕊同熟,花粉及柱头的活力期均较短,在开花当天均失去活性,有效授粉期(EPP)为10h左右,即为开花前3h到开花后7h。

【Objective】The study examined the pollen viability and stigma receptivity at different devel-opmental stages of passionfruit flowers and their effects on the fruit setting and fruit traits,so as to find out the effective pollination period(EPP).【Methods】In this study,the purple passionfruit of Guibai No.1 was used as the material,and the grafted seedings were planted in the experimental orchard of in-stitute of Horticulture of Guangxi Academy of Agricultural Sciences(108.24°E,22.85°N)in Septem-ber 2020 by the root-restriction method,with a spacing of 3 m×2 m.The experiment was conducted from April 15,2022 to July 20,2022.For determination of pollen viability,the flowering time,pistil and stamen development of Guibai No.1 were observed starting from the day before the experiment be-gan.The number of the flower bud samples was 100 from 20 plants each with 5.The sample collection was carried out at 5 h(-5 h),3 h(-3 h)and 1 h(-1 h)before flowering,or 0(0 h),1 h(1 h),3 h(3 h),covery,which indicates that pollen viability and stigma receptivity only affected fruit set but not fruit development.【Conclusion】Flowers of passionfruit are characterized by monochogamy,the viability of the pollen and stigma is short and quickly loses with time after flowering.The effective pollination peri-od(EPP)is about 10 h from 3 h before flowering to 7 h after flowering.