‘灰枣’传粉综合征及其繁育系统
Floral Syndrome and Breeding System of ‘Huizao’ (Zizyphus jujuba Mill.)

为探讨‘灰枣’高花果比的原因，通过田间观察和控制性试验研究‘灰枣’的繁殖生物学特征。结果显示，其花部特征表现为花小、结构简单、黄绿色、花蜜暴露于蜜盘、有香气，单花泌蜜量为0.94 μL±0.11 μL，含糖量38%±3%，符合蝇类传粉综合征；除外来物种意大利蜜蜂外，仍有6种当地野生昆虫是‘灰枣’的有效传粉媒介，并以蝇类昆虫为主，有效传粉距离在24 m内。杂交指数（OCI）大于4，人工异花授粉结实率高于自花结实率，表明‘灰枣’属于异交为主的繁育系统，需要传粉者；套袋不授粉处理不结实，表明‘灰枣’无自助的自花结实能力；人工辅助授其他品种花粉能显著提高结实率，表明花粉限制是其高花果比的原因之一。
In order to research the reasons of high flower:fruit ratio in jujube (Zizyphus jujuba Mill.cv.‘Huizao’),the breeding biology was studied by field observation and controlled test.Results were obtained as follows,the flower of ‘Huizao’ is simple,small,green yellow,and the nectar exposes on floral disc with sweet smell.The nectar volume per flower was 0.94 μL±0.11 μL and sugar content was 38%±3%.The floral traits of ‘Huizao’ implied the flies-pollination syndrome.The flowers were visited by alien species Apis melligera and 6 species of local insects,and flies were the main pollinators.Pollen flows showed that the effective distance of pollination was within 24 m.Both results of out crossing index (OCI)＞4 and higher fruit set of cross-pollination than self-pollination declare that outcrossing is the main form of breeding system and the pollinator is necessary for fruit setting of this cultivar.No fruit set in bagged flowers indicated that there is no spontaneous self-pollination in this cultivar.Significant difference was found in fruit set between flowers with open pollination and hand supplemental cross-pollination,suggesting that pollen limitation is one of the reasons for the high flower:fruit ratio in ‘Huizao’.