烟台甜樱桃柱头的可授性、形态特征与坐果率

采用数码照相、电镜扫描、联苯胺-过氧化氢测试及去雄套袋等技术手段, 对烟台甜樱桃(Cerasus avium)花期不同发育阶段柱头的可授性、形态特征和坐果状况进行了观察。结果表明, 烟台甜樱桃在套袋状态下, 柱头可授期从开花前1天开始可持续5–7天。从杯状花期到花瓣平展期, 柱头逐渐有乳突细胞破裂并呈现分泌液, 出现渐强的可授性; 从花瓣平展期到花瓣脱落期, 柱头由暗黄渐变至暗黑, 逐渐萎缩并丧失可授性。去雄套袋及人工授粉实验结果显示, 在大蕾期、杯状花期、花瓣展放期、花瓣平展期和花瓣脱落期进行人工授粉, 烟台甜樱桃的坐果率分别为60.50%、58.33%、62.08%、57.14%和39.13%。在自然条件下烟台甜樱桃的坐果率一般为30%–42%, 传粉成功的最佳期主要发生在杯状花期至花瓣平展期。

Stigma Receptivity, Stigma Morphology and Fruit Set of Yantai Sweet Cherry (Cerasus avium)

Stigmatic receptivity is a limiting factor of flower receptivity and fruit set in Cerasus avium. This study investigated stigma receptivity, morphological characteristics and fruit setting under defined developmental stages by scanning electron microscopy, benzidine testing, H₂O₂ testing and bagging experiments. Stigma receptivity occurs 1 day before blossoming and is retained for 5 to 7 days. Stigma receptivity is associated with collapse of papillae and production of cellular exudates. The loss of receptivity is accompanied by nigrescence and stigma shrinking, including severe stigma degeneration. The stages of bell-like flowers and flattened flowers showed increased stigma receptivity. As compared with emasculation and bagging, hand pollination could produce greater fruit set, and fruit set was maintained even at the stage of petal abscission. Successful pollination was 60.50% at the balloon-like stage, 58.33% at the petal unfurling stage, 62.08% at the fully open stage, 57.14% at the flattened petal stage, and 39.13% at the petal falling stage. Open pollination could produce pollination levels between 30% and 42%. The best pollination opportunity mainly occurs when petals are unfurling and when petals flatten. A longer receptivity period is helpful for stigmas to be visited and pollinated successfully by bees and gives cultivators the opportunity to apply remedial measures such as artificial pollination to increase pollination rates and fruit set.