Zuili plum （Prunus salicina L.） trees usually set fruit poorly, although they produce high quality fruit. To elucidate the causes of the poor fruit set, pollen tube growth into pistils and fruit set percentage were ...Zuili plum （Prunus salicina L.） trees usually set fruit poorly, although they produce high quality fruit. To elucidate the causes of the poor fruit set, pollen tube growth into pistils and fruit set percentage were investigated after cross-, self- and open-pollination. Ovule development in Zuili pistils was also investigated. Pollen tube penetration into the ovules via the obturator and micropyle was best when Zuili pistils were pollinated by cv. Black Amber （P. domestica） pollen grains, although cross-pollinations with Hongxinli and Miili （P. salicina） pollen were more effective than self- and open-pollination. The fruit set percentage was also highest in pistils pollinated with Black Amber pollen grains. Morphological observation of Zuili pistils revealed that the trees produce ＂double pistils＂, developing two ovaries from a basal pistil, at a rate as high as 28%. In such abnormal pistils, most ovules were lacking an embryo sac or were entirely degenerated. The percentage of normally developed ovules was 24.3% and 8.9% in normal and double pistils, respectively. From these results, we conclude that the main causes of poor fruit set of Zuili plums are a lack of effective cross-pollination and the production of high percentages of double pistils in which normally developed ovules are scarcely formed.展开更多
In order to investigate the cause of poor fruit set in 'Zuili' plums,anatomical examinations of post-bloom pistils were conducted and the dates of young fruit drop were recorded during the growing seasons of 2...In order to investigate the cause of poor fruit set in 'Zuili' plums,anatomical examinations of post-bloom pistils were conducted and the dates of young fruit drop were recorded during the growing seasons of 2008 and 2009.Pistils of cv.'Black Amber' were also examined as an abundant setting control.Two major dropping periods were detected in 'Zuili':one during the first 5 d after full bloom (DAF) and another between 10 and 17 DAF.Anatomical analyses of the pistils at the full bloom stage revealed that half of the ovules had not developed embryos,which may have caused their early drop.In most dropped pistils collected at 17 DAF,the micropyle had not been penetrated by a pollen tube,indicating that they were not fertilized.'Zuili' ovules initiated embryo division at 10-12 DAF,although thereafter embryo development was retarded when compared to the rates observed in 'Black Amber'.Ovule fertilization failure and inactive embryo development after ovule fertilization may be the major causes of the later fruit drop observed in 'Zuili' plum trees.展开更多
文摘Zuili plum （Prunus salicina L.） trees usually set fruit poorly, although they produce high quality fruit. To elucidate the causes of the poor fruit set, pollen tube growth into pistils and fruit set percentage were investigated after cross-, self- and open-pollination. Ovule development in Zuili pistils was also investigated. Pollen tube penetration into the ovules via the obturator and micropyle was best when Zuili pistils were pollinated by cv. Black Amber （P. domestica） pollen grains, although cross-pollinations with Hongxinli and Miili （P. salicina） pollen were more effective than self- and open-pollination. The fruit set percentage was also highest in pistils pollinated with Black Amber pollen grains. Morphological observation of Zuili pistils revealed that the trees produce ＂double pistils＂, developing two ovaries from a basal pistil, at a rate as high as 28%. In such abnormal pistils, most ovules were lacking an embryo sac or were entirely degenerated. The percentage of normally developed ovules was 24.3% and 8.9% in normal and double pistils, respectively. From these results, we conclude that the main causes of poor fruit set of Zuili plums are a lack of effective cross-pollination and the production of high percentages of double pistils in which normally developed ovules are scarcely formed.
基金Project(No.20031007)supported by the Jiaxing Municipal Science and Technology Projects,Zhejiang Province,China
文摘In order to investigate the cause of poor fruit set in 'Zuili' plums,anatomical examinations of post-bloom pistils were conducted and the dates of young fruit drop were recorded during the growing seasons of 2008 and 2009.Pistils of cv.'Black Amber' were also examined as an abundant setting control.Two major dropping periods were detected in 'Zuili':one during the first 5 d after full bloom (DAF) and another between 10 and 17 DAF.Anatomical analyses of the pistils at the full bloom stage revealed that half of the ovules had not developed embryos,which may have caused their early drop.In most dropped pistils collected at 17 DAF,the micropyle had not been penetrated by a pollen tube,indicating that they were not fertilized.'Zuili' ovules initiated embryo division at 10-12 DAF,although thereafter embryo development was retarded when compared to the rates observed in 'Black Amber'.Ovule fertilization failure and inactive embryo development after ovule fertilization may be the major causes of the later fruit drop observed in 'Zuili' plum trees.
