Study On The Reproductive Biology Of Prunus Domestica×armeniaca ’Fengweimeigui’

Prunus domestica×armeniaca ‘fengweimeigui’(Prunus, Rosacease) is one of sevencultivars introduced from America. Domestic introduction experiments shows it is very popularamong fruit grower and high-end fruit market due to its strong adaptability, early maturity,beautiful color, high soluble solids contents, unique flavor and good tastes. Although it hasstrong adaptability, its production is relatively low and fluctuates which restricts its extensions.It is the biology of flowing, the development of male and female gametophyte, the process ofpollination and fertilization, and the growth and development of fruits that lead us to find thereasons that result in low and unstable production, and this can provide theory for futher studyon the key technologies of high effiency production. Paraffin section and fluorescenceobservation were used in this study. The results were as follows:1. Flowering biologyThe flower of Prunus domestica×armeniaca ‘fengweimeigui’was herkogamy. It wasdistylic species and Some stigams aborted. The budding stage and the first flowering stage ofPrunus domestica×armeniaca ‘fengweimeigui’ was mid-to-end February and March,respectively. The flower was bisexual, white, solitary or fascicled, radiation symmetry,rosaceous corolla, indrawn tweezers. The difference of calyx tube, corolla, and the length offilament and stalk were not significant, while the length of stigmas was significantly differentdue to the existence of two types of flowers: one was long stigmas, the other one was theatrophied stigmas inclding short stigmas and aborted stigmas. The proportion of long stigmasand atrophied stigmas were significantly different in each tree and different years, while theproportion was not significant and stable between different trees in the same year.2. The development of male and female gametophyteThe development of macrospore, microspore,female gametophyte and male gametophytewas normal. Pistil ovary had one carpel and one room. Each room had two ovules. The ovulewas anatropous ovule, crassinucellate ovule, and double integuments. The development of embryo sac was polygonum type. The anther wall was a basis type, glandular tapetum.Microspore mother cell meiosis in the cytokinesis was successive type, tetrads were mostlytetrahedral. Mature pollen grains were two-celled with three apertures. During development,male and female gametophyte and flower morphology had relatively stable correspondence.3. The biology of pollination and fertilizationAlthough Prunus domestica×armeniaca‘fengweimeigui’was cross-pollinated by bees,the effiency of pollination was low due to unsynchronous flowering with pollinizer which wasPrunus domestica×armeniaca ‘konglongdan’. Both pollen viability and stigmas receptibilityincreased after blossom and reached its peak in four hours which was88.89%and77.50%,respectively. Pollen viability and stigmas receptibility lasted four to five days, respectively. Thepollen tube of self-pollination and cross-pollination reached the base of style in72hours and48hours and reached the ovule to double fertilization in96hours and72hours after pollination,respectively. None pollen was observed in the glass slides which were distributed in one to fivemeters of four directions on the ground around the tree. The pollinators were mainly bees, thefruquencies of pollination were low.4. The evaluation of matting systemThe out-crossing index of Prunus domestica×armeniaca ‘fengweimeigui’ was four.Pollen-ovule ratio was605.7±50.3. The fruit set rate of manual cross pollination was as highas30.19%, which was obviously higher than7.8%of self-pollination. As a result, the matingsystem was out-crossing with partial self-compatibility, which needed pollinators.5. The development of fruitsThe fruits of Prunus domestica×armeniaca ‘fengweimeigui’ had the same growthcharacteristics as most stone fruit did. The fruit growth curve was double S type growth curve.Exocarp consisted of epidermis covered by white wax in the oustide and collenchyma.Mesocarp consisted of large thin-walled cells and vascular bundles, which was the edible part.Endocarp consisted of suberized stone cells. Only one ovule in the Ovary developmented intoseed, the other one gradually degraded during the development.