Preliminary Research On Flowering And Fruiting Habits And Fruit Development Of Introduced Peach Varieties

In this research,nine introduced peach varieties of Alar district were used as test materials: Chunmei,Chunxue,Zhonghong,Chunmi,Zhongtao2-24,Zhongpan10,Zhongpan11,Shuangxihong,and Zhongnong Jinhui.The research on flowering phenophase,flowering fruit habits,pollination and fertilization process,dynamic changes of fruit growth and development,in order to provide the theoretical basis for scientific management of flower and fruit in high yield cultivation of peach.Research indicates:(1)The observation of the phenophase of the flowering of the introduced peach cultivars indicated that the flower buds enlargement period was concentrated between March 13 th and March 18 th,and the dew-opening stage was separated from the dew-opening stage by 3~4 days.The early flowering stages of the peach varieties were concentrated.From April 2th to April 4th,between April 4th and April 7th,the flowering period of ordinary peach and nectarine was 7-9 days,and the flowering period of flat peach was10-11 days.From April 20 th to April 23 td,fruiting period of ordinary peach varieties was earlier,nectarine matured in early July,and flat peach matured in late July.(2)There was a significant difference in the amount of single pollen among peach varieties,which ranged from 300.00 to 1322.22(grain/anther).Zhongtao2-24 had the highest amount of single pollen and Zhongpan11 had the lowest.The pollen viability of peach varieties was higher,ranging from 63.90% to90.61%.The pollen viability of flat peach was higher than that of ordinary peach and nectarine.(3)The abortion rate of flower buds of introduced peach cultivars differed greatly.The highest rate of pistil abortion was 17.54% in Zhongpan11,The lowest rate of pistil abortion was 1.46% in Chunmi;and the pistil abortion was closely related to peach bud type and fruiting branch type.The overall average pistil abortion rate of single flower buds was higher than that of multiple flowering buds.The pistil abortion rate of single flower buds of short fruit branches was higher,while the pistil abortion rate of multiple flower buds of middle fruit branches was higher than that of single flower buds;and the long fruit branch pistil abortion rate of most peach varieties was higher than that of other fruit branch types.(4)The self-pollination fruit setting rate of the introduced peach varieties was higher,between 57.83%and 70.15%,and the fruit-setting rate of natural-pollination average value is 71.40%,which was higher than self-pollination.The fruit-setting rate of most pollination combinations of Shuangxihong and Zhongnong Jinhui is higher than that of self-pollination.It can be seen that cross-pollination can improve the fruit-setting rate of peach varieties,the fruit-setting rate of different pollination combinations differed greatly,and the most cross combination of Zhongnong Jinhui fruit-setting rate of by middle fruiting branches;After Shuangxihong cross-pollination,the fruit setting rate of the short fruit branch is higher,followed by the long fruit branch.(5)Through the fluorescence microscopy observation of the dynamic changes of the 'Shuangxihong'pollination and fertilization process,it was found that the peach pollen grain can germinate on the stigma at4 h after pollination;After pollination between 8h~36h,the stigma pollen quantity reaches the maximum,From pollen tube entering stylus to extends to middle and lower part of stylus;the pollen tube enters the ovary 48 hours after pollination,the fertilization process takes place 72 hours after pollination;From 24 hours after pollination to the fertilization is completed,and the pollen tube growth process is not the same;90 hours after pollination,appears stigma atrophy,disintegration of pollen tubes.Paraffin sections of the ‘shuangxihong' ovary showed that: the pollen tube transported the sperm to the ovule at 60 h after pollination,and 72 h after pollination,the sperm entered the embryo sac;after pollination for 3 d,the peach embryo was developed.The observation of the longitudinal section of the fruit in the young fruit period revealed that the nucleus and seed coat of Shuangxihong grew rapidly within 17 to 44 days after flowering.(6)The variation of single fruit weight of introduced peach cultivars gradually increased,and the trend of fruit development was relatively gentle at the beginning of fruit development.The fruit weight increased rapidly from 60 days after anthesis;the variation of transverse diameter and longitudinal diameter of peach fruit basically conformed to the "double S" curve.The longitudinal growth of flat peaches was significantly smaller than that of ordinary peaches and nectarines.The fruit shape indexes of ordinary peach and nectarine showed a tendency of stabilizing after decreasing.The change of fruit shape index of flat peaches was small.The chlorophyll content of the peach peel decreased from the peach young fruit stage to the fruit ripening stage,and the anthocyanin content showed an upward trend.At the ripening stage of the peach fruit,the L value of peel brightness and the H value were significantly positively correlated with the pericarp anthocyanin.The content of anthocyanin was significantly negatively correlated with the chlorophyll content of the fruit peel.The best comprehensive character of the fruit surface was Zhongpan11.In the later period of fruit development,the hardness of the introduced peach varieties showed a decreasing trend;the content of soluble sugar and soluble solids in the early period of peach fruit development generally showed an upward trend,and decreased at the 2~3 weeks before the mature period,then increased to reach the maximum value;The titratable acid content of the fruit showed a decreasing trend overall;the principal component analysis of the ripening fruit was carried out,and the best comprehensive evaluation was Zhongpan11,followed by Chunmei and Shuangxihong.