Analysis the efficiency of inter and intra-specific hybridization of new cultivars of sweet cherry and chinese cherry

Abstract: 【Objective】To explore the rules of intra-specional and inters-pecific cross breeding of some new sweet cherry cultivars and improve the efficiency of cross breeding of sweet cherry in the area where winter is warm and summer is hot and moist.【Methods】The intraspecial and interspecifichybridization test of sweet cherry was carried out by using sweet cherry as the mother,using sweet cherry and chinese cherry as the father. The rate of fruit set,embryo,embryo abort of the cross and quality of the F0 fruit were investigated in order to analysis the efficiency of the cross.【Results】The four cultivars of sweet cherry'Jiangnanhong''Chaoyang-1''Changfeng-1'and'Van'were taken as the mother. Five sweet cherry cultivars or selections'04-8''04-11''Chaoyang-1''Van''Lapins' and five cultivars of chinese cherry'Chaozaohong''Duanbing''Gejiawu''Heizhenzhu''Zijing'were taken as the male parent. Among them'Jiangnanhong'and'Zijing'are newly identified cultivars in Zhejiang province,and'Chaoyang-1'and'Changfeng-1'are new selections. After pollination for 1 week,the fruit setting rate was relatively high and significant decrease in the 4 weeks and mature stages in intra and inter-species with the development of fruits. In the mature stage,all the fruit setting of the other cross of intra-species were higher than 5%,except that of'Jiangnanhong'×'04-11'was 1.85% lower than 3%,and that of'Changfeng-1'×'Lapins' was 4.35% lower than 5%,which indicates the basic affinity between the cross of intra-specific sweet cherry. The fruit setting rate of intraspecific cross was higher than that of interspecific cross. The fruit setting rate of'Chaoyang-1'was the highest in both intraspecific and interspecific hybridization. The interspecific hybrid combination of'Changfeng-1'had the lowest fruiting rate. The embryo rate and abortion rate of the intraspecific cross were higher than those of interspecific cross when the female parent is same. The abortion rate is high when hybrid embryos mature,and only 4 crosses group can obtain non-abortion embryos,which are the hybrid cross of'Jiangnanhong'with'04-8''Lapins' 'Chaozaohong',and the cross of'Changfeng-1'with'Van'. The abortion is lower when the hybrid embryos immature. The embryo rate was lowest and the abortion degree was the highest of the cross of'Jiangnanghong'in immature embryo stage. The cross with the mother of'Chaoyang-1'was the best with high setting rate,high embryo rate and low abortion rate in immature embryo stage,so'Chaoyang-1'is the best female parent in this test.'Chaoyang-1'and'Zijing'were the better fathers in the ten test male parents for the cross with them had a high embryo rate(65.84% and 75.21%,respectively),and most of the embryos were bright white and full with good development in the immature embryos stage.'Chaoyang-1'is the best female and male parent in this test.The cross between'Chaoyang-1'and'Van'shows'Chaoyang-1'is the better female than male parent. The ripening stage of F0 fruit was delayed,and the color and shape of F0 fruit showed the same color and shape of open pollination of parent fruit. The soluble solid of interspecific hybrid fruit was lower than that the intra-specific hybrid,and they all lower than that of the open pollinated female fruit. In order to obtain hybrid offspring,the author suggests three methods could be used in the area where is warm in winter,hot and moist in summer: one is selecting hybrid offspring which comes from the main producing areas,which means making cross and getting hybrid offspring in the main producing areas but select it in future planting area. The other is using embryos rescue technology after getting immature fruit; the third one is using mixed pollen for open pollination.【Conclusion】The fruit set and embryo development have significant differences among the different cross group in the area where winter is warm and summer is hot and moist. The fruit set is higher and the embryo abort is lower of intraspecific cross than that of interspecific cross when the mother is the same sweet cherry.'Chaoyang-1'is the best female and male parent in this test when making cross.