Studies On The Biological Characteristics And Pollination Effect Of Early Flowering Male Plants Of Actinidia Chinensis

Kiwifruit(Actinidia Lindl.)is a typical dioecious plant,which needs to be equipped with pollination trees in order to bear fruit normally.In this study,three early flowering male plants ‘M11’,‘M21’ and ‘YS1’ with excellent characters were selected in the 43 wild Actinidia chinensis male plant resources collected in the previous period based on the comprehensive evaluation were taken as the research object.Their biological characteristics were observed and analyzed.Main kiwifruit varieties ‘Donghong’,‘Jinyan’and A.eriantha excellent strain ‘Ganlv 1’ were pollinated with the three male plants and the pollination effects of and the effects of pollination treatment on key genes in AsA synthesis of L-galactose in fruits were studied.The purpose of this paper is to screen out the early flowering male plants of A.chinensis which can be used in production,and to clarify the effect of pollination on the key AsA synthesis genes of kiwifruit,so as to lay a foundation for revealing the regulation mechanism of A.chinensis pollen on fruit AsA content.The main results are as follows:(1)Through the observation and study on the biological characteristics of the A.chinensis ‘M11’,‘M21’ and ‘YS1’ we found that they had early flowering period in Xinfeng county,Jiangxi Province.‘M11’,‘M21’ and ‘YS1’ entered the initial flowering stage at the end of March and the beginning of April.The florescence of ‘M11’ and ‘YS1’is longer,which is 13 days and 19 days respectively,and the flowering period of ‘M21’ is 9days.At the same time,they all have ultra-high amount of pollen,and the amount of pollen can reach 816000,726984 and 649536 respectively per flower.Three early flowering male plants also had high pollen viability,which were 75.08%,71.61% and 84.85%,respectively.(2)The pollination treatment of A.chinensis early flowering male plants on main kiwifruit varieties ‘Donghong’,‘Jinyan’ and A.eriantha excellent strain ‘Ganlv 1’ showed that ‘YS1’ and ‘M11’ had outstanding pollination effect and excellent performance.1)‘YS1’ pollination treatment significantly increased the contents of AsA,total phenols and total flavonoids in ‘Donghong’ fruit.‘YS1’ can be used as the suitable male plant of‘Donghong’ kiwifruit.At the same time,‘M11’ can also be used as an alternative male plant for pollination of ‘Donghong’.2)‘YS1’ pollination treatment can significantly increase the contents of AsA,total phenols and flavonoids in the fruit of ‘Jinyan’,which can be used as a suitable male plant of ‘Jinyan’.3)The pollination treatment of ‘M11’made the fruit more green and significantly increased the contents of AsA and total phenol in the fruit of ‘Ganlv 1’.Therefore it can be used as a suitable male plant of ‘Ganlv 1’.(3)Through the study on the key genes of AsA synthesis of L-galactose pathway in three early flowering male plants of A.chinensis,it was found that there were differences in the regulation of fruit AsA content among different pollination treatments,which had different effects on the expression of key genes of AsA synthesis in L-galactose pathway.Most of the effects of different pollination treatments on fruit AsA content were achieved by regulating the expression of key genes GMP,GME,GPP,GalDH of L-galactose pathway,and some of them maybe achieved by regulating the expression of genes of the galacturonic acid pathway and AsA degradation and regeneration pathway.