Regulation Of Flower Time In ’Ziniangxi’ And ’Feizixiao’ Litchi

’Ziniangxi’and’Feizixiao’litchi (Litchi chinensis Sonn) two major cultivars in Hainan province which known as "blossom without fruit", the characteristics like that large of flowers, low rate of female, and male and female difficult to meet, to cause pollination and fertilization poorly, fruit drop are more serious. greatly reduce its market value and consumer acceptance. The author’s research group has reported:to test the regulation of S-3307, GA3, ETH, CPPU, NAA which were sprayed on flower panicles in bud stageon the floral dynamics, fruit setting and fruit quality of perennial’Ziniangxi’and’Feizixiao’ litchi. This paper based on the foliar application of potassium, To test the effects of diffrent treatment which were sprayed on flower panicles the floral dynamics, fruit setting and fruit quality of perennial ’Ziniangxi’ and ’Feizixiao’ litchi, as well as the change of flower endogenous hormones during different developmental stages. The relationship of flower dynamics and endogenous hormones were indicated by comparison of different treatment. the results showed that:(1)Effects of different plant growth regulators on the flowering of Ziniangxi litchi.S-3307 treatment could extend the flowering period, increase female flowers and female ratio. Ethylene treatment could accelerate blooming, shorten flowering period in a visible way, and reduce total flower number dramatically. CPPU treatment could delay the bloming of panicles, prolong flowering period and bring aboutstatic state. CPPU, NAA treatment could significantly increaseed male flowers, reduce female flowersto a low level which was 5.16% and 0.91%.(2)Effect of different plant growth regulators on the flowering and fruiting of Feizixiao litchi. S-3307 could delay the blooming, lengthen the blooming period, increase male flower number in a significant way, increase the initial fruit setting and finalyield, however, induced fruit drop at later stage so seriously that protection measures should be taken S-3307 also could induce seed abortionGA3 and Ethylene treatment could accelerate blooming, shorten flowering period in a visible way, and reduce total flower number dramatically. CPPU treatment could delay the decay of panicles, prolong flowering period, increase flower number and batch, increase initial fruit setting, accelerate fruit development and induce fruits peel thick. NAA treatment could increase the female ratio to 5%, and initial setting fruit number was 4 at average, which indicated that NAA treatment had negative effect on female flower development and fruit setting which resulted in low yields significantly.(3)Effect of different plant growth regulators treatments on the flower organ develoment of Ziniangxi litchi.S-3307 and CPPU could lead to blooming delays, which was about 2-3d compared with GA3, Ethephon, NAA and control did. Floral organ developmental differentiation order wereNAA> GA3>ETH> CK.(4)Effect of different plant growth regulators treatments on the flower organ develoment of Feizixiao litchi.GA3, Ethephon, NAA treatment showeda higher degree of stamen differentiation than other treatment and control did. S-3307, CPPU and control displayed blooming delays than other treatments did significantly.(5)Effects of different plant growth regulators treatments on fruit quality and characters of Feizixiao litchi.S-3307 could induce seed abortion and improve nuclear coke rate significantly, the length/diameter was nearly to 1, and fruit size approached to a circle, and the fruit quality was the best; Ethephon treatment could effectively reduce the TA, improve fruit quality. CPPU and NAA increased the length/diameter ratio of fruit and pericarp thickness significantly. GA3 treatment resulted in the lowest TSS and the highest TA,and the worst fruit quality.(6)Effect of different plant growth regulators treatments on endogenous hormone of Ziniangxi litchi flower.Our results showed that:the plant growth regulators could reduce the endogenous hormones GA and which reduced the (GA+IAA+CTK)/ABA ratio and changed the flowering dynamics which might be resulted from endogenous hormones change. Low concentrations of GA, ABA and high concentration of CTK were beneficial forstamen differentiation and increased male flowers significantly.(7)Effect of different plant growth regulators treatments on endogenous hormone of Feizixiao litchi flower.Our results showed that:all the plant growth regulators tested could reduced endogenous GA, and some increased ABA, which resulted in decreasing the (GA+IAA+ CTK)/ABA ratio. Low GA concentration and high ABA concentration were beneficial for female development, and increasing the female rate.