Effects Of Low-temperature Treatment On Flower And Fruit Development And Expression Of Related Genes Of Strawberry

The main factors affecting the flowering and fruiting of strawberry were the differentiation period,quantity and quality of flower bud.At present,in most areas of northern China,strawberry seedlings are mainly raised in open field,so flower bud differentiation is closely related to local climate conditions.If the related technology of low-temperature treatment can advance the flower bud differentiation of strawberry to a certain extent,combined with the standardized field cultivation and management technology,it can provide reference for the blank production of strawberry fresh fruit.In this study,Fragaria×ananassa‘Benihoppe’ was used as the experimental material to investigate the specific effects of low-temperature treatment on inflorescence,flower and fruit setting,fruit size and nutritional growth and comprehensively compared the changes of phenological period,growth index and fruit size of strawberry under low-temperature treatment;at the same time,the expression changes of Fa SVPs gene related to dormancy and Fa FT,Fa FLY and Fa AP1 gene related to flowering were analyzed from the gene level to reveal the internal mechanism of the effect of low-temperature treatment on dormancy and flowering of strawberry.The main results are as below:1.Low-temperature treatment significantly affected the phenological period of Fragaria×ananassa‘Benihoppe’.Compared with the control group,the low-temperature treatment advanced the flowering and harvesting period of Fragaria×ananassa‘Benihoppe’ by about 7-10 days,and the low-temperature treatment group significantly increased the average single fruit weigh.2.At the flowering and fruiting stage,the vegetative growth of the low-temperature treatment group was more vigorous than that of the control group at the same period.Under low-temperature treatment,plant height in this three stages increased by 16.55%,18.03% and 15.76% respectively,Stem diameter increased by 2.65%,2.74% and 9.86 % respectively,the leaf area increased by 19.79%,5.75% and 10.42% respectively,petiole length increased by 9.25%,13.82%,18.81%,respectively,compared with the control group.3.Low-temperature treatment promoted the down regulation of Fa SVPs gene expression in Fragaria×ananassa‘Benihoppe’.With the release of dormancy,the expression of Fa SVPs decreased gradually,and the down-regulation trend of Fa SVPs in the low-temperature treatment group was greater than that in the control group.4.The expression of three flowering related genes(Fa FT,Fa FLY and Fa AP1)in Fragaria×ananassa‘Benihoppe’ was significantly increased by low-temperature treatment.