Changes Of Endogenous Hormones And Cell Wall Enzyme Activities In Massive Fruit Bud Of ’Pingguoli’ Pear

In this study,the 20-year-old apple ’Pingguoli’ tree,’Pingguoli" pear and its large-fruited mutant from the experimental base of Yanbian Academy of Agricultural Sciences were used as test materials,to determine the basic indicators,endogenous hormones(IAA,ABA,ZT,GA3),cell wall enzymes(PE,PG,Cx)during fruit growth and development.Through the determination of fruit basic indicators,endogenous hormones(IAA,ABA,ZT,GA3)and cell wall enzymes(PE,PG,Cx)during fruit growth and development.The changes of endogenous hormones and cell wall enzymes in ’Pingguoli’pear and its large-fruited mutant during fruit development were analyzed.The ratios of different hormones during the development of’Pingguoli’pear and its large-fruited mutant buds were balanced.It was studied that endogenous hormones and cell wall enzyme activities correlation analysis,relationship between endogenous hormone content and fruit size.The results show:1.During fruit development,the horizontal,longitudinal diameter and single fruit weight of large-fruited mutant were higher than that of the ’Pingguoli’ pear.GA3 and ZT were positively correlated with fruit diameter during cell division,and IAA,GA3,ZT and fruit transverse diameter in rapid growth period.In a positive correlation,IAA was positively correlated with the longitudinal diameter,and GA3 was positively correlated with fruit weight,indicating that IAA,GA3,and ZT play an important role in fruit growth.2.It can be seen from the content and variation of endogenous hormones that IAA is closely related to the cell division phase of fruit development;high levels of GA3 and ZT play an important role in the cell division and cell expansion of fruit;The IAA content and the IAA/ABA ratio are mainly related to their high fruit setting rate.During the rapid growth period of "Pingguoli’pear and its large-fruited mutant,ZT and GA3 were closely related to fruit size during fruit ripening and fruit ripening period;the formation of fruity bud fruit of ’Pingguoli’pear and high ratio ZT/ABA,GA3/ABA related,this may be one of the main reasons for the emergence of’Pingguoli’ pear fruit buds.3.The change trend of Cx activity during the development of fruit buds of’Pingguoli’ pear and its large-fruited mutant was the same,and gradually became stronger with fruit development;PE had an important regulatory effect on the cell division and maturation of ’Pingguoli’ pear.PE and PG enzymes play an important role in cell wall relaxation and cell division elongation.One of the reasons for the expansion of large fruit bud fruit may be due to the enhancement of PE activity,and the production of Cx activity contributes to the division of fruit cells.And affect the ripening and softening of the fruit.4.Endogenous hormones interact with cell wall enzymes during fruit growth and development.The trend of IAA and Cx enzyme activity changes is opposite,indicating that IAA has a certain inhibitory effect on Cx,which is one of the factors leading to fruit enlargement;GA3,ZT and PG reach the highest value in the rapid growth period of fruit,indicating that GA3 and ZT can promote PG.The activity is enhanced;in the rapid growth period of the fruit,the high content of ABA,GA3,ZT promotes the enhancement of PE enzyme activity.IAA and GA3 promote the enhancement of PG enzyme activity.