Study On The Correlation Between Endogenous Hormone And Mandarin Fruits Puffing

Citrus is one of the worldwide fruits and the area and yield is the first in China.According to the statistics,the yield of Citrus fruits(such as tangerine,etc.)has reached 18.5 million tons,which accounts two-thirds of the total global production and set a new record of China in 2015 a.Puffiness is a common physiological disease which happened in the later mature period and during postharvest,which seriously affecting the quality and storage properties of fruit.Because of the complex impacts and a variety of internal and external factors,the mechanism of citrus Puffiness was not clear identified.It is difficult to take effective measures to control the puffiness.The quality of citrus fruit is determined by the external and internal quality.In this paper,Miyagawa puffing fruit and 'bud sport' anti-puffiness fruit were taken as materials.By comparing the differences of quality in both internal and external quality of fruit,a conclusion is arrived at that the bud sport fruit had a lager shape and much more rounded than the puffing fruit.The changes of puffiness were not easy happened in bud sport fruit compared to the puffing fruit.The soluble solids/acidity ratio,Vitamin C content of mutant fruit are higher than puffing fruit.We measured the endogenous hormone in the different developmental stages of white skin and compared the relationship between endogenous hormones and fruit floating skin then we found that the IAA content during the developement of puffing fruit in the white skin maintained a high level,while occured an abnormal peak during the growth stage.On the other hand,the IAA content in the white skin of mutant fruit keept a higher level in the early stage of fruit growth then declined during the rapid growth stage.The GA3 content had no significant different between puffing fruit and mutant fruit in the eraly development stage,but the content in puffing fruit was higher than mutant fruit in the rapid development of fruit.The ABA content in white cortex was increased in both puffing and mutant fruit,but the content in puffing fruit was higher then the mutant fruit all the time after the swelling period of fruit.It indicated that the cell division in puffing fruit was sharply dramatically changed than the mutant fruit before the development of fruit,while the ABA content in white cortex of puffing fruit increased after the enlargement period resulted a accelerated and advanced senescence than the mutant fruit.At the same time,real-time quantitative PCR was used to measure the expression pattern of GASA4 and CKI-1 at different developmental stages in white cortex of fruit.The results showed that the expression of these two genes were enhanced in the early development stage of puffing fruit,then reached a highest level in the early expanding stage.The leastest level was detected in the enlargement stage of puffing fruit.The expression of GASA4 and CKI-1 showed a similar change in mutant fruit contrast with the puffing fruit,but the genes expression level was higher than the puffing fruit.In summary,we preliminary think the differences of endogenous hormones maybe one of the reasons of Citrus reticulata puffiness.