In order to improve the fruit quality of melon,and to identify the characteristics of melon varieties that could satisfy the demanding of most consumer and different market trends,three melon varieties,Cucumis melo L.var.saccharinus Naud.cv.X228,Cucumis melo L.var.makuwa Makino cv.B154 and Cucumis melo L.var.conmmon Makino cv.H227 were selected to investigate the physiological mechanism of sucrose accumulation during fruit ripening.Fruit were sampled at each growth stages,and the fruit soluble solid content(Brix grade)and sugar(glucose,fructose,sucrose)content,as well as activities of sucrose phosphate synthase(SPS),sucrose synthase(SS),acid invertase(AI)and neutral invertase(NI)were measured.Results showed that the sucrose contents were significantly different among the varieties;glucose and fructose were the major sugars and only a little amount of sucrose was accumulated in immature and mature H227 fruits,while sucrose is the major sugar in B154 and X228 fruits.During fruit development,the contents of glucose and fructose in three melon varieties were not changed dramatic ally,and there were no pronounced differences in glucose and fructose contents among three varieties.The sucrose contents in B154 and X228 fruits increased remarkably during fruit development with obvious turning points.Moreover,the rise of sucrose content was accompanied by the increase of SPS activity and the decreases of AI and NI activities,while the relationship between the content of sucrose and SS was not significant.According to the changes of sucrose content in developing melon fruits,melon could be divided into two sucrose accumulation types:sucrose accumulation type,i.e.X228 and B154,and low-sucrose accumulation type,i.e.H227.In the sucrose accumulation type,the sucrose content increased accompanied by the increase of SPS activity and the decrease of AI and NI activities.In the low-sucrose accumulation type,the low sucrose content may be caused by low SPS activity.The results provided the theoretical foundation for the innovative u
Journal of Nuclear Agricultural Sciences
浙江省“三农六方”科技协作项目(SN 2016-07、SN 2017-14).
Cucumis melo L.
sucrose phosphate synthase