Research On The Rule Of Blossoming And Fruiting Of Different Varieties Of Chinese Chestnut In Qianxi Area

The Chinese Chestnut(Castanea mollissima BI.)belongs to Fagaceae Castanea.It has been cultivated very early in China,and also one of the important tree species of woody grain in China.Previous researches on the Chinese Chestnut mainly focused on its physiological and biochemical characteristics,breeding and cultivation techniques.While the study on flowering and fruiting of different Chinese Chestnuts can provide not only the basis for the study of reproduction and development,but also a scientific guidance for high yield cultivation techniques,such as artificial pollination,pollinizer collocation and scientific fertilization.This paper selected five species as the research objects,namely'Luotianwukeli','Yanchang','Changanmingjianli','Taianbokeli' introduced to Qianxi region and Qianxi local 'Yanlong',and the research was carried in three aspects:flowering characteristics,pollination,fruit characteristics.This paper aimed to provide a theoretical basis and practical guidance for grasping the rules of flowering phenology,cross breeding,pollinizer collocation and water and fertilizer management for the germplasm of the Chinese Chestnut in Qianxi region.The conclusions are as follows:1.In the selected species,'Luotianwukeli','Yanchang','Changanmingjianli','Taianbokeli' and'Yanlong',the male flower period lasted 20?26 days,and the female flower period was 21?27 days;among different species,the inflorescence lengths were in the distinct differences,while the total number of male inflorescence clusters was in small difference;among the same species,the inflorescence length in the male was longer than that of in the bisexual,and the longer the bisexual inflorescence was,the distance between male and female inflorescence would be;the significant character differences in the five species resulted from the different species,the site conditions and the climate.2.Based on the female parent of 'Yanlong',the experiments of cross pollination,self-pollination and natural pollination showed that 'Taianbokeli' and 'Changanmingjianli' were better pollination of'Yanlong',among which the 'Taianbokeli' pollination can significantly improve the 'Yanlong' in its base rate,bud seed setting rate,the number of nuts and bud nuts rate;'Changanmingjianli' pollination could significantly increase the 'Yanlong' in size,width,thickness,fresh weight,involucre length,involucre height and involucre width.The sugar content,starch content,soluble sugar content and fat content in'Yanlong' nuts had xenia effect,especially the soluble sugar content,and so did the content of mineral elements in the nut.The pollinations in different species had different influences on the content of protein,starch,soluble sugar,fat and mineral elements in the nuts of 'Yanlong'.3.While the fruits were growing,the change patterns for each of the five species,in the nut fresh weight,dry weight,involucral bracts fresh weight,dry weight of chestnut varieties,appeared to be "S"curve of "slow-fast-slow";the growth dynamic pattern for each of the five species,in the nut width,thickness,height and involucre length,width,height,appeared to be double "S" curve of "fast-slow-fast-slow".4.In the process of nuts growth and development,the number of protein content in the five different species was in downward trend,while that of the starch was increasing;the number of the soluble sugar showed a single-peak curve of increase first and decrease last;while the fat content was in a fluctuant trend;K,Fe contents showed a downward trend,and Mn,Ca contents increased first and decreased;while Cu,Zn,Na and Mg contents generally decreased.While the bracts were growing,K contents in chestnut skin of the five different species changed little;Mn content changed in fluctuant increasing trend;Cu and Zn content changed in a single-peak curve;Na content change increased first and decreased;Mg content changed in a double-peak curve;Ca,Fe content showed gradually reduced trend overall.