Research About Biological Characteristics And Genetic Diversity Of Germplasm Resources Of Carya Illinoensis

Pecan(Carya illinoensis(Wangench.)K.Koch)is a member of walnut family.It is native to the United States and Mexico.Pecan is a worldwide and important fruit,with strong adaptability,wide cultivation area and good development prospects in China.In this study,the following three aspects were studied in the case of the fine single plant of pecan planting resource base of Zhejiang Agriculture and Forestry University:(1)For two consecutive year,70 samples were collected from home and abroad for the whole year,and the 'Mahan' was used as the research object to study the open process and the anatomy of male and female flowers.(2)Genetic diversity analysis of 41 individual plants introduced from China.(3)The morphological indexes and the indexes of the main nutrient components were analyzed in 31 fruiting plants.The main findings are as follows:(1)45.70%(32 kinds of plant)of the male and female flowers hatchlings which were introduced from home and abroad reached the flower stage.ZL22 and ZL2 were the first to enter the powdery season in 10 protandrous type pecan.Among the 22 protogynous type pecan,ML11 was the earliest female flower can be granted and the longest duration of female flower was ZL15.There are five kinds of individual plants can meet the flowering(four for the protandrous type pecan,one for the protogynous type pecan),which can also called as simultaneous type: ZL39,HL26,HL29,ML5 and ML29.Other fine individual plants were not met,and the variety configuration table was constructed according to the observation results.Through observing the different varieties of female flowers,this study found that the structure of different varieties of female flower is quite different,the morphological changes of same species at different times are also very different.so in the production of cultivated species need to refer to the pollination configuration table(Table 2.6)for rational allocation.Through the scanning electron microscopic observation of the male and female flower buds of the hamster,it is understood that the morphological differentiation of the female flower buds takes eight periods: the formation of the female flower base?the formation of the female flower buds?the emergence of the bracts primordia?the formation of the flower primordia?the formation of the stigma Room bigger?stigma angle gradually become larger?female flower stigma fade,black.The morphological differentiation of male flower buds is summarized as six stages: male flower buds germination period?male flower buds stretch scale?inflorescence axis elongation?anther formation period?pollen grain formation period?male flower powdery season.In addition,the male pollen grains of 12 excellent plants were observed by scanning electron microscopy.The results showed that the pollen grains of 12 pecans were nearly spherical or oblong and each pollen had three germination holes,which were evenly distributed on the equatorial axis,the polar view is nearly triangular or nearly round,red face are oval.The results can provide a theoretical basis for the classification and identification of its varieties and the systematic evolution of the system.(2)Analysis of the genetic differences of the collected fine individual pecan: A total of 214 alleles were obtained from 19 pairs of SSR primers and 199 polymorphic loci were obtained,accounting for 92.99% of the total loci and the average polymorphism is 92.90%.The genetic similarity coefficients in 41 species of pecans were 0.0259~0.9828,among which ZL2 and ZL3 had the closest genetic relationship.The 41 species were quite different and the genetic diversity was abundant.(3)The individual whose morphological indexes performed the best is ZL41,while the worst is ZL47.Combine the amino acid composition and fatty acid composition of defatted kernels in 2015 and 2016,the results showed that the variability of the fatty acids was 6.12% ~ 26.20%,the variability of the amino acids was 16.51% ~ 28.13% and the variation of the fatty acid components was Wide and diverse.Finally,it was concluded that the seven excellent single plants ZL12,ZL41,ZL43,ZL45,Dongyang1,Nonglinda3 and HL29 were the better overall performance.The single plant ZL47 was the worst integrated plant.