Variation And Genetic Diversity In Cultivation Of Taxus Cuspidata

Taxus cuspidata is a Taxus plant of Taxacae,which is widely distributed in Changbai Mountain in Northeast China,Japan,Korea and Russia.Because its natural germplasm has been destroyed to a great extent and its existing population is very small,it has been listed as a rare and endangered protected plant in China.Yew can not only extract good anticancer drug paclitaxel,its material is hard,beautiful tree,is a high quality timber tree species is also a precious green tree species.The research on Taxus cuspidata mainly focuses on its chemical composition,physiological state,reproduction and cultivation,while the research on the variation and genetic mechanism of Taxus cuspidata under cultivation conditions is less.In this study,the SLAF library of Taxus cuspidata was constructed by using SLAFseq technology,and a large number of SLAF tags and SNP sites were developed to analyze the genetic diversity of Taxus cuspidata and the genetic relationship among varieties.At the same time,according to the morphological variation of Taxus cuspidata,the main characters such as provenance,leaf color and size,fruit color and size,leaf density,branch strength and seed wrapped by aril were analyzed,which provided necessary theoretical basis for the genetic improvement of Taxus cuspidata.The main results of this study are as follows:1.In this experiment,Hin CII was selected to cut the genome of Taxus cuspidata,and Oryza sativa ssp.japonica was used as the control group.61 experimental samples of Taxus cuspidata were sequenced using the Illumina sequencing platform.In this experiment,1 788 524 SLAF tags were obtained,and the average sequencing depth of the tags was 11.20 x.Among them,there were 470 725 polymorphic SLAF tags,and a total of 3 084 611 SNP tags were obtained.2.Population genetic structure analysis of 61 Taxus cuspidata samples.The ranges of observed allele number,expected allele number,observed heterozygosity,expected heterozygosity,nei diversity index,aroma index and polymorphism information content are 2,1.5636～1.6538,0.2391～0.4074,0.3315～0.3756,0.3414～0.4133,respectively,They are all higher than 2,0.3015,0.2320,0.3015,0.3043,0.4657 and 0.2460 of Taxus.It indicated that the individual genetic diversity of Taxus cuspidata was higher than that of Taxus species.3.61 Taxus cuspidata materials were analyzed by genetic diversity and PCA,and the phylogenetic tree was drawn.61 samples were divided into 2 groups,which was consistent with the results of K value of 2 and principal component coordinate analysis after cross-validation.4.Morphological variation analysis showed that 12 Taxus cuspidata materials were mainly from wild Taxus cuspidata,Japanese yew and Korean yew.The results of leaf analysis showed that the color of leaves was Japanese yew,Korean yew and wild Taxus cuspidata from dark to light.The length of leaves is wild Taxus cuspidata,Korean yew and Japanese yew in turn;The order of branching intensity is Japanese yew,Korean yew and Northeast yew.There are leaf color mutants-Cunninghamia lanceolata in all three strains.The results of fruit analysis showed that the fruit of wild Taxus cuspidata was the largest,followed by Korean yew and the smallest was Japanese yew.Japanese yew has the highest fruit density,followed by Korean yew,and Taxus cuspidata has the lowest fruit density.Preliminary analysis shows that fruit size is negatively correlated with fruit density.The fruit color of Taxus cuspidata is mostly bright red,but it is found that the individual whose fruit color changes to golden yellow in the Korean yew series is called Yellow fruit yew;Taxus cuspidata seeds are deeply immersed in aril,while Japanese yew mostly shows aril,but it is unstable.