| Wild type tea trees have original characteristics,mostly arbors,with large leaves and thick cuticle,corolla diameter of 4-8cm,8-15 petals,fruit diameter of 3-5cm,pericarp thickness of 0.2-1.2cm,low contents of amino acids,benzene polyphenols and EGCG biochemical components,and high contents of phenylalanine.The typical three-dimensional climate characteristics,the cross pollination characteristics of tea plants and people’s awareness of the protection of wild-type Tea Germplasm Resources in Guizhou in the process of economic and social development make Guizhou retain a large number of wild-type tea resources.In this study,159 wild-type Tea Germplasm Resources in Guizhou were used as materials,Genetic diversity,population structure,genetic differentiation(FST),genetic distance(GD)and linkage disequilibrium model of wild-type Tea Germplasm Resources in Guizhou were carried out by simplified genome sequencing(GBS)(LD)analysis;at the same time,the effects of drought stress on leaf physiological indexes,root indexes and photosynthetic indexes of 5 wild-type tea strains were studied by pot water control method,with 2 wild-type tea strains as research materials and cultivated tea strains as control,in order to provide a theoretical basis for the protection,utilization,drought resistance breeding and evolution of wild-type Tea Germplasm in Guizhou According to.The results are as follows:(1)By analyzing the population structure of wild-type Tea Germplasm Resources in Guizhou,three homozygous ancestral groups and one mixed group were determined,which were gt01,gt02,gt03 and gt04 respectively.The results of principal component and phylogenetic tree analysis further verified the accuracy of population structure analysis.(2)By analyzing the genetic diversity of inferred population of Guizhou wild-type tea germplasm resources,different kinds of Guizhou wild-type tea germplasm resources,Guizhou wild-type Tea Germplasm Resources in different regions,Guizhou wild-type Tea Germplasm Resources in different watersheds and Guizhou wild-type Tea Germplasm Resources in different latitudes,the results showed that the mixed group gt04 and the wild-type Tea Germplasm resources in Southwest Guizhou Tea germplasm resources are rich in genetic diversity.(3)Through the analysis of leaf physiological indexes,photosynthetic indexes and root indexes of five strains under drought stress,the results showed that under drought stress,the five strains increased osmotic regulators and enzyme activities to maintain cell swelling and protect cell membrane structure,increased root length,root surface area and reduced root diameter to improve the effective utilization of soil resources and adapt to drought stress More than a certain degree of drought stress,proline and enzyme activities will decline.(4)The drought resistance of two wild-type tea strains and three cultivated tea strains were comprehensively evaluated by principal component analysis.The results showed that the drought resistance of the five strains was A03 > A05 > A02 > A04 >A01.The drought resistance of the two wild-type tea resources in this study was stronger than that of the other three cultivated tea resources. |
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