Analysis Of Genetic Diversity And Screening Of Superior Germplasm In Pinellia Ternata

In the present study,35 Pinellia ternata(Thunb.)Breit.materials were collected from nine provinces and cities,grown in the same environment,to compare phenotypic characteristics of P.ternata from different origins and to analyze yield determinants.Combining genome size with chromosome number type,the cytological characteristics of P.ternata from different origins were analyzed.At the same time,DNA barcodes suitable for intraspecific identification of P.ternata species were developed and molecular identification of 35 P.ternata species was carried out.The genetic diversity of P.ternata was analyzed from three aspects: phenotypic comparison,cytological analysis and molecular identification,and excellent varieties of P.ternata were screened in combination with yield factors and quality indicators to provide theoretical basis and material basis for the protection,evaluation and utilization of P.ternata resources.The results of the study are as follows:1.By studying 35 P.ternata planting resources from different origins,statistics of their phenotypic traits and analysis of yield determinants.The results showed that there were significant variations in phenotypic traits,including leaf length/width,weight gain per plant and multiplication rate per plant;the two most important factors that determine the yield of P.ternata:the weight gain per plant is mainly affected by leaf size,plant height,petiole thickness and other aerial growth potential,the proliferation rate per plant is mainly affected by the number of bulbs.2.By Analyzing the cytological characteristics of P.ternata,and used flow cytometry to determine the size of the genome and chromosome pressing to explore the number of chromosomes in P.ternata,so as to analyze the cytological differences of P.ternata from different producing areas.The results showed that the genome of P.ternata species was relatively large,with an average genome size of 6.75 G and a variation range of 5.0～9.0 G among the 35 P.ternata germplasms;17 of them were selected for chromosome number analysis,and there were 13 different chromosome numbers,respectively.2 n=105,103,78,106,92,114,90,91,89,85,56,59,67;there are severe compound polyploidy and aneuploidy in P.ternata,and the chromosome number of P.ternata in the same population is different and in different populations is also the same.Correlation analysis of genome size with chromosome number revealed no correlation between the two.Correlation analysis of genome size with chromosome number revealed no correlation between the two.In addition,correlation analysis of the yield traits and cytological characteristics of P.ternata.revealed that P.ternata with small genomes seemed to be more favorable for plant shoot formation and underground tuber proliferation.3.The molecular identification of P.ternata species was carried out by DNA barcoding technology,and the intraspecific molecular differences of P.ternata species were explored.The results showed that the universal DNA barcodes ITS2,rp132-trn L,mat K,psb A-trn H and trn Ltrn F could not achieve intraspecific molecular identification of P.ternata species.Based on the genome sequence,a DNA barcode suitable for intraspecific molecular identification of P.ternata was developed,and the barcode BX12 was screened to better achieve intraspecific molecular identification of P.ternata.35 P.ternata species were divided into 5 subgroups..4.Combining yield factors with quality indicators,excellent germplasms of P.ternata were screened.First,high-yielding P.ternata varieties were screened from phenotypic identification,and then their quality was evaluated.The results showed that 10 high-yielding elite lines,P01,P02,P04,P14,P22,P23,P24,P28,P31 and P35,were screened from the phenotypic identification.The 10 germplasms were evaluated for quality,and the contents of extracts,total organic acids and total alkaloids were detected.The contents of three components in Hezhang P02 in Guizhou and P22 in Kunming in Yunnan were all higher;the contents of extracts and total organic acids in Hezhang P01 in Guizhou and P31 in Guiyang in Guizhou were higher;the contents in total alkaloids and total organic acids in Kaili P28 in Guizhou were higher.Combining the two characters of high yield and high quality,germplasm P01,P02,P22,P28 and P31 can be used as candidate materials for cultivating excellent varieties in artificial cultivation of P.ternata.