Morphological And Taxonomic Studies On The Parents And Their Hybrid Groups In The Natural Hybrid Region Of Glycyrrhiza

In this study,morphological classification and molecular identification methods were used to conduct taxonomic research on three types of medicinal Glycyrrhiza and their interspecific hybrid types in the Glycyrrhiza hybridization area,which laid the foundation for the research on the utilization of medicinal Glycyrrhiza germplasm resources and hybrid species formation.Morphological taxonomy numerically analyzed the morphological characters of 344 plant samples collected from 9 different Glycyrrhiza hybrid areas in Xinjiang and Gansu,revealing the morphological characteristics of the parent species and hybrid types in different hybrid areas;molecular identification was identified by morphology 106 samples of field hybridization areas,Glycyrrhiza specimens,and introduced cultivation areas with typical morphological characteristics were extracted.A total of 134 plant specimens were collected.According to the genetic law of plastid paternal lineage of Glycyrrhiza,nuclear gene ITS and cpDNA gene sequence analysis were carried out.The genotype analysis of the parent species,hybrid type and hybrid introgression species determines the genetic composition of the parent species and hybrid type.Finally,the morphological classification and molecular identification results are used to clarify the species composition of the Glycyrrhiza hybrid area.The main conclusions are as follows:The results of numerical classification show that: legume inflated,upper limit of foliolate,lower limit of foliolate,legume glandular hair,compound leaf length,no.of seeds per pod,compound rachis length,leaflet margin,infructescence length/ear width,infructescence length,leaflet length/leaflet wide,leaflet width,these 12 taxonomic traits are important taxonomic traits of the Glycyrrhiza hybrid type and its parent species.The correlation coefficients of leaf and fruit-related traits,fruit pod and compound leaf-related traits are all 1,indicating that leaf and fruit traits occur side by side and have a high correlation,which is an important basis for the morphological classification of Glycyrrhiza.The 9 natural hybridization areas can be divided into 3 types: the interspecific hybridization area of Glycyrrhiza inflata and Glycyrrhiza glabra;the interspecific hybridization area of Glycyrrhiza inflata and Glycyrrhiza uralensis;the mixed hybridization of Glycyrrhiza inflata,Glycyrrhiza glabra,and Glycyrrhiza inflata Area.The type of hybridization has different inter-species mosaic morphological characteristics,which is related to the type of hybridization area.Sequencing results show that there are mainly 3 haplotypes in the ITS sequence of the nuclear gene,with a fragment length of 720 bp,and there are 4 mutation sites in total;chloroplast gene: rbcL sequence has 2 haplotypes,the fragment length is 160 bp,and there are 2 Mutation sites;2 haplotypes in matK sequence,148 bp fragment length,6 mutation sites;4 haplotypes in trnH-psbA sequence,235 bp fragment length,3 mutation sites;trnV There are two haplotypes in the-ndhC sequence,the fragment length is 870 bp,and there is one mutation site.There are introgression genes of three kinds of medicinal Glycyrrhiza in the Hami hybrid area,and the 165 th base in the trnH-psbA sequence of some samples was mutated from C to A.This mutation did not appear in other regions,presumed to be the Hami region Base mutation caused by hybrid introgression and gene drift of three kinds of medicinal Glycyrrhiza.Combined with morphological and molecular identification,the difficult species in the morphological classification were revised to determine the Glycyrrhiza hybrid areas: Xinjiang Aral,Korla,Yanqi,Hami,Shanshan,Hotan,Turpan,Bohu and Minqin,Guazhou in Gansu,all the 10 Glycyrrhiza hybrid areas have G.inflate,among which Alar and Hami are distributed with G.inflate without introgression,other hybrid areas are hybrid or introgressive species containing G.inflate components;There are G.glabra in 8 hybrid areas of Glycyrrhiza in Korla,Korla,Yanqi,Hami,Shanshan,Yecheng,Turpan and Guazhou in Gansu,among which Alar in Xinjiang are distributed G.glabra without introgression,other hybrid areas are hybrid or introgressive species containing G.glabra components;G.uralensis is present in the investigated hybrid areas,of which Urumqi,Xinjiang and Minqin,Zhangye,Jiuquan areas are G.uralensis without introgression and other hybrid areas It is a hybrid or introgression seed containing G.uralensis.This study found a total of 16 haplotypes in the 134 Glycyrrhiza plant samples in the Glycyrrhiza hybrid area,including parent species without gene introgression,introgression parent species,interspecific hybrid types and hybrid introgression species,and recessive hybrids.The combination of molecular identification and morphological taxonomy makes up for the shortcomings of morphological identification,clarifies the genetic composition of introgressive species that are difficult to distinguish by morphological classification,and revises the species composition of the glycyrrhiza hybrid areas.