Screening And Identification Of High Yield Germplasm Of Mongolian Astragalus

Mongolian astragalus is the traditional medicinal materials.In this experiment,Mongolian astragalus were used as test materials.Through field and laboratory experiments,the seedlings of different root diameter grades of Mongolian astragalus were compared.The new germplasm with high yield of Mongolian astragalus was screened out,and the characteristics of the selected high yield germplasm were studied and compared.In order to provide the basis and theoretical basis for the breeding of the high yield varieties of Mongolian astragalus.The main research results are as follows:1.There were differences in root length,root diameter,lateral root number,stem number,stem diameter,yield per plant totaland,asteagaloside IV content and Calycosin7-O-β-D-Glucopyranoside content among different root diameter grades of Mongolian astragalus.Among them,the root length,root diameter,lateral root number,stem number,stem diameter,yield per plant of medicinal materials and Calycosin7-O-β-D-Glucopyranoside of A-grade seedling were significantly higher than those of other grades（P<0.05）.The correlation indicated that each index of root indexes had influence on the yield per plant of medicinal materials and Calycos-in7-O-β-D-Glucopyranoside content.The root indexes of A-grade seedlings were the highest.The yield per plant of medicinal materials（213.59g/plant）and the Calycosin7-O-β-D-Glucopyranoside content（0.068%）were the highest.2.There were differences in botanical characteristics and seed yield per plant among different root diameter grades of Mongolian astragalus.The stem diameter,branch number,internode length,leaf length,leaf area and lobular number of A-grade seedling were significantly higher than those of other grades（P<0.05）,and the seed yield per plant（15.54g/plant）was also significantly higher than those of other grades（P<0.05）.The pod length,pod diameter,embryo number and pod weight of A-grade seedlings were significantly higher than the contrast（P<0.05）.3.There were differences of photosynthetic rate,transpiration rate,stomatal conductance,intercellular CO₂concentration,water use efficiency and chlorophyll content among different root diameter grades of Mongolian astragalus.The results showed that the photosynthetic rate,transpiration rate,stomatal conductance and intercellular CO₂concentration of A-grade seedlings were generally higher than those of other grades（P<0.05）.The contents of chlorophyll a,chlorophyll b,carotenoid and chlorophyll of A-grade seedlings were higher than the contrast.There is a strong correlation between photosynthetic efficiency indexes.The contents of chlorophyll a was negatively correlated with water use efficiency（P<0.01）.4.This study showed that there were some differences in seedling biological characteristics and root morphology of the high yield germplasm of Mongolian astragalus.The absolute stem height,main stem diameter,internode length,compound leaf length,compound leaf width,compound leaf number,leaflet number,leaflet length,leaf width,root length,root diameter and root fresh weight of the high yield germplasm were significantly higher than other germplasm（P<0.05）.Correlation analysis showed that botanical characteristics at seedling stage had important influence on root system.