Identification And Evaluation Of Agronomic Characters Of Germplasm Resources Of Crotalaria Pallida

Crotalaria pallida is an annual herb of the genus Crotalaria.It is widely distributed in southern of China This species has a series of characteristics such as strong adaptability,fast growth,large biomass and abundant rhizobia,so it has natural advantages in soil and water conservation,and green fertilizer utilization.In recent years,it has been widely planted as landscaping and green fertilizer utilization.Up to now,there is no research on breeding,and there is no good cultivar variety and the production and utilization are completely dependent on wild materials.Due to the mixed provenances,the performance of drought tolerance and barren tolerance in the cultivated progeny is very different,which seriously limits the popularization and utilization.But there is no doubt,wild germplasm resources contain important gene carriers for genetic improvement,often have some excellent characters,and are important original materials for variety selection and breeding.In this study,accessions of Crotalaria pallida were identified and evaluated for their agronomic traits and drought tolerance at germination stage.The purpose of this study was to preliminarily explore the diversity of agronomic traits and select drought tolerant germplasm,systematically classify resource groups from phenotypic characteristics,and explore superior germplasm materials for cultivar breeding,so as to promote the basic research on Evaluation and utilization of Crotalaria pallida.The main results are as follows:(1)From 237 accessions(Note: There are 12 resources withered in the early stage of growth)of Crotalaria pallida in different areas of the agronomic traits of the identification and analysis,through the character index of variation situation analysis,has the rich diversity of 26 characters,the ordinal number,three out of the compound leaf area,The small variations of fresh weight and leaf area were the largest,with coefficients of variation greater than 30%.Coefficient of variation of leaf number,pod number,leaf circumference and leaf length was greater than 20%,Which also showed a great degree of variation.the coefficient of variation in the whole growth period was the smallest and the expression was stable.the diversity of floret stripes was the most abundant among the quality traits.the chara cters of flower and leaf were the main source of variation.(2)Correlation analysis showed that there was a strong correlation between the agronomic traits.The longer the flowering stage and the whole growth period,the larger the fresh weight,1000-seed weight and central leaflet area,and the more the number of leaves,branches,flower Ordinal Numbers,florets and fruit pods of the tall germplasm.The more branches,the more florets,the more pods.The greater the leaf length and width,the greater the leaf circumference and central leaflet area.The quality traits of stem growth habit,stem color,leaf color,florescence stripe,leaf tip,pod color,pod shape and seed background color were significantly correlated.Principal component analysis found that three compound leaf leaf area,leaf length,stem growth habit,small leaf perimeter,central foliage area,petiole,pod color,leaf,leaf width,leaf color,seed kernels,ordinal number,stem color,full bloom,color,number of pod and seeds in the whole stages,floret number,fresh weight,plant height and floret of the contribution rate is higher,after can be used as C.pallida hybrid parent choose important evaluation indexes.(3)Using 26 phenotypic traits,the 237 materials were divided into 4 groups by cluster analysis.The average agronomic traits of each group were significantly different.The first group consisted of 55 materials,which belonged to fast growing,short and wide elliptical leaflets.The second group contains 122 materials,belonging to the fast-growing,leafy type.The third group contained 57 materials,belonging to large leaf,tall plant and high yield type.The fourth group,consisting of three materials,belongs to the low-yielding obovate-lobular type.Different groups of materials can be selected according to needs.There was no correlation between the resource groups and their geographical sources,but the germplasm resources from Yunnan showed the most abundant characters,and all the four groups were distributed.(4)It was found that A72,A185,A145 and A191 had better comprehensive performance at three different growth stages through comprehensive evaluation of the main yield traits,plant height,number of leaves and fresh weight per plant.(5)It is determined that the suitable concentration of PEG-6000 solution for the identification of drought tolerance during the germination period of C.pallida is 15%.Under the stress of 15% PEG-6000 solution,Selected from 249 C.pallida germplasm resources to two average value is greater than 0.8 drought-resistant germplasm(grade 1),and Numbers for A127 A32,respectively from yunnan lincang and wenchang in hainan;The material numbers of 7 drought-tolerant germplasm(grade 2)were A30,A128,A52,A73,A35,A63 and A94,with average membership values greater than 0.6 and less than0.8.Intermediate germplasm(grade 3)41;More sensitive germplasm(grade 4)182;17sensitive germplasm(grade 5).