| In recent years,along with the continuous promotion of China’s socio-economic and modern agricultural industrial structure optimization and adjustment,China’s grassland livestock industry has been continuously developed,but factors such as the small number of new forage varieties selected and cultivated by China’s forage selection and low technological content seriously restrict the development of China’s modern agriculture,animal husbandry and ecological environment,so it is urgent to select,introduce,improve and develop new excellent forage varieties.Lotus corniculatus,a perennial legume with high herbaceous production,soft stems and leaves,and rich in tannins and carbohydrates,is now widely distributed around the world,with most of them in wild and semi-wild states,and has an exceptionally rich germplasm resource,which provides a rich material basis for the selection and breeding of good species of L.corniculatus.In the present study,23 germplasm of Phyllostachys spp.from home and abroad were used as research materials to study the genetic diversity of L.corniculatus by developing SSR molecular markers and combining morphological and quality traits to discover high-quality germplasm resources,aiming to provide scientific basis for the utilization of L.corniculatus.resources and the selection and breeding of good varieties.The results of the study are as follows:1.Based on the transcriptome sequencing results,we developed SSR molecular markers for L.corniculatus and selected 29 SSR primer pairs with good polymorphism from 100 pairs of primers designed.2.Based on the optimized PCR reaction system,genetic diversity analysis was performed on 23 L.corniculatus germplasm,and 299 alleles were detected with an average of 10.168.The effective number of alleles(Ne)was 368.623 with an average of 12.711.the Shannon information index(I)was 3.167.the observed heterozygosity(Ho)was 1.064;the expected heterozygosity(He)was 1.521.the polymorphic information content(PIC)of the primers was 0.740.the genetic similarity coefficient was 0.773.3.The clustering analysis revealed that when the genetic distance was 0.65,the 23 L.corniculatus germplasm could be divided into three major categories.The genetic similarity coefficient of two germplasm from Beijing(No.03046)and Russia(No.07880)was found to be 0.983,indicating that their relatives are the closest among all germplasm.4.The analysis of seven phenotypic traits and five quality traits of 23 L.corniculatus germplasm from different geographical sources showed that the coefficients of variation of the two types of traits ranged from 18.50% to 31.76% and8.08% to 38.53%,respectively,and most of the traits belonged to medium to high variability and had a wide range of variation,which could be optimized by germplasm improvement and cultivation measures to achieve the optimal values of each trait.Most of the traits are in the middle to high range of variation and can be optimized through germplasm improvement and cultivation measures to achieve optimal values for each trait.5.Cluster analysis with quantitative traits as clustering index can classify all germplasm into five categories(Q1 to Q5).Among them,Q1 can be used as a source of germplasm with high crude protein and high crude fat;Q2 can be used as a germplasm for leaf morphology improvement;and Q5 can be used as a source of high quality germplasm for total sugar and stem thickness.Most of the germplasm traits in the five categories can be judged by the quality ratings to be excellent and can be exploited as germplasm resources for a certain trait improvement.6.It was found that the agronomic and quality traits of L.corniculatus germplasm numbered 01887(New Zealand),08521(Shaanxi),05689(Xinjiang),01886(West Germany),and 01888(Canada)performed better and had rich variation,which were suitable for further research.The germplasm 01887 has the best performance and is a potential high-quality L.corniculatus germplasm resource suitable for further exploitation.It was found that the individual of L.corniculatus is rich in genetic diversity,and the 29 pairs of fluorescent marker primers and the optimized SSR-PCR amplification reaction system were developed to provide a research basis for the subsequent study of L.corniculatus germplasm resources and molecular marker-assisted breeding.The high-quality germplasm 01887(New Zealand)screened by agronomic and quality traits also provided a theoretical basis for the selection and further development of L.corniculatus germplasm resources. |
PDF Full Text Request