Identification And Evaluation On Germplasm Resources Of Medicago Ruthenica L.in Inner Mongolia

Medicago ruthenica L.,an excellent perennial leguminous forage,was widely distributed in Northern Region of China where there were high nutritional value,good palatability,and was high drought tolerance,cold tolerance,barren resistance. M. ruthenica formed a variety of ecotypes in different habitats, with the potential of new varieties to resistance to drought and cold. 28 accessions of wide M. ruthenica were collected and studied on morphological biology, drought tolerance and seed storage protein to provide scientific and theoretical basic for germplasm innovation, breeding, exploiture and utilization of M. ruthenica germplasm materials. The main results were as fellows:1. M. ruthenica germplasm had rich phenotypic characteristics variation. No matter nutritional organs, seed characters or production traits all had a wide range of variation. The principal component analysis results showed that plant high, ratio of stem and leaf, seed length, 1000-seed weight, dry matter weihgt, plant diameter, area of leaf and branch length were the main traits that determined phenotypic variation among populations.All M. ruthenica materials could return green in late April or early May. This indicated that they could survive over winter safely in arid and semi-arid areas of Inner Mongolia. All the tested accessions could vegetate well and had better adaptability to local eco-climatic conditions. But different materials had significant differences growth period under the same environmental conditions. Dry/fresh matter ratio of most accessions belonged to the range of 0.3～0.4. The leaf and stem ratio of most accessions belonged to the range of 1.0～2.0, and MR-1, MR-10, MR-18 and MR-19 were higher than 2.0. Comprehensive analysis showed that MR-1, MR-7, MR-9, MR-13, MR-19 and MR-23 were the top of 6 germplasm. They all gave higher performances and could be used in breeding and production first.2. The drought resistance of M. ruthenica from different habitats was investigated by using potted plants to simulate soil drought condition. The results showed that with the days of drought stress increased, relative water content decreased significantly, while the relative electrical conductivity, proline content and MDA content were increased distinctly. After analysis of the values of jurisdiction degree, drought resistance of 28 materials were divided into three categories, MR-16 and MR-21 were strong drought resistance, that the average value of membership function were 0.9071 and 0.7437. MR-1 was drought resistance, that the average value of membership function was 0.3145. The others had drought resistance. Made an identification of drought resistance on large wild M. ruthenica, relative water content, relative electrical conductivity, proline content and MDA content could be used as indicators. They reflected the material to adapt to drought stress to some extent.3. The genetic diversity of seed storage protein among the 28 specimens was tested by SDS-PAGE. The results showed that a total of 30 genotypes were separated through electrophoresis and polymorphism amounted to 83.33%. Observed number of alleles were 1.8667, Effective number of alleles were 1.1983. Nei's gene diversity was 1.1548. Shannon's Information index was 0.2744, which showed rich genetic diversity and large genetic differentiation of M. ruthenica accessions. 28 accessions can be divided into six groups. In most cases, accessions from the same region were classified into four the same group, which displayed a certain degree of regional laws.All these study results showed that the adaptive traits of M. ruthenica accessions were consisitent with morphological structure, physiological characteristics and genetic variation. Cluster analysis showed that M. ruthenica germplasm materials had converagence adaptation character. M. ruthenica had abundant genetic diversity, steady structure and strong adaptability adjustment characteristic, which were inherent guarantee of strong adaptability and wide distribution. These results provided scientific basis for the protection and utilization of M. ruthenica germplasm.