Research On Qualitative Characters Of Elymus Nutans Populations In Alpine Meadow

Elymus nutans is a gramineous forage with extensive adaptability, cold resistance, high nutritive value and good palatability. It is also a common resown grass in the improvement of degraded alpine meadow. In the present study, the seeds of 11 populations of E. nutans, which were collected from Gansu, Qinghai and Sichuan Province, were sowed in Xiahe experimental station of Gannan during the past two years. The variations of nutritional values (WSC,CP and P) and the biological characters (stem/leaf ratio and individual biomass) of each population in different growing stages were investigated. The biological characters and nutritional values at early flower stage (plant height, unit area reproductive branch number, hay yield, WSC, WSC and its components, CP and amino acids) were also evaluated. The study aimed to better understand the characters of biological and nutritive of each population, and to select excellent materials which can be used as breeding materials. The main results are as follows:1. The variations of eleven E. nutans populations were great in biological characters and nutritive qualities. Some good materials were obtained based on the yield and nutrition characters. The highest hay yield was 4379.28 kg/hm2 for GE16, respectively, which has the best biological characters and could be used for breeding material.GE22,GE22 and QE42 had high sugar content;being 6.03%,5.38% and 4.98%;while QE36 had high proteins and their respective value was 23.92%; P content of QE36 was significantly higher than the others. Based on qualitative characters, GE16,QE39 was high yield and middle sugar materials; GE31,QE36 was middle yield and high nitrogen materials; while GE01,SE26 was middle yield and high sugar materials.2. The nutritive value of E. nutans populations varied significantly in different growing stages. The WSC content firstly increase and then decrease from jointing stage to full ripe stage, the highest value appeared between early blooming stage and full blooming stage; The contents of CP and total P decreased gradually with the growing stage progressed. The CP content of E. nutans decreased with the stem/leaf ratio or unit area reproductive branch number increased. The P content was significantly and positively correlated to the CP content, while the relationship between WSC and CP contents was a negative correlation.3. The order of the contents of WSC components of each E. nutans was sucrose>fructose>glucose, and the sucrose content was significant negatively correlated to the contents of fructose and glucose. The contents of total amino acid and all amino acid components of high protein material (QE36) was higher than the control (GE07), and the essential amino acid content of the former was 1.6 times higher than the latter. The diurnal variation trend of sucrose, glucose and WSC showed a single-peak pattern, and highest value of WSC appeared at 12 o’clock.