低温处理下不同禾本科牧草的生理变化及其抗寒性比较

Changes analysis in physiological properties of several gramineous grass species and cold-resistance comparison on under cold stress

研究牧草根系抗寒性的动态变化,对寒冷地区的牧草引种筛选意义重大。试验以美国引进的禾本科牧草高山早熟禾(Poa Aalpine)、俄罗斯野麦(Elymus junceus)、无芒冰草(Agropyron inerme)、爱达荷冰草(Agropyron inerme)(品种名Secar)和爱达荷冰草(Agropyron inerme)(品种名Goldar)为研究材料,人工控温进行低温抗寒锻炼、冷冻处理和解冻恢复生长,测定每一阶段下根系中MDA、可溶性蛋白质、可溶性糖和脯氨酸的含量及SOD活性。结果表明,MDA含量在抗寒锻炼后略有增加,随后维持基本稳定;SOD活性在抗寒锻炼后升高,冷冻处理后显著降低;返青后又显著升高(P<0.05);可溶性蛋白质、可溶性糖和脯氨酸含量在抗寒锻炼和冷冻处理后升高,返青后降低;其中,SOD活性、可溶性糖和脯氨酸的含量随处理不同变幅较大,MDA和可溶性蛋白质的含量随处理不同变幅较小。运用Fuzzy数学中隶属函数法进行抗寒性综合评判,得出抗寒性强弱顺序为:高山早熟禾>俄罗斯野麦>爱达荷冰草(Secar)>无芒冰草>爱达荷冰草(Goldar)。

Research on the dynamic variation of cold resistance in forage＇s root system has great importance for forage introduction and screening, especially in cold areas. Using Poa Aalpine, Elymus junceus, Agropyron inerme, Agropyron inerme （Secar） and Agropyron inerme（Goldar） as experimental materials, the dynamic variation of MDA,SOD,soluble sugar and protein in the of different grass species were investigated in different growth phases treatments of cold acclimation, freezing treatment, thawing and recovering growth under controlled temperature condition. The results indicated that for all the materials, the content of MDA increased a little in cold acclimation treatment and then maintained basically stable ; The activity of SOD increased in cold acclimation treatment and decreased dramatically under freezing treatment, then after thawing, it increased again in recovering treatment and the increase was significant; The content of soluble sugar, protein and proline showed the same tendency of increasing in acclimation and freezing treatments, and decreasing in turning green treatments. Furthermore, unlike SOD activity, soluble sugar content and proline content, the variation of MDA content and soluble protein content are not significant under different treatments. At last, by using fuzzy mathematics method, the cold resistance ability of those gramineous grass species tested was evaluated as Poa Aalpine 〉 Elymus junceus 〉 Agropyron inerme （Secar） 〉 Agropyron inerme 〉 Agropyron inerme （Goldar）.