不同苜蓿越冬期根系生理代谢响应研究

Study on root physiological metabolism response of different alfalfa in winter

为探究苜蓿越冬期根系生理代谢响应机制,筛选适宜黑龙江地区种植的耐寒苜蓿种质材料,本研究以国内外5个苜蓿品种为试验材料,通过对苜蓿越冬期根系生理指标如游离脯氨酸(Pro)、可溶性蛋白(SP)、可溶性糖(SS)、丙二醛(MDA)、超氧化物歧化酶(SOD)和相对电导率进行测定,利用隶属函数评价筛选出耐寒苜蓿品种。结果表明:冷胁迫下,龙牧801和公农2号根系内Pro、SS含量和SOD活性显著高于其他品种(P<0.05);冻胁迫下,龙牧801根系内Pro含量最高,为628.21 nmol/g,且龙牧801、公农2号和草原3号的SS、SP含量和SOD活性显著高于其他品种(P<0.05),而皇后和赛迪苜蓿的MDA和相对电导率显著高于其他品种(P<0.05)。运用隶属函数对各品种的抗寒性进行评价,最终得出品种的抗寒强弱顺序为:龙牧801>公农2号>草原3号>皇后>赛迪。

This study was aimed to explore the physiological response mechanism of alfalfa root during overwintering period by screening cold-resistant alfalfa germplasm materials suitable for planting in Heilongjiang Province.Five alfalfa varieties in China and abroad were used as experimental materials.Physiological indexes including proline(Pro),soluble protein(SP),soluble sugar(SS),malondialdehyde(MDA),superoxide dismutase(SOD)and relative electrical conductivity were measured.The cold-resistant alfalfa varieties were screened by membership function evaluation.The results showed that Pro,SS content and SOD activity in roots of Longmu 801 and Gongnong No.2 were significantly higher than those of other varieties under cold stress(P<0.05).Under freezing stress,the Pro content in root of Longmu 801 was the highest(628.21 nmol/g),and the SS,SP content and SOD activity of Longmu 801,Gongnong No.2 and Caoyuan No.3 were significantly higher than those of other varieties(P<0.05),while the MDA and relative electrical conductivity of Queen and Sardi alfalfa were significantly higher than those of other varieties(P<0.05).Membership function was used to evaluate the cold resistance of varieties.The cold resistance of alfalfa varieties from high to low was as follows:Longmu 801>Gongnong No.2>Caoyuan No.3>Queen>Sardi.