苜蓿幼苗对铝胁迫的生理响应及综合评价

为探讨铝胁迫对苜蓿(Medicago sativa)幼苗生长和生理特性的影响,对铝胁迫下苜蓿地上和地下生物量、光合色素及根尖胼胝质含量进行测定,并对根尖结构进行观察,最后采用隶属函数分析法对苜蓿耐铝性进行评价。结果表明,随着铝胁迫的增加,苜蓿地上、地下部分生物量呈降低趋势,低浓度和高浓度铝胁迫使苜蓿生物量显著下降(P0.05);苜蓿的叶绿素含量呈下降趋势,胼胝质积累量增多;中、高浓度铝胁迫使根尖胼胝质含量显著上升。随铝胁迫浓度升高,根尖横切面细胞发生较大变化,尤其在高浓度时,细胞干瘪且排列紊乱。隶属函数分析结果表明,No. 12和No. 18苜蓿材料的耐铝性较好,可在南方酸性富铝化土壤中推广应用。

Physiological Response and Comprehensive Evaluation of Alfalfa Seedlings to Aluminum Stress

In order to understand the effects of aluminum on growth and physiological characteristics of alfalfa (Medicago sativa) seedlings, the above-and under-ground biomass, contents of leaf chlorophyll and callus in root tips were measured, the structure of root tips was observed, and the aluminum resistance of alfalfa was evaluated using membership function analysis. The results showed that with increment of aluminum concentration, the above-and under-ground biomass of alfalfa decreased, which significantly decreased under low and high aluminum concentrations (P<0.05). With increment of aluminum stress, the chlorophyll content of alfalfas dropped, while the accumulation of calluses increased, particularly under middle and high aluminum stress. Under aluminum stress, the cells of root tip had a big changes, which collapsed and in disorder under high aluminum stress. According to comprehensive evaluation, the aluminum resistance of No. 12 and No. 18 was better than that of others, suggesting that they could be applied in acid aluminized soil in southern China.