Physiological Response and Comprehensive Evaluation of Alfalfa Seedlings to Aluminum Stress

Abstract:

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.

Key words:Medicago sativa;Aluminum stress;Biomass;Chlorophyll;Seedling;Physiology