稀土对麻楝幼苗抗寒性的影响

在低温胁迫下采用不同浓度的稀土喷施叶面，研究稀土对麻楝幼苗的抗寒性的影响。结果表明：麻楝幼苗的相对电导率在300mg．L-1稀土处理后有所增加，700～1500mg．L-1处理组均显著下降或相对稳定。不同稀土浓度处理的麻楝幼苗的脯氨酸含量有不同程度的增加，可溶性蛋白质含量保持稳定或小幅增加，叶绿素含量增加或显著增加，SOD活性保持稳定。300mg．L-1稀土喷施叶面使幼苗的丙二醛含量增加，而700—1500mg．L-1稀土处理使丙二醛含量先有所增加，然后减少或显著减少。用主成分分析对各浓度稀土处理的幼苗抗寒性进行评价，得出1500mg．L-1稀土处理后幼苗抗寒性最佳，其次是1000和700mg．L-1处理。

Effects of Rare Earth on Cold Resistance of Chukrasia tabularis A. Juss. Seed- lings

The effect of rare earth solution on the cold resistance of Chukrasia tabularis seedlings was studied. The results showed that under low temperature stress, the relative electrical conductivity of the seedlings sprayed with 300 mg.L-1 had a significantly increase, whereas those sprayed with 700-1 500 mg.L-1 significantly decreased or fluctuated slightly. The content of free proline in seedlings sprayed with various concentrations of rare earth solution increased in a certain degree, the content of soluble protein remained stable or increased slightly, the chlorophyll content increased or significantly increased, and the SOD activity remained stability. The MDA content of seedlings sprayed with 300 mg.Ll increased, whereas that of seedlings sprayed with 700-1 500 mg-L1 increased initially and then decreased or decreased significantly. The cold resistance of seedlings treated with five concentrations of rare earth solution was evaluated by analysis of principal components, the seedlings treated with 1 500 mg.L-x rare earth solution had best cold resistance and then the cold resisitance order was 1 000 and 700 mg.L-1 treatments.