不同木豆品种耐铝性的基因型差异及其机理研究

以6个品种的木豆为材料，探讨了木豆品种间耐铝性的基因型差异及其机制。铝对根伸长的抑制大小及苏木精对根尖的染色模式的研究结果表明，不同品种木豆的耐铝性基因型差异明显。在铝胁迫条件下，去除根尖吸附的粘胶，耐铝的基因型MD2和敏感的基因型MD5根的伸长率均减少，而根尖被苏木精染色程度加深；去除粘胶对MD2的影响大于MD5，说明粘胶对根尖的保护是木豆抵御铝毒的一个重要机制。虽然铝胁迫可诱导木豆根系分泌柠檬酸和苹果酸，但根系苹果酸的分泌量在MD2和MD间无显著差异，MD2柠檬酸的分泌量甚至低于MD5。

Genotypic variation of Al-tolerance and corresponded mechanism in different cultivars of pigeon pea

Genotypic variation of Al-tolerance and corresponded mechanism in 6 cultivars of pigeon pea were investigated in present study.The results in term of Al-induced inhibition of root elongation and the hematoxylin dyeing pattern of root apices showed that the genotypic variation of Al-tolerance in varied cultivars of pigeon pea was considerable.The removal of mucilage from root apices resulted in both a decrease of root elongation and heavy staining of root apices in Al-tolerant genotype(MD2) and Al-sensitive genotype(MD5).Moreover,the effect of the removal of mucilage in MD2 was more remarkable than that in MD5,suggesting that the protection of root apices from Al injure is an important mechanism for pigeon pea to resistant Al.Aluminum induced the secre-tion of citrate and malate from roots of both genotypes.However,malate exudations from MD2 and MD5 showed no considerable difference,and citrate exudation from MD5 was even more than that from MD2.