低磷胁迫下木豆利用磷的基因型差异及其机制  

Genotypic variation in putilization of Cajanus Cajan (L.) Millsp under low-p stress and corresponded mechanisms

作　　者：秦丽凤[1] 玉永雄[2] 黎晓峰[3] 顾明华[3] 

机构地区：[1]桂林医学院生物技术学院,广西桂林541004 [2]西南大学动物科技学院,重庆北碚400716 [3]广西大学农学院,广西南宁530005

出　　处：《生态环境》2007年第6期1719-1722,共4页Ecology and Environmnet

基　　金：国家973项目(2007CB108901);广西自然科学基金项目(桂科自0339007)

摘　　要：以木豆[Cajanus Cajan(L.)Millsp]MD2、MD5、MD7为材料,采用水培试验方法研究了木豆对磷的吸收、利用的基因型差异及其机理。结果表明:低磷(P1 μmol·L-1)胁迫下,木豆对磷素的吸收和利用效率存在明显的基因型差异,其中MD2、MD7属于磷素吸收、利用效率较强的基因型,而MD5为磷素效率较低的基因型。低磷培养16d后,磷高效的基因型的根/冠比显著增加,根分泌的酸性磷酸酶(APA)活性较高,说明木豆对磷素的吸收效率与植株的根冠比及根分泌的酸性磷酸酶活性有关。在低磷胁迫下,虽然MD7、MD2的含磷量较低,但是磷素利用效率和根尖中APA活性较高,说明根中高APA活性是磷利用效率高的重要原因之一。Genotypic variation of pigeon pea [Cajanus Cajan （L.） Millsp,cv. MD2, MD5 and MD7] in P uptake, P utilization and corresponded mechanisms were investigated by hydroponic experiments. Significant genotypic variations in P uptake and P utilization were found in pigeon peas grown in 1 μmol L^-1 P solution. It was shown that MD7 and MD2 were higher P-efficiency genotypes, while MD5 was lower one. Significant increase in the ratio of root to shoot and the activities of acid phosphatase （APA） secreted from roots was found in high P-efficiency genotypes after the plants were treated with low phosphorus （P 1 μmol L^-1） for 16 d, suggesting that the ratio of root to shoot and APA secreted from roots are involved in higher P uptake-efficiency of pigeon pea. Under low P stress, P content in plants of MD7 and MD2 was lower than that in MD5, while P utilization efficiency and the activities of APA in root apices were higher, indicating that high activity of APA in roots is one of the important reasons for plant utilizing P efficiently.

关 键 词：木豆[Cajanus Cajan(L.)Millsp] 磷胁迫 磷利用效率 基因型 机理 

分 类 号：Q945.78[生物学—植物学]