大豆不同品种对磷胁迫反应的研究

通过大田试验，探讨不同来源的8个大豆品种对南方酸性低磷红壤的适应性，并初步分析其磷效率的机理。试验表明：生物学产量、经济学产量、总体磷效率和磷吸收效率具有显著的品种差异。从吸收效率(以吸磷量为标准)来看，BX10属于磷高效、不敏感品种，BD2、GD1和GD3属于磷低效、敏感品种，而BX11、BD1、GD2和GD4则表现不稳定。供试大豆总体磷效率(以生物量为标准)与磷吸收效率表现趋势基本一致，而磷利用效率并没有显著的品种差异。在本试验中，总体磷效率主要取决于磷吸收效率。此外，磷吸收效率较高的品种，其根长和根表面积并没有优势，供试大豆对土壤磷的吸收效率可能受其它根系性状，如根构型和根分泌物等的影响。

STUDY ON THE RESPONSE OF SOYBEAN VARIETIES TO P DEFICIENCY

Field experiments were carried out to investigate the adaptability of 8 soybean varieties from different origins to low-P acid red soils in South China and the mechanism of P efficiency. The results showed that there were significant varietal differences in plant biomass, yield, P efficiency and P acquisition efficiency among the 8 tested soybean varieties. Based on P acquisition efficiency (defined as P content), variety BX10 was higy efficient but nonresponsive,BD2, GD1 and GD3 were inefficient but responsive, while the performances of other varieties, BX11, BD1, GD2 and GD4, were unstable. Furthermore, the overall P efficiency (defined as biomass) of the tested soybean varieties showed the same pattern as P acquisition efficiency. On the other hand, there was no significant varietal difference in P utilization efficiency. This indicates that the overall P efficiency is mainly attributed to P acquisition efficiency in the present field study. Meanwhile, since the P-efficient varieties did not have longer root length and larger root surface area, P acquisition efficiency of the 8 tested soybean varieties may be dominated by other root traits, such as root architecture and root exudates under the present experimental conditions.