How does aerobic rice mobilize Zn from soil?
We conducted a pot experiment and a rhizotron experiment to find out if mycorrhizal effects or rhizosphere effects are involved in tolerance to low Zn availability. Results from the pot experiment indicated that AMF-inoculated plants produced more biomass and took up more Zn than nonmycorrhizal controls. There was, however, a negative correlation between plant Zn uptake by non mycorrhizal plants and mycorrhizal Zn responsiveness, indicating genotypes are either responsive to AMF or have alternative mechanisms to mobilize Zn. Breeding for maximum mycorrhizal responsiveness may not lead to crops that are most efficient in taking up zinc from soils with low zinc levels. With three aerobic rice genotypes having a similar root surface area but different levels of Zn uptake, a rhizotron experiment was conducted in which in situ soil solution in rhizosphere was collected and analysed for malate. Results showed that all genotypes responded to Zn deficiency with increased root exudation of malate. Moreover, genotype with higher Zn uptake showed a stronger increase in malate exudation than the genotype with a lower Zn uptake, suggesting that the variation in Zn uptake among aerobic rice genotypes be related to their capacity to exude malate into the rhizosphere in response to Zn deficiency.
aerobic rice genotypic variation mycorrhizal rhizosphere malate zinc
Xiaopeng Gao Thomas W. Kuyper Fusuo Zhang Ellis Hoffland
China Agricultural University, Dept. Plant Nutrition, Yuanmingyuan West Road No 2, Haidian District, Wageningen University, Dept. Soil Quality, P O Box 8005, 6700 EC Wageningen, The Netherlands China Agricultural University, Dept. Plant Nutrition, Yuanmingyuan West Road No 2, Haidian District,
国际会议
第九届痕量元素生物地球化学国际会议(9th International Conference on the Biogeochemistry of Trace Elements)
北京
英文
266-267
2007-07-15（万方平台首次上网日期，不代表论文的发表时间）