丛枝菌根真菌在田间的分布特征、代谢活性及其对甘薯生长的影响

研究了大田条件下丛枝菌根(AM)真菌的分布特征、代谢活性及其对甘薯的生长效应.结果表明,接种Glomus intraradices 8周后,甘薯地上部干重,薯块鲜重和薯块个数均明显高于不接种对照;植株地上部和根系的吸磷量显著提高.与不接种对照相比,接种处理的甘薯菌根侵染率、甘薯根外菌丝密度以及甘薯根内菌丝的活性(根内菌丝碱性磷酸酶活性)显著提高.进一步分析甘薯根际不同方位上的菌丝分布,发现接种处理中平行于垄的方向的菌丝密度显著高于苗子下方的菌丝密度,而不接种处理的各个方向总菌丝密度无差异;活菌丝(具琥珀酸脱氢酶活性的菌丝)密度在各个方向的分布规律与总菌丝密度的分布规律一致.接种后根内菌丝活性的增强,根外活性菌丝密度的增加及其分布特征的改变,是甘薯产量增加的主要原因.

Field distribution pattern and metabolic activity of AM fungi and their effects on Ipomoea batatas growth

The study showed that after eight weeks of inoculating sweet potato seedlings with AM fungus Glomus intraradices BEG141 under field condition,the shoot dry weight,individuals of tuber and their fresh weight,as well as the P uptake by the plant increased significantly.Compared with the control,the root colonization rate,extraradical hyphal density and intraradical alkaline phosphatase(ALP)activity were greatly increased.After inoculation with BEG141,the total and succinate dehydrogenase(SDH)-active hyphae paralleling with ridge were much more than those in underside direction,while there was no significant difference in different directions in the control.The increase of intra-and extraradical active hyphae density and the change of AM fungus distribution pattern after inoculation with mycorrhizal fungi may be the main reasons for the growth improvement of sweet potato.