紫穗槐丛枝菌根(AM)根系分泌物诱导根瘤菌结瘤因子及作用研究

Amorpha fruticosa Arbuscular Mycorrhizal(AM)Root Exudates Induced Nodulation Factors of Rhizobia and Their Interactions

为了进一步揭示丛枝菌根(AM)真菌促进紫穗槐结瘤数量及提高固氮能力的机制,试验采用高效液相色谱法(HPLC)并结合结瘤因子生物检测法,研究了菌根化紫穗槐苗木根系分泌物对根瘤菌结瘤因子的诱导效果,以及结瘤因子紫穗槐苗木生长的作用。结果表明,菌根分泌物能够显著诱导根瘤菌产生结瘤因子,HPLC检测图谱33min出现的色谱峰物质能够诱导紫穗槐的根毛产生变形;结瘤因子回接盆栽紫穗槐实生苗结果表明,在灭菌基质上播种的紫穗槐苗木能够产生根瘤原基并结瘤,且双接种结瘤因子和AM真菌处理的紫穗槐苗木产生根瘤原基的数量显著高于单独接结瘤因子处理的苗木;结瘤因子提高了紫穗槐的菌根侵染率,结瘤因子的量越大,AM真菌对紫穗槐的侵染效果越显著;结瘤因子与AM真菌混合接种能显著提高紫穗槐苗木的生物量。

In order to reveal the mechanism of Amorpha fruticosa nodulation nitrogen fixation ability promoted by arbuscular mycorrhizal（AM）fungi,HPLC and bioassay experiments were used to study the effect of AM fungi on nodulation factor secretion of Rhizobia.Through A.fruticosasingle inoculated nodulation factor（Nod＋）,A.fruticosa both inoculated AM fungi and the nodulation factor（AM＋Nod＋）and blank control.The effect of nodulation factor on A.fruticosa was verified.These results showed that mycorrhizal secretions could significantly induce rhizobia nodulation factor production.The material collected by 33 min detection peak in HPLC could induce deformation of A.fruticosaroot hairs.Re-inoculation experiments showed that the nodulation factor could promote nodulation of A.fruticosain the absence of rhizobia,and the inoculation of AM fungi could significantly improve nodulation.In addition,nodulation factor could enhance AM fungi inoculation.The larger the amount of nodulation factor,the greater the inoculation of AM fungi.Nodulation factor（Nod＋）of A.fruticosasingle inoculated could increase plant height,fresh weight and root length significantly.Double inoculation of AM fungi and nodulation factor（AM＋Nod＋）treatment increased more than those of single inoculated.These results further determined that the nodulation factor concentration of A.fruticosaincreased by inoculation of AM fungi and further enhanced rhizobia nodulation ability.Besides,nodulation factor promoted AM fungus inoculation efficiency.