多胺对共生条件下丛枝菌根真菌及宿主植物生长发育的影响

Effect of polyamine on growth and development of arbuscular mycorrhizal fungi and host plant in symbiotic culture condition

为探讨多胺对共生条件下丛枝菌根真菌及其宿主植物生长发育的影响,本研究以丛枝菌根真菌(Gigaspora margarita)为试验材料,通过施用不同浓度的多胺(Polyamine,PA)及其生物合成抑制剂[Methylglyoxal bis(guanylhydrazone),MGBG]处理接种丛枝菌根真菌的葡萄微繁苗,研究共生培养条件下外源多胺及多胺合成抑制剂对丛枝菌根真菌孢子萌发、芽管菌丝及其宿主植物生长发育的影响。试验结果表明,共生培养条件下,一定浓度的外源PA对丛枝菌根真菌及其宿主植物的生长发育具显著促进作用,丛枝菌根真菌孢子数、菌丝长度、侵染率、丛枝丰富度及菌根化葡萄幼苗生长势均显著提高。MGBG则表现较强的抑制作用,且该抑制作用可被外源PA部分解除,证明外源多胺对菌根化葡萄微繁苗生长发育的促进作用是通过活化根系土壤中丛枝菌根真菌,促进微繁苗丛枝菌根共生体的良好发育,最大程度地发挥菌根化效应得以表现的。

The effects of exogenous polyamine on the growth and development of arbuscular mycorrhizal fungi （AMF） and host plant in the symbiotic culture condition were investigated by micropropagating grape plantlets infected with AMF （Gigaspora margarita） and then treated with exogenous polyamine （PA） and polyamine biosynthesis inhibitor [methylglyoxal bis （guanylhydrazone）, MGBG]. The effects of exogenous PA and MGBG on spore germination, hyphal growth of AMF and development of the host plant in symbiotic culture condition were analyzed. The results indicate that certain doses of exogenous PA have significant effect on symbiotic development, grape plantlets and AMF. AMF arbuscular abundance, hyphal length, spore number and infection rate increase after treatment with exogenous PA. Meanwhile, PA biosynthesis inhibitor （MGBG） has opposite effect which is suppressed by application of exogenous PA. This implies that PA also has significant stimulating effect on the growth and development of AMF inex vitro conditions. Because exogenous PA activates AMF in the rhizosphere, potential AMF infection is enhanced. Thus, AMF symbiotic association with grape plantlets can establish at early weaning stage and develop with time.