AM真菌种间差异对枳壳生长及耐热性效应的研究※

用地表球囊霉、莫西球囊霉、珠状巨孢球囊霉及其混合菌剂接种无菌根枳壳幼苗进行盆栽试验,25℃培养4个月,观察对枳壳菌根形成和营养生长的影响,在40℃高温胁迫30d,调查分析菌根枳壳的耐热性。试验结果表明:接种AM真菌的根系形成了20%～80%的菌根侵染率;菌根枳壳的苗高、苗质量、节间长、茎基粗、须根数量和须根长度等营养生长显著增加;叶片中的SOD,POD活性和根系活力显著增强,可溶性蛋白、可溶性糖含量显著升高,叶片中的MDA含量降低,膜透性显著变小,枳壳苗的耐热性显著提高;但是,AM真菌在促进枳壳苗菌根化、营养生长和提高耐热性方面存在着种间差异,地表球囊霉、莫西球囊霉、珠状巨孢球囊霉、混合菌剂与枳壳根系形成丛枝菌根的侵染率依次为20.4%±1.2%、61.8%±3.4%、85.7%±2.7%、83.3%±2.2%,促进枳壳苗营养生长提高枳壳苗耐热能力的AM真菌依次为:地表球囊霉<莫西球囊霉<珠状巨孢球囊霉<混合菌剂,认为珠状巨孢球囊霉和莫西球囊霉是枳壳耐高温胁迫菌根化育苗的重要优良菌种。

THE EFFECTS OF INTER-SPECIES DIFFERENCE OF ARBUSCULAR MYCORRHIZAL FUNGI ON GROWTH AND HEAT-RESISTANT OF TRIFOLIATE (PONCIRUS TRIFOLIATA RAF.) SEEDLINGS

Pot experiments for trifoliate (Poncirus trifoliata Raf.) seedlings inoculated with arbuscular mycorrhizal fungi (AM fungi) of Glomus versiforme, G. mosseae, Gigaspora margarita and their mixture was carried out in order to observe the effects of different AM fungi on mycorrhizal development and vegetative growth of trifoliate seedling and to evaluate its heat-resistant characters under the durative high temperature stress. The experimental result showed that there was 20%~80% mycorrhizal infection rate in trifoliate seedling roots inoculated with AM fungi. Compared with the control, the vegetative growth such as height, mass, internodes length, shoot base diameter, and fibre number, fibre length of mycorrhizal trifoliate seedlings were increased remarkably. Then, physiological and biochemical indexes reflecting heat-resistant capacity were surveyed after the experimental seedling had been treated with the consecutive stress temperatures at 40℃ for 30 days. The activity of SOD and POD, the content of soluble protein and soluble sugar in leaves as well as the roots activity of mycorrhizal trifoliate seedlings were improved remarkably as compared with the control. Both of MDA content and membrane damage degree in leaves of mycorrhizal seedlings were reduced evidently. So, the heat-resistant of trifoliate seedlings was improved observably by arbuscular mycorrhizae. However, the inter-species effects of AM fungi on mycorrhizal infection rate, vegetable growth and heat-resistant of trifoliate seedlings were different. The mycorrhizal infection rate of seedling roots were 20.4%±1.2%、61.8%±3.4%、 85.7%±2.7%、83.3%±2.2% for Glomus versiformei, G.mosseae, Gigaspora margarita and their mixture respectively. The AM fungal order for stimulating seedling growth and improving seedling heat-resistant is Glomus versiforme < G. mosseae < Gigaspora margarita < mixture inoculant. So, we concluded that both species of Gigaspora margarita and Glomus mosseae are important good inoculant for mycorrhizal trifoliate seedlings to withstand the high temperature stress in the citrus production area localized along the Yangtse River.