三峡库区桑树菌根发育特征及菌根对桑苗生长的促进作用

为探索桑树在西南山区逆境中的生态重建潜能,对三峡库区海拔170～175 m区域自然生长桑树的根系与丛枝菌根(AM)真菌共生形成菌根的情况进行调查,并通过盆栽桑苗接种AM真菌研究菌根对桑苗生长的促进作用。调查结果表明,库区桑树根系82%左右的根尖不同程度被AM真菌侵染形成菌根,菌根内有菌丝、丛枝、泡囊、孢子等结构,菌根外菌丝上有辅助细胞。桑苗在光照培养箱和网室中培育都容易被AM真菌侵染,接种15 d左右就有菌丝附着在根上并形成附着胞,菌根侵染率随时间延长逐渐升高,光照培养箱中生长90 d的接种桑苗菌根侵染率为40.56%±3.61%,网室中生长70 d和90 d的接种桑苗菌根侵染率分别为46.82%±4.10%和50.72%±5.32%。接种桑苗的株高、主根长、单株根尖数量、单株根尖总长、单株叶片数量,以及第3真叶叶长、叶宽、叶面积等都显著高于对照,单株根尖数量、单株根尖总长和叶面积的相对增长量超过100%,极大地提高了桑苗的根系吸收能力和地上部分的光合面积。研究结果证实:桑树是典型的丛枝菌根植物,菌根有利于桑树在极端逆境中生长,接种AM真菌能显著地促进桑苗的营养生长。

Developmental Features of Mycorrhiza and Its Promotion Effect on Growth of Mulberry Saplings in Three Gorges Reservoir Region

In order to further explore the ecological reconstruction potential of mulberry(Morus L.) in adverse environment of the southwestern mountainous region,an investigation was conducted on the formation of mycorrhiza by arbuscular mycorrhizal(AM) fungi and root system of mulberry naturally growing at 170 ~175 m altitude of the Three Gorges Reservoir area.Moreover,AM fungi were used to inoculate potted mulberry saplings for evaluation of the effect of mycorrhiza to mulberry sampling growth.The results showed th...