万寿菊当归多样性种植对土壤真菌多样性的影响

利用万寿菊与当归间作控制当归根结线虫病已经成为云南滇中地区防治当归根结线虫的重要途径之一,但其机理尚不清楚。有理论认为万寿菊根系分泌物可影响土壤微生物群落的组成,进而产生控制寄生线虫的效果。本试验以万寿菊和当归多样性种植为研究模式,采用PCR-DGGE技术研究不同种植方式对土壤真菌多样性的影响及不同时期真菌群落多样性的变化规律,目的是为阐明万寿菊杀线机制提供理论支持。试验结果表明,以当归单作为对照,当归/万寿菊轮作和当归/万寿菊间作的土壤真菌群落在整个生长季变化相对较小,DGGE的条带变化率分别为-39.13%、-30.77%,而万寿菊单作土壤真菌条带变化率为-69.23%;主成分分析表明不同种植模式与其土壤真菌群落的组成存在对应关系,当归单作的真菌种类组成与当归、万寿菊多样性种植模式中的真菌种类组成差异较大,且当归/万寿菊间作的中后期与前期差异最大;聚类分析表明,在同一时期内,当归单作与当归/万寿菊轮作、当归/万寿菊间作的土壤真菌种类组成均表现出明显的差异。

Effects of marigold diversified cropping with angelica on fungal community in soils

Although marigold diversified cropping with angelica has become one of the important alternative means for nematode depression across central Yunnan angelica production region, the mechanism is still unclear. One of the hypotheses speculates that marigold root exudates could affect rhizosphere microorganism community so as to achieve nematode depression. In the present study, by using PCR DGGE technology, we attempted to elucidate the effect of marigold diversified cropping on fungal diversity and fungal community changing patterns at individual field stages, and our goal is to shed light on marigold nematode depression mechanism. The results showed that, with angelica monoculture as the control, marigold inter planting and rotation with angelica could significantly affect rhizosphere fungal community, with a band change rate of -39.13% and -30.77%, respectively, and marigold monoculture gave the highest rate -69.23%. PCA results revealed that rhizosphere fungal community was congruent with planting patterns, and it also showed that angelica monoculture harbored a distinctive community. Furthermore, through cluster analysis, at individual growth stage, it showed a distinct difference in rhizosphere fungal community between angelica monoculture and its corresponding diversified cropping patterns.