茄子与香蕉轮作配施生物有机肥对连作蕉园土壤微生物区系的影响

Effect of eggplant-banana rotation with bioorganic fertilizer treatment on soil microflora in banana continuous cropping orchard

  • 摘要: 连作现象在香蕉生产上非常普遍,而长期连作会导致严重的连作障碍。本文针对香蕉连作障碍,选择连作香蕉13年的地块,采用常规方法结合变性梯度凝胶电泳(PCR-DGGE)技术,在田间条件下研究了轮作茄子配施生物有机肥对高发枯萎病连作蕉园土壤可培养微生物数量、土壤化学性状以及土壤细菌群落结构的影响。结果表明:与连作香蕉相比,轮作茄子处理可显著降低可培养尖孢镰刀菌数量,使其数量从种植初的104 cfu·g-1(干土)下降到103 cfu·g-1(干土),同时提高了土壤pH,增加了土壤有机质、速效钾、碱解氮含量。无论是轮作还是连作种植模式,与配施普通有机肥相比,配施生物有机肥对可培养尖孢镰刀菌、真菌和细菌数量影响均不显著;但在轮作模式下,施用生物有机肥处理的细菌数量与真菌数量比值(B/F,381.2)显著高于配施普通有机肥处理(270.3)。PCR-DGGE分析结果表明,轮作茄子配施生物有机肥显著改变了土壤细菌群落结构,增加了细菌丰度、稳定性和多样性,其中多样性指数(Shannon-Wiener指数,3.22)较连作香蕉配施普通有机肥处理(2.89)显著增加。以上结果表明,茄子与香蕉轮作有利于连作蕉园土壤的微生态环境,同时轮作配施生物有机肥效果更优。

     

    Abstract: Banana Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense race 4, has been reported to be the most limiting factor in Cavendish-banana production worldwide since 1996. With the development of banana industry and regularization of produce in recent years, continuous banana cropping has become a common farming system. Furthermore, Cavendish-banana production comprises of about 90% of banana growing areas in south China, of which more than 200 000 hm2 banana orchards have suffered the disease. Among the management control of Fusarium wilt, rational crop rotation in combination with bio-organic fertilizer has been an effective and stable means of prevention of the disease. In this study, eggplant-banana rotation system was used to investigate the effect of cultivating eggplants combining bio-organic fertilizer on soil microflora in banana continuous cropping orchard with serious Fusarium wilt diseases using the plate count method and denaturing gradient gel electrophoresis (PCR-DGGE) technique. The chemical properties of the soil were also analyzed in the experiment. Results showed that the effects of application of bio-organic fertilizer on the number of culturable F. oxysporum, fungi and bacteria for both continuous cropping system and rotation with eggplant system of banana were not extremely significant compared with those of organic fertilizer treatment. However, compared with continuous cropping banana, rotation with eggplant of banana significantly reduced the number of culturable F. oxysporum, the number of culturable F. oxysporum decreased from 104 cfu·g-1 to 103 cfu·g-1 in dry soils. Despite no observed significant differences in soil physico-chemical properties between bio-organic fertilizer and organic fertilizer treatments of the eggplant-banana rotation system, soil pH, organic matter and available N, P and K contents increased under bio-organic fertilizer treatment. The ratio of bacteria to fungi (B/F) in eggplant-banana rotation system was significantly higher in bio-organic fertilizer than that in organic fertilizer treatment. Based on DGGE results, soil bacterial structure was obviously altered after eggplant-banana rotation with bioorganic fertilizer treatment for a year, and then soil bacterial richness, stability and diversity index increased compared with the control (continuous cropping of banana). The effect of eggplant-banana rotation system under bio-organic fertilizer treatment was good, and had a diversity index (Shannon-Wiener) of 3.22, while the control treatment with organic fertilizer had a diversity index of 2.89. In conclusion, the rotation of eggplant with banana could effectively improve soil microflora, and plus bio-organic fertilizer application even had a better effect.

     

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