發(fā)布時間：2018-05-05 04:39

  本文選題：蚯蚓 + 連作障礙　； 參考：《中國農(nóng)業(yè)大學(xué)》2016年博士論文

【摘要】：蚯蚓是土壤中重要的動物,其對植物生長有促進(jìn)作用。然而,蚯蚓對連作系統(tǒng)種植的作物生長和病害的影響及機理尚不清楚。如果能夠利用蚯蚓自身特點,來緩解作物連作障礙,具有重要的意義。本研究以連作草莓為例,通過接種蚯蚓,利用盆栽實驗及微宇宙實驗,對蚯蚓緩解連作障礙的效應(yīng)進(jìn)行了研究,并從蚯蚓對化感物質(zhì)的降解以及對微生物群落的調(diào)控入手,揭示了蚯蚓緩解連作障礙的機理,主要研究結(jié)果如下：(1)蚯蚓能夠促進(jìn)連作草莓的生長,提高草莓的生物量和產(chǎn)量,并能顯著降低由尖孢鐮刀菌引起的枯萎病(P0.05)。在盆栽條件下,威廉腔蚓和赤子愛勝蚓可使病情指數(shù)降低至11.8和27.7,而對照組病情指數(shù)為50.9。(2)蚯蚓的作用,加速了連作土壤中的酚類物質(zhì)的降解。蚯蚓具有回避土壤中較高濃度酚酸(大于120μgPA/g)的特點,但是這種行為可以通過添加葉片抵消。另外,蚯蚓降解酚類物質(zhì)的能力與蚯蚓種、蚯蚓密度、以及酚類物質(zhì)的來源有關(guān)。威廉腔蚓降解酚類物質(zhì)的效率要高于赤子愛勝蚓：當(dāng)威廉腔蚓的密度達(dá)到300條/m2時,降解效率最高；與根系腐解產(chǎn)生的酚類相比,葉片腐解產(chǎn)生的酚類更利于被蚯蚓降解。(3)蚯蚓對酚類物質(zhì)的降解是通過對微生物的調(diào)控實現(xiàn)的,當(dāng)土壤滅菌后,蚯蚓本身不能降解酚類物質(zhì)。蚯蚓的活動加速了酚類物質(zhì)降解過程中微生物的演替進(jìn)程,提高了降解過程中微生物的活性和多樣性,最終加快了酚類物質(zhì)的降解。(4)蚯蚓對于土壤中不同的酚酸降解效果不同,蚯蚓活動一方面加速了總酚的降解,另一方面加快了對香豆酸、綠原酸等草莓連作土壤中濃度較高的酚酸的降解,而對于另外一些酚酸,其降解效果并不顯著。因此蚯蚓的活動改變了土壤中酚酸的比例。(5)草莓連作系統(tǒng)中蚯蚓的活動,提高了微生物量、微生物的活性以及微生物的多樣性,微生物這些性質(zhì)的改變,有利于土壤生態(tài)系統(tǒng)穩(wěn)定性提高,進(jìn)而提高了生態(tài)系統(tǒng)的抗病功能。同時,蚯蚓的活動,也提高了某些病原菌拮抗菌的比例,也有利于防控草莓的病害。(6)蚯蚓對于連作草莓主要有兩方面的作用：一方面是直接調(diào)控連作土壤微生物的群落結(jié)構(gòu),提高微生物的多樣性和活性,以及某些有益微生物的比例,從而提高根際區(qū)土壤的抑病能力；另一方面是其活動加快了某些化感物質(zhì)的降解,尤其是草莓連作土壤中積累濃度較大的酚酸,而這些酚酸具有抑制植物生長、促進(jìn)病原菌并破壞微生態(tài)平衡的特性,因此,蚯蚓對酚酸的降解間接地促進(jìn)了植物的生長,提高了植物的抗病性。另外,蚯蚓這兩方面的作用也是相互影響的,降解酚酸有利于恢復(fù)微生態(tài)平衡,而調(diào)控微生物也有利于酚酸的降解,綜合作用的結(jié)果緩解了草莓的連作障礙。
[Abstract]:Earthworms are important animals in soil, which can promote plant growth. However, the effects and mechanisms of earthworms on crop growth and disease in continuous cropping system are unclear. It is of great significance to use the characteristics of earthworms to alleviate crop continuous cropping obstacles. By inoculating earthworm, pot experiment and microcosmic experiment, the effects of earthworm on alleviating the obstacle of continuous cropping were studied, and the degradation of allelochemicals and the regulation of microbial community by earthworm were studied in this study. The main results are as follows: (1) Earthworm can promote the growth of continuous cropping strawberry, increase the biomass and yield of strawberry, and significantly reduce Fusarium oxysporum wilt caused by Fusarium oxysporum. Under the condition of pot culture, the disease index was decreased to 11.8 and 27.7, while the disease index of the control group was 50.9.22), which accelerated the degradation of phenols in continuous cropping soil. Earthworms have the characteristic of avoiding higher concentration of phenolic acid (> 120 渭 g PA / g) in soil, but this behavior can be counteracted by adding leaves. In addition, the ability of earthworms to degrade phenolic substances is related to earthworm species, earthworm density and sources of phenolic substances. The efficiency of degradation of phenolic substances by the worm was higher than that of Aisheng vermis. When the density of the worm reached 300 / m2, the degradation efficiency was the highest, compared with the phenol produced by root decomposition. The phenols produced by leaf decomposition are more favorable to be degraded by earthworms.) the degradation of phenolic substances by earthworms is realized through the regulation of microbes. When soil sterilizes, earthworms cannot degrade phenols themselves. The activities of earthworms accelerated the process of microbial succession during the degradation of phenolic substances, increased the activity and diversity of microorganisms in the degradation process, and finally accelerated the degradation of phenolic substances. 4) the effects of earthworms on the degradation of phenolic acids in soil were different. Earthworm activity accelerated the degradation of total phenol on the one hand, and on the other hand accelerated the degradation of phenolic acid in strawberry continuous cropping soils such as coumaric acid and Lv Yuan acid, but the degradation effect of other phenolic acids was not significant. Therefore, earthworm activity changed the proportion of phenolic acid in soil. 5) earthworm activity in strawberry continuous cropping system increased microbial biomass, microbial activity and microbial diversity. The stability of soil ecosystem was improved and the disease resistance function of soil ecosystem was improved. At the same time, the activity of earthworms also increased the proportion of antagonistic bacteria of some pathogens, and was also beneficial to the prevention and control of strawberry diseases. The earthworm had two main effects on continuous cropping strawberry: on the one hand, it directly regulated the community structure of microbes in continuous cropping soil. Increasing the diversity and activity of microbes, as well as the proportion of certain beneficial microbes, thereby increasing the ability of rhizosphere soils to suppress disease; on the other hand, their activities accelerate the degradation of certain allelochemicals, Especially the accumulation of phenolic acids in strawberry continuous cropping soil, which has the characteristics of inhibiting plant growth, promoting pathogenic bacteria and destroying microecological balance. Therefore, the degradation of phenolic acids by earthworms indirectly promotes the growth of plants. The disease resistance of plants was improved. In addition, the role of earthworm in these two aspects is also mutual, the degradation of phenolic acid is conducive to restore the micro-ecological balance, while the regulation of microorganisms is also conducive to the degradation of phenolic acid.
【學(xué)位授予單位】：中國農(nóng)業(yè)大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：S668.4;S154.5
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本文編號：1846254