本文關(guān)鍵詞： 黃瓜 瓜類植物 內(nèi)生真菌 物種多樣性 促生作用　出處：《中國農(nóng)業(yè)科學院》2015年碩士論文　論文類型：學位論文

【摘要】：內(nèi)生真菌能夠存活在世界上幾乎所有植物的組織中。大量內(nèi)生真菌生活于瓜類植物中,其中有些能促進植物生長。對植物有益的真菌被稱為植物促生真菌(PGPF),它們能以不同類型的機制促進植物生長、保護寄主植物免遭環(huán)境脅迫。植物促生內(nèi)生真菌的促生機制與根際促生真菌的機制相似,但內(nèi)生真菌能進一步地寄生于植物組織內(nèi),相比于附著在根際的促生真菌更能為寄主提供高效而直接的保護。因此,內(nèi)生真菌在各種環(huán)境條件下促進植物生長方面很可能優(yōu)于類似的非內(nèi)生真菌。本研究比較了由兩種分離培養(yǎng)方法揭示的內(nèi)生真菌多樣性,探討了內(nèi)生真菌對黃瓜生長的促進作用。本研究中,三種無病癥的常見葫蘆科植物黃瓜、絲瓜和南瓜采集自北京延慶和大興兩地,用稀釋培養(yǎng)法和組織分離法分別從植株的上部莖、下部莖和根三個部位共分離到68株內(nèi)生真菌。基于形態(tài)特征和rDNA ITS序列比對進行鑒定,這些菌株中,鐮刀菌屬Fusarium是最常分離到的屬。其他屬有木霉屬Trichoderma,青霉屬Penicillium,肉座菌屬Hypocrea,伏革菌屬Corticium,曲霉屬Aspergillus,炭疽菌屬Colletotrichum,枝孢屬Cladosporium,裂褶菌屬Schizophyllum,穗枝霉屬Clonostachys,鏈格孢屬Alternaria和叢赤殼屬Nectria。所分離到的內(nèi)生真菌菌株中,有30株只分離自組織分離法,28株只分離自稀釋培養(yǎng)法,其余10株則在兩種方法中都分離到。通過所分離到的內(nèi)生真菌數(shù)量來評價物種豐富度,依據(jù)得到的物種豐富度對兩種分離方法進行了比較。共有43株選擇的內(nèi)生真菌用于本研究,它們均由本實驗室的其它同學分離自瓜類植物并保存在中國農(nóng)業(yè)微生物菌種保存管理中心(ACCC)。為探索利用內(nèi)生真菌促進黃瓜生長的方法,盆栽試驗在溫室中進行,采用孢子懸液接種和培養(yǎng)物接種兩種方式接種。結(jié)果表明,采用兩種接種方式接種內(nèi)生真菌的植物都比對照組的植物生長有顯著增加。通過比較發(fā)現(xiàn),培養(yǎng)物接種的方法能更好地促進黃瓜生長。在用培養(yǎng)物接種的處理中,接種菌株3F8、Jcl44和F87的生物量增加的最高,與對照相比它們分別使生物量增加了90.45%、89.79%和82.18%。超氧化物歧化酶(SOD)活性分析顯示其變化趨勢與對應的生物量相同,表明接種內(nèi)生真菌有益于寄主植物生長。各處理的植株中酶活最高的幾個菌株依次為4F8(1533.87±336.55 unit/ml)、3F59(873.79±147.62 unit/ml)和Jcl44(737.58±98.49 unit/ml),對照組的酶活為254.69±62.67 unit/ml。在17個植物促生內(nèi)生真菌菌株的發(fā)酵液里都發(fā)現(xiàn)了與植物生長素相關(guān)的吲哚類化合物:吲哚乙酸(IAA),吲哚乙醛(IAAld)和吲哚乙醇(IEt)。用MS培養(yǎng)基代替PDA所做試驗的結(jié)果暗示,內(nèi)生真菌的提取物可能代替植物生長素作為生長調(diào)節(jié)劑促進黃瓜植株的生長。因此,本試驗中使用的部分內(nèi)生真菌菌株也許可以用作黃瓜植株的生長促進劑。
[Abstract]:Endophytic fungi can survive in almost every plant tissue in the world. A large number of endophytic fungi live in melons. Some of them promote plant growth. Fungi that are beneficial to plants are called plant-promoting fungi, PGPF, and they promote plant growth through different types of mechanisms. The promotion mechanism of plant endophytic fungi is similar to that of rhizosphere fungi, but endophytic fungi can further parasitize in plant tissues. They provide more efficient and direct protection to the host than to the rhizospheric growth promoting fungi. Endophytic fungi may be superior to similar non-endophytic fungi in promoting plant growth under various environmental conditions. This study compared the diversity of endophytic fungi revealed by two methods of isolation and culture. The effects of endophytic fungi on the growth of cucumber were studied. In this study, three common cucurbitaceae plants, luffa and pumpkin, were collected from Yanqing and Daxing, Beijing. 68 strains of endophytic fungi were isolated from the upper stem, lower stem and root of the plant by dilution culture method and tissue separation method respectively. Other genera include Trichoderma, Penicillium, Hypocrea, Corticium, Aspergillus, Colletotrichum, Cladosporium, Schizophyllum, Clonostachys, Alternaria and Nectria. Of the endophytic fungi isolated, 30 strains were isolated by self-tissue isolation method and 28 strains by self-dilution culture method. The other 10 strains were isolated in both methods. The species richness was evaluated by the number of endophytic fungi isolated. A total of 43 selected endophytic fungi were used in this study. All of them were isolated from other students in our laboratory and preserved in ACCCC.In order to explore the method of using endophytic fungi to promote cucumber growth, pot experiment was carried out in greenhouse. Spore suspension inoculation and culture inoculation were used to inoculate endophytic fungi. The results showed that the growth of plants inoculated with endophytic fungi was significantly higher than that of the control group. The method of culture inoculation could promote cucumber growth better. The biomass of inoculated strains 3F8 Jcl44 and F87 increased the highest in the treatment of inoculation with culture. Compared with the control, they increased the biomass by 90.45% and 82.18%, respectively. The analysis of the activity of superoxide dismutase (SOD) showed that the change trend was the same as that of the corresponding biomass. The results showed that inoculation of endophytic fungi was beneficial to the growth of host plants. The highest enzyme activity of the plants treated was 4F833.87 鹵336.55 unit-r.ml) and Jcl44(737.58 鹵98.49unitr.ml. respectively. The enzyme activity of the control group was 254.69 鹵62.67 unit / ml. In the fermentation broth of 17 strains of endophytic fungi, the enzyme activity of the control group was 254.69 鹵62.67 unit.ml. in the fermentation broth of 17 strains of endophytic fungi, the enzyme activity of the control group was 254.69 鹵62.67 unit / ml. Indole compounds related to plant growth hormone, such as indoleacetic acid, indoleacetaldehyde (IAAld) and indoleethanol (IET), were found. The results of the experiment using MS medium instead of PDA suggested that, The extracts of endophytic fungi may be used as growth regulators instead of plant growth regulators. Therefore, some of the endophytic fungi strains used in this experiment may be used as growth promoters for cucumber plants.
【學位授予單位】：中國農(nóng)業(yè)科學院
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：S182
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本文編號：1548535