论文总字数：17912字

摘 要

石榴在中华文化中寓意众多，它代表着团圆和喜庆，寓意家庭和睦，也有的地方将它视作多子多福，后代兴旺，石榴可谓是中华民族公认的吉祥果。石榴原产阿富汗、伊朗等国已经有2000多年的栽培历史。^[1]石榴的外表晶莹剔透，白里透红十分好看，而且它的营养也十分丰富，它所富含的许多营养成分都是人体所必需的。石榴果实中的Vc含量比苹果、梨要高出两倍。石榴也有助于抗菌，营养补充，美容护肤，还可预防心血管疾病，缓解腹泻痢疾。四川大凉山会理县是有名的石榴之乡，据调查发现在2018年，会理的石榴种植面积大约在40万亩左右，也延续了前几年的高产量，果品预计会达到70万吨，其中的95%都将被作为商品果销往全国各地甚至海外，光是石榴产业就可以为会理带来约56亿元的收入。石榴成为了当地老百姓的经济支柱，但石榴容易发各种病症, 影响我国石榴发展的主要病害有石榴疮痂病、石榴干腐病和石榴褐斑病等。^[2]但此次凉山的石榴出现了一种类似于腐烂类的疾病给石榴种植行业造成打击，也对百姓的生计产生了较大影响。因此对石榴腐烂病的研究势在必行。

本论文对四川凉山发病的石榴树枝进行处理，然后采用组织分离法分离出一株真菌，并提取DNA，进行PCR处理，测序后比对后确定该菌株为镰刀类枝顶孢菌（Xenoacremonium falcatus）。该病原菌为首次发现，之前的报道少之又少。确定菌之后还对该病原菌进行致病性测定以及生物学特性研究。

再从泥土样品中筛选出一株对病原菌具有拮抗效果的细菌，经过测序并结合实验结果发现该菌株为解淀粉芽孢杆菌。

关键词：石榴腐烂病 镰刀类枝顶孢菌 解淀粉芽孢杆菌

Screening and identification of pathogenic bacteria and biocontrol bacteria of pomegranate canker disease

Abstract

Pomegranate is a symbol of reunion and happiness, prosperity and harmony in traditional Chinese culture.Pomegranate not only looks good, nutrition is also very rich, contains many nutrients required by the human body.Pomegranate fruit contains three times more vitamin C than apples and pears.Pomegranate also helps with antibacterial, nutritional, beauty and skin care, as well as preventing cardiovascular disease and relieving diarrhea.Huili county, daliang mountain, sichuan province, is a famous hometown of pomegranates. According to statistics, the planting of pomegranates in huili county will be stable at 400,000 mu in 2018, with a fruit output of 700,000 tons, a commodity fruit rate of 95% and an output value of about 5.6 billion yuan.Pomegranate has become the economic pillar of the local people, but pomegranate is prone to a variety of diseases, the main diseases affecting the development of pomegranate in China are pomegranate scab, pomegranate dry rot and pomegranate brown spot disease. however, the emergence of a disease similar to ulcer in the pomegranate of liangshan has dealt a blow to the pomegranate planting industry and exerted a great impact on people's livelihood.Therefore, the study of pomegranate canker disease is imperative.

In this paper, the pathogenic pomegranate branches in liangshan, sichuan were treated, and then a fungus was isolated by tissue separation, and DNA was extracted for PCR treatment. After sequencing, comparison found that this strain was Xenoacremonium falcatus.The pathogen is the first to be identified, and previous reports have been sparse.The pathogenic bacteria were determined and the biological characteristics were studied.^[3]

A strain of bacteria with antagonistic effect was screened from the soil sample and found to be bacillus amylolyticus by sequencing.

Key words:Pomegranate rot;Xenoacremonium falcatus;Bacillus amylopsis

目录

摘要 I

Abstract II

第一章 文献综述 1

1.1引言 1

1.2真菌致病菌 1

1.3细菌生防菌 1

1.4微生物防治 1

1.4.1竞争作用 2

1.4.2拮抗作用 2

1.4.3 寄生和溶菌作用 2

1.4.4 诱导抗性 2

1.4.5 促进植物生长 2

1.5微生物防治的优点 2

1.6论文意义 3

第二章 实验材料与方法 2

2.1石榴腐烂病病原菌分离 2

2.2 DNA提取 2

2.3 PCR扩增 3

2.4电泳与序列分析 4

2.5致病性测定 5

2.6生物学特性研究 5

2.6.1温度对菌丝生长的影响 5

2.6.2PH对菌丝生长的影响 6

2.6.3不同营养条件对菌丝生长的影响 6

2.7生防菌的筛选和鉴定 6

2.7.1生防菌分离 6

2.7.2生防菌DNA提取 7

2.7.3PCR扩增 8

2.7.4拮抗作用 9

第三章 结果与讨论 10

3.1病原菌形态特征 10

3.2病原菌PCR扩增结果 10

3.3病原菌DNA测序结果 11

3.4病原菌致病性测定 11

3.5病原菌生物学特性 12

3.5.1温度对菌丝生长的影响 12

3.5.2PH对菌丝生长的影响 13

3.5.3碳源对菌丝生长的影响 13

3.5.4氮源对菌丝生长的影响 14

3.6生防菌的拮抗作用 14

第四章 总结与展望 16

4.1总结 16

4.2展望 16

参考文献 18

致谢 19

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