危害核桃的胶孢炭疽菌对核桃组织侵染过程的研究

发布时间：2018-01-20 10:46

本文关键词： 胶孢炭疽菌(Colletotrichum gloeosporioides) 核桃(Juglans regia) 分生孢子萌发附着胞形成侵染过程　出处：《山东农业大学》2017年硕士论文　论文类型：学位论文

【摘要】：核桃(Juglans regia L.)是重要的“木本粮油”生态树种,为二倍体植物(2n=32),全基因组667 Mb。核桃作为“21世纪的超级食品”,果仁营养成分极其适宜于人体健康,能有效预防心血管疾病,是Ⅱ型糖尿病人的首选食品。近年来,随着核桃集约栽培面积的扩大和病害日渐严重。由胶孢炭疽菌(Colletotrichum gloeosporioides)引起的核桃炭疽病(walnut anthracnose)可致果实坏疽、叶片焦枯,同时还危害嫩梢,发病严重时可使30%~50%的青果脱落,导致产量损失,是目前核桃生产中的灾难性病害。本论文探究了影响胶胞炭疽菌分生孢子(conidia)萌发的条件,观察胶胞炭疽菌在适宜条件下的生活过程;以保存于山东农业大学林学试验站的核桃抗病品种‘瑞嘉’和无性系4-23、B26及B29为材料,解剖学观察了胶胞炭疽菌侵染核桃组织的过程及核桃组织被侵染后的形态学变化;并对影响分生孢子(conidia)萌发的不同的环境因素进行探究,以及观察分生孢子在适宜条件下的生活过程。主要结果如下:1.影响胶孢炭疽菌分生孢子萌发的条件。孢子萌发最适萌发温度为28-30℃、最适pH值为6.0、最适光照条件为全黑暗培养条件、最适湿度为100%湿度。以单糖为碳源均能促进孢子萌发,但最适合孢子萌发的碳源为葡萄糖和麦芽糖。以L-天冬氨酸、酵母提取物、牛肉膏和蛋白胨为氮源时,均能促进孢子萌发,但最适合孢子萌发的氮源为酵母提取物。2.供试材料对胶胞炭疽菌抗性的鉴定。室内接种核桃叶片和果实的发病率均高于田间接种。4-23果实平均发病率室内和田间分别为84.44%和84%,显著高于其他,表现为果实易感病,而叶片室内和田间平均发病率分别为2.00%和1.33%,显著低于其他品系,表现为叶片相对抗病。‘瑞嘉’果实发病率最低,室内和田间平均发病率分别为51.11%和50%,显著低于其他,表现为果实相对抗病。3.胶孢炭疽菌孢子的萌发过程。分别添加了葡萄糖为碳源及酵母提取物为氮源的培养基上,培养10h后,部分分生孢子萌发并产生芽管,培养18h后,绝大部分分生孢子萌发。培养24h后,分生孢子芽管的顶端膨大形成附着胞(appressorium)。培养36h后,附着胞的中心位置有侵染钉(penetration peg)的形成。培养48h后,侵染钉膨大形成初生菌丝。培养60h后,初生菌丝(primary hyphae)继续生长,形成膨大的初生菌丝,培养72h后,菌丝继续生长,形成次生菌丝(secondary hyphae)。4.胶孢炭疽菌对核桃的侵染过程。用分生孢子悬浊液对核桃无性系B29叶片侵染,结果发现,接种24h,分生孢子在叶片表面萌发,并形成附着胞附着于叶片表面;解剖学观察结果显示,叶片侵染部位表皮细胞出现略微凹陷。接种48h,附着胞中心部位出现侵染钉,同时,分生孢子的形态发生略微变化;解剖学观察结果显示,叶片侵染部位表皮细胞出现明显凹陷。接种60h,附着胞上产生侵染丝伸入到叶片气孔腔内,气孔腔周围外层的组织中出现少量的初侵染丝;解剖学观察结果显示,叶片侵染部位表皮细胞破损,叶片内部组织细胞凹陷明显。接种72h,初生菌丝生长并产生次生菌丝,细胞出现程序性死亡;解剖学观察结果显示,叶片侵染部位表皮细胞破损,内部组织细胞出现部分消解。接种96h,侵染部位叶片出现褐色病斑,发病部位长出分生孢子梗,分生孢子梗产生新的分生孢子,至此完成一个侵染循环;解剖学观察结果显示,叶片侵染部位表皮细胞破损,内部组织细胞大量消解。
[Abstract]:Walnut (Juglans regia L.) is an important "woody grain and oil" ecological species, diploid plants (2n=32), whole genome 667 Mb. walnuts as a "super food" in twenty-first Century, very suitable for nuts nutrition to human health, can effectively prevent cardiovascular disease, is the food of choice for people with type II diabetes. In recent years, with the expand the area of intensive cultivation and walnut disease. By Colletotrichum gloeosporioides (Colletotrichum gloeosporioides) walnut anthracnose caused by (Walnut anthracnose) can cause fruit gangrene, leaf scorch, also harm shoots, serious incidence of the 30%~50% fruit shedding, lead to yield loss, is currently in the production of walnut disaster disease. This paper explores the effects of Colletotrichum gloeosporioides conidia germination conditions (conidia), observe the life of Colletotrichum gloeosporioides in suitable conditions of the process; to preserve in Shandong agriculture University Forestry Experimental Station of walnut resistant cultivar 'Regal' and clones 4-23, B26 and B29 as materials, anatomical observation process of Colletotrichum gloeosporioides infection of walnut tissues and walnut tissues was morphological changes after infection; and the effects of conidia (conidia) germination of different environmental factors to explore, and observation conidia under suitable conditions of the life process. The main results are as follows: 1. the effect of Colletotrichum gloeosporioides conidia germination conditions. The spore germination of optimal germination temperature of 28-30, the optimum pH value is 6, the optimal light conditions for the dark culture condition, the optimum humidity is 100% with humidity. Monosaccharide as carbon source could promote spore germination, but the most suitable for spore germination of carbon source was glucose and maltose. L- aspartic acid, yeast extract, beef extract and peptone as nitrogen source, could promote spore germination, but the most suitable for spore germination The nitrogen source was yeast extract.2. for identification of test materials of Colletotrichum gloeosporioides resistance. Indoor inoculation walnut leaves and fruits of the incidence rate higher than the average incidence rate of.4-23 fruit field inoculation indoor and field were 84.44% and 84%, significantly higher than the other, as susceptible fruits, and leaves the average incidence of indoor and field rates were 2% and 1.33%, significantly lower than that of other strains, were relatively resistant. "Regal" leaves the lowest incidence of fruit, indoor and field average incidence rates were 51.11% and 50%, significantly lower than that of the other, for the germination process of fruit disease.3. against Colletotrichum gloeosporioides. Spores were added to glucose carbon source and yeast extract as nitrogen source on the 10h after culture, part of the conidia germination and germ tube, after 18h, the vast majority of conidia germination. After 24h culture, top spore germ tube Enlargement of appressorium formation (appressorium). After 36h culture, the center position of appressorium infection (penetration peg) nail formation. After 48h culture, the development of primary hyphae. Nail infection after 60H, primary hyphae (primary hyphae) continue to grow, to form a swollen primary hyphae, after 72h, hyphae continue to grow the formation of secondary hyphae (secondary, hyphae).4. infection process of Colletotrichum gloeosporioides on walnut. With conidia suspension of B29 infected leaves, walnut department found that inoculation with 24h clones, conidia germination on the leaf surface, and appressorium formation attached to the leaf surface; anatomical observation showed that slightly sunken leaves the infected part of epidermal cells. 48h inoculation, appressorium Center site infection nail, at the same time, conidia morphology changes slightly; anatomical observation showed that the leaf epidermal cells showed obvious infection site Sag. Inoculation of 60H, appressorium on produce infection into silk leaf stomatal cavity, stomatal cavity around the outer tissue in small primary infection silk; anatomy observation showed that the leaf epidermal cells of the infected part is damaged, the blade internal organization cell depression significantly. 72h vaccination, primary hyphae grow and produce secondary hyphae, the cells appeared program death; anatomical observation showed that the leaf epidermal cells of the infected part is damaged, the internal organization of cell part digestion. Inoculation with 96h infection leaves brown spots appeared, incidence of long conidiophores, conidia to produce new conidia, thus completing a cycle of infection; anatomical observation showed that leaf epidermal cells of the infected part is damaged, a large number of internal tissue digestion.

【学位授予单位】：山东农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S436.64

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