兰州大学机构库 >草地农业科技学院
紫花苜蓿炭疽病的病原及其致病性研究
Alternative TitleStudy on the Pathogen and its Pathogenicity of AlfalfaAnthracnose
徐杉
Thesis Advisor李彦忠
2019-09-10
Degree Grantor兰州大学
Place of Conferral兰州
Degree Name博士
Degree Discipline草学
Keyword紫花苜蓿炭疽病 病害调查 病原研究 致病性测定 品质损失
Abstract炭疽病是一类造成经济损失,普遍存在,毁灭性的植物病害。它是限制紫花苜蓿生产的重要因素,但目前我国有关紫花苜蓿炭疽病的研究较少,尚不明确其病原种类、病原致病性强弱、分布地区、危害现状和品质损失等信息,为查明该病的上述信息,为其防治提供依据。本研究以我国西北地区(甘肃、宁夏、新疆),西南地区(云南、四川)和北方地区(内蒙、黑龙江)栽培的紫花苜蓿为研究对象,于2014年至2018年,通过田间试验、室内试验和温室试验,对各地区的紫花苜蓿炭疽病进行了病害调查、病原分离、形态学鉴定、分子生物学鉴定、致病性测定和常规营养成分测定等工作,获得如下结果。1. 我国西北、西南和北方共7省16个调查地区中,确定6省8个地区发生紫花苜蓿炭疽病,由5种炭疽属病原(Colletotrichum spp.)引起。其中,三叶草炭疽菌(C. trifolii)引起的苜蓿炭疽病发生于甘肃酒泉、宁夏银川和新疆昌吉;平头炭疽菌(C. truncatum)引起的苜蓿炭疽病发生于内蒙赤峰和内蒙沙尔沁;毁灭炭疽菌(C. destructivum)引起的苜蓿炭疽病发生于四川新都;北美炭疽菌(C. americae-borealis)引起的苜蓿炭疽病发生于云南小哨、甘肃民乐和内蒙沙尔沁;菜豆炭疽菌(C. incanum)引起的苜蓿炭疽病发生于内蒙赤峰。这些病原中,菜豆炭疽菌(C. incanum)引起的苜蓿炭疽病属于首次报道,为世界新记录,苜蓿为该种的新寄主,而北美炭疽菌(C. americae-borealis)引起的苜蓿炭疽病属于我国首次报道,为我国新记录。2. 根据菌落特征、形态学特征以及多基因系统发育学,明确了5种炭疽属病原有3种类型的分生孢子,位于4个复合种群中,即北美炭疽菌和毁灭炭疽菌为直孢子属于毁灭炭疽复合种(destructivum complex);平头炭疽菌和菜豆炭疽菌为弯孢子分别属于平头炭疽复合种(truncatum complex)和白蜡树炭疽复合种(spaethianum complex);三叶草炭疽菌为圆柱孢子属于黄瓜炭疽复合种(orbiculare complex)。另外,对我国已报道的吉林苜蓿炭疽属病原的相关序列重新进行了分析和研究,证实了吉林苜蓿炭疽病病原种JL01为北美炭疽菌,而不是亚麻炭疽菌。因此,我国目前尚无苜蓿亚麻炭疽菌的报道。同时,对5种炭疽菌种代表性菌株的生物学特性和产孢方式进行测定,明确了各菌种的最适生长温度(25—30°C)和最适pH范围(5—7),发现了三叶草炭疽菌和平头炭疽菌存在细胞产孢和刚毛产孢两种产孢方式,而其它3种炭疽菌以细胞产孢为主。3. 通过田间调查,发现苜蓿炭疽病主要危害植株茎杆,也会危害叶片,病害发生严重时会危害根颈。各地区不同炭疽属病原引起的炭疽病症状特征基本相同,无明显差异。紫花苜蓿炭疽病发生地区中,甘肃酒泉、宁夏银川、内蒙赤峰3个地区炭疽病发生严重,导致枝条干枯,危害程度高,发病率在39.5%~61.7%之间,病情指数在32.7%~45.4%之间。内蒙沙尔沁,四川新都,甘肃民乐,云南小哨4个地区炭疽病发生较轻,病情指数均在30%以下。对上述炭疽病发生严重地区,感染炭疽病枝条和健康枝条的干重、常规营养成分和18种氨基酸含量进行测定,分析结果表明3个地区健康枝条干重和粗蛋白含量均显著大于感染炭疽病的枝条(P<0.05),且干重损失量达17.05%~22.35%,粗蛋白损失量达18.2%~30.03%。健康枝条中性和酸性洗涤纤维的含量均显著小于感染炭疽病的枝条(P<0.05),而粗脂肪含量健康枝条与感染炭疽病枝条间无显著差异(P>0.05)。总体上,感染炭疽病枝条的总氨基酸含量和必需氨基酸含量均显著低于健康枝条(P<0.05),且总氨基酸损失量达24.85%~30.26%,必需氨基酸损失量达21.37%~30.86%。另外,炭疽病害发生与干重、常规营养成分和氨基酸含量的冗余分析结果表明,植物的干重、粗蛋白、粗灰分、木质素、总氨基酸和必需氨基酸含量与炭疽病害发生呈负相关,而中性洗涤纤维和酸性洗涤纤维与炭疽病害发生呈正相关。4. 通过致病性测定,明确了5种炭疽属病原接种苜蓿种子、生长4天幼苗、生长4周植株后,均可造成病害并引致炭疽症状,并且对种子萌发和幼苗生长影响较大,所以这些病原可能是田间苜蓿播种到发芽死亡的病因。综合来看,测试所用的6个炭疽菌株对紫花苜蓿致病力依次为三叶草炭疽菌C. trifolii(JQLYZ21)> 平头炭疽菌C. truncatum(CFLYZ34)> 毁灭炭疽菌C. destructivum(XDLYZ45)> 北美炭疽菌C. americae-borealis(SEQ2LYZ14)> 菜豆炭疽菌C. incanum(CFL2YZ41)> 北美炭疽菌C. americae-borealis(MLLYZ28)。5. 通过调查、病原物分离鉴定和致病性测定,明确了四川西昌发生的苜蓿茎斑病(Nothophoma sp.)是一种新病害,于我国首次报道。甘肃发生的苜蓿黄萎病(Verticillium alfalfae)和赤峰发生的苜蓿根腐病(Cylindrocladium sp.)为我国两种苜蓿病害新记录,且苜蓿黄萎病是我国的一种对外检疫病害。
Other AbstractAnthracnose is a kind of destructive, widespread fungus disease that causes economic losses of many plants, and this disease is also the one of factors that limits production of alfalfa. But there are few studies on alfalfa anthracnose in China at present, and it is hardly known the information about the pathogen species, pathogenicity, distribution area, disease severity and quality losses. Studies are needed in order to obtain the information above, and to find out the control strategy. In this present study, the cultivated alfalfa in northwest (Gansu, Ningxia and Xinjiang provinces), southwest (Yunnan and Sichuan provinces), and north (Inner Mongolia and Heilongjiang provinces) of China were used as research material. Disease investigations, pathogens isolation, morphological and molecular identification, pathogenicity tests, and the conventional nutrition tests of alfalfa anthracnose were carried out through field trial, laboratory trial, and greenhouse trial from 2014 to 2018, and obtain the main results as follows. 1. There were 16 surveyed areas in 7 provinces in total, alfalfa anthracnose caused by five Colletotrichum spp. was found in 8 surveyed areas in 6 provinces. Alfalfa anthracnose caused by C. trifolii occurred in Gansu (Jiuquan), Ningxia (Yinchuan), and Xinjiang (changji). Alfalfa anthracnose caused by C. truncatum occurred in Inner Mongolia (Chifeng) and (Shaerqin). Alfalfa anthracnose caused by C. destructivum occurred in Sichuan (Xindu). Alfalfa anthracnose caused by C. americae-borealis occurred in Yunnan (Xiaoshao), Gansu (Minle) and Inner Mongolia (Shaerqin). Alfalfa anthracnose caused by C. incanum occurred in Inner Mongolia (Chifeng). Among these Colletotrichum species, it is the first report that alfalfa anthracnose caused by C. incanum in the world, and alfalfa was the new host out of soybean. It is also the first report that alfalfa anthracnose caused by C. americae-borealis in China. 2. According to the colony characteristics, morphological characteristics and polygenic phylogeny, it is determined that five Colletotrichum spp. have three different shape conidia and belong to four species complex in Colletotrichum, namely C. americae-borealis and C. destructivum belong to destructivum complex with straight conidia. C. truncatum and C. incanum respectively belong to truncatum complex and spaethianum complex with curved conidia. C. trifolii belong to orbiculare complex with cylinder conidia. In addition, the related sequences of reported pathogen JL01 of alfalfa anthracnose in Jilin were re-analysed and studied and confirmed that strain JL01 was C. americae-borealis rather than C. lini, therefore it has not reported that alfalfa anthracnose caused by C. lini in China. To test the effect of temperature and pH on fungal growth, representative strains of each Colletotrichum species were used and it was found that temperature range from 25 to 30 °C and pH range from 5 to 7. The morphology study also comfirmed that the conidium production from setal apices was only fould in C. trifolii and C. truncatum, and conidia from conidiogenous cells was common in other species. 3. Through field investigation, it was found that alfalfa anthracnose caused symptoms and damage mainly on stems, sometimes on leaves, and also on root crown when the disease was serious. The symptoms of anthracnose caused by different pathogens from each region was basically the same without significant differences. Among the 6 provinces, 8 anthracnose areas, the alfalfa anthracnose occured in cultivated in Gansu (Jinta), Ningxia (Yinchuan), and Inner Mongolia were the most serious, with 39.5% to 61.7% incidence and 32.7% to 45.4% disease severity. While the alfalfa anthracnose occured in Inner Mongolia (Shaerqin), Sichuan (Xindu), Gansu (Minle), Yunnan (Xiaoshao) the effects were relatively mild with less than 30% disease seveirty. The conventional nutrition, 18 kinds of amino acid between, and dry weight between anthracnose-diseased and healthy plants from serious areas were examined, and the analysis results indicated that the dry weight and the crude protein of healthy plants were significant higher than infected plants (P<0.05), and the loss of dry weight were 17.05% to 22.35%, and the loss of crude protein were 18.2% to 30.03%. The ADF and the NDF of healthy plants were significant lower than for infected plants (P<0.05), and there is no significant difference in crude fat between healthy and infected plants (P>0.05). In general, the total amino acid and essential amino acid content of anthracnose-infected plants were significantly lower than that of healthy plants (P<0.05), and the loss of these two measures were 24.85% to 30.26% and 21.37% to 30.86%, respectively. In addition, the redundancy analysis of the occurrence of anthracnose and dry weight, conventional nutrients and amino acids showed that the dry weight, crude protein, crude ash, lignin, total amino acid and essential amino acid were negatively correlated with the occurrence of anthracnose, while ADF and NDF were positively correlated with the occurrence of anthracnose. 4. For the pathogenicity tests confirmed that five Colletotrichum spp. from alfalfa were the pathogens that caused anthracnose on different growth stage of alfalfa including seeds, 4-days-old seedlings and 4-weeks-old plants. Moreover, it had great influence on seeds germination and seedlings growth, therefore these pathogens were the possible reason for the alfalfa death in fields from sowing to germination. On the whole, the pathogenicity of six Colletotrichum spp. strains to alfalfa were C. trifolii (JQLYZ21) > C. truncatum (CFLYZ34) > C. destructivum (XDLYZ45) > C. americae-borealis (SEQ2LYZ14)> C. incanum (CFL2YZ41) > C. americae-borealis (MLLYZ28). 5. Through disease investigation, pathogens isolation and identification, and pathogenicity, it is determined that alfalfa stem blight caused by Nothophoma sp. in Xichang, Sichuan was the new diseases, unknown anywhere else in the world. Verticillium wilt of alfalfa caused by Verticillium alfalfae in Gansu, and root rot of alfalfa caused by Cylindrocladium sp. in Chifeng were new records from China. While Verticillium wilt of alfalfa is also a quarantined disease in China.
Pages166
URL查看原文
Language中文
Document Type学位论文
Identifierhttp://ir.lzu.edu.cn/handle/262010/337998
Collection草地农业科技学院
Affiliation草地农业科技学院
Recommended Citation
GB/T 7714
徐杉. 紫花苜蓿炭疽病的病原及其致病性研究[D]. 兰州. 兰州大学,2019.
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