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Usman Ijaz Michael Ayliffe Kedar Adhikari Harbans Bariana Urmil Bansal 《Plant pathology》2020,69(7):1227-1236
Uromyces viciae-fabae, rust of faba bean, parasitizes other legume crops such as lentils (Lens culinaris) and field peas (Pisum sativum) in some environments. In this study we examined the host range of two Australian isolates of U. viciae-fabae collected and purified from a faba bean crop and classified as U. viciae-fabae ex V. faba. Field pea (P. sativum), chickpea (Cicer arientinum), lupin (Lupinus spp.), lentil (L. culinaris), and mung bean (Vigna radiata) genotypes were tested with these isolates, as well as resistant and susceptible genotypes of the faba bean host. Race specificity for these two pathogen isolates was observed on Vicia faba, with two faba bean genotypes showing partial resistance. Both U. viciae-fabae isolates also colonized field pea seedlings and successfully produced uredinia under glasshouse conditions, despite this fungus not being known as a pathogen of Australian field pea crops. No sporulation of either isolate of U. viciae-fabae ex V. faba was observed on any of the remaining legume species tested. However, obvious differences in fungal growth were observed, ranging from small infection sites with very rare haustorium formation in mung bean to more extensive growth and the development of potential uredinial structures in chickpea. These observations are discussed in relation to the phylogenetic relationship of these host and nonhost species. 相似文献
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Tomato chlorosis virus (ToCV) is a plant virus that is mainly propagated by Bemisia tabaci in a semi-persistent and non-circulative manner.It has a wide range of host plants,and has been reported in many countries,causing serious economic losses in vegetable production.In 2019,we investigated about 10 fields,one ha each in Shouguang,Shandong province (China),and in each field we observed symptoms of interveinal chlorosis on lower leaves of the Solanum torvum Swartz,and a large number of B.tabaci gathered on the back of its leaves.To determine the presence of ToCV,total RNA of S.torvum was extracted followed by RT-PCR.The 1 074 (GenBank accessions number MN545620) and 466 bp (GenBank accessions number MN545621) fragments were gel purified and sequenced.The sequences shared 99.44% and 99.57% similarity with ToCV reference sequence tomato chlorosis virus segment RNA1 (AY903447) and RNA2 (AY903448).The results of insect transmission test confirmed that ToCV can spread from S. torvum to tomato.This study confirms S.torvum as a newly reported host of ToCV. 相似文献
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畜禽粪便厌氧发酵过程抗生素抗性基因归趋及驱动因子分析 总被引:1,自引:1,他引:0
针对畜禽养殖业抗生素抗性基因(antibiotic resistance genes, ARGs)污染问题,该文选取厌氧发酵技术,对比不同厌氧发酵体系内ARGs消长与潜在宿主菌,挖掘不同因子与ARGs的相互关系。结果表明,厌氧发酵体系内微生物群落变化是ARGs消长的主要驱动因子,确定ARGs的潜在宿主菌是目前研究的难点;抗生素和重金属也是ARGs消长的重要驱动因子,控制抗生素污染和重金属污染可有效减缓ARGs污染;可移动遗传元件在ARGs水平传播过程中起着重要作用。综合而言,厌氧发酵体系内各个因子直接或间接影响ARGs消长,其中工艺参数是控制整个厌氧发酵体系的先决因素,在特定工艺参数下,微生物群落与体系物化指标相互影响与制约;微生物通过分子内部可移动遗传元件实现ARGs在不同微生物之间的水平传播。综上所述,通过综合协调各类因子实现厌氧发酵体系内ARGs消控是今后研究重点。 相似文献
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pH调控对瘤胃液接种稻秸厌氧消化中水解菌及产甲烷菌的影响 总被引:1,自引:0,他引:1
为了研究pH值调控对瘤胃液接种厌氧消化体系的影响,在半连续条件下考察了稻秆水解和产甲烷特性,并分别利用相对定量PCR(Q-PCR)和Mi Seq高通量测序技术分析了微生物菌群的变化。结果表明:有机负荷为1.5、3.5 g·L-1·d-1和7 g·L-1·d-1时,调控体系中甲烷产率分别比对照提高了1.98、1.99倍和1.53倍;沼气中的甲烷含量明显提高(P0.05),在24%~32%之间变动。pH调控使乙酸和丙酸之间比例逐渐增大,体系中pH值维持在6.24~7.77之间,适宜稻秸产甲烷代谢;滤纸酶和羧甲基纤维素酶活性呈增加趋势。厌氧消化后GH 5水解菌群结构变化明显,梭状芽孢杆菌属(Clostridium)占主导地位,瘤胃球菌属(Ruminococcus)相对丰度提高了12.47倍;来源于瘤胃的纤维杆菌属(Fibrobacter)从体系中消逝。甲烷短杆菌属(Methanobrevibacter)相对丰度提高到3.73%,同时甲烷八叠球菌属(Methanosarcina)相对丰度增加。研究表明,pH调控体系通过强化水解和产甲烷菌活性提高了稻秸厌氧消化的效率。 相似文献
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猪粪厌氧发酵消化液回流体系微生物群落结构特征与产气关系研究 总被引:4,自引:3,他引:1
为明确厌氧发酵消化液回流体系中微生物群落结构的特征,采用Miseq高通量测序技术,研究回流过程中微生物的多样性和群落结构变化,并分析其与产气性能的关系。结果表明:消化液回流体系中,细菌的丰富度、多样性均高于产甲烷古菌,并随回流时间的延长明显增加,而产甲烷古菌无明显变化;细菌群落主要分为厚壁菌门(Firmicutes)、拟杆菌门(Bacteroidetes)和变形菌门(Proteobacteria)等8个不同的门类,厚壁菌门、梭菌纲(Clostridia)、梭菌属(Clostridium)是不同水平上的优势细菌,相对丰度分别从初期的62.79%、58.62%、35.44%上升到81.46%、68.19%、39.10%;产甲烷古菌中,广古菌门(Euryarchaeota)占绝对优势,在接种物中,第68 d和第219 d相对丰度分别为94.76%、99.89%、99.59%,属分类上主要有7种,其中甲烷八叠球菌属(Methanosarcina)的相对丰度由23.99%升高到72.28%,而甲烷短杆菌属(Methanobrevibacter)和甲烷球菌属(Methanosphaera)分别由16.34%、21.71%降低至3.70%、12.93%;日平均产气率由初期的409 m L·g~(-1)升高至477 m L·g~(-1),在219 d的试验中,氨氮和有机酸浓度均呈升高趋势,但并未对厌氧发酵产生抑制作用。研究表明:厌氧发酵回流体系中微生物以梭菌属和甲烷八叠球菌属为优势菌属,产气率随其相对丰度的增大而升高,而与甲烷短杆菌属和甲烷球菌属呈负相关。 相似文献
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Freshwater nucleated pearl quality is influenced by host mussel growth traits in Hyriopsis cumingii 下载免费PDF全文
Hyriopsis cumingii is one of the most important freshwater pearl mussels in China. Recently, this species can produce freshwater nucleated pearls of high quality. Here, we investigated whether nucleated pearl quality is influenced by the growth traits of the host mussel or other factors like cultivation period. We implanted host mussels with a spherical nucleus consisting of a small piece of mantle tissue from donor mussels. After 24 and 36 months of culture, host mussel growth traits including body weight and shell length, height, width and weight were recorded. These factors were then correlated with the quality traits of the pearls they produced, such as nacre thickness, size, weight, lustre and colour. Results indicated pearls obtained at 36 months after seeding were significantly larger in terms of nacre thickness, size and weight compared to those harvested at 24 months. In particular, nacre thickness (r = 0.33–0.48, P = 0.00), pearl size (r = 0.39–0.43, P = 0.00) and pearl weight (r = 0.35–0.47, P = 0.00) were showed to be significantly correlated with host mussels shell length, body weight and shell weight at 24 or 36 months. Larger and heavier host mussels tended to produce bigger pearls. In contrast, host mussels did not affect pearl colour. Cumulatively, our results suggest that longer culturing times and a larger host mussel may help produce better quality nucleated pearl. This information can help guide selective breeding programs designed to improve pearl quality produced by H. cumingii. 相似文献