Common bean root rot becomes serious in continuous cropping fields with over-application of chemical fertilizer.Through the standard field fertilization,the disease might be alleviated.This study aimed to investigate ...Common bean root rot becomes serious in continuous cropping fields with over-application of chemical fertilizer.Through the standard field fertilization,the disease might be alleviated.This study aimed to investigate the impacts of standard field fertilization practices on bean root rot severity and rhizosphere microbial community shifts under continuous cropping.From 2018 to 2021,beans were monocultured for eight cycles in field soil in the greenhouse at an average interval of 4 months.Root rot severity was assessed at each cycle,and rhizosphere microbial communities were analyzed at 1^(st),5^(th),and 7^(th) cycles using high-throughput sequencing approach.Bean root rot severity was found to keep increasing until the 5^(th) cycle and decreased sharply at the 7^(th) cycle.Corresponding to the disease aggravation and suppression,Fusarium exhibited the highest abundance at the 1^(st) cycle,followed by Plectosphaerella at the 5^(th) cycle,and Dactylonectria at the 7^(th) cycle.Pseudomonas showed the highest abundance in the rhizosphere soils at the 1^(st) and 7^(th) cropping cycles.Correlation analysis indicated that the soil microbes were closely related to disease severity as well as soil nitrogen and phosphorus contents.These findings suggest that continuous cropping of bean with standard field fertilization practices could create suppressive soil with reduced disease severity.This study revealed the microecological immune mechanism of continuous cropping of bean against root rot and provided cost-effective and highly efficient techniques for sustainable farming.展开更多
Anthracnose, caused by </span><i><span style="font-family:Verdana;">Colletotrichum lindemuthianum</span></i><span style="font-family:Verdana;">, is a major disea...Anthracnose, caused by </span><i><span style="font-family:Verdana;">Colletotrichum lindemuthianum</span></i><span style="font-family:Verdana;">, is a major disease of common bean and results in high yield loss. Due to the high degree of pathogenic variability of the fungus and the continual emergence of new races, genetic resistance in the host is not durable. Gene pyramiding using Marker Assisted Selection (MAS) is proposed as a viable approach to improve the durability of major genes conditioning resistance to anthracnose. In this study a common bean line Urugezi x AND 1062 susceptible to anthracnose but already improved for </span><i><span style="font-family:Verdana;">Pythium </span></i><span style="font-family:Verdana;">root rot resistance was improved for anthracnose resistance through a backcross breeding program. Genotypic selection was done in Rubilizi laboratory in Kigali, Rwanada whereas phenotypic selection was conducted in an anthracnose hotspot at Rwerere, a research Centre of the Rwanda Agricultural and Animal Resources Development Board (RAB).</span></span><span style="font-family:""><span style="font-family:Verdana;"> Analysis of variance for effect of bean varieties and anthracnose isolates on disease expression showed significant differences (p < 0.001) among varieties and isolates and for the interaction between isolates and varieties. Developed BC</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">F</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;"> plants were 41% of them resistant and 59% susceptible to anthracnose. However, the observed proportion of 26 resistants and 37 susceptible in BC</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">F</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;"> plants didn’t fit the goodness of fit of the expected proportion of 75 resistants to 25 susceptible. Only 41% of BC</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">F</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;"> plants inherited the resistance genes and were phenotypically resistant. Presence of SCAR-markers, SAB3 and SBB14, in the developed resistant lines </span></span><span style="font-family:Verdana;">h</span><span style="font-family:Verdana;"> suggested successful resistance transfer of anthracnose resistance genes.展开更多
为明确山东省小麦根腐病的病原菌种类,于2012—2014年从山东省10个地市采集小麦病株,通过组织分离法获得了185株分离物,利用形态学鉴定方法,结合基于5.8S r DNA-ITS序列或TEF-1α基因序列分析的分子鉴定方法对分离物进行了鉴定。结果表...为明确山东省小麦根腐病的病原菌种类,于2012—2014年从山东省10个地市采集小麦病株,通过组织分离法获得了185株分离物,利用形态学鉴定方法,结合基于5.8S r DNA-ITS序列或TEF-1α基因序列分析的分子鉴定方法对分离物进行了鉴定。结果表明:分离物中共得到135株麦根腐平脐蠕孢Bipolaris sorokiniana,占分离病原菌总数的72.97%,属优势种群;50株镰孢属Fusarium菌株,其中14株尖孢镰孢菌Fusarium oxysporum、19株层出镰孢菌Fusarium proliferatum和17株黄色镰孢菌Fusarium culmorum;按照柯赫氏法则进行致病性测定,证实了4种病原菌对鲁麦21号具有致病性,麦根腐平脐蠕孢的致病力较强,病情指数显著高于镰孢菌属真菌。研究表明,山东小麦根腐病主要是由麦根腐平脐蠕孢和镰孢属真菌侵染引起的,麦根腐平脐蠕孢为优势菌群。展开更多
基金supported by the Agriculture Research System of China(Grant No.CARS-23-C04)the National Key Research and Development Program(Grant No.2022YFD1602400).
文摘Common bean root rot becomes serious in continuous cropping fields with over-application of chemical fertilizer.Through the standard field fertilization,the disease might be alleviated.This study aimed to investigate the impacts of standard field fertilization practices on bean root rot severity and rhizosphere microbial community shifts under continuous cropping.From 2018 to 2021,beans were monocultured for eight cycles in field soil in the greenhouse at an average interval of 4 months.Root rot severity was assessed at each cycle,and rhizosphere microbial communities were analyzed at 1^(st),5^(th),and 7^(th) cycles using high-throughput sequencing approach.Bean root rot severity was found to keep increasing until the 5^(th) cycle and decreased sharply at the 7^(th) cycle.Corresponding to the disease aggravation and suppression,Fusarium exhibited the highest abundance at the 1^(st) cycle,followed by Plectosphaerella at the 5^(th) cycle,and Dactylonectria at the 7^(th) cycle.Pseudomonas showed the highest abundance in the rhizosphere soils at the 1^(st) and 7^(th) cropping cycles.Correlation analysis indicated that the soil microbes were closely related to disease severity as well as soil nitrogen and phosphorus contents.These findings suggest that continuous cropping of bean with standard field fertilization practices could create suppressive soil with reduced disease severity.This study revealed the microecological immune mechanism of continuous cropping of bean against root rot and provided cost-effective and highly efficient techniques for sustainable farming.
文摘Anthracnose, caused by </span><i><span style="font-family:Verdana;">Colletotrichum lindemuthianum</span></i><span style="font-family:Verdana;">, is a major disease of common bean and results in high yield loss. Due to the high degree of pathogenic variability of the fungus and the continual emergence of new races, genetic resistance in the host is not durable. Gene pyramiding using Marker Assisted Selection (MAS) is proposed as a viable approach to improve the durability of major genes conditioning resistance to anthracnose. In this study a common bean line Urugezi x AND 1062 susceptible to anthracnose but already improved for </span><i><span style="font-family:Verdana;">Pythium </span></i><span style="font-family:Verdana;">root rot resistance was improved for anthracnose resistance through a backcross breeding program. Genotypic selection was done in Rubilizi laboratory in Kigali, Rwanada whereas phenotypic selection was conducted in an anthracnose hotspot at Rwerere, a research Centre of the Rwanda Agricultural and Animal Resources Development Board (RAB).</span></span><span style="font-family:""><span style="font-family:Verdana;"> Analysis of variance for effect of bean varieties and anthracnose isolates on disease expression showed significant differences (p < 0.001) among varieties and isolates and for the interaction between isolates and varieties. Developed BC</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">F</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;"> plants were 41% of them resistant and 59% susceptible to anthracnose. However, the observed proportion of 26 resistants and 37 susceptible in BC</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">F</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;"> plants didn’t fit the goodness of fit of the expected proportion of 75 resistants to 25 susceptible. Only 41% of BC</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">F</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;"> plants inherited the resistance genes and were phenotypically resistant. Presence of SCAR-markers, SAB3 and SBB14, in the developed resistant lines </span></span><span style="font-family:Verdana;">h</span><span style="font-family:Verdana;"> suggested successful resistance transfer of anthracnose resistance genes.
基金国家转基因生物新品种培育重大专项(2016ZX08002-001-004)国家自然科学基金项目(31471494)资助The study was supported by the National Major Project for Developing New GM Crops(2016ZX08002-001-004)~~
