Thinopyrum elongatum （2n = 2x = 14, EE）, a wild relative of wheat, has been suggested as a potentially novel source of resistance to several major wheat diseases including Fusarium Head Blight （FHB）. In this study...Thinopyrum elongatum （2n = 2x = 14, EE）, a wild relative of wheat, has been suggested as a potentially novel source of resistance to several major wheat diseases including Fusarium Head Blight （FHB）. In this study, a series of wheat （cv. Chinese Spring, CS） substitution and ditelosomic lines, including Th. elongatum additions, were assessed for Type II resistance to FHB. Results indicated that the lines containing chromosome 7E of Th. elongatum gave a high level of resistance to FHB, wherein the infection did not spread beyond the inoculated floret. Furthermore, it was determined that the novel resistance gene（s） of 7E was located on the short-ann （7ES） based on sharp difference in FHB resistance between the two 7E ditelosomic lines for each arm. On the other hand, Th. elongatum chromosomes 5E and 6E likely contain gene（s） for susceptibility to FHB because the disease spreads rapidly within the inoculated spikes of these lines. Genomic in situ hybridization （GISH） analysis revealed that the alien chromosomes in the addition and substitution lines were intact, and the lines did not contain discernible genomic aberrations. GISH and multicolor-GISH analyses were further performed on three trans- location lines that also showed high levels of resistance to FHB. Lines TA3499 and TA3695 were shown to contain one pair of wheat-Th. elongatum translocated chromosomes involving fragments of 7D plus a segment of the 7E, while line TA3493 was found to contain one pair of wheat-Th, elongatum translocated chromosomes involving the D- and A-genome chromosomes of wheat. Thus, this study has established that the short-arm of chromosome 7E of Th. elongatum harbors gene（s） highly resistant to the spreading of FHB, and chromatin of 7E introgressed into wheat chromosomes largely retained the resistance, implicating the feasibility of using these lines as novel material for breeding FHB-resistant wheat cultivars.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
[Objective] The aim of this study was to breed new strains which have higher inhibitory effects on the pathogens of watermelon fusarium wilt.[Method] The endophytic Bacillus subtilis B47 strain was obtained from tomat...[Objective] The aim of this study was to breed new strains which have higher inhibitory effects on the pathogens of watermelon fusarium wilt.[Method] The endophytic Bacillus subtilis B47 strain was obtained from tomato stems by UV mutagenesis for two consecutive times,then genetic stability as well as physiological and biochemical properties of mutant strains were studied.[Result] The antibacterial activity of all the three mutant strains F303,F304 and F305 was higher than that of B74 strain.After subculture of 10 successive generations,the antibacterial activity of all the three mutant strains for the pathogens of watermelon fusarium wilt decreased,but the antibacterial activity of F305 strain decreased the least,indicating its best genetic stability among the tested strains.The antibacterial circle diameter of F305 strain was 5 mm larger than that of wild strain B47 under the same condition.The mutant strain F305 was in logarithmic growth phase within 36 h and in stationary phase within 36-96 h,while its optimum growth temperature was 35 ℃.F305 strain could grow in sodium salt with the concentration of 1%-10%,but it grew best at the concentration of 1%.Physiological and biochemical responses of F305 strain were in accordance with those of wild strain B47.[Conclusion] This study lays the foundation for the factorial production of antagonistic substance by B47 strain and new methods of preventing from the pathogens watermelon fusarium wilt.展开更多
基金supported by the grant of the National High Technology Research and Development Program("863"Program)of China(No.2011AA100101)
文摘Thinopyrum elongatum （2n = 2x = 14, EE）, a wild relative of wheat, has been suggested as a potentially novel source of resistance to several major wheat diseases including Fusarium Head Blight （FHB）. In this study, a series of wheat （cv. Chinese Spring, CS） substitution and ditelosomic lines, including Th. elongatum additions, were assessed for Type II resistance to FHB. Results indicated that the lines containing chromosome 7E of Th. elongatum gave a high level of resistance to FHB, wherein the infection did not spread beyond the inoculated floret. Furthermore, it was determined that the novel resistance gene（s） of 7E was located on the short-ann （7ES） based on sharp difference in FHB resistance between the two 7E ditelosomic lines for each arm. On the other hand, Th. elongatum chromosomes 5E and 6E likely contain gene（s） for susceptibility to FHB because the disease spreads rapidly within the inoculated spikes of these lines. Genomic in situ hybridization （GISH） analysis revealed that the alien chromosomes in the addition and substitution lines were intact, and the lines did not contain discernible genomic aberrations. GISH and multicolor-GISH analyses were further performed on three trans- location lines that also showed high levels of resistance to FHB. Lines TA3499 and TA3695 were shown to contain one pair of wheat-Th. elongatum translocated chromosomes involving fragments of 7D plus a segment of the 7E, while line TA3493 was found to contain one pair of wheat-Th, elongatum translocated chromosomes involving the D- and A-genome chromosomes of wheat. Thus, this study has established that the short-arm of chromosome 7E of Th. elongatum harbors gene（s） highly resistant to the spreading of FHB, and chromatin of 7E introgressed into wheat chromosomes largely retained the resistance, implicating the feasibility of using these lines as novel material for breeding FHB-resistant wheat cultivars.
基金Supported by the Fund of Science and Technology in GuangXi Zhuang Autonomous Region(0009018)~~
文摘[Objective] The aim of this study was to breed new strains which have higher inhibitory effects on the pathogens of watermelon fusarium wilt.[Method] The endophytic Bacillus subtilis B47 strain was obtained from tomato stems by UV mutagenesis for two consecutive times,then genetic stability as well as physiological and biochemical properties of mutant strains were studied.[Result] The antibacterial activity of all the three mutant strains F303,F304 and F305 was higher than that of B74 strain.After subculture of 10 successive generations,the antibacterial activity of all the three mutant strains for the pathogens of watermelon fusarium wilt decreased,but the antibacterial activity of F305 strain decreased the least,indicating its best genetic stability among the tested strains.The antibacterial circle diameter of F305 strain was 5 mm larger than that of wild strain B47 under the same condition.The mutant strain F305 was in logarithmic growth phase within 36 h and in stationary phase within 36-96 h,while its optimum growth temperature was 35 ℃.F305 strain could grow in sodium salt with the concentration of 1%-10%,but it grew best at the concentration of 1%.Physiological and biochemical responses of F305 strain were in accordance with those of wild strain B47.[Conclusion] This study lays the foundation for the factorial production of antagonistic substance by B47 strain and new methods of preventing from the pathogens watermelon fusarium wilt.
