海南五指山热带雨林区Bt菌株的分离及其新型cry基因鉴定

五指山原始热带雨林区位于海南岛中部,是海南岛地区面积最大的热带原始雨林。我们依据不同的海拔高度对五指山原始雨林区进行了系统的取样,共采集了234份土壤样品,采用醋酸钠-高温处理的方法分离出各类产芽孢杆菌886株,并通过显微镜观察鉴定出产伴胞晶体蛋白的Bt菌株21株,其Bt菌株分离率为2.3%。为了进一步挖掘五指山丰富的Bt杀虫基因资源,还利用PCR方法结合测序技术对21株Bt分离株的cry基因进行了鉴定,鉴定结果显示cry1、cry4、cry39、cry40、cry31和cry46等基因型存在,表明五指山热带Bt菌株含有丰富cry基因资源,这将为为进一步开展Bt杀虫基因的分离克隆打下基础。     

海南岛热带雨林区芽孢杆菌收集及Bt菌鉴定

本研究系统地对海南岛热带雨林自然保护区进行了土壤样品的采集、芽孢杆菌的分离收集和Bt菌株的鉴定.从尖峰岭热带雨林区、五指山热带雨林区、吊罗山热带雨林区、霸王岭热带雨林区总共采集了土壤样品1 882份,采用醋酸钠培养基结合高温方法分离出芽孢杆菌3 924份,鉴定出Bt分离株158份,Bt菌株的分离率和出菌率分别为4.03%和8.40%.结果分析表明,海南岛热带雨林区芽孢杆菌及Bt菌株分布对环境和生态表现出一定的规律性,一般海拔900 m至1 400 m的Bt菌株含量高、植被覆盖率高,土壤腐殖质含量高的热带沟谷雨林带Bt菌株含量最高.显微观察发现,获得的Bt菌株其伴胞晶体有菱形、球形、方形、椭球形、不定性等多种形状.利用SDS-PAGE方法对获得的Bt分离株进行了伴胞晶体进行分析,发现伴胞晶体的分子量有20 kD到150 kD不等.进一步利用PCR-RFLP技术对Bt分离株进行了cry基因型的分析,初步发现这些Bt菌株含有cry1、cry3、cry4、cry6、cry30、cry40等基因型.我们还利用鳞翅目昆虫小菜蛾和鞘翅目昆虫椰心叶甲进行部分Bt分离株的生物测定,初步结果显示本研究鉴定出的Bt分离株具有不同的抗虫靶标,对同一靶标昆虫也表现出不同的杀虫活性.整体而言,本研究结果显示出海南岛热带热带雨林自然保护区因其独特的热带地理生境、自然的生物演化系统,使得热带雨林区蕴藏了Bt菌株资源多样化,值得期待挖掘出一些新的菌株和新的基因资源.     

苏云金芽胞杆菌的鉴定及对椰子织蛾的致死作用

【背景】利用采集到的样品分离出苏云金芽胞杆菌菌株,针对椰子织蛾幼虫进行室内生物活性测定,以期获得对椰子织蛾幼虫具有高毒力菌株,并为椰子织蛾的生物防控提供理论和技术依据,同时为转Bt基因作物提供新的基因资源。【方法】在海南岛椰子织蛾潜在分布区采集样品,利用温度法筛选苏云金芽胞杆菌并进行形态学和分子生物学鉴定,采用浸叶法进行Bt菌株对椰子织蛾幼虫的生物活性测定。【结果】海南省保亭县土壤样品中筛选出8株菌株,电子显微镜下观察到该批菌株含有菱形、球形、方形晶体;通过分子生物学鉴定明确了6株菌株含有cry基因,2株没有鉴定出cry基因;利用相同浓度菌悬液对椰子织蛾幼虫进行了生物活性测定,结果表明,50μg·m L-1的BAT10菌株杀虫晶体蛋白对椰子织蛾幼虫的致死率达100%,同样浓度的29-15-4与BAT20菌株杀虫晶体蛋白对椰子织蛾幼虫的致死率超过80%,其余5株Bt的杀虫晶体蛋白致死率较低,致死率小于50%。【结论与意义】本试验筛选出1株高毒力菌株和2株效果较好的Bt菌株,可应用于椰子织蛾的生物防控。     

黑龙江省苏云金杆菌的分离及对夜蛾科昆虫高毒力菌株的筛选

【目的】为了发掘新的苏云金杆菌(Bacillus thuringiensis)的资源,在黑龙江省不同地区采集不同类型的土壤样品分离出对夜蛾科具有高毒力的菌株。【方法】采用醋酸钠选择性筛选法筛选Bt菌株,利用10对通用引物对分离株进行基因型分析,SDS-PAGE进行杀虫晶体蛋白分析,同时测定苏云金杆菌分离株对棉铃虫Helicoverpa armigera(Hübner)、甘蓝夜蛾Mamestra brassicae(Linnaeus)、斜纹夜蛾Spodoptera litura(Fabricius)的杀虫活性。【结果】从黑龙江省不同地区采集的352份不同类型的土壤样品中,共分离出46株苏云金芽孢杆菌野生菌株,出菌率为13.06%。油镜下可观察到伴孢晶体的形态有菱形、球形、镶嵌形及不规则形。结果表明产菱形晶体的菌株多含有cry1类基因,而同时产生菱形、球形及不规则形晶体的菌株则含有多种基因型。SDS-PAGE蛋白分析发现这些菌株主要表达130、90、60 ku蛋白。对其中的部分菌株进行毒力测定,结果表明有4株菌株对3种夜蛾科昆虫具有高毒力。【结论】黑龙江省苏云金芽孢杆菌分布广泛,类型多样,已获得对夜蛾科昆虫有高毒力的菌株,这对夜蛾科害虫的绿色防控及延缓其抗性具有重要意义。     

我国海南省杀蚊球形芽孢杆菌的分离和分布

在我国海南省共采集158个各种类型的泥土样品,采用选择性培养基（PBMYS）进行样品分离,并结合形态学观察、血清学鉴定和生物测定,获得对致倦库蚊（Culexquinquefasciatus）幼虫有毒性的球形芽孢杆菌（Bacillussphaericus）73株,有毒株的分离率占样品总数的342％。血清学试验表明,新分离菌株有71株属H5a5b型,两株属在我国首次分离出比型菌株。许多球形芽bqn杆菌新菌株对致倦库蚊幼虫具有很强的毒杀作用。其中228－2和117－1菌株的丙酮粉剂效     

土壤中对甲虫有活性苏云金芽胞杆菌的筛选

近几年来,甲虫已成为十字花科蔬菜的头号害虫。本文采集了湖北省各地区192份土壤样品,分离到苏云金芽胞杆菌(简称Bt)菌株74株,以甲虫代表——黄粉虫为靶标昆虫筛选了15株典型Bt,得到一株对甲虫有活性的Bt L1;生物测定该菌的半致死浓度(LC50)为221.20μg·g-1;聚丙烯酰胺凝胶电泳(SDS-PAGE)显示L1至少具有3个杀虫晶体蛋白;PCR扩增杀虫晶体蛋白基因,测序发现Bt L1中含有cry1Ac,cry1Aa,cry1Ia基因,推测Bt L1中对甲虫活性的杀虫晶体蛋白基因为cry1Ia。     

广西大王岭和大明山自然保护区苏云金芽孢杆菌收集与鉴定

从广西大王岭和大明山两个自然保护区共采集到土样264份,共分离出597株芽孢杆菌,通过光学和电子显微镜检观察,16株分离株观察到伴胞晶体蛋白,初步确定为苏云金芽胞杆菌(Bacillus thuringiensis,简称Bt),出菌率为6.06%.在16株Bt分离株中,有4株在芽孢形成过程中能产菱形晶体蛋白,其余12株能产圆形和其他形状的晶体蛋白.利用PCR-RFLP方法和SDS-PAGE方法对16株Bt分离菌进行了蛋白和基因型的鉴定,结果表明,16株分离株中含有4株cry1Ac基因,表达约130 kD的晶体蛋白,其中含有cry30基因和cry40基因的菌株分别1株和3株,表达大约75 kD的晶体蛋白;另外8株Bt菌株表达蛋白大小不一,其基因型尚不能确定,有待进一步分析.生物测定表明,产菱形晶体含有cry1Ac基因的4株Bt分离株对鳞翅目小菜夜蛾幼虫有很强的毒杀活性,而其它分离株对小菜夜蛾没有毒杀活性.     

cry4Aa、cry4Ba和cry11Aa基因在苏云金杆菌无晶体型菌株中的表达

利用穿梭载体pBU4,将苏云金杆菌以色列亚种（Bti)的cry4Aa、cry4Ba和cry11Aa基因分别转入Bti无晶体突变株4Q7中,获得了转化菌株Bt-B601、Bt-B611和Bt-B640。SDS－PAGE结果显示：cry4Aa、cry4Ba和cry11Aa蛋白均分别获得了表达。透射电镜下观察,转化菌 有产生球形或菱形伴胞晶体。转化菌株对敏感和抗性致倦库蚊及白纹伊蚊幼虫的生物测定结果显示：cry4Aa、cry4Ba和cry11Aa蛋白对库蚊和伊蚊的毒力较低,二元毒素抗性库蚊幼虫对Bti杀蚊毒素蛋白无明显的交叉抗性。     

中国苏云金芽孢杆菌的分布与cry基因的多样性

采集全中国27个省、自治区及4个直辖市昆虫孳生地粉尘、土壤等样品1080份,在其中的406份中分离到苏云金芽孢杆菌965株.镜检可观察到大菱形、小菱形、方形、长方形、圆形、椭圆形、镶嵌形和不规则形等8种主要形态的伴孢晶体;采用cryⅠ、cryⅡ、cryⅢ、cryⅣ和cryⅤ基因的通用引物对221株Bt分离株进行的PCR检测结果表明各类基因的含量依次为cryⅠ＞cryⅡ＞cryⅤ＞cryⅢ基因,分别占被检菌株的75.6%、67.9%、58.4%和14.5%,没有检测到cryⅣ基因,共得到10种基因组合类型.对其中含有cryⅠ基因的菌株分别以cryIAc、cryIC和cryIE基因的特异性引物进行PCR检测,得到20株同时含有cryIAc、cryIC、cryⅡ和cryⅤ优良基因组合的Bt分离株,其中菌株Bt-15A3对棉铃虫、甜菜夜蛾及小菜蛾均表现出高毒力,具有生产开发潜力.     

苏云金芽孢杆菌的筛选和初步鉴定

采集四川温江昆虫孳生地的土壤样本94份,利用醋酸钠-抗生素法分离、筛选,共获得苏云金芽孢杆菌9株。镜检可观察到大菱形、小菱形、方形、圆形等四种主要形态的伴胞晶体;采用cryⅠ、cryⅡ、cryⅢ、cryⅤ基因的通用对9株Bt分离菌进行的PCR检测结果表明：9株菌全部含cryⅠ和cryⅤ基因,2株菌含cryⅡ基因,5株菌含cryⅢ基因,而且各菌株均包含2—3个基因型。利用这些菌株对菜青虫进行了室内和室外生物毒力测定,达到了较好的杀虫效果。     

Isolation and characterization of <Emphasis Type="Italic">Bacillus thuringiensis</Emphasis> strains from different grain habitats in Turkey

Bacillus thuringiensis (Bt) is a gram-positive, spore-forming bacterium and it produces insecticidal crystal (cry) proteins during sporulation. Because the genetic diversity and toxic potential of Bt strains differ from region to region, strains have been collected and characterized all over the world. The aim of this study is to isolate Bt strains in grain-related habitats in Turkey and to characterize them on the basis of crystal morphology, cry gene content, and chromosomal and plasmid DNA profiles. Four approaches were taken analysis with phase contrast (PC) microscopy, polymerase chain reaction (PCR), pulsed field gel electrophoresis (PFGE) and plasmid isolation. Ninety-six samples were collected from Central Anatolia and the Aegean region. Bt was isolated from 61 of 96 samples (63.5) and 500 Bt-like colonies were obtained. One hundred and sixty three of the colonies were identified as Bt based on cry protein formation using PC microscopy. Among the examined colonies, the overall proportion identified (as Bt index) was 0.33. We found that 103 isolates were positive for the five different cry genes (cry1, cry2, cry3, cry4 and cry9) examined with PCR. In addition, plasmid profiling of 37 cry gene-positive isolates indicated that the 15 kb plasmid band was present in all isolates; however, 11 of 37 isolates had more than one plasmid band at different sizes. Finally, chromosomal DNA profiling by PFGE gave rise to different DNA patterns for isolates containing the same cry gene which suggests a high level of diversity among the Bt strains isolated.     

Host range and gene contents of Bacillus thuringiensis strains toxic towards Spodoptera exigua

Thirty-five strains of the entomopathogenic bacterium Bacillus thuringiensisactive on Spodoptera exigua, were characterized by means of serological identification and determination of crygene contents by PCR. The insecticidal activity of these 35 strains was further confirmed against S. exiguaand tested against two other species of the same genus: S. littoralisand S. frugiperda. The results indicate that serovars aizawai, thuringiensis, and kurstakiwere the most frequent within S. exigua-active strains and that serovar aizawaihad the highest number of strains exhibiting toxicity against the three species bioassayed. The presence in crygenes as determined by PCR suggests a non random distribution of some crygenes among serovars. Genes cry1C, cry1D, and cry1E, which are known to code for proteins toxic against Spodopteraspecies, were very common within S. exigua-active strains, specially in those belonging to serovar aizawai. However, some strains harbouring one or more of these genes were not toxic to S. littoralisor S. frugiperda; and some strains lacking all of the Spodoptera-active genes were found to be toxic to all three species. This suggests differences in the expression levels among strains bearing toxic genes and the involvement of other genes toxic to Spodopteraspecies. Since strains sharing the same crygenes exhibited different host ranges, the results indicate the need to perform toxicity bioassays in addition to other tests (serological identification and PCR) in order to determine the insecticidal activity of B. thuringiensisstrains.     

Toxicity of a <Emphasis Type="Italic">Bacillus thuringiensis israelensis</Emphasis>-like strain against <Emphasis Type="Italic">Spodoptera frugiperda</Emphasis>

Bacillus thuringiensis (Bt) Berliner is a promising agent for microbial control of agriculturally and medically important insects. This study aimed at searching for Bt strains encoding Cry proteins that act more efficiently against fall armyworm. Thirty Bt strains were isolated from soil samples in Pernambuco State and evaluated through bioassays. Among these, strain I4A7 was the most efficient against the fall armyworm, Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae), and thus it was characterized by biochemical sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) and molecular (polymerase chain reaction (PCR) and sequencing reaction) methods. The protein pattern of this strain on a SDS–PAGE was similar to that of B. thuringiensis israelensis (Bti). Moreover, I4A7 cry DNA sequence showed high identity (99–100%) to genes cry4Aa, 4Ba, 10Aa, 11Aa, cyt1Aa and cyt2B from Bti. The toxicity of the newly isolated Bti-like strain upon S. frugiperda should be considered as this strain might be used in combination with other Bt strains, such as B. thuringiensis var. kurstaki (Btk). Handling Editor: Helen Roy.     

`Cloning of <Emphasis Type="Italic">vip1/vip2</Emphasis> genes and expression of Vip1Ca/Vip2Ac proteins in <Emphasis Type="Italic">Bacillus thuringiensis</Emphasis>

Forty-one Bacillus thuringiensis (Bt) standard reference strains and 118 Bt local isolates were screened for vip1/vip2 genes by PCR amplification, with only three strains (HD201, HD109 and HD12) producing the desired bands. Southern blot showed that vip1/vip2 genes were located on a 10 Kb EcoRV fragment of their total DNAs. Furthermore, the vip1Ca/vip2Ac genes were cloned from a partial genomic library of HD201. Sequence homologous analysis revealed that vip2Ac gene was highly conserved and encoded a protein possibly having ADP-ribosyltransferase activity, and that vip1Ca gene was of low homology, especially at its 3-terminus. Western blot showed that Vip1Ca and Vip2Ac proteins could be detected from middle logarithmic phase to the stationary phase in Bt HD201. However, bioassays of HD201 supernatants exhibited no activity against Culex quinquefasciatus, Spodoptera exigua, S. litura, Helicoverpa amigera and Tenebrio molitor larvae. Whether Vip1Ca and Vip2Ac proteins have any toxicity to other susceptible targets still needs to be investigated.     

Detection and characterisation of a Bacillus thuringiensis crystal protein with nematicidal activity against the pinewood nematode Bursaphelenchus xylophilus

Nematicidal Bacillus thuringiensis (Bt) strains were isolated from forests in Zhejiang, China for further characterisation. PCR analysis was performed with nine pairs of primers specific for cry1, cry2, cry3, cry4, cry5, cry6, cry9, cry11 and cry13 to characterise and classify cry gene groups from Bt isolates. The isolates from individual cry groups were tested for nematicidal activity against the pinewood nematode Bursaphelenchus xylophilus, which is implicated in pine wilt disease. PCR identified 14 different categories of cry gene combinations, indicating a large diversity of cry genes. The cry1 gene was by far the most abundant in Bt isolates and was found in 68% of samples. The Bt isolates zjfc85 and zjfc392 were from two distinct classes, but shared the same cry5 amplification profile and the same ~130 kDa protein; they had the highest nematicidal activity against pinewood nematode during the 48 h exposure tests, resulting in 90 and 59% mortality (9% of mortality under control conditions), respectively. The ~130 kDa Cry protein from isolate zjfc85 was purified and named as Cry5Ba3. Bioassay results indicated pinewood nematode was highly susceptible to Cry5Ba3 and exhibited profound growth abnormalities after exposure to Cry5Ba3. Our results are a novel finding and provide a potential strategy to manage pine wilt disease caused by B. xylophilus based on a nematicidal Bt.     

Distribution and diversity of Dipteran-specific cry and cyt genes in native Bacillus thuringiensis strains obtained from different ecosystems of Iran

One hundred and twenty-eight Bacillus thuringiensis isolates from fields of different ecological regions of Iran were collected to study the distribution and diversity of Dipteran-specific cry and cyt genes. The percentage of samples with Bt showed significant differences between different regions and also between different fields. The most Bt frequency was observed in the soil samples collected from Caspianic zone (7%) and soils of cotton (17%). Characterization of isolates was based on morphological characteristics of crystals, plasmid profiles and protein band patterns as well as PCR analysis using general and specific primers for 22 different cry and cyt genes encoding proteins active against mosquitoes. Thirty-eight different cry gene profiles were detected in this collection. Several of them were found to be different from all previously published profiles and none of the previous researches reported these numbers of profiles. Strains containing cry2-type genes were the most abundant and represent 57.1% of the isolates. Strains harboring cry24 and cry10 genes were also highly abundant (38.7 and 32.8%, respectively). cry11, cry4, cry17, cry19, cry21, cry29, cyt1, and cry9 genes were less abundant, found in 25.7, 14.3, 11.4, 1.4, 4.3, 1.4, and 10% of the strains, respectively. Among the cry2 gene containing isolates, 37.5% strains harbored cry2Aa, 55% cry2Ab, 2.5% cry2Ac, and 5% other or novel cry2-type genes. Among the cry4 gene containing isolates, 0% strains harbored cry4A, 60% cry4B, and 40% cry4C, cry4D or novel cry4 type genes. Finally, based on crystal morphology, protein patterns and PCR, 21 strains were selected as potentially high Dipteran-active for bioassays. Also our results showed that some of the isolates may harbor minimum a putative novel cry gene.     

Novel toxicity of native and HD Bacillus thuringiensis strains against to the sugarcane borer Diatraea saccharalis

Diatraea saccharalis (F.) (Lepidoptera: Pyralidae) is a pest that causes great economic losses to sugarcane producers in Mexico. In order to obtain alternatives for control of this pest, several Bacillus thuringiensis strains (native and from the Howard Dulmage collection) were tested. In bioassays, strains HD-133, HD-551, GM-7, GM-10, and GM-34 caused more than 50% mortality with a 50 g/ml spore-crystal complex concentration, and were selected as toxic strains. The lowest LC₅₀ value corresponded to GM-34 (33.21 g/ml). Cry1B and cry1C genes were detected by PCR analysis in the toxic strains. HD-133 and GM-10 habored cry1C gene, HD-551 and GM-7 strains harbored cry1B gene, while GM34 strain did not contain cry1B nor cry1C. An additional PCR analysis was performed to detect cry1A-type genes. All the toxic strains habor at least one cry1A-type gene. Immunoblotting revealed that all strains cross-reacted with an antiCry1A, and only the HD-551 gave a positive signal with antiCry1B polyclonal antisera. GM-7 crystal protein showed no cross-reaction with polyclonal Cry1B antiserum. The toxicity of these strains may be related to some member of the Cry1A toxin class.     

Diversity of Bacillus thuringiensis strains from soil in China and their pesticidal activities

A large number of Bacillus thuringiensis (Bt) isolates have been obtained from soil samples in China. The flagellar antigen serotypes, cry genes and crystal proteins of 570 Bt isolates were determined, and the pesticidal activity was assayed against the insects, Plutella xylostella, Heliothis armigera, Phaedon brassicae and Locusta migratoria manilensis, and the snail, Oncomelania hupensis. The results indicated that the Bt isolates were distributed within 35 H-serotypes, in which isolates of H3 were the most abundant (20%) followed by H5 (13%), H7 (9%) and H4 (8.7%), whereas isolates of other H-serotypes were less than 6%. The percentage of isolates containing the genes cry1Ac, cry1Aa/cry1Ac, cry1Aa/cry1Ac/cry1Ab, and cry1Aa/cry1Ac/cry1C was 14.7%, 6.6%, 5.6%, and 7.0%, respectively, while 265 isolates, representing 46.5% of the 570 Bt isolates, did not show any amplification product for the genes cry1Aa, cry1Ac, cry1C, cry2, cry3, cry4, cry7Aa. Some of the 570 Bt isolates caused high mortality of the assayed pests with 14.9%, 6%, 1.6%, 1.1%, and 0.2% of the isolates killing more than 90% of P. xylostella, H. armigera, P. brassicae, O. hupensis, and L. migratoria manilensis, respectively. The remaining 76.2% of the 570 isolates caused no mortality or less than 90% mortality against the tested insect and snail species.     

Molecular and biological characterization of native <Emphasis Type="Italic">Bacillus thuringiensis</Emphasis> strains for controlling tomato leafminer (<Emphasis Type="Italic">Tuta absoluta</Emphasis> Meyrick) (Lepidoptera: Gelechiidae) in Colombia

Twenty-eight soil samples were obtained from open fields and greenhouses used for tomato cultivation in various regions of Colombia. For functional characterization, 99 Bacillus thuringiensis (Bt) strains were isolated and characterized by abundance and morphology of microscopic crystals, SDS–PAGE of protein extracts and M-PCR analyses of genes of the cry1 family, as well as for their insecticidal activity against Tuta absoluta second instar larvae. Native Bt strains had amorphous (5%), bi-pyramidal (27%), square (8%), spherical (38%) and triangular (22%) crystal forms. Based on the presence of 1–4 different crystal forms, 18 different profiles were established. The SDS–PAGE analyses of protein extracts established ten different strain groups based on their protein band weight and potential biological activity. The M-PCR technique identified 35 native Bt strains based on the presence of the 6 genes cry1Aa, cry1Ab, cry1Ac, cry1B, cry1C and cry1D, whose frequency of occurrence was 76, 26, 21, 35, 32 and 8.8%, respectively. Thirteen different PCR profiles were found in native Bt strains. Several gene combinations tended to co-occur with elevated frequency, such as the pairs cry1Ac/cry1C, cry1Ab/cry1Ac and cry1Ab/cry1B, for which Pearson correlation coefficients were 0.69, 0.52 and 0.54, respectively. Native strains ZBUJTL39 and ZCUJTL11 had up to three times higher biological activity against T. absoluta second instar larvae than the reference strain Bt var. kurstaki HD1, with an LD₅₀ of 2.4 μg/ml (P < 0.05) for native Bt strain ZCUJTL11. This study suggests a high biodiversity of native Bt strains from tomato growing regions in Colombia, which has important implications for designing biological control strategies for T. absoluta.     

新疆野果林苹果腐烂病病原菌鉴定及药用植物内生细菌对其抑菌效果

【背景】药用植物内生细菌能产生与寄主植物相同或相似的化合物及一些新的次级代谢产物等,具有促进宿主植物生长、抵抗病虫害、降解有毒有害化合物等作用。【目的】进一步提高苹果腐烂病生物防治的效率,丰富新疆药用植物内生细菌拮抗功能菌株的资源库。【方法】从新疆伊犁新源县和塔城额敏县野果林中采集带腐烂病病斑的果树枝条,分离鉴定苹果腐烂病病原菌,并采用平板对峙法从药用植物内生细菌中筛选对苹果腐烂病具有抑制作用的拮抗菌株。【结果】从两地共分离获得234株分离株,筛选鉴定出25株Valsa malicola和2株Valsa mali;同时,筛选出92株具有抑菌效果的内生细菌菌株,其中70株来自甘草植物内生细菌。【结论】药用植物甘草中富含较为丰富的抗苹果腐烂病病原菌的微生物菌株资源。本研究在新疆野果林苹果腐烂病的生物防治及药用植物内生细菌的开发利用等方面具有重要意义。