本课题组前期研究获得玉米GRMZM2G455909基因,该研究拟对GRMZM2G455909基因开展生物信息学分析,明确其分子特征;构建过表达载体pCAMBIA1301a-GRMZM2G455909,通过农杆菌介导法获得转GRMZM2G455909基因拟南芥植株,分析转GRMZM2G455909基因拟南芥植株抗病能力及其抗病信号通路.研究表明,GRMZM2G455909基因所编码的蛋白序列属于NBS-LRR类蛋白家族;Pst DC3000处理转GRMZM2G455909基因拟南芥植株,发现转基因植株体内菌体数量明显下降,其抗病性显著增强,推测Pst DC3000可能诱导转GRMZM2G45590基因拟南芥体内形成水杨酸抗病信号通路.研究结果可为作物遗传育种抗病性的改良提供新的路径.

课题组前期从健康杜仲叶片中分离得到1株内生细菌枯草芽孢杆菌DZSG23,此菌可以较好地防控小麦赤霉病.为明确芽孢杆菌DZSG23在小麦中的定殖与强化抗病机制研究,利用抗生素标记法分析了DZSG23菌体在小麦组织中的定殖情况,采用荧光定量PCR技术检测不同生育期小麦穗部PR-1、AOS、ACOI等基因的表达水平变化.结果表明,DZSG23可在苗期小麦植株和小麦穗表面稳定定殖;DZSG23浇灌接种苗期小麦后的第34天,DZSG23在苗期小麦植株的根、茎和叶中的定殖量分别达到1.437×106 CFU·g-1、3.285×103 CFU·g-1和2.377×103 CFU·g-1;DZSG23喷施小麦穗表面15 d后,穗表面菌群密度仍可达7.146×103 CFU·g-1.此外,诱导系统抗性(ISR)信号通路研究表明,拮抗菌DZSG23可以诱导PR-1和AOS基因的上调表达,表明拮抗菌DZSG23引入小麦后可诱导小麦的水杨酸(SA)和茉莉酸(JA)信号通路,增强其抗病性.

在黔南烟区烟草青枯病严重发病的田块采集健康烟草根际土壤进行分离、纯化和培养后共获得35株细菌,通过抑菌圈法筛选出2株对烟草青枯病菌具有良好拮抗效果的菌株S3-1和S3-2,抑菌圈直径分别为1.3cm和1.4cm,抗青枯病的模式菌FZB抑菌圈为1.3cm;通过对目标菌株S3-2开展16S rDNA序列测定,并对测序结果开展BLAST比对,初步鉴定出S3-2菌株属于芽孢杆菌属.

The antimicrobial activity of endophytic bacterium from Morus alba L. was examined against wheat head blight using dual culture test and disease-control pot experiment, and the related enzymes activities (PPO, PAL and POD) in wheat spike treated with antagonistic endophytic bacteria SSY26 were detected by spectrophotometric method. The results showed that the SSY26 strain had strong inhibit effect against wheat head blight, with inhibitory rate of 58.65%, and the SSY26 strain, which was identified as Bacillus by molecular identification, could cause the expansion and deformity of phytopathogen mycelia of wheat head blight. The pot experimental results showed that the inhibit effect was 27.30% in the eighteenth day after treated with suspensions of SSY26 strain, without significant difference between SSY26 strain suspensions and chemical treatment, and the enzymes activities of PPO, PAL and POD in wheat spike increased treated with the suspensions of SSY26 strain.

为了筛选出适合庐江县气候特点及土壤情况的鲜食玉米品种,特在2018年选择了10个鲜食玉米品种进行了品种比较试验.结果 表明,徽甜糯810、宏中玉2个品种适合在庐江县作为主要的鲜食玉米品种种植;粤甜28产量虽然高但是不稳定,建议继续试种;暄糯255、昊生糯1号、桂甜糯218这3个品种建议在庐江县可以适当搭配种植.

DNA甲基化作为表观遗传的一种表现形式,在植物的生长发育、抗逆和抗病过程中发挥重要作用.前期研究中从杜仲体内分离筛选到一株拮抗内生芽孢杆菌DZSY21,其可在玉米中定殖,定殖后明显增强玉米抗病性.为明确内生菌DZSY21在玉米中定殖与其DNA甲基化水平的关系,该试验利用甲基敏感扩增多态性分析技术(MSAP)和全基因组DNA甲基化(WGBS)分别对内生菌DZSY21处理的玉米基因组进行DNA甲基化水平的定性和定量研究.定性和定量结果均表明拮抗菌DZSY21引入玉米植株,可引起玉米基因组DNA总甲基化水平降低;全基因组DNA甲基化(WGBS)定量测序结果显示玉米基因组DNA总甲基化水平降低了0.89％,DNA甲基化差异性区域数据库中共有5820个差异性甲基化区域(DMRs),且GO聚类分析和Pathway功能显著性富集分析结果显示DMR相关的基因主要涉及糖代谢、氨基酸合成以及蛋白激酶活性等与抗病相关的主要功能.该结果为深入研究DNA甲基化在内生菌DZSY21定殖增强玉米抗病性中的调控机制提供理论基础.

The enzyme composition and concentration,protoplast preparation,electrophoresis conditions and molecular karyotype of Paecilomyces tenuipes (Teleomorph:Cordyceps takaomontana) were investigated.The higher production(1.0×10~7/mL) of the protoplasts were obtained under the following conditions:the mycelia cultured for 18h,digested by the mixed enzyme solution consisting of 1% lywallzyme,1%cellulase and 1% snailase with shaking of 120r/min for 2.5h at 30℃,then the suspension concentration of protoplasts was adjusted approximately to 1.0×10~8/mL and mixed with 1.4% agarose (L.M.P).The agarose plugs with 2mg/mL proteinase K and proteolysis was performed at 50℃ for 48h.Finally,the agarose plugs were washed 3 times of 1h each with washing ET buffer and kept in storage solution at 4℃.The electrophoresis experiment was carried out by using CHEF system with Hansenula wingei YB-4662-VIA and Schizosaccharomyces pombe 972h-chromosome DNA as molecular weight markers,and CHEF patterns obtained were analyzed by Alpha Ease Fc software.The results showed P.tenuipes had eight chromosomes varied from 0.43 to 5.78 mega base pairs (Mb),ranked as 0.43,2.45,2.55,2.88,3.28,3.94,4.70 and 5.78Mb.The total genome sizes were estimated to be 26.01Mb.

Electrophoretic karyotype of Paecilomyces militaris was analyzed by use of contour-clamped homogeneous electric field(CHEF) electrophoresis.Using chromosomal size standards from Hansenula wingei and Schizosaccharomyces pombe,the chromosomal number of P.militaris was 7 from 2.0 to 5.7 mega base pairs(Mb).The results showed that the karyotype are not all homological among the same species.

During a screening of pigment of entomogenous fungi,a strain of Septafusidium bifusisporum RCEF3669,mycelia,presented obvious yellow color.An orange yellow pigment Sb-1 from mycelia of RCEF3669 was effectively extracted with methanol and was isolated with HPLC.The pigment was identified with HPLC-MS and HPTLC as a pure compound.High resolution MS analysis revealed that the molecular formula of the compound was C26H32O9,which could possibly be a new compound according the searching results of Chapman&Hall natural products database.

The preliminary investigation on fruiting body of Cordyceps pruinosa was taken by adding 3 kinds of plant hormones into the solid medium according to orthogonal design.The results showed that the fruiting bodies were obtained in all treatments,but the significance of factors and its levels were different due to different indices.All 3 kinds of plant hormones have significant effects on Cordyceps pruinosa,IAA for the growth of fruiting body,cAMP for the fresh weight and KT for the dry weight.While they have no obvious effect on the number of fruiting body(the growth point).