摘要
将诱饵法与组织分离法相结合,对甘肃中部干旱地区菜豆根围土壤中的腐霉菌进行分离,共得到6株腐霉菌株.通过挑单菌丝的方法获得纯培养菌系,在对纯化菌株形态特征、培养特性、生长速度和温度的适应范围研究的基础上,对编号为18-51 D的腐霉菌株培养后提取DNA,采用真核生物核糖体基因(rDNA)转录间隔区(ITS)通用引物ITS1(5′-TCCGTAGGTGAACCTGCGG-3′)和ITS4(5′-TCCTCCGCTTATTGATATGC-3′)进行PCR扩增;扩增产物直接测序并输出全序列,获得947 bp的序列;将该序列在GenBank中进行比对,用DNAStar分析软件将同源性较高的登记菌株的序列与18-51D腐霉菌株用邻接法构建系统发育树,结果发现18-51 D与菌株DQ211524(Pythium carolinianum)和AY987038(P.carolinianum)聚为一类.依据形态学特征和分子鉴定,将这6株腐霉菌株鉴定为卡地腐霉P.carolinia num.这是第一次在菜豆根围土壤和在甘肃分离到卡地腐霉P.carolinianum,为甘肃腐霉新记录种.用平皿法测定该菌种对三科九种栽培植物的致病性,发现所有供试植物的胚根仅部分有轻微褐变,未见对生长有明显影响,说明P.carolinianum对这些植物基本无致病性.
The rhizosphere soil of Phaseolus vulgaris sampled from the middle areas of Gansu province were isolated via both baiting and tissue methods and 6 isolates of Pythium were obtained.After a studying of its morphology,cultural characteristics,growth rates and adaptions to different temperatures of the single-hyphaed strain 18-51D,its DNA was extracted and PCR product at primers ITS1（5＇-TCCGTAGGTGAACCTGCGG -3＇） and ITS4（5＇-TCCTCCGCTTATTGATATGC-3＇） was sequenced,and 947 bp bases were obtained.The blasting of the sequence in GenBank and its phylogenetic tree through DNAStar showed that the strain 18-51D was clustered closely with Pythium carolinianum（AY987038）.Combined with its morphology,the strain 18-51D was identified as Pythium carolinianum,which is reported for the first time in Gansu province.The pathogenicity and aggressiveness of the strain to 9 species in 3 families were tested, and the result showed that the roots of all of the tested plants turned a little bit brown,while their growth did not change,which meant that Pythium carolinianum exhibited no pathogenecity to these 9 species in 3 families.
出处
《兰州大学学报（自然科学版）》
CAS
CSCD
北大核心
2010年第6期84-89,95,共7页
Journal of Lanzhou University(Natural Sciences)
基金
甘肃省科学事业费项目(甘科计[2001]21号)
甘肃省中药材产业科技攻关项目(GYC09-01)
甘肃省教育厅项目(032-08)
甘肃农业大学科技创新基金项目(GAU2CX0504)
国家科技支撑计划项目(2006BAD21B053)
