Identification And Molecular Detection Of Potato Rot Nematode (Ditylenchus Destructor)

Potato Rot Nematode was a kind of transfered entoparasitic nematode which affect plant roots.they ate fungi without higher plants. Potato Rot Nematode was a kind of important pathogenic nematode. The nematodes occured in Beijing, Tianjin, Shandong, Hebei, Henan, Jiangsu, Zhejiang, Fujian, Liaoning, Gansu, Hainan, and other provinces in China.Morphological and molecular identification for six stem nematode populations colleted from Beijing,heibei,jiansu province,China were researched.The ITS regions of rDNA were sequenced and analyzed.A real-time quantitative polymerase chain reaction method for diagnosis of Ditylenchus destructor was developed in present study. Main results or conclusions of the research were as fellows:1. A few methods and conditions culturing potato stem nematode were compared in present study. The result indicated: It was the best method that cultured the nematode with carrot dish. The optimized condition was at 25℃,70% relative humidity under darkness.2. rDNA-ITS sequence analysis of all samples: the amplification of the rDNA-ITS region from three stem nematode populations of Beijing city, Daxing of Beijing city,Funing of Hebei province(code Des-5,Des-6,Des-7) in China and D.diapci from Netherlands yielded one single fragment of 942bp ,whereas the PCR products of ITS from three stem nematode populations of Zhangbei of Hebei province, Jiangsu province (Code Des-1,Des-3,Des-4) in China and from stem nematode group of Korea was 1130bp. The ITS section was made sure by the sequence of rDNA-ITS region from GenBank. There was a 188bp of absent fragment in ITS1 section of Des-5,Des-6,Des-7. There was some little repeated fragment in the absent section. The content of G+C was steady in ITS section of six stem nematode populations.3. RT-PCR method was established for diagnosis of D. destructor: the probes and primers for D. destructor were designed basis on the align sequence of the amplified internal transcribed spacer region of ribosomal DNA of Ditylenchus spp. by using the CLUSTSAL 1.81 of the sequence software. A optimal reaction system: 0.5μM forward / reverse primer, 0.5μM probe, 3mM Mg2+. A optimal reaction programe: 95℃3min;95℃...