Imported Allium hookeri is sometimes infected by some quarantine nematodes like Meloidogyne spp., Pratylenchus spp. Hot water treatment(HWT) is reported as the most effective treatment method for disinfection of nematodes. The primary goal of this research was to determine the temperature tolerance of Allium hookeri and lethal temperature of Meloidogyne spp., preferably in the range of 5~30minutes at 48~53℃. Second stage juveniles of Meloidogyne spp. were successfully eliminated in hot water bath treated at 48℃ within 1 minute. Egg hatching was suppressed completely at 48℃ more than 26 minutes. No evidence of growth damage was observed on plants treated with HWT even at 48℃ for 30 minutes and 49℃ for 10 minutes. Therefore, the optimum range of HWT is recommended at 48℃ for 30 minutes and 49℃ for 10 minutes on Allium hookeri infected root-knot(Meloidogyne spp.) nematode.

Recently, researches of molecular biology for the identification of root-knot nematode (RKN) species have been reported in plant quarantine. In this study, applicable and reproducible method to extract high quality genomic DNA from single nematode (Meloidogyne spp.) was developed. Also, the modified method was verified by DNA manipulation techniques such as PCR amplification and cloning. Single juvenile was floated in a drop of water and digested with proteinase K for 24 h. After that, DNA was extracted by using distilled water as extraction buffer. PCR amplification was carried out with universal primers spanning the internal transcribed spacer (ITS) region to distinguish species. When using the existing DNA detection method, quantification results showed that 42.86% of the deposited DNA was extracted. Whereas the modified DNA extraction method was increased to 100%. When PCR products test the direct sequencing using the ITS rDNA primers, it was also identified as M. javanica, M. incognita, and M. hispanica. Based on the studies conducted, the application of this modified method would be useful and efficient on plant parasitic nematode molecular assay.

Radopholus similis belong to the plant parasitic nematode family, Pratylenchidae and was recognized that injure the plant. R. similis was generally identified from bananas and plantain in the tropics. However, the occurrence of infection of R. similis on new host plant was confirmed recently. The aim of this study was to report the determination of new host plant for R. similis on Staurogyne sp. The species identification was evaluated the morphological and molecular characteristics of nine R. similis. Molecular assay was designed from the internal transcribed spacer region (ITS) of ribosomal DNA to distinguish species. Nematodes from Staurogyne sp. showed almost similar morphological and morphometric characteristics in general R. similis, but some variation in tail shape was confirmed. Also, male was not detectable. Molecular assay showed a high level (97%) of similarity in the TW81-AB28 and 18S-28S sequences (ITS region) with corresponding NCBI sequence. The quarantine should be more intensely to detect the prohibited nematode.

The aim of the study is to report Radopholus similis detected from Agathis dammara in Thailand as new host plant. Existing host of R. similis was known as coffee, pepper, sugarcane and banana etc. This nematode in this study was observed morphologic character using Carl Zeiss Axioimager M2 and Axiovision Rel. 4.8 program. The result shows that a and b of the female was distorted toward maximum value of original description of species, and b′, c and stylet length was distorted toward minimum value of original description of species. This nematode was morphologically distinguished from originally detected R. similis, but measured value was similar in range of original description of species. For more information, molecular assay was also confirmed the R. similis with 98% homology with the sequence of the internal transcribed spacer region (ITS) of ribosomal DNA. We provided PCR-amplified ITS nucleotide sequence.

Polydnaviruses (PDVs) are a group of insect double stranded DNA viruses and symbiotically associated with host endoparasitoid wasps. Their segmented genome is located in host chromosome(s) in a proviral form. Viral replication is initiated at the ovary during late pupal stages. Little is known about the factors involved in the viral replication. This study analyzed the ovarian transcripts of an endoparasitoid wasp, Cotesia plutellae, by 454 pyrosequencing and subsequent gene annotation. Out of 2,226 contigs and 12,457 singletons, 50 transcripts categorized in DNA replication, coat proteins, and viral origins were selected as putative viral replication factors. The selected genes were analyzed in their expressions according to host wasp development. Quantitative real-time RT-PCRs showed that some of the selected genes were expressed during the viral replication at late pupal stage. Using RNA interference, five putative genes were tested in their implication in the viral replication by analyzing viral DNA amplification, structure of ovarian calyx, and parasitism. RNA interference of contig#1004 (broad complex) or contig#174 (a viral DNA polymerase gene) significantly inhibited DNA amplification without any impairment of viral formation, and subsequently resulted in significant reduction in the wasp parasitism. This study reports that two wasp genes (or not encapsidated viral genes) are implicated in the viral DNA amplification and viral coat protein production during the polydnaviral replication.