Description of Tylenchulus musicola sp. n. (Nematoda: Tylenchulidae) from banana in Iran with molecular phylogeny and characterisation of species of Tylenchulus Cobb, 1913

Abstract

During a survey conducted on banana plantations in Sistan and Blouchestan province, south-east Iran, a new species of Tylenchulus was extracted from the soil and roots of banana plants. This species, named Tylenchulus musicola sp. n., is characterised by mature females having a swollen, hook-shaped body with a conical and elongate post-vulval portion ending in a round terminus, males having a weak stylet and a cylindrical and thick tail ending in a bluntly rounded and smooth terminus, and by second-stage juveniles having a slender body and a posterior body portion ending in a finely pointed or mucronate terminus. The results of glasshouse host tests indicated that the new species does not parasitise sugarcane ratoons or sour orange seedlings. Tylenchulus musicola sp. n. is distinguished from other known Tylenchulus species by the sequences of D2-D3 expansion segments of 28S rRNA and ITS rRNA genes. Phylogenetic relationships within Tylenchulus were reconstructed based on rRNA gene sequences using Bayesian inference. Diagnostic PCR-ITS-RFLP profiles are presented for T. musicola sp. n., T. furcus, T. graminis, T. palustris, T. semipenetrans and Trophotylenchulus floridensis. PCR with species-specific primers and genus-specific primer are tested and developed for rapid identification of five Tylenchulus species. An identification key to Tylenchulus species is provided.

Distribution, morphology, seasonal dynamics, and molecular characterization of Tylenchulus semipenetrans from citrus orchards in southern Iran

“…(DQ328716) and Coslenchus costatus (DQ328719) were used as outgroup. This selection was based on earlier studies (Decraemer & Hunt 2006;Tanha Maafi et al 2012;van Megen et al 2009). The original partial 28S sequences of T. semipenetrans are deposited in the GenBank under accession numbers KM598333 (Citrus sp.…”

Development and Evaluation of Loop-Mediated Isothermal Amplification Assay for Rapid Detection of Tylenchulus semipenetrans Using DNA Extracted from Soil

“…Furthermore, for PCR-based detection methods, DNA extraction is performed using individual nematode from a nematode suspension (Liu et al, 2011; Maafi et al, 2012; Rashidifard et al, 2015). The operational procedures of these methods are time-consuming, and require J2 of T. semipenetrans to be distinguished from the nematode mixture as well, which is not a simple and rapid diagnosis for T. semipenetrans .…”

“…In the present study, the LAMP primers were designed for detection of T. semipenetrans based on differences in the rDNA-ITS1 sequences of T. semipenetrans and other Tylenchulus species. The genus Tylenchulus presently contains five species: T. semipenetrans , T. furcus , T. graminis , T. musicola, and T. palustris (Maafi et al, 2012), but except for T. semipenetrans , other Tylenchulus species do not occur in China. To determine the efficiency and specificity of the LAMP assay, we used DNA extracted from T. semipenetrans and 12 other nematode species as templates for the LAMP assay.…”

“…In particular, it is difficult to distinguish J2 of T. semipenetrans from many other plant-parasitic and non-plant-parasitic nematode species microscopically. As an alternative strategy for T. semipenetrans identification, molecular diagnostic methods based on polymerase chain reaction (PCR) have been developed and applied, including PCR-restriction fragment length polymorphism (RFLP) of the internal transcribed spacer region (ITS) (Maafi et al, 2012; Park et al, 2009) and PCR with species-specific primer sets designed from rDNA-ITS (Liu et al, 2011; Maafi et al, 2012). While PCR-based detection methods provided faster, more reliable and more sensitive tools for T. semipenetrans identification when compared with traditional morphological method, they are not generally available for routine practical applications at grassroots quarantine stations and plant protection organizations because expensive and sophisticated laboratory equipment and skilled technicians are needed.…”

“…Detecting the presence of T. semipenetrans in the soil is essential for both the diagnosis of the disease and many cropping decisions, especially for establishing a citrus nursery site (Liu et al, 2011). Although PCR-based methods described above identified J2 of T. semipenetrans , they were designed to use DNA extracted from isolated individuals that requires a long operation time and experienced personnel (Liu et al, 2011; Maafi et al, 2012; Rashidifard et al, 2015). Hence, a rapid, simple and time-saving nematode extraction method is also needed for quick diagnostic of T. semipenetrans .…”