Plant-parasitic nematodes associated with sugarcane in Kilimanjaro, Tanzania

Abstract

Morphological and molecular analyses of plant-parasitic nematodes (PPN) from 12 sugarcane plantation sites of Tanganyika Planting Company (TPC) Limited in Kilimanjaro region of Tanzania revealed the presence of six PPN genera, i.e. Helicotylenchus, Hemi cycliophora, Pratylenchus, Rotylenchulus, Scutellonema, and Tylenchorhynchus. The genera with the highest densities and present in virtually all samples were Pratylenchus and Rotylenchulus, and the most important species appeared to be R. parvus, P. zeae, T. crassicaudatus, and T. ventrosignatus. A total sequences of 11 partial ITS, 15 D2-D3 of 28S, and 6 partial 18S of rRNA gene, and 7 partial COI gene of mtDNA of these species were obtained in this study. Morphology and molecular data comparisons between the Tanzanian R. parvus and the South African R. parvus indicated that R. parvus is a cryptic species complex. Based on the results of morphological and molecular analyses of T. crassicaudatus and T. agri from China, Haiti, Indonesia, Iran, Niger and the USA, T. agri syn. n. is proposed as a junior synonym of T. crassicaudatus.

Molecular identification of root-lesion nematodes, Pratylenchus spp. in agricultural crops from Costa Rica

“…Therefore, the presence of this crops permits the reproduction and survival of the nematode species and might reduce the positive impact of the sugar cane/rice rotation system (Nzogela et al, 2020;Santos et al, 2012). P. zeae has been associated with significant yield reduction in sugarcane and rice crops (Namu et al, 2018;Nzogela et al, 2020;Singh et al, 2020). The genetic heterogeneity shown within the P. zeae populations from Costa Rica is consistent with previous reports (Carta et al, 2001;Mwamula et al, 2020;Subbotin et al, 2008), and supports that P. zeae could be a species complex.…”

“…However, the identification of the genus Pratylenchus is complex due to the number of validated species and the variation within the same species (Nguyen et al, 2019). The morphological identification of Pratylenchus is challenging for diagnostics because of the presence of cryptic species (Bogale et al, 2021) that make some of the species identifiable only by DNA analysis (Singh et al, 2020). Molecular tools for species identification can help to overcome these problems and have become essential for accurate classification (De Luca et al, 2012;Janssen, Karssen, Couvreur, et al, 2017;Janssen, Karssen, Orlando, et al, 2017;Palomares-Rius et al, 2014).…”

An Integrated Approach for Synonymization ofRotylenchus rhomboideswithR.goodeyi(Nematoda: Hoplolaimidae) Reveals High Intraspecific Mitogenomic Variation

“…Such high intraspecific variability in ITS is not uncommon in nematodes, as was demonstrated for several PPNs, including Pratylenchus spp. (De Luca et al 2011;Janssen et al 2017;Troccoli et al 2008;Waeyenberge et al 2000), R. eximius populations from Italy and Tunisia (18% differences; Singh et al 2021a), and Rotylenchulus parvus populations from Tanzania and South Africa (18 to 21% differences; Singh et al 2020b). In addition to the high intraspecific variability in ITS, a high intraindividual ITS variability has been demonstrated, for example, within Pratylenchus spp.…”

Phytonematodes associated with the yellowing disease of Javanese long pepper plants in Sumenep, East Java

“…Tail is slightly longer than that of immature females. Spicules are arcuate ventrally [18]. IOP Publishing doi:10.1088/1755-1315/974/1/012032 5 monodelphic reproductive system.…”