Tags: Business Disaster Recovery PlanEssay Writing About SchoolAssigned OptionsBusiness Plan Of A Car WashHow To Write A Literature EssayEssays In Persuasion
More than 4,100 species of plant-parasitic nematodes (PPNs) have been identified (Decraemer and Hunt, 2006) and some of them cause damage to economically important crops.
In some cases, the effect of nematode parasitism is not only associated with the feeding site, but it extends to adjacent tissues; for example, in the case of Meloidogyne spp. “Nematode parasitism of plants,” in Physiology and Biochemistry of Free-Living and Plant Parasitic Nematodes, eds R.
or Nacobbus aberrans, the first produce coenocytes and the second a syncytium, both with similar cell proliferation around the feeding sites that finally form a root gall.
Plant-parasitic nematodes (PPNs) interact with plants in different ways, for example, through subtle feeding behavior, migrating destructively through infected tissues, or acting as virus-vectors for nepoviruses. doi: 10.1093/jxb/ert219 Pub Med Abstract | Cross Ref Full Text | Google Scholar Jones, J.
They are all obligate biotrophic parasites as they derive their nutrients from living cells which they modify using pharyngeal gland secretions prior to food ingestion.
For this feeding and interaction with plants, they need a stylet (a hollow mouth spear, like a hypodermic needle), which is highly variable in length and shape.
Furthermore, PPNs usually possess three to five pharyngeal glands that produce secretions, most of which are emitted thorough the stylet, that assist plant-nematode interaction (i.e., penetration, internal migration, and parasitism).
The fourth-stage juveniles penetrate plant trough buds, petioles, lenticels, or stomata and subsequently move intercellularly through the middle lamella. Some of these have been recently separated as individual species (i.e., D. (F) Longitudinal section of parenchyma of a stem portion showing sub-epidermal cavities (ca) surrounded by necrotic cells.
Symptoms in the plant are leaf or bulb deformities, short internodes, and in some species true neoplastic tissues similar to galls are formed (Figures 1A–G). (G) Cross-section of flower parenchyma showing a nematode (n), and hypertrophied nuclei (hn) in the attacked cells (Vovlas et al., 2015b; with permission of Cambridge University Press). doi: 10.1111/j.1364-3703.2009.00539.x Pub Med Abstract | Cross Ref Full Text | Google Scholar Hogenhout, S.
Groups iii and iv are the most important in terms of crop losses.
This variability of feeding sites may be related in some way to PPN life style (migratory ectoparasites, sedentary ectoparasites, migratory ecto-endoparasites, migratory endoparasites, or sedentary endoparasites).