Pratylenchus brachyurus
| Pratylenchus brachyurus | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Nematoda |
| Class: | Adenophorea |
| Subclass: | Diplogasteria |
| Order: | Tylenchida |
| Superfamily: | Tylenchoidea |
| Family: | Pratylenchidae |
| Subfamily: | Pratylenchinae |
| Genus: | Pratylenchus |
| Species: | P. brachyurus |
| Binomial name | |
|
Pratylenchus brachyurus |
|
| Synonyms | |
Pratylenchus brachyurus is a plant parasitic nematode.
Pratylenchus brachyurus, like many other plant-parasitic nematodes, are microscopic worms that can be damaging to many agricultural crops. Across the world, many billions of dollars each year are lost due to the damaging abilities of nematodes on cash crops.P. brachyurus is a migratory endoparasite that enters the roots and moves throughout the root tissue while completing its life cycle.
Under the old classification system based on morphology, these nematodes were under the Class Adenophorea. This changed in 2004 when a new classification system was presented by De Ley and Blaxter using SSU rDNA for comparison between different species of nematodes. Using this new system, De Ley and Blaxter placed P. brachyurus in the Class Chromadorea, Order Rhabditida. In 1929 Godfrey first described P. brachyurus as the main cause for pineapple-root disease and called them Tylenchus brachyurus. He also discussed several other nematodes which were all later put into the Pratylenchus genus. In 1934, Filipjev proposed the genus Pratylenchus. This proposed new genus name came with some challenges because the International Code of Zoological Nomenclature states that the new genus name must come with a statement as to why you want to change the name. It must also give reasons differentiating the new genus plus give the name of the type species. In 1936 the new genus name was universally accepted.
This nematode is a migratory endoparsite that ranges from about 0.4 to 0.5 mm long and has a lip region that is angular and offset from the body. It is generally low and flat and has two distinct annules. P. brachyurus has a short strong stylet about 20 um long and large round basal knobs. It also has a short ventral overlap of the esophagus. The females have lateral fields marked by four incisures. Males are very rare and have one single outstretched testis.
Pratylenchus are second only behind Meloidogyne in terms of crops infested and the extent of crop damage and loss. Pratylenchus brachyurus is widely spread throughout the warmer regions of the world. In Brazil it is the most widely distributed root lesion nematode on coffee. They introduce necrosis in the cortex of the root which is detrimental to the plant. Lesion nematodes severely damage a plant and open points of entry for other bacteria and fungus to enter the root. In the US it is mainly found in southern regions and in Florida it is found in nearly every county. A study in 1969 showed that it is found in 90% of the citrus groves in Florida. Due to P. brachyurus being able to infest a wide range of crops and being so damaging, it is of high economic importance.
These nematodes have the general nematode life cycle with four juvenile stages keeping their vermiform shape throughout the entire life cycle except the egg stage. Any of the stages, except the egg and J1 which molts inside the egg, can infect the root. The nematodes get inside the roots and move throughout the root laying eggs individually in the root cortex and maybe a few in the soil. This particular species of Pratylenchus reproduces by parthenogenesis. The males of this species have not been found very often.
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