This paper presents the most common methods for extracting (including Baermann funnel, mistifier, maceration, sieving, elutriation and flotation techniques), processing, examining (handling and fixing) and detecting plant and soil nematodes. Some molecular techniques (e.g. DNA extraction, PCR, sequencing and amplified fragment length polymorphism) available for detection and identification of nematodes are also discussed.
These findings demonstrate that a range of factors influence a woman's choice of contraceptive. This highlights the importance of individualized counselling during contraceptive selection to ensure that the option recommended is tailored to the personal preferences of each woman to improve compliance, continuance and prevention of an unwanted pregnancy.
The hermaphroditic species Rhabditis guentheri sp. n. from decaying tissue of rice plants in Vietnam is described, separated from previously described Rhabditis species by its more or less reduced posterior ovotestis. In rare cases sperms or oocytes are formed in it, though it could not be determined whether eggs ever matured and were fertilized. Only three degenerate males were found. This species exhibits a very poor fecundity with a maximal number of 60 offspring. The new species belongs to the Dolichura-group. Though the species of the Insectivora-group have a leptoderan and those of the Dolichura-group a peloderan bursa, there are convincing apomorphic characters to hypothesize both as sister taxa. They are united under the subgenus name Oscheius (Andrássy, 1976) with Dolichorhabditis as junior synonym. So a peloderan bursa must have been evolved independently within Rhabditis; and Pellioditis is not monophyletic. Diagnoses are presented for Oscheius, the Dolichura-group (seven species) and the Insectivora-group (five species); likewise a key to identify all the known species of the Dolichura-group. Rhabditis brzeskii is nom. nov. for Cruznema velatum Brzeski, 1989. R. guentheri sp. n. is a transitory form to a nematode possessing only an anterior hermaphroditic gonad. This form is discussed in detail in the more general context of whether a didelphic or a monodelphic condition is primitive within nematodes and if there are constraints for a reduction of one genital branch.
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