Parasite (1982)

Khan

Nematologist, AICRP (nematode), Directorate of Research, Bidhan Chandra Krishi Viswavidyalaya, PO Kalyani, Nadia, Pin-741235, West Bengal, India

Email: mrkhanbckv@rediffmail.com

Operation of the resistance in crops is one of the most efficient and environmentally friendly components of integrated pest management and the inclusion of this property allows an increased yield of crops in the presence of the nematode. The resistance of nematodes in the host plant is manifested by reduced levels of nematode reproduction, and consequently low population density of nematodes in the rhizosphere of crops as a sentient being. The crop cultivars showing high degree of resistance of all functions are generally acceptable agronomic recommended for fields infested with nematodes, or as a culture of routine or sequence of crop rotation. Therefore, the growth of nematode resistant cultivars against the target nematode species of nematodes correct identity claims with the dominant race (s) existing in the region.

Screening germplasm / varieties against plant parasitic nematodes require preparation of inoculum pure nematode species identified and races, sterile soil, and evaluation or scale inoculation technique for evaluating the resistance response nematodes. For screening, a simple dosing is most essential for processing large numbers of genetic material. The main objective of testing is to expose people to the plant parasitic nematode resistant genotypes to differentiate those susceptible. Often, the dosage cons nematodes, the final nematode population (Pf) is compared with the initial population inoculated (Pi) for calculating reproduction factor (RF = Pf / Pi). Generally the resistance in the host countries is characterized by the ability of nematodes to reproduce on the host genotype and / or responses of compatibility.

root-knot nematodes induce symptoms most common and conspicuous of galls on roots and masses of eggs on hosts very sensitive. The size of galls vary from small (1-2mm in diameter) to large tumor size (> 1 cm in diameter) as hosts. The blister appears on the root system either quietly or galls many merged galls forming a manifold. The largest galls can contain more than one female in small galls contain a single woman. The galls on the roots do not necessarily mean that there should be a female Meloidogyne because it is a symptom of an attack by nematodes. Therefore, the clinical diagnosis of the root system is essential in the dissection of roots under a microscope for confirmation of participation with the symptoms of nematodes (Taylor & Sasser, 978).

For the process of routine screening of crop germplasm, the term most commonly used "resistant" and "sensitive" with various intermediate categories are used to express the degree of response of genotypes resistant test. To evaluate the response resistant against nematodes, host suitability / compatibility for the nematode is determined by their reproductive capacity of the host. Usually, the plant high resistance, nematode reproduction is lower compared to moderate and weak plants. Thus, the sensitivity is mainly measured by the reproduction of the nematode on the host and not on the basis of root galling one.

Plant-parasitic nematodes are obligate parasite need nutritional needs and environment of the host for its survival, but any kind of inhibition or resistance response exhibited by the host to establish the results of the feeding site poor development of parasites. After entering into the host by the second-stage juveniles, t.