In the present paper genetic relationships of twenty varieties of cashew are described on the basis of morphological characters and RAPD (Randomly Amplified Polymorphic DNA) markers. Results obtained for the phenotypic characters based on similarity coefficient were divided into four clusters with 70% similarity. By means of similarity coefficients (S G ), cluster I was found to consist of twelve varieties. Cluster II consisted of a single variety, NRCC-1, cluster III consisted of six varieties and cluster IV had only one variety, Vridhachalam-2. The analysis started by using RAPD markers that allowed us to distinguish 20 varieties. A total of 80 distinct DNA fragments ranging from 0.2 to 3.0 kb were amplified by using 11 selected random 10-mer primers. Genetic similarity analysis was conducted for the presence or absence of bands in the RAPD profile. Cluster analysis clearly showed that 20 varieties of cashew grouped into two major clusters based on similarity indices. The first major cluster comprised one minor cluster. The other major cluster was divided into two sub-minor clusters, one sub-minor cluster having three varieties and the other sub-minor cluster was represented by 15 varieties. Among the 20 varieties, Ullal-3 and Dhana (H-1608) showed the highest similarity indices (87%). It was noted that Vengurla-2 and Vengurla-3 were not grouped into a single cluster but Vengurla-4 has 82% similarity to Vengurla-3. The variety Vengurla-2 has very close similarity (85%) with variety Vridhachalam-3 (M-26/2). The analysis of genetic relationships in cashew using morphological traits and RAPD banding data can be useful for plant improvement, descriptions of new varieties and also for assessment of variety purity in plant certification programmes.

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Phosphogypsum (PG) is the major solid waste generated by phosphate fertilizer plants and is used worldwide as sulfur and calcium supplement in agricultural soil. Considering the probability of elevated doses of PG during agricultural applications, this study was carried out to assess its impact on the connective tissue, tissue cholinesterase (ChE) activity, lactate dehydrogenase (LDH) activity, and lipid peroxidation (LPX) level of the tropical earthworm Glyphidrillus tuberosus (Stephenson) found in abundance in the rice fields in India. Consistent loss of connective tissue and sloughing of the intestinal epithelium were observed in worms exposed to 10%, 15%, and 20% concentrations of PG in soil over an incubation period of 30 days. ChE, LDH activities, and the level of LPX indicated highly significant variation (p < 0.01) between pre and postclitellar regions of the worm and concentrations of treatment. ChE activity was higher in postclitellar with respect to preclitellar region; however, the values for LDH activity and LPX level were higher in preclitellar region in comparison to postclitellar region in both PG treated and control worms. It was concluded that PG concentration at and beyond 10% could cause damage to muscle fibers and bring about significant alterations in these enzyme activities in G.tuberosus thus affecting the physiology and ecological functions of these worms.

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Alterations of soil characteristics that result in reduction in ecosystem services invariably cause soil quality degradation. Such changes could be caused due to a variety of stressors, which might be physical, chemical, or biological and come from both anthropogenic and natural causes. Out of the wide variety of soil pollutants, agrochemicals contaminate soil biota the most. Numerous research’ findings have confirmed that soil has been the most preferred site for the disposal of xenobiotics and therefore is likely to be the source of contamination for other natural resources like ground and surface waters. The ecological risk associated with contaminated soils depends on many physicochemical and biological processes that govern the transport and transformation of pesticides. Nevertheless, the persistence of pesticides in soil is a serious threat to both below and above ground organisms which play key roles in sustaining soil functions. One of the viable methods to decontaminate soil is by utilizing living soil biota selectively. This process called. Bioremediation has traditionally been employed to remove chemical residues from soil or to lessen their toxicity levels. Although microbes have been extensively used for bioremediation, chemical breakdown and remediation are significantly aided by certain dominant soil fauna, such as earthworms. Since they modify soil quality, earthworms are regarded as soil engineers. Earthworms can participate in the degradation of pesticide residues, either directly through the release of detoxifying enzymes in their gut or indirectly through their positive influence on microbial populations which could degrade pesticides. The earthworm supported pesticide degradation is largely confined to the gut microenvironment and the soil processed by the worms. The impact of earthworm species on pesticide degradation is widely variable which could be related to their feeding habits and microhabitats. Molecular docking studies have provided evidence in support of binding of organic molecules with agrochemicals. High level of organic matter in soil is expected to increase the binding of hydrophobic pesticides to organic ligands with consequent reduction in their bioavailability to microorganisms and increasing their persistence. Activities of earthworms is likely to induce growth of aerobic microbes capable of pesticide degradation. Among the various earthworm species, Lumbricus terrestris, Perionyx excavatus and Metaphire posthuma have shown promising results as remediating agents of pesticides contaminating farm soils. The present article focuses on the remediation process of hazardous pesticide polluted soil using biological agent like earthworm. This approach may be both efficient and environmentally beneficial.