नीलतरण केकडा के पालन पद्धति में व्यवस्थित अशन योजना

कृपया पूरा लेखा पढ

Some observations on the trend of zooplankton and Its probable influence on local pelagic fisheries at Colachel during 1973-74

The zooplankton standing crop showed three peaks of abundance, in March, September and December, the first two peaks during the periods of high salinity. In the order of abundance, the forms which constituted the bulk of the plankton were copepods, cladocerans, cirrepede larvae, Lucifer, chaetognaths and appendicularians. The copepod distribution was found to have characters common both to that of the adjacent coastal waters of Bay of Bengal on the southeast coast and to that of the Arabian sea on the southwest coast. The peak occurrence of cladocerans during May-July was followed by the appearance of juvenile mackerels in early August. Pelagic fish catch, consisting mostly of anchovies and lesser sardines, showed clear peaks, closely following the primary and secondary peaks of plankton. The peak occurrence of anchovies during September-October seems to be in prey-predator relationship with ribbonfish, the peak of which followed closely

Piper barberi gamble - a redescription of the species with a note on the karyotype

P. barberi was described by Gamble (1924) based on the male plants only. Here the species is being redescribed based on the female plant characters as well. P. barberi is a unique species among the Piper taxa occurring in South India. The somatic chromosome numbel' of P. barberi was determined to be 2n = 52. &nbsp

Mechanism of Resistance in Mungbean [Vigna radiata (L.) R. Wilczek var. radiata] to bruchids, Callosobruchus spp. (Coleoptera: Bruchidae)

Mungbean [Vigna radiata (L.) R. Wilczek var. radiata] is an important pulse crop in Asia, and is consumed as dry seeds and as bean sprouts. It is an excellent source of digestible protein. Bruchids [Callosobruchus chinensis (L.) and Callosobruchus maculatus (F.)] are the important pests of mungbean and cause damage in the field and in storage. Bruchid infestation reduces the nutritional and market value of the grain and renders seeds unfit for human consumption, agricultural and commercial uses. These pests are controlled mainly by fumigation with highly toxic chemicals such as carbon disulfide, phosphene, and methyl bromide, or by dusting with several other insecticides, which leave residues on the grain, thus, threatening food safety. Some plant-based extracts have been found useful in controlling bruchids, but are not fully successful due to their short-term activity, rapid degradability, and potentially negative effect on seed germination. Although some wild sources of bruchid resistance in mungbean have been reported, which have been used to develop bruchid- resistant lines, undesirable genetic linkages threaten the proper exploitation of genetic diversity from wild germplasm into commercial cultivars. Further, biotype variation in bruchids has rendered some mungbean lines susceptible that otherwise would have been resistant to the pest. Host plant resistance is a cost-effective and a safe alternative to control bruchids in mungbean and is associated with morphological, biochemical, and molecular traits. These traits affect insect growth and development, thereby, reduce the yield losses by the pests. Understanding the defense mechanisms against insect pests could be utilized in exploiting these traits in crop breeding. This review discusses different traits in mungbean involved in defense against bruchids and their utility in pest management. We also highlight the breeding constraints for developing bruchid-resistant mungbean and how can these constraints be minimized. We further highlight the importance of supporting conventional breeding techniques by molecular techniques such as molecular markers linked to bruchid resistance

Observations on the distribution and seasonal fluctuations of Chaetognaths off Vizhinjam, Southwest coast of India

The distribution and seasonal abundance of Chaetognaths belonging to the genera Sagitta Quoy and Gaimard and Ptemagitta Costa collected during the cruises of Cadahin-VI between January and December, 1990 from three sectors off Vizhinjam, on the southwest coast of India, were studied in relation to hydrographic factors. Sagitta urfIata was the most dominant species for the greater part of the year and the present study revealed that this species is a continuous breeder with several peaks of intensive spawning. Species such as Sagitta farox. S. robusta and S. pacifca are recorded only during the premonsoon and later postmonsoon periods

Genome-wide association study in accessions of the mini-core collection of mungbean (Vigna radiata) from the World Vegetable Gene Bank (Taiwan)

Background: Mungbean (Vigna radiata (L.) R. Wilczek, or green gram) is important tropical and sub-tropical legume and a rich source of dietary protein and micronutrients. In this study we employ GWAS to examine the genetic basis of variation in several important traits in mungbean, using the mini-core collection established by the World Vegetable Center, which includes 296 accessions that represent the major market classes. This collection has been grown in a common field plot in southern European part of Russia in 2018. Results: We used 5041 SNPs in 293 accessions that passed strict filtering for genetic diversity, linkage disequilibrium, population structure and GWAS analysis. Polymorphisms were distributed among all chromosomes, but with variable density. Linkage disequilibrium decayed in approximately 105 kb. Four distinct subgroups were identified within 293 accessions with 70% of accessions attributed to one of the four populations. By performing GWAS on the mini-core collection we have found several loci significantly associated with two important agronomical traits. Four SNPs associated with possibility of maturation in Kuban territory of Southern Russia in 2018 were identified within a region of strong linkage which contains genes encoding zinc finger A20 and an AN1 domain stress-associated protein. Conclusions: The core collection of mungbean established by the World Vegetable Center is a valuable resource for mungbean breeding. The collection has been grown in southern European part of Russia in 2018 under incidental stresses caused by abnormally hot weather and different photoperiod. We have found several loci significantly associated with color of hypocotyl and possibility of maturation under these stressful conditions. SNPs associated with possibility of maturation localize to a region on chromosome 2 with strong linkage, in which genes encoding zinc finger A20 and AN1 domain stress associated protein (SAP) are located. Phenotyping of WorldVeg collection for maturation traits in temperate climatic locations is important as phenology remains a critical breeding target for mungbean. As demand rises for mungbean, production in temperate regions with shorter growing seasons becomes crucial to keep up with needs. Uncovering SNPs for phenology traits will speed breeding efforts

Larval rearing of mud crab, Scylla tranquebarica (Fabricius, 1798) and feeding requirements of its zoea

Feeding experiments were conducted with zooplankton to find out the suitable food for zoea1 of the mud crab Scylla tranquebarica. Zoeae1 from seven berried females, three from wild and four from rematured specimens were the source material for the present study. The veliger larvae (50-55μm) of pearl oyster and two species (Pseudodiaptomus spp. and Labidocera spp.) of pelagic copepods (500-1000 μm) were tested as feed. However, the zoea1 accepted only the former. The feeding activity could be resolved into 5 stages. Significant role of the serrated caudal setae in prey abrasion into required size suitable to mandibles for mastication and the size preference of the items of diet in relation to the growth of the mandibles with the advancement of zoeal stage also have been discussed. In all the 7 feeding experiments that were conducted by providing rotifer, Brachionus rotundiformis (<100 μm), the zoea1 advanced to zoea3/zoea4 or the first crab stage. The present study is a significant development in narrating the feeding behaviour of zoea1