• Title/Summary/Keyword: accessions

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Effect of Extended Egg Preservation Schedule in Conservation of Mutant Silkworm (Bombyx mori L.) Genetic Stocks in Gene Bank

  • Muthulakshmi M.;Mohan B.;Balachandran N.;Sinha R. K.;Thangavelu K.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.11 no.2
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    • pp.93-98
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    • 2005
  • Studies on extended egg preservation schedule from 120 days to 180 days was taken up with 20 germplasm accessions of mutant silkworm genetic stocks of Bombyx mori L. Statistical analyses of the data collected over three trials revealed no significant changes both in the qualitative and quantitative traits of the genetic stocks between treatment (6 months egg preservation) and control (4 months egg preservation), except for fifth instar larval duration in TMS-61, TMS-62, TMS64, TMS-31 and TMS-34 shell weight in TMS-62, TMS-64 and TMS-66. Thus, the results indicate that extended schedule of 6 months egg preservation can safely be adopted, which will reduce the cost of conservation and minimize the genetic erosion owing to reduced crop cycle.

Conservation of Multivoltine Silkworm (Bombyx mori L.) Germplasm in India - An Overview

  • Kumaresan, P.;Sinha, R.K.;Mohan, B.;Thangavelu, K.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.9 no.1
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    • pp.1-13
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    • 2004
  • Indian multivoltine mulberry silkworm (Bombyx mori L.) strains are poor in silk productivity and fibre quality. However, they are commercially exploited for the past five decades either in the form of pure breeds or cross breeds because of their adaptability to adverse climatic condition and acclimatization to specific regions and seasons. In the present paper conservation strategies of multivoltine silkworm genetic resources are dealt along with detailed information on accessibility of genetic resources, method of genetic resources conservation, characterization of genetic resources for morphological and productivity traits of economic importance. Selection of best ten accessions based on various economic parameters including yarn quality and their scope for future utilization are discussed.

Study on Inheritance of Potato virus X Resistance in Capsicum annuum

  • Shi, Jinxia;Choi, Do-Il;Kim, Byung-Dong;Kang, Byoung-Cheorl
    • The Plant Pathology Journal
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    • v.24 no.4
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    • pp.433-438
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    • 2008
  • Potato virus X (PVX) resistance in potato is one of the best-characterized resistance models, however little is known in pepper. To evaluate the resistance to PVX in Capsicum annuum, a total of eleven pepper accessions were used for resistance screening against two PVX strains, USA and UK3. None of them were resistant against strain UK3, whereas four resistant genotypes were found against strain USA, three of which were further characterized. Two unlinked dominant genes were identified for both genotypes Bukang and Perennial; resistance in the genotype CV3 seemed to be conferred by two complementary dominant genes. These results demonstrated that the resistance to PVX in C. annuum is different from that in potato. This is the first report on genetic analysis of PVX resistance in C. annuum.

The taxonomic status of Angelica purpuraefolia and its allies in Korea : Inferences based on ITS molecular phylogenetic analyses

  • Lee, Byoung Yoon;Kwak, Myounghai;Han, Jeong Eun;Kim, Se-Jung
    • Korean Journal of Plant Taxonomy
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    • v.41 no.3
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    • pp.209-214
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    • 2011
  • The taxonomy of the umbelliferous species Angelica amurensis and its allies was reviewed on the basis of molecular phylogenies derived from sequences of nuclear ribosomal DNA internal transcribed spacer (ITS) regions. Strict consensus of six minimal length 119-step trees derived from equally weighted maximum parsimony analysis of combined nuclear rDNA ITS1 and ITS2 sequences from 29 accessions of Angelica and outgroups indicated that Angelica purpuraefolia, known to be endemic to Korea, is the same species as A. amurensis. Comparisons of sequence pairs across both spacer regions revealed identity or 1-2 bp differences between A. purpuraefolia and A. amurensis. These results indicated that the two taxa are not distinguished taxonomically. Also, nuclear rDNA ITS regions are discussed as potential barcoding loci for identifying Korean Angelica.

Variability in Specific Leaf Weight in Mulberry Germplasm and Its Inheritance Pattern

  • Sarkar, A.;Mogili, T.;Chaturvedi, H.K.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.7 no.1
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    • pp.69-73
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    • 2003
  • Specific leaf weight (SLW), defined as the mass of tissue per unit leaf area has been found to be an important physiological parameter as it indicates the relative thickness of leaves. Greater SLW provides more photosynthetic potential per unit area of leaf and hence it is frequently been considered as correlated with photosynthesis in several plant species. Collections of 165 mulberry (Morus sp.) germplasm accessions, both Indian and exotic in origin were evaluated for their variability with respect to SLW. The mean specific leaf weight ranged from 35.3 to $72.3 g/m^{-2}$. The distribution of SLW was found to be normal. High heritability (97.08%) and a small difference between genotypic and phenotypic variance demonstrates the genetic control over SLW. Significant heterotic effect with respect to SLW was observed in crosses when parents with high and low SLW were chosen.

Divergence time estimation of an ancient relict genus Mankyua (Ophioglossaceae) on the young volcanic Jejudo Island in Korea

  • GIL, Hee-Young;KIM, Seung-Chul
    • Korean Journal of Plant Taxonomy
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    • v.48 no.1
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    • pp.1-8
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    • 2018
  • Mankyua chejuense is the only member of the monotypic genus Mankyua (Ophioglossaceae) and is endemic to Jejudo Island, Korea. To determine the precise phylogenetic position of M. chejuense, two cpDNA regions of 42 accessions representing major members of lycophytes are obtained from GenBank and analyzed using three phylogenetic analyses (maximum parsimony, maximum likelihood, and Bayesian inference). In addition, the divergence time is estimated based on a relaxed molecular clock using four fossil calibration points. The phylogenetic position of Mankyua still appears to be uncertain, representing either the earliest diverged lineage within Ophioglossaceae or a sister to the clade containing Ophioglossum and Helminthostachys. The most recent common ancestor of Ophioglossaceae and its sister lineage, Psilotum, was estimated to be 256 Ma, while the earliest divergence of Mankyua was estimated to be 195 Ma in the early Jurassic.