Molecular Evaluation of Plant Genetic Resources

Clegg, Michael T.

doi:10.1007/978-1-4899-1136-0_6

Cited by 5 publications

(3 citation statements)

References 38 publications

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“…In deciding to invest substantial resources in this international scheme for maintaining germplasm banks, we have essentially placed a value on the genetic diversity accumulated in crop species. This can also be calculated using what we have learned from coalescence theory (Clegg 1993). If we assume that it would take hundreds of thousands of years to restore genetic diversity once it was lost, we may approximate the future cost of genetic diversity loss in economically important species by applying a modest rate of interest to a crop's value (say 1% a year for several hundred thousand years).…”

Section: Timescales and Diversitymentioning

confidence: 99%

Millions of generations old: Once lost, diversity of gene pools cannot be restored

Clegg¹

1995

Cal Ag

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The present diversity of species is the result of a very long and slow process of genetic change and adaptation. The time necessary for the emergence of new species, and even for the accumulation of genetic variants at individual gene loci within species, greatly exceeds the time since the emergence of Homo sapiens. New techniques of molecular biology combined with recent theories in population genetics allow us to assess the time dimension of genetic change; these suggest that some genetic polymorphisms may have originated over a million generations ago. In other words, once lost, any particular genetic adaptation cannot be regained in any realistic time interval. We depend on biological systems for food, fiber, energy and medicinal needs. Continued advances in each of these areas may be compromised by losses of the

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Section: Timescales and Diversitymentioning

confidence: 99%

Millions of generations old: Once lost, diversity of gene pools cannot be restored

Clegg¹

1995

Cal Ag

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“…There are relatively few reports of genetic markers providing key information for designing and implementing new in situ or ex situ germplasm management programs for newly acquired germplasm. It is somewhat surprising that such genetic assessments, articulated so clearly by a decade ago and reiterated more recently (Clegg 1993), apparently are not conducted frequently as a prelude to germplasm maintenance or utilization efforts. In this section, several examples ofgenetic marker characterization that have preceded, or have helped redirect, plant germplasm management efforts are reviewed.…”

Section: B Acquisitionldistributionmentioning

confidence: 99%

Genetic Markers and Plant Genetic Resource Management

Bretting,

Widrlechner

1993

HortSci

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When suitably deployed, genetic markers facilitate all phases of plant genetic resource management, from acquisition through enhancement. This paper will review the kinds of plant genetic resources and genetic markers, analytical methods for marker data, and specific applications of genetic markers to plant genetic resource management, such as (i) assessing a collection's “gaps” and redundancy; sampling strategies; characterizing newly acquired germplasm; maintaining “trueness to type”; monitoring genetic shifts; monitoring germplasm viability and health; developing optimal utilization strategies from genetic marker data; exploiting associations among horticulturally meritorious traits and genetic markers. Finally, general conclusions and forecasts regarding future prospects for applying genetic markers to these tasks will be presented.

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“…The description, classification of genetic diversity is a main problem of biology (Clegg, 1993). Nowadays, many molecular markers are used to analyze the genetic diversity.…”

Section: Molecular Evaluationmentioning

confidence: 99%

Pharmacognostic specification and rotenone content in derris elliptica stems, macroscopic, microscopic and molecular identification of selected derris species in Thailand

Phairoh¹

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The genus Derris belonging to Fabaceae family are distributed along the equatorial zone in Africa and Asia. In Thailand, 16 species of Derris species can be found throughout the country. Derris elliptica (Hanglai-Dang), is well-known among fishermen and gardeners as fish poison and insecticide, especially the stem and root which contain isoflavonoid compound named rotenone. This study established the pharmacognostic specification of Derris elliptica dried stem crude drug and developed the quantitative analysis of rotenone content in D. elliptica stem using TLC-densitometry and image analysis. The physico-chemical parameters of D. elliptica stem included total ash, acid-insoluble ash, loss on drying and water contents that should not be more than 7, 1, 5 and 8 g/ 100g crude drug, respectively. The ethanol and water extractive values should not be less than 4 and 11 g/ 100 g crude drug, respectively. Microscopic characteristics (transverse section and powder) of D.elliptica stem were illustrated by hand drawing. Rotenone contents obtained from both quantitative TLC were 0.2870 ± 0.1242 and 0.2844 ±0.1209 g/100 g crude drug, respectively which was not statistically significantly different (P > 0.05). In vitro biological activities of the stem ethanolic extract and rotenone revealed the antioxidant, α-glucosidase inhibitory properties and brine shrimp toxicity. MTT assay revealed that the ethanolic extract and rotenone were marginal cytotoxic (LC50 > 20 µg/ml) against the cancer cells (MAD-231, HepG2, HT-29, CaCo-2). Microscopic leaf characteristics including leaf constant numbers of 8 Derris ( D. amonea, D. malaccensis, D. elliptica, D. reticulate, D. trifoliate, D. indica, D. solorioides ) were shown that stomatal number, stomata index, palisade ratio, epidermal cell area, trichome number could be used as the identification key for selected 8 species. DNA fingerprinting using ISSR 11, 12, 14, 17 and 35 as primers produced a total of distinct and reproducible 256 bands. The genetic relationship among selected Derris species presented the similarity index between 0.11 to 0.43. The information from this research can be applied for identification of D. elliptica stems in Thailand as well as providing the information of pharmacogenetic specification, including rotenone content in and in vitro biological properties of D. elliptica stem.

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Molecular Evaluation of Plant Genetic Resources

Cited by 5 publications

References 38 publications

Millions of generations old: Once lost, diversity of gene pools cannot be restored

Millions of generations old: Once lost, diversity of gene pools cannot be restored

Genetic Markers and Plant Genetic Resource Management

Pharmacognostic specification and rotenone content in derris elliptica stems, macroscopic, microscopic and molecular identification of selected derris species in Thailand

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