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Registro Completo |
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Biblioteca(s): |
Embrapa Meio Norte / UEP-Parnaíba. |
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Data corrente: |
09/12/1993 |
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Data da última atualização: |
09/12/1993 |
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Autoria: |
FRANKEL, O. H. |
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Afiliação: |
CSIRO Division of Plant Industry, Canberra, Australia. |
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Título: |
Genetic resources as the backbone of plant protection. |
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Ano de publicação: |
0 |
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Fonte/Imprenta: |
s.n.t. |
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Idioma: |
Português |
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Conteúdo: |
The defence against parasites has come to be regarded as probably the biggest problem in the production of the plants on which our own survival depends. The problem has always been there, but in our pure-bred cultivars extending over large areas it has assumed disaster proportions. The wild ancestors of many crop species evolved in balance with parasite species, their regions of genetic diversity coinciding. Domestication led to geographical dispersal and genetic differentiation of host and, presumably, of parasite species. Genetic heterogeneity may have been the saving grace of the primitive cultivars by which fairly stable populations lived for some 5000 to 10000 years. We are now aware of the advantages and of the dangers of genetic homogeneity, and "genetic vulnerability" is now more than a catch phrase. We are responding to it in a variety of ways, each involving some use of new or increased genetic variation. They extend from the scarch for new oligogenic resistance sources, to multiple resistance, and to the various forms of "horizontal" or polygenic resistance. We turn to the genetic resources accumulated in the much neglected wild and primitive gene pools which helped our ancestors to survive epidemies. And we turn furcher towards the full circle by deliberately adopting heterogeneity in multilines of various descriptions and in varietal blends. The rate at which resistance sources are "used up" in the different systems now in use is discussed, in the light of the urgent need for economizing and... MenosThe defence against parasites has come to be regarded as probably the biggest problem in the production of the plants on which our own survival depends. The problem has always been there, but in our pure-bred cultivars extending over large areas it has assumed disaster proportions. The wild ancestors of many crop species evolved in balance with parasite species, their regions of genetic diversity coinciding. Domestication led to geographical dispersal and genetic differentiation of host and, presumably, of parasite species. Genetic heterogeneity may have been the saving grace of the primitive cultivars by which fairly stable populations lived for some 5000 to 10000 years. We are now aware of the advantages and of the dangers of genetic homogeneity, and "genetic vulnerability" is now more than a catch phrase. We are responding to it in a variety of ways, each involving some use of new or increased genetic variation. They extend from the scarch for new oligogenic resistance sources, to multiple resistance, and to the various forms of "horizontal" or polygenic resistance. We turn to the genetic resources accumulated in the much neglected wild and primitive gene pools which helped our ancestors to survive epidemies. And we turn furcher towards the full circle by deliberately adopting heterogeneity in multilines of various descriptions and in varietal blends. The rate at which resistance sources are "used up" in the different systems now in use is discussed, in the light of the u... Mostrar Tudo |
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Palavras-Chave: |
Diseases; Doencas; Melhoramento genetico; Plant; Resistance. |
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Thesagro: |
Planta; Resistência. |
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Thesaurus Nal: |
breeding. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 02027naa a2200217 a 4500
001 1073987
005 1993-12-09
008 bl --- 0-- u #d
100 1 $aFRANKEL, O. H.
245 $aGenetic resources as the backbone of plant protection.
260 $c0
520 $aThe defence against parasites has come to be regarded as probably the biggest problem in the production of the plants on which our own survival depends. The problem has always been there, but in our pure-bred cultivars extending over large areas it has assumed disaster proportions. The wild ancestors of many crop species evolved in balance with parasite species, their regions of genetic diversity coinciding. Domestication led to geographical dispersal and genetic differentiation of host and, presumably, of parasite species. Genetic heterogeneity may have been the saving grace of the primitive cultivars by which fairly stable populations lived for some 5000 to 10000 years. We are now aware of the advantages and of the dangers of genetic homogeneity, and "genetic vulnerability" is now more than a catch phrase. We are responding to it in a variety of ways, each involving some use of new or increased genetic variation. They extend from the scarch for new oligogenic resistance sources, to multiple resistance, and to the various forms of "horizontal" or polygenic resistance. We turn to the genetic resources accumulated in the much neglected wild and primitive gene pools which helped our ancestors to survive epidemies. And we turn furcher towards the full circle by deliberately adopting heterogeneity in multilines of various descriptions and in varietal blends. The rate at which resistance sources are "used up" in the different systems now in use is discussed, in the light of the urgent need for economizing and...
650 $abreeding
650 $aPlanta
650 $aResistência
653 $aDiseases
653 $aDoencas
653 $aMelhoramento genetico
653 $aPlant
653 $aResistance
773 $ts.n.t.
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Registro original: |
Embrapa Meio Norte / UEP-Parnaíba (CPAMN-UEPP) |
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