Population structure and phylogenetic relationships in Brassica rapa L. subspecies by using isozyme markers / Estrutura populacional e relações filogenéticas em subespécies de Brassica rapa L. utilizando marcadores isoenzimáticos

Abstract The present study aimed to assess population structure and phylogenetic relationships of nine subspecies of Brassica rapa L. represented with thirty-five accessions cover a wide range of species distribution area using isozyme analysis in order to select more diverse accessions as supplementary resources that can be utilized for improvement of B. napus. Enzyme analysis resulted in detecting 14 putative polymorphic loci with 27 alleles. Mean allele frequency 0.04 (rare alleles) was observed in Cat4A and Cat4B in sub species Oleifera accession CR 2204/79 and in subspecies trilocularis accessions CR 2215/88 and CR 2244/88. The highest genetic diversity measures were observed in subspecies dichotoma, accession CR 1585/96 (the highest average of observed (H0) and expected heterozygosity (He), and number of alleles per locus (Ae)). These observations make this accession valuable genetic resource to be included in breeding programs for the improvement of oilseed B. napus. The average fixation index (F) is significantly higher than zero for the analysis accessions indicating a significant deficiency of heteozygosity. The divergence among subspecies indicated very great genetic differentiation (FST = 0.8972) which means that about 90% of genetic diversity is distributed among subspecies, while 10% of the diversity is distributed within subspecies. This coincides with low value of gene flow (Nm = 0.0287). B. rapa ssp. oleifera (turnip rape) and B. rapa ssp. trilocularis (sarson) were grouped under one cluster which coincides with the morphological classification.

Resumo O presente estudo teve como objetivo avaliar a estrutura populacional e as relações filogenéticas de nove subespécies de Brassica rapa L. representadas com 35 acessos, cobrindo uma ampla gama de áreas de distribuição de espécies usando análise isoenzimática, a fim de selecionar acessos mais diversos como recursos suplementares que podem ser utilizados para melhoria de B. napus. A análise enzimática resultou na detecção de 14 loci polimórficos putativos com 27 alelos. A frequência média de 0,04 alelo (alelos raros) foi observada em Cat4A e Cat4B, nas subespécies Oleifera CR 2204/79 e nas subespécies trilocularis CR 2215/88 e CR 2244/88. As maiores medidas de diversidade genética foram observadas na subespécie dicotômica CR 1585/96 (a média mais alta observada (H0) e heterozigosidade esperada (He) e número de alelos por locus (Ae). Essas observações tornam esse acesso um valioso recurso genético a ser incluído em programas de melhoramento de oleaginosas B. napus. O índice médio de fixação (F) é significativamente maior que 0 para os acessos à análise, indicando uma deficiência significativa de heterozigose. A divergência entre as subespécies indicou uma grande diferenciação genética (FST = 0,8972), o que significa que cerca de 90% da diversidade genética é distribuída entre as subespécies, enquanto 10% da diversidade é distribuída nas subespécies. Isso coincide com o baixo valor do fluxo gênico (Nm = 0,0287). B. rapa ssp. oleifera (nabo) e B. rapa ssp. trilocularis (sarson) foram agrupados conforme a classificação morfológica.

Population structure and phylogenetic relationships in Brassica rapa L. subspecies by using isozyme markers.

The present study aimed to assess population structure and phylogenetic relationships of nine subspecies of Brassica rapa L. represented with thirty-five accessions cover a wide range of species distribution area using isozyme analysis in order to select more diverse accessions as supplementary resources that can be utilized for improvement of B. napus. Enzyme analysis resulted in detecting 14 putative polymorphic loci with 27 alleles. Mean allele frequency 0.04 (rare alleles) was observed in Cat4A and Cat4B in sub species Oleifera accession CR 2204/79 and in subspecies trilocularis accessions CR 2215/88 and CR 2244/88. The highest genetic diversity measures were observed in subspecies dichotoma, accession CR 1585/96 (the highest average of observed (H0) and expected heterozygosity (He), and number of alleles per locus (Ae)). These observations make this accession valuable genetic resource to be included in breeding programs for the improvement of oilseed B. napus. The average fixation index (F) is significantly higher than zero for the analysis accessions indicating a significant deficiency of heteozygosity. The divergence among subspecies indicated very great genetic differentiation (FST = 0.8972) which means that about 90% of genetic diversity is distributed among subspecies, while 10% of the diversity is distributed within subspecies. This coincides with low value of gene flow (Nm = 0.0287). B. rapa ssp. oleifera (turnip rape) and B. rapa ssp. trilocularis (sarson) were grouped under one cluster which coincides with the morphological classification.

Population structure and phylogenetic relationships in Brassica rapa L. subspecies by using isozyme markers

Abstract The present study aimed to assess population structure and phylogenetic relationships of nine subspecies of Brassica rapa L. represented with thirty-five accessions cover a wide range of species distribution area using isozyme analysis in order to select more diverse accessions as supplementary resources that can be utilized for improvement of B. napus. Enzyme analysis resulted in detecting 14 putative polymorphic loci with 27 alleles. Mean allele frequency 0.04 (rare alleles) was observed in Cat4A and Cat4B in sub species Oleifera accession CR 2204/79 and in subspecies trilocularis accessions CR 2215/88 and CR 2244/88. The highest genetic diversity measures were observed in subspecies dichotoma, accession CR 1585/96 (the highest average of observed (H0) and expected heterozygosity (He), and number of alleles per locus (Ae)). These observations make this accession valuable genetic resource to be included in breeding programs for the improvement of oilseed B. napus. The average fixation index (F) is significantly higher than zero for the analysis accessions indicating a significant deficiency of heteozygosity. The divergence among subspecies indicated very great genetic differentiation (FST = 0.8972) which means that about 90% of genetic diversity is distributed among subspecies, while 10% of the diversity is distributed within subspecies. This coincides with low value of gene flow (Nm = 0.0287). B. rapa ssp. oleifera (turnip rape) and B. rapa ssp. trilocularis (sarson) were grouped under one cluster which coincides with the morphological classification.

Resumo O presente estudo teve como objetivo avaliar a estrutura populacional e as relações filogenéticas de nove subespécies de Brassica rapa L. representadas com 35 acessos, cobrindo uma ampla gama de áreas de distribuição de espécies usando análise isoenzimática, a fim de selecionar acessos mais diversos como recursos suplementares que podem ser utilizados para melhoria de B. napus. A análise enzimática resultou na detecção de 14 loci polimórficos putativos com 27 alelos. A frequência média de 0,04 alelo (alelos raros) foi observada em Cat4A e Cat4B, nas subespécies Oleifera CR 2204/79 e nas subespécies trilocularis CR 2215/88 e CR 2244/88. As maiores medidas de diversidade genética foram observadas na subespécie dicotômica CR 1585/96 (a média mais alta observada (H0) e heterozigosidade esperada (He) e número de alelos por locus (Ae). Essas observações tornam esse acesso um valioso recurso genético a ser incluído em programas de melhoramento de oleaginosas B. napus. O índice médio de fixação (F) é significativamente maior que 0 para os acessos à análise, indicando uma deficiência significativa de heterozigose. A divergência entre as subespécies indicou uma grande diferenciação genética (FST = 0,8972), o que significa que cerca de 90% da diversidade genética é distribuída entre as subespécies, enquanto 10% da diversidade é distribuída nas subespécies. Isso coincide com o baixo valor do fluxo gênico (Nm = 0,0287). B. rapa ssp. oleifera (nabo) e B. rapa ssp. trilocularis (sarson) foram agrupados conforme a classificação morfológica.

The homology of the major storage protein of jack bean (Canavalia ensiformis) to pea vicilin and its separation from α-mannosidase.

The major storage protein of jackbean (Canavalia ensiformis) has been purified by a protocol involving ammonium-sulphate precipitation, gel filtration and ion-exchange chromatography. The protein was shown by partial amino-acid-sequence data to be homologous to vicilin, a major storage protein of pea (Pisum sativum), and is thus a member of the family of legume 7S proteins exemplified by pea vicilin. This protein is thus referred to as jack-bean vicilin rather than "canavalin" or "precanavalin" as previously used. Other properties of the jack-bean vicilin (e.g. subunit relative molecular mass (Mr) and structure, resistance to proteolysis) show similarity to phaseolin, the major 7S storage protein ofPhaseolus vulgaris. Jack-bean vicilin contained no detectable α-mannosidase activity, either as isolated from mature or germinating seeds, or after proteolytic treatment. α-Mannosidase was also purified from jack beans, and was shown to have a subunit Mr of approx. 120,000; it was separated completely from jack-bean vicilin by a similar protocol to that used for purifying the latter. The α-mannosidase was proteolytically cleaved after seed germination, but did not give polypeptides of the same Mr as jackbean vicilin. It was concluded that α-mannosidase and jack-bean vicilin are not related proteins.