ABSTRACT
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.
Subject(s)
Brassica napus , Brassica rapa/genetics , Phylogeny , Genetic Variation/genetics , Plant Breeding , Isoenzymes/geneticsABSTRACT
Genetically modified (GMO) rapeseed (Brassica napus) is not grown commercially in European Union, but several lines have been approved for production and use as food and feed. A case-specific monitoring of herbicide-tolerant rapeseed, events RT73, RF3 and T45 was established by Ministry of Agriculture of Republic of Serbia. The objectives of the present study were to introduce methods for detection of herbicide-tolerant GM oilseed rape, investigate occurrence and monitor the presence of GM rapeseed in seed and the feed products, as well as to develop a protocol for quantification. The study was based on 48 samples, rapeseed (33) and feed (15) products, imported from EU countries (Germany, Belgium, France, Czech Republic, Austria) and from domestic market. Seven positive feed samples and no positive seed samples have found. The percent of GMO in feed samples, estimated on semi-quantitative way, was below labelling threshold. Adventitious presence of GM materials in non-GM grain, derived food and feedstuffs is a concern to international grain trade and needs continuous monitoring.
Subject(s)
DNA, Plant/analysis , Brassica rapa/genetics , Environmental Monitoring , Organisms, Genetically Modified , DNA, Plant/genetics , Polymerase Chain Reaction , YugoslaviaABSTRACT
Many novel lines were established from an intergeneric mixoploid between Brassica rapa (2n = 20) and Orychophragmus violaceus (2n = 24) through successive selections for fertility and viability. Pedigrees of individual F(2) plants were advanced to the 10th generation by selfing. Their breeding habit was self-compatible and different from the self-incompatibility of their female parent B. rapa, and these lines were reproductively isolated to different degrees from B. rapa and B. napus. The lines with high productivity showed not only a wide spectrum of phenotypes but also obvious variations in fatty acid profiles of seed oil and glucosinolate contents in seed meal. These lines had 2n = 36, 37, 38, 39 and 40, with 2n = 38 being most frequent (64.56%), and no intact O. violaceus chromosomes were detected by genomic in situ hybridization (GISH) analysis. Amplified fragment length polymorphism (AFLP) analyses revealed a high extent of variation in genomic compositions across all the lines. O. violaceus-specific bands, deleted bands in B. rapa and novel bands for two parents were detected in these lines, with novel bands being the most frequent. The morphological and genetic divergence of these novel types derived from a single hybrid is probably due to rapid chromosomal evolution and introgression, and provides new genetic resources for rapeseed breeding.