To investigate the relationship between genetic distance (GD) and hybrid performance, two types of molecular markers, microsatellites (simple sequence repeats, SSRs) and intro-simple sequence repeats (ISSRs), were emp...To investigate the relationship between genetic distance (GD) and hybrid performance, two types of molecular markers, microsatellites (simple sequence repeats, SSRs) and intro-simple sequence repeats (ISSRs), were employed to detect the genetic diversity of 3 double low self-incompatible lines and 22 male parental varieties of Brassica napus from different geographical origins. Hybrids were produced in a NCⅡ mating design by hand-pollination. The result indicated that 25 parental varieties (lines) could be divided into six groups by Un-weighted Pair Group Mathematics Average (UPGMA) clustering based on GDs. SI-1300 and SI-1320 could be singly clustered into one group, respectively. Varieties from China could be separated into another group, SI-1310 and varieties from foreign countries could be separated into other three groups. The grouping was generally consistent with parental pedigrees and geographical origins. Significant differences in yield, quality and phenological period traits were observed among these parent groups. Although hybrid yield/plant showed significantly positive correlation with genetic distance based on SSR and ISSR markers, but the determination coefficient was low. It appeared to be unsuitable for using the genetic distance based on SSR and ISSR markers to predict heterosis and hybrid performance in Brassica napus.展开更多
S-locus genes were cloned from three Brassica napus and three B. campestris lines by using PCR walking and homologuesequence methods. A phylogenetic gene tree was constructed based on the six cloned genes and fifty-on...S-locus genes were cloned from three Brassica napus and three B. campestris lines by using PCR walking and homologuesequence methods. A phylogenetic gene tree was constructed based on the six cloned genes and fifty-one previouslyreported SLG/SRK genes of Brassica and Raphanus. The SLGs from R. sativus were dispersed in the phylogenetic treeintermingling with SLG/SRKs from B. oleracea, B. napus and B. campestris. The SLG/SRK genes of classⅡclusteredindependently in one group. The SLG/SRK genes of classⅠshowed to be more divergent than classⅡgenes. Theseresults suggested that the divergence of classⅠand classⅡ should have occurred before the differentiation of thegenera Brassica and Raphanus. In addition, SLG and SRK of the same S haplotypes belonged to the same class. Itsuggested that class-Ⅰ and class-Ⅱ group divergence occurred first, and then SLG and SRK diverged. The three SC SRKgenes from B. napus and B. campestris were grouped into one cluster, displaying difference from the SC SLG of B.oleracea. These three SC SRK genes were close to SI SRK of SI1300, SI271 and guanyou in phylogenetic relationships.These results indicated that SC and SI genes diverged more recently. It is not clear yet whether the differentiation of SCand SI genes was earlier than the differentiation of Brassica and Raphanus. Studies based on more genes are necessaryfor a comprehensive elucidation of the phylogenetic relationships in Brassicaceae.展开更多
文摘To investigate the relationship between genetic distance (GD) and hybrid performance, two types of molecular markers, microsatellites (simple sequence repeats, SSRs) and intro-simple sequence repeats (ISSRs), were employed to detect the genetic diversity of 3 double low self-incompatible lines and 22 male parental varieties of Brassica napus from different geographical origins. Hybrids were produced in a NCⅡ mating design by hand-pollination. The result indicated that 25 parental varieties (lines) could be divided into six groups by Un-weighted Pair Group Mathematics Average (UPGMA) clustering based on GDs. SI-1300 and SI-1320 could be singly clustered into one group, respectively. Varieties from China could be separated into another group, SI-1310 and varieties from foreign countries could be separated into other three groups. The grouping was generally consistent with parental pedigrees and geographical origins. Significant differences in yield, quality and phenological period traits were observed among these parent groups. Although hybrid yield/plant showed significantly positive correlation with genetic distance based on SSR and ISSR markers, but the determination coefficient was low. It appeared to be unsuitable for using the genetic distance based on SSR and ISSR markers to predict heterosis and hybrid performance in Brassica napus.
基金supported by the Outstanding Youth Science Funds(39825117)Bohai University Science Funds(BJ2004001),P.R.China
文摘S-locus genes were cloned from three Brassica napus and three B. campestris lines by using PCR walking and homologuesequence methods. A phylogenetic gene tree was constructed based on the six cloned genes and fifty-one previouslyreported SLG/SRK genes of Brassica and Raphanus. The SLGs from R. sativus were dispersed in the phylogenetic treeintermingling with SLG/SRKs from B. oleracea, B. napus and B. campestris. The SLG/SRK genes of classⅡclusteredindependently in one group. The SLG/SRK genes of classⅠshowed to be more divergent than classⅡgenes. Theseresults suggested that the divergence of classⅠand classⅡ should have occurred before the differentiation of thegenera Brassica and Raphanus. In addition, SLG and SRK of the same S haplotypes belonged to the same class. Itsuggested that class-Ⅰ and class-Ⅱ group divergence occurred first, and then SLG and SRK diverged. The three SC SRKgenes from B. napus and B. campestris were grouped into one cluster, displaying difference from the SC SLG of B.oleracea. These three SC SRK genes were close to SI SRK of SI1300, SI271 and guanyou in phylogenetic relationships.These results indicated that SC and SI genes diverged more recently. It is not clear yet whether the differentiation of SCand SI genes was earlier than the differentiation of Brassica and Raphanus. Studies based on more genes are necessaryfor a comprehensive elucidation of the phylogenetic relationships in Brassicaceae.
