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81.
82.
Rong-Cai Yang Mohan R. Thiagarajah Vipan K. Bansal Gary R. Stringam M. Habibur Rahman 《Euphytica》2006,148(3):217-225
Summary The segregation and linkage between glufosinate (transgenes ‘Rf3’ and ‘T177’) and blackleg resistance genes in canola (Brassica napus L.) were assessed using F1 microspore-derived doubled haploid (DH) populations from four crosses including reciprocals, two involving the transgene ‘Rf3’ and the other two involving the transgene ‘T177’. To relax the assumption of no segregation distortion required for the conventional analysis of segregation and linkage, we employed Bailey's analysis that allows detecting segregation distortion at linked loci. The significant departures from the 1:1 segregation were detected in the crosses involving the transgene ‘T177’ but not in the crosses involving the transgene ‘Rf3’. The apparent deficit of the herbicide tolerant DH lines in the crosses with the transgene ‘T177’ is likely due to differential selection against the gametes carrying ‘T177’ during microspore culture. The linkage was strong between blackleg resistance and the transgene ‘Rf3’ but weak or absent between blackleg resistance and the transgene ‘T177’, suggesting that the two transgenes are probably inserted into distant regions of the genome. The observed linkage offers an opportunity to develop new canola cultivars with both glufosinate tolerance conferred by transgene ‘Rf3’ and blackleg resistance. 相似文献
83.
Peyman Norouzi Mohammad Sabzehzari Hasan Zeinali 《Journal of Crop Science and Biotechnology》2015,18(5):319-323
Sugar beet (Beta vulgaris L.) is one of the two major products supplying sugar (sucroses) in the world. Rhizomania is one of the most destructive diseases of sugar beet world-wide. Holly is the major source of resistance to rhizomania. The objectives of this study were to identify the dominant homozygous genotypes resistant to rhizomania using ZN1 molecular marker, to field evaluate S1 progenies of plants already proved to be containing the marker and also to determine the relationship of this and other SCAR (sequence characterized amplified region) markers with SNP1 (single nucleotide polymorphism) marker associated with the Rz 1 gene. Molecular analysis was carried out on 27 O-type populations (consisting of 13 susceptible and 6 resistant genotypes). Field evaluation and scoring of the phenotypic traits including greenness, growth, uniformity and disease score of 12 O-type populations were carried out on a rhizomania-infested field. The percent agreement of coupling marker ZN1 and repulsion marker ZN8 with disease score was 0.91 and 0.93, respectively. Although all O-types had the Rz 1 resistance gene but the phenotypic differences were observed due to the effect of different genetic backgrounds and modifier genes. Overall, the results showed that the selected markers can be used for marker-assisted selection (MAS) to reduce the time and cost of breeding programs and increase the efficiency of selection. 相似文献
84.
Resynthesis of Brassica napus L. for self-incompatibility: self-incompatibility reaction, inheritance and breeding potential 总被引:3,自引:0,他引:3
M. H. Rahman 《Plant Breeding》2005,124(1):13-19
Self-incompatibility (SI) in Brassica has been considered as a pollination control mechanism for commercial hybrid seed production, and so far has been extensively used in vegetable types of Brassicas. Oilseed rape Brassica napus (AACC) is naturally self-compatible in contrast to its parental species that are generally self-incompatible. Introduction of S-alleles from its parental species into oilseed rape is therefore needed to use this pollination control mechanism in commercial hybrid seed production. Self-incompatible lines of B. napus , carrying SI alleles in both A and C genomes, were resynthesized from self-incompatible B. oleracea var. italica (CC) cv.'Green Duke' and self-incompatible B. rapa ssp. oleifera (AA) cv. 'Horizon', 'Colt' and 'AC Parkland'. All resynthesized B. napus lines exhibited strong dominant SI phenotype. Reciprocal cross-compatibility was found between some of these self-incompatible lines. The inheritance of S-alleles in these resynthesized B. napus was digenic confirming that each of the parental genomes contributed one S-locus in the resynthesized B. napus lines. However, the presence of two S-loci in the two genomes was found not to be essential for imparting a strong SI phenotype. Possible use of these dominant self-incompatible resynthesized B. napus lines in hybrid breeding is discussed. 相似文献
85.
Starch biosynthesis in plants involves the concerted action of a numberof enzymes, including ADPglucose pyrophosphorylase, starch synthases,branching enzymes and debranching enzymes. We report on the cloningand characterisation of genes encoding these enzymes from wheat and ontheir chromosomal locations. The prospects for manipulating wheat starchstructure and functionality using these genes is discussed. 相似文献
86.
Inter-generation correlations between F2-F3, F2-F4 and F3-F4 in six crosses of chickpea were calculated by using individual plant/progeny means. In general, correlation values in case of plant height, seeds per pod and 100-seed weight were higher between F3 and F4 than those between F2 and F3 and F2 and F4. However, inter-generation correlations were mostly non-significant in case of pods per plant and grain yield. These results clearly show that selection in F3 can be fruitful for seeds per pod and 100-seed weight. However, selection for pods per plant and grain yield in early generations may not show any relationship with later generation performance for these traits. 相似文献
87.
A yellowish brown‐seeded Brassica alboglabra was resynthesized from a (B. alboglabra×Brassica carinata) ×B. alboglabra cross, followed by self‐pollination. The resynthesized B. alboglabra lost the allele of the isozymic locus glucosephosphate isomerase‐2 (GPI‐2) from natural B. alboglabra, which was replaced by an allele from the corresponding genome in B. carinata. A simple Mendelian segregation of these two alleles was observed in the F2 population of a natural × resynthesized B. alboglabra cross. Furthermore, these two alleles segregated independently from the seed colour. 相似文献
88.
Diurnal raptors were surveyed in Central Sulawesi on foot in 16 sample areas, and by car along 2700 km road transects in August-September 2000. All 23 resident species were recorded and their frequency of occurrence assessed in broad habitat categories. Farmlands were unusually poor in raptors. Of their six associated species, the formerly common black kite (Milvus migrans) may be almost extirpated. Indiscriminate pesticide use is suspected to be a major factor. Wetlands and sea-coasts are limited in area and are also the most heavily disturbed natural habitats. All four piscivorous eagles were found to be rare or very local. Among them, only the grey-headed fishing-eagle (Ichthyophaga ichthyaetus) was found to be more frequent than was previously known. Excessive human fishing pressure may be the main threat, together with extensive wetland conversion into ricefields or fishponds. Forest raptors (13 species), including all Sulawesi endemic Falconiformes, were the most numerous and widespread birds of prey. Although they exhibited a fairly high tolerance to forest degradation and fragmentation (insular syndrome), their main threat is the high deforestation rate, especially the loss of the presumably more productive lowland forests. 相似文献
89.
90.
Common bean (Phaseolus vulgaris L.) proved to be very sensitive of low pH (4.3), with large genotypic differences in proton sensitivity. Therefore, proton toxicity did not allow the screening of common bean genotypes for aluminium (Al) resistance using the established protocol for maize (0.5 mM CaCl2, 8 μM H3BO3, pH 4.3). Increasing the pH to 4.5, the Ca2+ concentration to 5 mM, and addition of 0.5 mM KCl fully prevented proton toxicity in 28 tested genotypes and allowed to identify differences in Al resistance using the inhibition of root elongation by 20 μM Al supply for 36 h as parameter of Al injury. As in maize, Al treatment induced callose formation in root apices of common bean. Aluminium‐induced callose formation well reflected the effect of Ca supply on Al sensitivity as revealed by root‐growth inhibition. Aluminum‐induced callose formation in root apices of 28 bean genotypes differing in Al resistance after 36 h Al treatment was positively correlated to Al‐induced inhibition of root elongation and Al contents in the root apices. However, the relationship was less close than previously reported for maize. Also, after 12 h Al treatment, callose formation and Al contents in root apices did not reflect differences in Al resistance between two contrasting genotypes, indicating a different mode of the expression of Al toxicity and regulation of Al resistance in common bean than in maize. 相似文献