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931.
Detection and analysis of inter- and intraspecific diversity of Pratylenchus spp. using isozyme markers 总被引:1,自引:0,他引:1
The root-lesion nematodes of the genus Pratylenchus are an economically important group of plant parasitic nematodes that show high similarity among sibling species. Isozyme patterns obtained by isoelectrofocusing (IEF) were used to differentiate and establish genetic relatedness among Pratylenchus species. A total of 40 populations comprising 9 Pratylenchus species and Radopholus similis from broad host and geographic origins was examined to compare isozyme patterns of esterase (EST), hexoquinase (HK), isocitrate dehydrogenase (IDH), malate dehydrogenase (MDH), phosphoglucose isomerase (PGI), phosphoglucomutase (PGM) and superoxide dismutase (SOD). Of these systems, only EST, MDH, PGI and PGM were useful for differentiation of P. vulnus , P. goodeyi , P. penetrans , P. scribneri , P. thornei and R. similis populations. The greatest intraspecific diversity was found within P. coffeae based on the isozyme patterns for MDH, PGI and PGM. Intraspecific variability was also detected among R. similis populations, which showed two isozyme patterns in EST and PGI systems. Less intraspecific variation was found within the P. penetrans group. The P. goodeyi population from Cameroon differed from the other populations in this specific group in its MDH, PGI and PGM phenotypes. Highly similar banding patterns of EST, MDH and PGI activity were found among the P. scribneri populations and the one population of P. agilis . A cluster analysis of the 40 populations, generated from the four enzyme banding patterns, produced groupings that broadly matched the previous classification into specific groups, reflecting intraspecific variability in some cases. The results confirm the potential use of isozyme patterns as markers for these nematode species and their value for diagnostic application. 相似文献
932.
933.
934.
甘蓝型油菜人工合成种遗传多样性分析 总被引:11,自引:0,他引:11
用RAPD及SSR技术对98份甘蓝型油菜人工合成种与46份甘蓝型油菜品种(系)进行遗传多样性分析。30条随机引物共扩增出332条带,其中多态性带309条,多态性比率为93.07%。33对SSR引物共扩增出134条带,其中多态性带129条,多态性比率为96.27%。经聚类分析与主成分分析,表明甘蓝型油菜人工合成种遗传多样性十分丰富。因此通过人工 相似文献
935.
内蒙古绒山羊产绒量和体重性状RAPD标记的初步研究 总被引:8,自引:0,他引:8
利用12条随即引物对27只内蒙古绒山羊基因组DNA进行预扩增,筛选出具有多态性扩增产物的4条引物进行RAPD分析,共得到51个标记,其中可变标记43个,标记条带多态性频率为0.84,扩增片断长度在176-2940bp之间。RAPD标记条带与经济性状关系分析表明:CY0816引物扩增产物的ABCFHO组合、F09引物的INR组合为内蒙古绒山羊产绒量的优势组合型;CY0816引物扩增产物的GIJOPQR条带组合为体重性状标记的优势组合型。 相似文献
936.
Comparisons of RFLP and PCR-based markers to detect polymorphism between wheat cultivars 总被引:1,自引:0,他引:1
Previously chromosome 3A of wheat (Triticum aestivum L.) was reported to carry genes influencing yield, yield components, plant height, and anthesis date. The objective of current
study was to survey various molecular marker systems for their ability to detect polymorphism between wheat cultivars Cheyenne(CNN)
and Wichita (WI), particularly for chromosome3A. Seventy-seven `sequence tagged site' (STS), 10simple sequence repeat (SSR),
40 randomly amplified polymorphic DNA (RAPD) markers, and 52 restriction fragment length polymorphism (RFLP) probes for wheat
homoeologous group 3 chromosomes, were investigated. Three (3.9%) STS-PCR primer sets amplified polymorphic fragments for
the two cultivars, of which one was polymorphic for chromosome 3A. Sixty percent of SSR markers detected polymorphism between
CNN and WI of which 50% were polymorphic for chromosome 3A. Twenty percent of RAPD markers detected polymorphism between CNN
and WI in general, but none of these detected polymorphism for chromosome 3A. Of the fifty-two RFLP probes, 78.8% detected
polymorphism between CNN and WI for group 3 chromosomes with one or more of seven restriction enzymes and 42% of the polymorphic
fragements were for chromosome 3A. These high levels of RFLP and SSR polymorphisms between two related wheat cultivars could
be used to map and tag genes influencing important agronomic traits. It may also be important to reconsider RFLP as the most
suitable marker system at least for anchor maps of closely related wheat cultivars.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
937.
938.
RFLP analysis allows for the identification of alfalfa ecotypes 总被引:2,自引:0,他引:2
Three seed lots, obtained from different ‘foundation farms’, for each of the alfalfa, Medicago sativa L., ecotypes ‘Vogherese’ and ‘Maremmana’, together with the variety ‘Iside’ as a control, were studied to test the possibility of distinguishing them through restriction fragment length polymorphism analysis. Twenty plants per seed lot were analysed with 25 DNA probes that yielded 155 informative polymorphic fragments. Variance partitioning showed that within‐population variability accounted for nearly 98% of the total variance, while a small but significant contribution to the total variance was due to among‐lot variability.‘Vogherese’ was more homogeneous than ‘Maremmana’, as a consequence of the greater environmental homogeneity of the adaptation area of the former ecotype compared with the latter. Bulk analysis yielded eight variety‐specific bands, 12 bands present in both ecotypes and absent in the variety and one band specific of ‘Maremmana’. Results are discussed in relation to the practical use of molecular markers for alfalfa ecotype identification. 相似文献
939.
Molecular mapping and gene action of Scm1 and Scm2, two major QTL contributing to SCMV resistance in maize 总被引:4,自引:0,他引:4
Sugarcane mosaic virus (SCMV) is one of the most important virus diseases of maize in Europe. In this study, the gene action at two major quantitative trait loci (QTL) affecting resistance to SCMV in maize was mapped and characterized. A total of 121 F3 lines from cross F7 (susceptible) × FAP1360A (resistant) were evaluated for SCMV resistance in replicated field trials across two environments under artificial inoculation at seven scoring dates. The genotypic variance was always highly significant and heritability increased up to 0.92 for later scoring dates. The method of composite interval mapping was employed for QTL mapping using four simple sequence repeat (SSR) markers flanking two regions identified in a previous study with cross D145 × D32. The presence of two QTL for SCMV resistance, one on chromosome 6 (Scml region) and one on chromosome 2 (Scm2 region), was confirmed. These two QTL together explained between 15% (first score) and 62% (final score) of the phenotypic variance at various stages of plant development. Gene action was additive for the Scm1 region but completely dominant for the Scm2 region. Comparison of results of this study with those obtained for cross D145 × D32 suggested that the resistance alleles in the two populations are identical for the Scm1 region but different for the Scm2 region. 相似文献
940.
The scald susceptible barley cultivar ‘Clipper’ and a third‐backcross (BC3) line homozygous for the Rrs14 scald resistance gene that originally came from Hordeum vulgare ssp. spontaneum were grown in replicated field trials. The level of resistance that Rrs14 confers against field populations of the pathogen Rhynchosporium secalis, the causal agent of scald disease, was evaluated. The Rrs14 BC3 line exhibited 80% and 88% less leaf damage than ‘Clipper’ in 1995 and 1996, respectively. Given this effectiveness of Rrs14, research was undertaken to identify a linked marker locus suitable for indirect selection of Rrs14. Based on linkage to a set of previously mapped loci, Rrs14 was positioned to barley chromosome 1H between the seed storage protein (hordein) loci Hor1 and Hor2, approximately 1.8 cM from the latter locus. The Hor2 locus is thus an ideal codominant molecular marker for Rrs14. The tight linkage between Rrs14 and Hor2 and the availability of alternative biochemical and molecular techniques for scoring Hor2 genotypes, permits simple indirect selection of Rrs14 in barley scald resistance breeding programmes. 相似文献