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991.
植物数量抗病基因克隆及其抗性机理的研究进展 总被引:5,自引:0,他引:5
培育广谱、持久抗病的作物品种,不仅需要深入研究质量抗病性,而且需要更深入地洞悉数量抗病性的可能作用机理。而目前,人们对数量抗病基因的可能特征和数量抗病性的机理的认识还相当模糊,这在很大程度上限制了数量抗病基因在育种实践中的应用。本文首先综述数量性状座位(quantitative trait loci,QTL)的克隆策略和精确获取数量抗病性状值的方法;其次根据数量抗性座位(quantitative resistance loci。QRL)的相关研究进展,对QRL的可能特征进行一定的综述,认为部分QRL的抗性机理直接对应于R基因、抗病基因类似物(resistance geneanalogs,RGA)、防卫基因、防卫反应途径中的相关基因等在植物抗病性上的作用机理;最后,作者推测存在4种抗性特征的QRL,即小种特异性或非特异性QRL和“病原菌”特异性或广谱性QRL,并认为数量抗性持久性的遗传基础与这些不同特征的QRL间有着密切的联系。该综述将对QRL的候选基因分析和克隆、数量抗病机理研究和QRL的育种应用提供有益的参考。 相似文献
992.
993.
患出血病鲫鱼主要组织可溶性蛋白质变化的研究 总被引:4,自引:0,他引:4
采用SDS-聚丙烯酰胺凝胶电泳法(SDS-PAGE)对正常和患出血病的鲫鱼心、肝、肾、鳃、脑、肌肉、肠、眼8种组织中可溶性蛋白质进行比较分析。结果表明:病鱼的心、肝、肾、鳃、脑、肌肉6种组织的蛋白质电泳谱带与正常鱼相比有较大变化,心和肾各缺失5条谱带;肝新诱导出1条谱带,另有1条谱带缺失;鳃中新诱导出2条谱带,有2条谱带缺失;脑中增加了4条新谱带,1条谱带缺失;肌肉新增5条谱带。说明鱼在遭受病原菌侵袭后,蛋白质的合成代谢受到较大影响。这些变化可作为辅助疾病诊断的生化指标。 相似文献
994.
真空碳热还原酸浸含钛高炉渣制备TiC分析 总被引:1,自引:0,他引:1
含钛高炉渣中含有20%~30%的TiO 2,是一种附加值较高的二次资源,但在综合利用过程中存在氧化物还原难度大,硅钛难分离,二次污染严重等问题。基于热力学理论基础,采用真空碳热还原联合酸浸工艺处理含钛高炉渣制备TiC。结果表明:真空有助于钛氧化物彻底还原,可实现渣中硅钛彻底分离,减少酸耗量,降低二次污染。真空碳热还原联合酸浸工艺处理含钛高炉渣(TiO 2含量23%左右)制备TiC的最佳条件为:炉渣粒度200目,还原温度1 673 K,渣碳质量比100∶38。 相似文献
995.
996.
以口蹄疫病毒株OA/58 RNA为模板,反转录并扩增目的cDNA,然后与pGEM-T easy载体连接并转化JM109菌株,提取的重组质粒用凝胶电泳、PCR和EcoR Ⅰ酶切法鉴定.运用同源模建得到OA/58 VP1蛋白3D结构,并结合理化性质、亲水性、可塑性和免疫原性进行分析,预测OA/58 VP1的抗原表位.结果 OA/58 VP1存在多个潜在的抗原表位位点,可能的蛋白质抗原表位区域:2~11,15~35,38~50,77~88,90~107,121~125,131~135,140~149,154~163,169~175,178~189,197~213.应用同源模建得到的OA/58 VP1蛋白3D模型来预测其B细胞表位,为进一步研究OA/58 VP1功能,构建突变体和选择表达新型OA/58 VP1蛋白分子提供有参考价值的信息. 相似文献
997.
Evaluation of common wheat cultivars for tan spot resistance and chromosomal location of a resistance gene in the cultivar 'Salamouni' 总被引:2,自引:0,他引:2
A total of 50 wheat (Triticum aestivum L.) cultivars were evaluated for resistance to tan spot, using Pyrenophora tritici‐repentis race 1 and race 5 isolates. The cultivars ‘Salamouni’, ‘Red Chief’, ‘Dashen’, ‘Empire’ and ‘Armada’ were resistant to isolate ASC1a (race 1), whereas 76% of the cultivars were susceptible. Chi‐squared analysis of the F2 segregation data of hybrids between 20 monosomic lines of the wheat cultivar ‘Chinese Spring’ and the resistant cultivar ‘Salamouni’ revealed that tan spot resistance in ‘Salamouni’ was controlled by a single recessive gene located on chromosome 3A. This gene is designated tsn4. The resistant cultivars identified in this study are recommended for use in breeding programmes to improve tan spot resistance in common wheat. 相似文献
998.
W. D. Bovill W. Ma K. Ritter B. C. Y. Collard M. Davis G. B. Wildermuth M. W. Sutherland 《Plant Breeding》2006,125(6):538-543
Crown rot (causal agent Fusarium pseudograminearum) is a fungal disease of major significance to wheat cultivation in Australia. A doubled haploid wheat population was produced from a cross between line ‘W21MMT70’, which displays partial seedling and adult plant (field) resistance to crown rot, and ‘Mendos’, which is moderately susceptible in seedling tests but partially resistant in field trials. Bulked segregant analysis (BSA) based on seedling trial data did not reveal markers for crown rot resistance. A framework map was produced consisting of 128 microsatellite markers, four phenotypic markers, and one sequence tagged site marker. To this map 331 previously screened AFLP markers were then added. Three quantitative trait loci (QTL) were identified with composite interval mapping across all of the three seedling trials conducted. These QTL are located on chromosomes 2B, 2D and 5D. The 2D and 5D QTL are inherited from the line ‘W21MMT70’, whereas the 2B QTL is inherited from ‘Mendos’. These loci are different from those associated with crown rot resistance in other wheat populations that have been examined, and may represent an opportunity for pyramiding QTL to provide more durable resistance to crown rot. 相似文献
999.
E. C. Roumen 《Euphytica》1992,64(3):173-182
Summary Neck nodes of eight rice genotypes were inoculated with a virulent isolate of the blast pathogen at four slightly different, increasingly older stages of panicle development shortly after flowering. Resistance to infection as well as resistance to growth of the pathogen after infection was assessed. Significant differences between genotypes were found for both components of resistance. Resistance to growth of the pathogen sharply increased with aging of the neck node as was indicated by a large reduction of the length of the lesions on the culm, but resistance to infection did not change much. The lesion length was closely related to yield loss. A small delay in time of infection can lead to a large decrease in yield reduction. Meaningful comparison of partial resistance to neck blast between genotypes therefore requires infection at an identical stage of panicle development. In the field, where panicles are in different stages of development, selection of genotypes that do show the symptoms of neck blast together with relatively little yield loss in infected panicles is recommended. 相似文献
1000.
Summary Male meiosis of the interspecific hybrid between Allium roylei and A. cepa is undisturbed relative to its parents. Based on meiotic data, A. roylei is concluded to be a closer relative of A. cepa than A. fistulosum. Segregation ratios for downy mildew resistance among BC1 and F2 progenies from the F1 between A. roylei and A. cepa indicate the presence of two dominantly inherited, weakly linked nuclear resistance genes, Pd
1 and Pd
2, in A. roylei (recombination frequency 0.32±0.03). Presumably Pd
1 and Pd
2are the first genes described in Allium residing in one linkage group. The prospects of exploiting A. roylei in onion breeding seem very promising. 相似文献