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Seven markers linked to QTL involved in CTV accumulation, leafminer resistance and apomictic reproduction were used to characterize 64 sour orange ( Citrus aurantium L.) accessions from three national collections in order to identify a representative core in which the resistance behaviour against two Citrus tristeza virus (CTV) isolates was studied. Different degrees of apomixis were found between the foreign collections. Most of the C. aurantium accessions fall into three main groups based on three multilocus genotypes. The haplotype diversity at three CTV accumulation QTL-linked markers was further studied by sequence analysis of alleles. Genotypic and allelic diversity at one of them, tightly linked to Ctv-R 2 in Poncirus trifoliata (L.) Raf. , match the plant–CTV interaction types reported among Poncirus and Citrus species. Only those selected accessions from the major group presented CTV resistance during 30 months of continuous growth, but later the resistance broke down in some plants. CTV tolerance appears related to slow growing genotypes. Certain micronutrients: Mn, and B depending on the accession, might play a relevant role in this host–pathogen interaction particularly in alkaline soils. 相似文献
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Elymus rectisetus( Nees in L ehm ) A.L ove et Connor是目前小麦族 ( Triticeae)中发现的唯一的无融合生殖种。本研究以普通小麦 ( Triticum aestivum L.;2 n=6x=4 2 ,AABBDD)为母本 ,以E.rectisetus( 2 n=6x=4 2 ,SSYYWW)为父本进行杂交 ,经过幼胚拯救获得了属间杂种 F1。杂种 F1分蘖力强 ,具有多年生习性 ,其形态特征偏向于父本。杂种 F1高度雄性不育 ,自交不结实。对杂种根尖体细胞的细胞学观察发现 ,杂种 F1体细胞染色体数 2 n=9x=63( SSYYWWABD) ,其中 2 1条来自普通小麦 ,4 2条来自 E.rectisetus。花粉母细胞染色体配对频率为 :2 2 .69 16.15rod 3.0 1ring 0 .83 0 .0 1 。小麦白粉病抗性鉴定结果表明 ,杂种 F1及父本 E.rectisetus表现免疫 ,而母本Fukuhokomugi高度感染白粉病。上述杂种的获得为将 E.rectisetus无融合生殖基因及抗白粉病基因向小麦中转育奠定了基础。 相似文献
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摩擦禾属于禾本科玉蜀黍族摩擦禾属,起源于美洲,与玉米、大刍草具有共同祖先,其在玉米的起源与进化过程中可能扮演着重要角色。摩擦禾是一种多年生暖季型丛生C4禾草,常用于优质饲草料生产、控制土壤侵蚀和生物质能源。其作为玉米的近缘属材料,保存有栽培玉米不具有的优质、抗病、抗寒、耐涝、耐盐和多年生等多种优良基因,是拓展玉米遗传基础的重要种质。本文从摩擦禾属的习性和分布、摩擦禾属的分类、摩擦禾属的种间可杂交性、摩擦禾属与玉蜀黍属杂交性、摩擦禾属的优良特性和摩擦禾基因向玉米转移的途径等方面进行综述,为摩擦禾属的研究和利用提供参考。 相似文献
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中国水稻无融合生殖的研究进展 总被引:1,自引:0,他引:1
目前,在二倍体水平上选育水稻无融和生殖种质的难度较大,而在多倍体水平筛选水稻无融和生殖新种质已成为水稻无融和生殖研究新的生长点。研究者已明确提出水稻无融合生殖育种的主要目标,即全显性和简单性、专一性和自发性、兼有性和致死性、多倍性和杂和性。 相似文献
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