优良水稻品种“明恢63”基因组的cosmid文库

以优良水稻（ＯｒｙｚａｓａｔｉｖａＬ．）品种“明恢６３”为材料,以“ＳｕｐｅｒＣｏｓ１”为载体构建了Ｃｏｓｍｉｄ文库。共获得了４５０００个克隆,平均插入片段大小为４０ｋｂ左右,含插入片段的频率为１００％。该文库的容量约为水稻单倍体基因组的４．２倍。     

优良水稻品种“明恢63”BAC文库的构建

“明恢６３”是我国许多重要的水稻杂交组合中的恢复系。为了对其进行深入的遗传学研究以及克隆控制重要农艺性状的基因,以细菌人工染色体（ｐＢｅｌｏＢＡＣ１１）为载体,克隆经限制性内切酶消化后部分收集的“明恢６３”基因组ＤＮＡ,将连接混合物转化细菌ＤＨ１０Ｂ,构建了细菌人工染色体（ＢＡＣ）文库。该文库共有２６０００个转化子,插入片段为９０～２４０ｋｂ,平均大小为１５０ｋｂ。经计算该文库覆盖９倍水稻基因组。该文库正在用于构建几个基因所在区段的物理图谱,为图位克隆打下基础     

广谱型花生根瘤菌97—1菌株在花生和大豆根瘤中的分化和繁殖能力

比较了广谱型花生根瘤菌97—1菌株在花生和大豆根瘤中的形态分化和类菌体的繁殖能力。结果表明,97—1菌株在花生根瘤中分化为典型的球状类菌体,未观察到它们的繁殖,根瘤小杆菌的繁殖率也很低,并表现出随瘤龄增加而加大的趋势,渗透压保护条件对幼龄根瘤小杆菌的繁殖有一定影响。但在大豆根瘤中却分化为典型的杆状粪菌体,其繁殖能力随瘤龄加大而增加,并且不需要渗透压保护条件。本研究结果直接证明,宿主植物影响根瘤菌在根瘤中的形态分化和繁殖特性。     

The defense-responsive genes showing enhanced and repressed expression after pathogen infection in rice (Oryza sativa L.)

Despite large numbers of studies about defense response, processes involved in the resistance of plants to incompatible pathogens are still largely uncharacterized. The objective of this study was to identify genes involved in defense response by cDNA array analysis and to gain knowledge about the functions of the genes involved in defense response. Approximately 20000 rice cDNA clones were arrayed on nylon filters. RNA samples isolated from different rice lines after infection with incompatible strains or isolates of Xanthomonas oryzae pv. oryzae or Pyricularia grisea, respectively, were used to synthesize cDNA as probes for screening the cDNA arrays. A total of 100 differentially expressed unique sequences were identified from 5 pathogen-host combinations. Fifty-three sequences were detected as showing enhanced expression and 47 sequences were detected as showing repressed expression after pathogen infection. Sequence analysis revealed that most of the 100 sequences had various degrees of homology with