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21.
甘薯愈伤组织中的淀粉酶   总被引:7,自引:0,他引:7  
从甘薯愈伤组织和块根可溶性提取物中淀粉酶的非变性凝胶电泳和活性染色发现 ,愈伤组织和块根的淀粉酶完全不同。前者有 4种不同大小的淀粉酶 (2种α 淀粉酶和 2种 β 淀粉酶 ) ,而后者只有一种 (β 淀粉酶 ) ;其次 ,块根 β 淀粉酶对EDTA和 β 巯基乙醇都不敏感 ,而愈伤组织的淀粉酶对EDTA和 β 巯基乙醇都敏感。这些结果表明甘薯愈伤组织中不仅淀粉酶同工酶的数量多 ,而且包括α和 β两种类型。  相似文献   
22.
Sphagnum mosses serve as a unique habitat for microorganisms, which play an important role both for the host plants and the peatland ecosystems. The aim of the present study was to isolate endophytic bacteria from the tissues of Sphagnum mosses and to screen them for strains promising for further application in agricultural microbiology. About 50 samples of Sphagnum fallax (H. Klinggr.) H. Klinggr. and Sphagnum magellanicum Brid. were collected in the Austrian Alps and the Lenindgrad Region of Russia in 2009–2010. Endophytic bacteria were detected inside the moss plants using fluorescent in situ hybridization (FISH) followed by confocal laser scanning microscopy (CLSM). Altogether, 283 isolates were obtained by cultivation on the nutrient media. Examination of the isolates for the antagonistic activity revealed that more than 50% of them could suppress the growth of phytopathogenic and toxigenic fungi. More than 30% of isolates showed some antagonistic activity against microbial phytopathogens. The isolated strains could colonize crops and promote their growth. Molecular-genetic identification coupled with physiological/biochemical characterization showed that the dominant endophytic groups belonged to the genera Burkholderia, Pseudomonas, Flavobacterium, Serratia and Collimonas. The isolated endophytes were shown to be promising objects for the development of effective growth-promoting and protective microbiological preparations to be used in agriculture.  相似文献   
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The degree of dominance and the heritability coefficient have been investigated as the markers of allelic interactions of the loci Rht8 and Rht-B1. The interaction is characterized by partial or total dominance or even by overdominance of greater plant height and by low or medium heritability. The alleles that exert a weaker direct negative effect or no such effect predominate over the alleles that predispose to a more pronounced reduction of plant height. The impact of weather conditions on the switch of dominance is discussed. The Kooperatorka line has an additional allele (or alleles) that predisposes to greater plant height; the mode of inheritance of these alleles is partially recessive. An unidentified semidominant gene (or genes) that determines small plant height is present in the genotype of the Odes’ka 3 line. The presence of heterosis related to heterozygosity for certain genes not critically relevant for the present study makes the assessment of the allelic interaction characteristics under investigation more complicated.  相似文献   
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依据1996年、2003—2007年扎龙保护区丹顶鹤巢址数据,利用Voronoi图理论,分析了巢址的空间分布特征,计算了其拓扑指数—Voronoi图面积。结果表明,丹顶鹤巢址空间分布具有明显的空间聚类特征。以扎龙保护区的2006年巢址、居民点、国道和铁路为对象,构成其Voronoi图,较好地说明了人类活动对丹顶鹤巢址的空间格局的影响,研究结果对丹顶鹤栖息地的保护将起到重要作用。  相似文献   
28.
非生物胁迫下植物表观遗传变异的研究进展   总被引:2,自引:0,他引:2  
植物在整个生命过程中固着生长,不能主动躲避外界不良环境的危害,需要通过自身的防御机制来抵御和适应外界胁迫,而表观遗传修饰在调控植物应对不良环境胁迫中起重要作用。该文从DNA甲基化、组蛋白修饰、染色质重塑和非编码RNA等方面进行了综述,主要阐述了近年来国内外有关非生物胁迫下植物的表观遗传变化,以期为利用表观遗传变异提高植物的抗胁迫能力提供参考。  相似文献   
29.
目的:建立人CTRP4基因的转基因小鼠,为脂肪细胞因子CTRP4的体内功能研究奠定基础。方法首先构建人CTRP4的转基因小鼠线性化表达载体,再利用显微注射的方法将载体注射入小鼠受精卵,从而构建人CTRP4的首建鼠( Founder )并与野生型小鼠交配繁殖得到F1代阳性小鼠,再通过近亲繁殖与测交的方法,得到CTRP4转基因纯合子小鼠,并通过PCR和western blot 的方法对纯合子小鼠进行鉴定。结果得到人CTRP4转基因小鼠纯合子小鼠两个品系,western blot鉴定该转基因小鼠心脏,肝脏,脑,肾脏等多种组织中均呈现CTRP4高表达。结论成功构建了人CTRP4转基因小鼠纯合子小鼠。  相似文献   
30.
Investigation of the pleiotropic effects of GA-sensitive (Rht8) and GA-insensitive (Rht-B1 and Rht-D1) winter bread wheat dwarfing genes and the gene that determines the response of plants to photoperiod—Ppd-D1—were carried out for 3 years in the southern step region of the Black Sea bank on five different genetic backgrounds. It is shown that, in addition to direct effects on plant height, GA-sensitive and GA-insensitive dwarfing genes have pleiotropic effects on all studied traits except the number of fertile spikelets. Presence of the dwarfing genes in the genotype of tall forms led to the decrease of stem and ear length, and, at the same time, to the increase of ear density. The number of spikelets per spike decreased due to sterile spikelets, whereas the number of fertile spikelets did not change. There was a significant increase in the number of grains per ear as a result of increasing of spikelets in ears. The number and weight of grains did not decrease, even though the plants were characterized by a smaller number of productive tillers. The presence of Rht8x allele on genetic background of variety Stepnyak resulted in a significant decrease of plants productivity. However, in combination with Ppd-D1a allele, plants with Rht8x increased the potential productivity and surpassed the parental form (Rht8x Ppd-D1a). The presence of Rht-Ble allele resulted in reduction of weight of kernels from the main ear and 1000-kernels weight, increase of l/h, and left the number of seeds per spikelet stable in comparison with Rht8x.  相似文献   
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