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981.
采用室内控制生长条件的营养液培养技术,通过检测缺铁条件下20个中国春的Hope染色体代换系及其亲本中国春和Hope小麦植物铁载本分泌的动态变化规律以及植物铁载体分泌高峰期内5次测定值的汇总资料,对六倍体小麦PS分泌基因进行染色体定位。PS分泌率通过根分泌物对新形成的Fe(OH)3的活化能力进行测定,在缺铁症出现时每隔2,3天测定1次,随着缺铁失绿症严重程度的增加,PS分泌率呈现迅速增高再逐渐降低的 相似文献
982.
983.
Changes of chlorophyll metabolism during the albinic stage including both degreening and regreening processes were studied. The results indicated that an decrease of Cato content was nor the cause of mutant degreening, and that the mutant belonged to the total Chl-dificient type. The changes of Chlase activity level indicated that Chi breakdown was not the main factor which led to degreen of the mutant. A greater changes of content of intermediates of Chl biosynthesis during the albinic period δ-aminolevulinic acid (ALA) and porphohilinogen (PBG) were accumulated, but uroporphyrin Ⅲ (Uro Ⅲ ), protoporphyrin IX (Proto IX ), Mg-protoporphyrin IX (Mg-Proto IX ) and protochlorophyll (ide) (Pchl (lide)) were decreased. Specialy during the degreening process Uro Ⅲ was gradually decreased, but an initiation of regreening, the Uro Ⅲ was markedly accmulated. It was proved that there was a blockage in Chi biosynthesis in the mutant, which could be somewhere in the formation of uroporphyrinogen Ⅲ (Urogen Ⅲ ). 相似文献
984.
985.
介绍了一种灵敏、简便、快速测定双链PCR产物或DNA片断单个碱基差异的方法。该法借助常规PAGE电泳,能区分出有单个碱基错配而发生构型改变的异双聚体与碱基互补配对的同源双聚体双链DNA分子;并判断出序列中碱基错配的百分率。 相似文献
986.
经过10代自交选择,从157细胞质雄性不育基因源中育成了Bao I、 Bao II细胞质雄性不育系。应用35个自交系作测交试验,用小斑菌O、C、T生理小种做人工接种试验,初步确定这二个新类型的属组。Bao I型可能属S组,而Bao II型则为其它组。 相似文献
987.
家蚕分子连锁图谱的构建及分子标记育种研究进展 总被引:1,自引:0,他引:1
国际蚕分子育种计划(International Silkworm Project)是Rhode Island大学的M.R.Goldsmith在1991年提出来的,也叫基因标记育种计划[1].该计划主要包括两步工作:第一步是制作蚕的分子基因图, 第二步是数量性状定位分析(简称QTL分析,也叫数量性状定位作图:QTL Mapping).最后利用分子标记直接在DNA水平进行重要经济性状(数量性状)的选择、固定,即实施"分子育种",用很短时间育成兼具高抗、强健、丝多、质优、易繁等特性的新蚕品种,本文对此进行简要介绍. 相似文献
988.
J. Langbein ‡ M. R. Hutchings § S. Harris C. Stoate † S. C. Tapper† S. Wray 《Mammal Review》1999,29(2):93-116
Over the last few decades, there have been significant declines in Brown Hare Lepus europaeus numbers throughout Europe, leading to concern for their status in many countries. In Britain, there were no quantified data on the extent of this decline, on current population levels, or any baseline against which to monitor future population changes. The need for a quantified national hare survey led to this evaluation of the techniques available to assess hare numbers. Published information on counting hares is reviewed, and various techniques compared by applying them to a number of sites in southern England. Three basic approaches are available: counts of inactive hares, counts of active hares and indirect methods. Counts of inactive hares include total clearance, wide belt and line transect counts. Total clearance counts give an absolute figure, but are labour intensive and can only be applied to restricted areas. Wide-belt assessments are difficult to apply in certain habitats and even in open areas tend to produce a substantial over-estimate. Line transect counts are easy to undertake and are not labour intensive but should only be applied to large areas, or data from several small areas combined. Counts based on active hares are more problematical, because it is difficult to determine what proportion of the population is inactive at any one time. Spotlight counts based on variable circular plots are the most accurate but difficult to apply widely, and twilight counts are very subjective in their interpretation, especially when surveying small areas or areas with a large proportion of concealing habitats. Of the indirect methods, dung pellet counts can be valuable in specific areas but are difficult to apply across a range of habitats. We concluded that, of the various techniques considered, line transect counts have the greatest potential for a national survey, but need to be stratified so that enough transects are undertaken within each habitat stratum to obtain a reliable mean population estimate for each stratum. 相似文献
989.
本文对银杏叶中聚戊烯醇类化合物的研究作了综述,主要包括它们的化学结 构、提取分离方法、光谱特征、分析方法、作用,以及多萜醇的合成等。并对其研究前景进 行了展望。 相似文献
990.