Genetic Diversity and Pathogenicity Variation in Rhizoctonia solani Isolates from Rice in Sichuan Province, China

Fifty-five representative samples of Rhizoctonia solani isolates, which were collected and isolated from five different ecological regions in Sichuan Province, China, were purified and analyzed for the pathogenicity and molecular genetic variation. The hyphal fusion test revealed that almost all the isolates belonged to the AG-IIA group except the isolate D42. In addition, some of the isolates were ‘bridging isolates’, which could fuse with several groups simultaneously. The pathogenicity analysis on in vit...     

黑土滩恢复演替过程中植物功能群及牧草品质变化

应用空间序列代替时间序列的方法,对高寒草甸不同恢复演替阶段黑土滩植物群落结构、植物功能群及牧草品质的变化进行了研究。结果表明:物种数与演替梯度间呈显著正相关关系:y=5.594x+0.643,(R²=0.8811);Shannon指数与演替梯度间呈非线性单峰曲线关系:y=-0.0528x²+0.6584x+0.3874(R²=0.7531);生物量与演替梯度间亦呈单峰曲线关系:y=-8.7647x²+86.696x+67.14(R²=0.6164)。一年生植物在群落中的数量呈下降趋势;禾本科植物在群落中的数量呈上升趋势;莎草类及杂类草植物在群落中的数量均呈增加趋势,但莎草类植物增幅不大,而杂类草植物则急剧增加。牧草品质随演替时间的延长而发生不同的变化:劣等牧草生物量在群落中呈下降趋势;中等和优等牧草生物量的变化趋势相同:随着演替时间的增加,均呈现幅度较大的增加趋势;而良等牧草生物量的变化则与之不同,生物量的峰值出现在演替的4-5年间。随着黑土滩的恢复演替,植物群落结构、功能群类型及草地生产性能均发生了重要变化。     

四川地方玉米种质的SSR聚类分析

利用SSR分子标记方法研究28个玉米自交系的遗传变异。分析四川地方玉米种质的遗传基础,并进行SSR聚类分析,探讨四川地方玉米种质与国内主要杂种优势群的关系。结果表明：大部分四川地方玉米种质均可被划分到常见的几大杂种优势群中去,少数地方玉米自交系可形成单独的类群,四川地方玉米种质具有广泛的遗传基础;SSRs能较真     

适合丝核菌营养亲和群划分的培养基的筛选研究

比较了10种不同培养基对丝核菌(Rhizoctonoa)菌株营养亲和群的划分效果,结果证明,培养基(3)-麦芽蛋白胨培养基(Ⅱ)划分营养亲和群的效果最好,培养基(1)、(2)、(7)、(9)效果次之,(4)、(10)效果较差,培养基(6)效果最差,不能区分出营养亲和群.并用麦芽蛋白胨培养基(Ⅱ)对分离、纯化的272个立枯丝核菌菌株进行营养亲和群的划分,共分出7个营养亲和群.     

陕西秦岭北坡森林公园总体规划初探

在分析秦岭北坡森林公园整体发展态势的基础上,指出缺乏总体性发展规划、规划滞后、执行不力及规划后续工作缺乏、规划队伍专业面较窄是目前秦岭北坡森林公园在规划方面存在的主要问题.认为制定秦岭北坡森林公园总体规划,组建秦岭森林公园旅游集团是秦岭北坡森林公园可持续发展的理想模式,并对秦岭北坡森林公园的主题形象规划,分区、分项规划,支持性规划及对如何解决多种所有制问题和加强管理进行了初步探讨.     

烤烟品种资源的聚类分析

 应用计算机系统对 1 0 4个国内外烤烟品种的 1 4个性状进行聚类分析 ,形成了烤烟品种的系统分类。烤烟可分为 4个品种群和 6个品种亚群 :优质烟品种类群 (内含 2个品种亚群 ,39个品种 ) ;低烟碱多叶品种类群 (内含 1 3个品种 ) ;低糖高蛋白品种群 (内含 1 3个品种 ) ;高糖碱比品质欠佳类群 (内含 4个品种亚群 ,39个品种 )     

Anti-Copy and Anti-Digital Simulation in Software Security Key

This paper discussed the basic technique of setting security key and produced group security key to anti-copy and dynamic reading security key to anti digital simulation. These two methods can prevent effectively the software from attacking.     

福建天然阔叶林经营类型组织的研究

对福建天然阔叶林经营类型的组织依据、各组织依据之间的关系、各经营类型的组织及命名和各经营类型的经营措施体系要点进行探讨 ,为福建天然阔叶林可持续经营的实践提供基础依据     

小鼠发情周期不同时期超数排卵效果的研究

实验分析了108只昆明白小鼠发情周期与超数排卯的关系，结果表明在发情周期不同时期进行超数排卵，效果有差异，以发情初期和间情后期超数排卵效果最好，见栓率高达84．20％，3．5d取胚，平均胚胎数达30．57枚，而且胚胎的质量也最好，多数是桑椹胚和囊胚，占胚胎总数的78．73％。     

Purification and characterization of phospholipase A2 isoforms from the hepatopancreas of red sea bream, Pagrus major1

Two phospholipase A₂ (PLA₂) isoforms, tentatively denoted as DE-1 and DE-2 PLA₂s, were purified from the hepatopancreas of red sea bream (Pagrus major) to near homogeneity by sequential column chromatography on S-Sepharose fast flow, DEAE-Sepharose fast flow and butyl-Cellulofine, and by ion-exchange, gel-filtration and reversed-phase HPLC. The purified DE-1 and DE-2 PLA₂s both showed a single band with the apparent molecular mass of approx. 13.5 kDa by SDS-polyacrylamide gel electrophoresis, and were found to be both related to group I PLA₂ based on the N-terminal amino acid sequences. DE-1 PLA₂ had a pH optimum in the alkaline region at around pH 10 and required approximately 10 mM of Ca²⁺ and 4-10 mM of sodium deoxycholate for its maximal activity, using 2 mM of phosphatidylcholine and phosphatidylethanolamine as substrates. DE-2 PLA₂ also had a pH optimum in the alkaline region at around pH 8-9 and required >10 mM of Ca²⁺ and approximately 6 mM of sodium deoxycholate for its maximum activity with 2 mM of phosphatidylcholine as a substrate; its enzymatic activity towards phosphatidylethanolamine was greatly inhibited by the addition of sodium deoxycholate. The results demonstrate that red sea bream hepatopancreas contains two enzymatically distinct group I PLA₂ isoforms.