NaN_3诱变“邯7086”后代变异研究及变异系的SSR分析

为创造新的小麦种质系,并探讨叠氮化钠对小麦诱变处理的适宜方法,采用了＂种子处理同时鼓入空气＂、＂种子处理不鼓入空气＂、＂颖苞内滴加＂、＂生长点注射＂、＂穗茎注射＂5种方法诱变小麦＂邯7086＂.其中＂种子处理同时鼓入空气＂方法处理的种子出苗率高,后代性状变异类型丰富,变异率高,是适合小麦诱变处理的一种切实可行的好方法.通过多代选择选出了Ymfl-23、Ymfl-42、Ymfl-46三个稳定的变异种质系;利用SSR分子标记检测＂邯7086＂及其变异种质系,引物xgwm148、xgwm304、xgwm645检测出了丰富的多态性片段,从分子水平上证明了叠氮化钠对＂邯7086＂的诱变效果.     

Effects of overburden, rock strength and pillar width on the safety of a three-parallel-hole tunnel

During the excavation of three-parallel-hole tunnel, the tunnel might collapse due to over-stress as a result of inadequate rock pillar width. Treating the rock overburden depth, rock strength, and rock pillar width as variables, a series of 3D numerical analysis was carried out to examine the effect of each variable on the safety of the tunnel, in particular the rock pillar. A stress strength ratio （SSR） was used to define whether the safety of the rock pillar was exceeded. A simple design chart for the case of three-parallel-hole tunnel, which took into account the influence of overburden depth, rock pillar width, and rock strength, was also proposed for used in the preliminary design stage.     

水稻早世代稳定株系特有分子标记研究

SSR和ISSR分子标记已广泛应用于研究遗传行为和基因定位。在对水稻早世代稳定遗传特性的研究中,选用分布于水稻12条染色体上的168对多态性较好的SSR引物,对28个稳定株系的F_1、F_2、F_3及同组合的分离株系进行了SSR标记分析；选用26个多态性较好的ISSR引物对5个组合中出现的8个稳定株系及同组合的分离株系进行了ISSR分子标记。结果显示：稳定株系的标记带型出现三种类型：(1)母本带出现,父本带消失；(2)父本带出现,母本带消失；(3)出现非父母标记带型。分离株系表现为杂合标记带。推测水稻早世代稳定是在遗传因子作用下,在杂交受精或合子早期发育中发生了双亲染色体重排,形成纯合的F_1单株。     

SSR引物开发方法概述

SSR标记因其丰富的多态性和共显性等优点,得以广泛应用.而应用该技术的前提是要有相应的SSR引物.文章概述了引物的来源,并对其中的开发引物进行了重点叙述.在引物开发中对各种方法作了分析和比较,并提倡在开发大量引物时使用磁珠富集法.     

SSR分子标记技术在遗传学实验教学中的应用

该实验是科研成果转化为实验教学的一个案例。选择位于水稻不同连锁群上的6对SSR引物构建了2个杂交稻及其亲本的SSR指纹图谱,建立了一套适合于本科生实验的杂交水稻亲本鉴定的稳定的SSR技术体系。筛选的6对引物进行PCR扩增得到的杂交稻均有2条带。由SSR指纹图谱分析可得:杂交稻P5的亲本是P2和P4,P6的亲本是P1和P3。通过本实验巩固了学生关于分离定律的学习,并有所延伸。     

针禾属植物羽毛针禾基因组DNA提取方法的研究

传统的CTAB DNA提取法步骤多.较烦琐,DNA产率低,而且由于酚、单宁、色素、多糖很难完全去除,容易影响随机扩增多态、微卫星等标记工作的效率.采用SDS裂解法提取了针禾属植物幼嫩叶片的基因组DNA,所获得的DNA可用于PCR反应.并且在针禾属植物的研究中得到了较好的结果.     

中学ESL语法教学的效能评析

文章对国内中学ESL语法教学的效能进行了客观评析,而后以认知心理学中“记忆原理”和“原型理论”为依据对传统语法教学模式进行创新,从认知铺垫、解码、存储、提取四个环节进行教学模式设计,构建了以“必背短句”为媒介的英语语法教学体系;作者还为短句遴选设置了标准,通过对比分析和数据统计,从理论和实践两个层面证明这种新教学法的效能及科学性。     

Developing new SSR markers from ESTs of pea (Pisum sativum L.)

The development of expressed sequence tags (ESTs) from pea has provided a useful source for mining novel simple sequence repeat (SSR) markers. In the present research, in order to find EST-derived SSR markers, 18 552 pea ESTs from the National Center for Biotechnology Information (NCBI) database were downloaded and assembled into 10 086 unigenes. A total of 586 microsatellites in 530 unigenes were identified, indicating that merely 5.25% of sequences contained SSRs. The most abundant SSRs within pea were tri-nucleotide repeat motifs, and among all the tri-nucleotide repeats, the motif GAA was the most abundant type. In total, 49 SSRs were used for primer design. EST-SSR loci were subsequently screened on 10 widely adapted varieties in China. Of these, nine loci showed polymorphic profiles that revealed two to three alleles per locus. The polymorphism information content value ranged from 0.18 to 0.58 with an average of 0.41. Furthermore, transferable analysis revealed that some of these loci showed transferability to faba bean. Because of their polymorphism and transferability, these nine novel EST-SSRs will be valuable tools for marker-assisted breeding and comparative mapping of pea in the future.     

Assessment of genetic diversity by simple sequence repeat markers among forty elite varieties in the germplasm for malting barley breeding

The genetic diversity and relationship among 40 elite barley varieties were analyzed based on simple sequence repeat (SSR) genotyping data. The amplified fragments from SSR primers were highly polymorphic in the barley accessions investigated. A total of 85 alleles were detected at 35 SSR loci, and allelic variations existed at 29 SSR loci. The allele number per locus ranged from 1 to 5 with an average of 2.4 alleles per locus detected from the 40 barley accessions. A cluster analysis based on the genetic similarity coefficients was conducted and the 40 varieties were classified into two groups. Seven malting barley varieties from China fell into the same subgroup. It was found that the genetic diversity within the Chinese malting barley varieties was narrower than that in other barley germplasm sources, suggesting the importance and feasibility of introducing elite genotypes from different origins for malting barley breeding in China.     

西藏白菜型油菜SSR标记遗传多样性初探

利用SSR分子标记技术,分析了22份来自西藏不同地区的白菜型油菜材料的遗传多样性及其地理分布的相关性.结果表明,基于遗传距离聚类法可将22份供试材料分为两大类群,品种的地域性同聚类结果无密切相关性;10对SSR引物在22份供试材料中共获得50条清晰可辨的条带,其中45条是多态性,多态性位点比率为90%,平均每对SSR引物检测出5条带,4.5条带为多态性;琼吉与扎囊野油菜之间的遗传相似系数最小,相似系数为0.51;表明它们之间存在很大的遗传差异.