水稻93-11 EMS诱导突变体的分离与鉴定

利用EMS对籼稻品种93-11进行诱变处理,以构建基因突变群体。M1单本移栽并单株收获。M2播种5000个家系,根据各个生育阶段表现鉴别出411个家系发生了形态突变,并收获271个家系。M3代对M2代收获材料按照系谱法进行跟踪观察和验证。结果表明,形态性状的突变频率为8．22％。其中一些突变体具有优良农艺性状,有可能在育种中得到利用。     

以PCR为目的的大豆叶片DNA提取方法的比较研究

模板DNA的质量直接影响PCR扩增的结果,而不同提取方法及其缓冲液的成份与浓度对提取DNA的质量有重要影响。本文以5个栽培大豆品种的叶片为材料,比较分析了SDS与CTAB两种提取方法以及不同浓度CTAB提取缓冲液对所提取的DNA质量的影响,并通过PCR进行检验。实验结果表明：用1％(W/V)、2％(W/V)浓度的CTAB提取缓冲液和1．25％(WV)SDS提取缓冲液所提取的大豆叶片DNA的质量较好,均能满足PCR扩增模板的需求,其中以1．25％(W／V)SDS提取得到的大豆叶片DNA质量最好,以其为模板扩增的效果最佳,而4％浓度的CTAB不适宜提取大豆叶片DNA。     

Identification and Genetic Mapping of a Lesion Mimic Mutant in Rice

A lesion mimic stripe mutant,designated as lms1(lesion mimic stripe 1),was obtained from the M2 progeny of a 60Co γ-radiation treated japonica rice variety Jiahua 1.The lms1 mutant displayed propagation type lesions across the whole growth and developmental stages.Physiology and histochemistry analysis showed that the mutant exhibited a phenotype of white stripe when grown under high temperature(30 ℃),and the lesion mimic caused by programmed cell death under low temperature(20 ℃).The genetic analysis indicated that this lesion-mimic phenotype is controlled by a single locus recessive nuclear gene.Furthermore,by using simple sequence repeat markers and an F2 segregating population derived from two crosses of lms1 × 93-11 and lms1 × Pei'ai 64S,the lms1 gene was mapped between markers Indel1 and MM0112-4 with a physical distance of 400 kb on chromosome 6 in rice.     

Evaluation of Rice Seedling Tolerance to Constant and Intermittent Low Temperature Stress

M202,IR50 and advanced backcross(BC 4 F 6) lines carrying the cold tolerance QTLs qCTS4 and qCTS12 were evaluated using three low temperature stress assays(constant,intermittent and constant with recovery period).Under constant stress,two BC 4 F 6 lines(MIb 4853-9 and MIb 6885-2) exhibited differences in seedling growth and accumulation of stress-related compounds although both carry the two QTLs in the IR50 background.Differences between these lines were also observed in the constant with recovery period assay,although both of them performed comparably under intermittent stress.MIb 6885-2 performed more similarly to M202 in the constant and constant with recovery period assays,suggesting that this line contains an introgressed region(s) not present in MIb 4853-9.The three assays were also applied to assess variations in cold tolerance in a set of diverse germplasms.Performance metrics and visual ratings were comparable for evaluating tolerance to constant stress.However,differences in response to intermittent stress were more evident from growth and total chlorophyll measurements than from visual ratings.With regard to the constant with recovery period assay,about 15% of the germplasm accessions did not recover.However,some lines which exhibited chilling injuries of comparable severity were able to overcome them.This recovery phenotype may improve rice performance in the field and warrant further investigation.     

粳稻叶绿素含量QTL与其合成降解相关基因的比较分析

为剖析水稻叶绿素不同时期的表达规律及后期持绿的遗传机制,以沈农265和丽江新团黑谷的粳-粳交重组自交系为材料,对水稻分蘖期、抽穗期和成熟期的叶绿素含量以及生育后期的持绿能力进行QTL定位分析。检测到5个控制分蘖期叶绿素含量的QTL、7个控制水稻抽穗期叶绿素含量的QTL和10个控制成熟期叶绿素含量的QTL,分布在除第5染色体以外的11条染色体上。比较它们与编码叶绿素合成及降解过程中的重要酶的基因发现,虽然生育前期检测到的QTL较少,但对应的叶绿素合成降解相关基因却较多。随生育期的推移,检测到的QTL数目增多,但对应的叶绿素合成降解相关基因却减少。暗示生育前期大多数叶绿素合成(降解)相关基因表达的水平差异不大,后期控制叶绿素合成降解的个别关键基因表达水平增加。并以此为基础提出了叶片生育后期持绿的两种可能遗传基础。     

柽柳dir基因的克隆及序列分析

在柽柳cDNA文库测序中获得了dir基因的全长cDNA序列,去除PolyA后,该基因全长为724bp,其中5′非翻译区26bp,3′非翻译区143bp,开放阅读框(ORF)长555bp,编码184个氨基酸.基因编码蛋白的分子量为19·69kD,理论等电点为6·96·疏水性分析表明,蛋白的前41个氨基酸为亲水性的.dir基因编码的蛋白质参与木质素的形成,与植物体的病菌防御有关.该基因的Genbank登录号为DQ462418(基因)和ABE73781(蛋白).     

质量-数量性状的遗传分析——Ⅱ.世代平均数和遗传方差

本文阐述由自花授粉作物的两个纯系杂交而衍生的各种世代群体的质量-数量性状的遗传表达。根据遗传组成和加性-显性遗传模型下的基因效应,给出了各有关群体质量-数量性状的平均数和遗传方差的分量。在此基础上,论述了主、微基因遗传变异的统计测验和主、微基因加性、显性变异分量的样本估计方法。     

电子PCR

电子PCR(Electronic PCR,e-PCR)现已是一种常用的核苷酸序列电子分析工具,它在DNA片段的染色体定位、基因组测序、基因组辅助作图、PCR引物辅助设计和基因的克隆等方面发挥着重要作用。本文介绍了电子PCR技术的原理、方法和功能及其相关的数据库和应用发展趋势。     

马尾松大配子体的SSR多样性及其遗传作图策略研究

本研究利用马尾松单株160粒种子的胚乳（大配子体）和235对微卫星（SSR）引物构建马尾松遗传图谱。经过筛选得到30对具有多态性的引物,产生97个分离位点,平均1.62位点/引物,偏分离率为11.34%。利用FsLinkageMap2.0软件对其进行连锁关系分析,74个标记分布在11个连锁群,有23个标记未连锁到任何连锁群上。该图谱覆盖的基因组总长度为927.91cM,最大连锁群图距为359.89cM,最小连锁群图距为20.44cM。平均每个连锁群的长度为84.36cM,标记间最大间距为28.2cM,最小间距为0,标记平均距离为12.54cM。估算的马尾松基因组大小为2541.21cM,基因组覆盖度为36.5%。利用马尾松大配子体构建该树种较饱和的遗传图谱,大约需要超过1250个标记,并应积极尝试AFLP和SRAP等标记;群体数目应超过200个;同时应开发适于半同胞群体的作图软件。     

L-半胱氨酸对农杆菌介导的大豆子叶节转化的影响

通过在共培养基中添加L-半胱氨酸,研究了L-半胱氨酸对农杆菌介导的大豆子叶节转化的影响。结果表明:L-半胱氨酸对大豆子叶节的转化有明显的促进作用,其中质量浓度为500 mg/L时转化效率最为显著。以此浓度为基础,通过GUS染色和分子检测,得到了大豆转基因植株,使转化效率由不加L-半胱氨酸的1.17%提高到了2.21%。