利用分子标记辅助选择培育转 Bt基因抗虫水稻

为培育转Bt基因抗虫水稻品种材料,以传统杂交的方法将3个Bt明恢63中的Bt基因cry1C*、cry2A*和cry1Ac/Ab,转育到水稻品种秀水123、湘晴、旱恢3号和沪旱1B中;以回交二代自交三代（BC2F3）水稻叶片为材料,利用分子标记辅助选择、田间除草剂筛选和试纸条检测方法,以获得新型转Bt基因株系。并在全生育期实行除不喷施农药外的正常田间管理的转基因植株的田间抗虫鉴定方法筛选出抗虫性良好、农艺性状优良的株系,为后续抗虫育种提供材料。 BC2 F3代PCR检测及试纸条检测的结果显示分别获得cry1C*和cry2A*基因的沪旱1B、秀水123和湘晴的纯合株系。同时,在田间自然诱发虫害条件下,转基因株系对稻纵卷叶螟虫表现出强抗性。     

新基因Xa22[t]在滇粳优1号中的运用及其MAS体系的建立

本研究利用回交方法将抗白叶枯病新基因Xa22[t]导入云南高原区主栽品种滇粳优1号,在BC3F1群体中利用PCR分子标记对目标性状和背景进行辅助选择,结合田间接种鉴定,选出了5株抗病性和农艺性状均符合要求的植株,改良了滇粳优1号的抗病性,并为今后的抗病分子育种工作提供相应的信息。     

Integration of molecular genetic technology with quantitative genetic technology for maximizing the speed of genetic improvement

To date,most genetic progress for quantita-tive traits in livestock has been made by selec-tion on phenotype or on estimates of breedingvalues(BBV)derived from phenotype,withoutknowledge of the number of genes that affect thetrait or the effects of each gene.In this quantita-tive genetic approach to genetic improvement,the genetic architecture of traits of interest hasessentially been treated as a‘black box’.De-spite this,the substantial rates of genetic im-provement that have been and continue to be a-chie...     

Application of P and Al MAS NMR for phosphate speciation studies in soil and aluminium hydroxides: promises and constraints

Magic angle spinning (MAS) nuclear magnetic resonance (NMR) was used to investigate the chemical environment of P in soil and soil components. ³¹P and ²⁷Al MAS NMR spectra are presented of synthetic aluminium hydroxides (amorphous aluminium hydroxide and gibbsite), reacted with P under different conditions of P concentration, temperature and pH. The reaction product is amorphous octahedral aluminium phosphate, which transforms (partly reversibly) to tetrahedral aluminium phosphate upon drying. Results of several experiments on excessively fertilized sandy soil material are discussed. The soil particle fraction smaller than 50 μm was used for NMR analysis. ³¹P and ²⁷Al MAS NMR spectra show a Ca---P pool and an Al---P pool. A six-fold water extraction removes part of both P pools. Oxalate extraction removes all Ca---P and Al---P from the sample. Removal of the labile P pool by the HFO-DMT long-term P desorption technique, does not drastically change the ³¹P MAS NMR spectrum. The formerly mentioned Ca---P and Al---P are thus stable P pools. The ¹H---³¹P cross-polarization (CP) spectrum of the original soil sample revealed a third chemical environment, which was identified as labile Ca---P: this P pool does not appear in the ¹H---³¹P CP spectrum of the soil sample from which the fast P pool had been removed. The combination of MAS and CP MAS NMR can thus reveal at least three different P species in soil, of which two pools were identified as stable, and one as labile.     

小麦多酚氧化酶(PPO)活性的SSR标记筛选与验证

小麦多酚氧化酶(PPO)活性是引起面条和面团储存期间颜色褐变的主要因素。发掘可应用于籽粒PPO活性辅助选择的分子标记，将有助于小麦面粉颜色性状的遗传改良。本研究选用来自全国不同麦区的203份冬小麦品种，验证SSR(simple sequence repeat)引物Xgwm312的PCR扩增片段大小与籽粒PPO活性的关系。结果表明，198bp扩增片段的有无同籽粒PPO活性大小密切相关，该片段的出现通常意味着籽粒PPO活性较高。Xgwm312可应用于籽粒PPO活性的分子标记辅助育种。     

Application of the New Gene Gm6 Against Rice Gall Midge in Resistance Breeding Through PCR-Based Marker Aided Selection

The research results of marker aided selection (MAS) for resistant varieties and lines against rice gall midge Orseolia oryzae Wood-Mason successfully in 1999-2002 were reported in the present paper. The molecular markers linked to the gene Gm6 against rice gall midge were used to select and breed the resistant varieties and lines. The RAPD marker OPM06 was used to verify the existence actually of gene Gm6 in ten developed varieties resistant to gall midge such as Duokang1, Duokang2, Kangwen2, Kangwen3, Kangwen5, Duokangzaozhan, Kangwenqinzhan, which were derived from Daqiuqi. For resistance breeding through PCRbased marker aided selection (MAS), the polymorphisms in the resistant and susceptible parents were identified by RG476/AluⅠ and RG476/ScaⅠ respectively. The RAPD marker OPM06 (1.4 kb) was used to identify 15 new resistance lines from F3 lines of Fengyinzhan1/Daqiuqi in 1999. 21 and 7 resistance lines were selected from F4 and F6 lines of KWQZ/Gui99 (restored line of hybrid rice) using RG476/AluⅠin 2000-2001 respectively. The Gm6 gene was transferred into the restored line of hybrid rice. In 2001-2002, RG214/HhaⅠ and G214/ScaⅠ were used for selecting 11 and 5 resistance lines from F3 lines of KWQZ/IR56 and AXZ/KWQZ successfully. The application of the resistance gene through PCR-based marker aided selection is a new and effective approach in resistance breeding.     

分子标记辅助选择改良三系杂交稻恢复系R225稻瘟病抗性

稻瘟病是水稻的主要病害,培育抗稻瘟病品种是防治稻瘟病的有效途径。本研究通过分子标记辅助选择与杂交育种相结合的方式,将稻瘟病抗性基因Pi1、Pi2和Pi9导入到三系杂交稻恢复系R225。对BC3F3代材料进行苗期和成熟期稻瘟病抗性鉴定,携带1个或2个抗性基因的目标株系抗性达到中抗以上水平,稻瘟病抗性显著高于各自的轮回亲本。SSR标记分析表明,改良株系的遗传背景回复率达到86.1%~95.3%。通过标记辅助选择获得的改良材料为三系杂交稻恢复系的培育提供了稻瘟病抗性亲本。     

分子标记在植物抗病育种中的应用

植物种质库通常有携带抗病基因的植物材料,通过育种的方法将这些抗病基因导入植物是保护植物免于病虫害的重要而有效的方法。当前研究表明,抗病基因分子标记将有利于高效筛选含抗病基因的植物材料。该文简要概述了分子标记的特点,重点分析了其在植物抗病育种研究中的应用,主要在辅助选育多基因聚合体,构建抗病基因相关的遗传图谱,抗病基因定位及克隆,遗传多样性分析等方面进行阐述,并对其发展趋势作出展望。     

利用分子标记辅助选择技术育成抗白叶枯病杂交稻协优218

利用分子标记辅助选择技术把白叶枯病抗性基因Xα21导人到强优恢复系辐恢838中,选育出抗白叶枯病恢复系中恢218,组配出强优势杂交中晚稻新组合协优218。该组合具有产量较高、抗白叶枯病、易制种等特性,于2002年2月通过江西省品种审定。     

野生稻增产QTL导入9311之近等基因系的构建

以超级杂交中稻恢复系9311为受体和轮回亲本,马来西亚普通野生稻(O.rufipogon)为增产QTL yld1.1和yld2.1的供体进行杂交和连续回交,各世代采用分子标记辅助选择,至BC6F1后自交,得到BC6F2群体,通过分子标记检测,获得分别携带野生稻增产QTL yld1.1、yld2.1及同时携带yld1.1和yld2.1的3套近等基因系.对同时携带yld1.1和yld2.1的近等基因系进行遗传背景分析,发现其与受体9311的遗传组成有93.9%一致.田间试验表明,野生稻增产QTL近等基因系的产量均高于受体,说明将野生稻增产QTL转移至杂交稻恢复系中,能提高其产量水平,且2个QTL的增产效果大于单个QTL的效果.