利用种间杂交途径向栽培稻转移非AA组野生稻有利基因的研究进展

利用种间有性杂交向栽培稻转移非AA组野生稻有利基因的研究在三个方面取得进展,即单体异附加系的培育、渗入系的建立以及有利性状的遗传及基因定位。栽培稻与非AA组野生稻种间杂交存在严重的生殖障碍,表现在不可交配性和杂种不育性两个方面,这是限制非AA组野生稻有利基因转移的“瓶颈”。传统的有性杂交手段和生物技术相结合是克服种间生殖障碍,提高非AA组野生稻有利基因育种利用效率的可行途径。     

稻属种间天然异交种的分子细胞学鉴定

利用基因组荧光原位杂交（GISH）技术快速鉴定了栽培稻与野生稻的天然异交种的基因组组成,分析了该杂种在减数分裂中期Ⅰ的染色体配对情况。根据根尖细胞的染色体数目,发现该杂种是具有36条染色体的三倍体;通过减数分裂中期Ⅰ染色体的配对研究,发现该杂种染色体很少发生配对,绝大部分染色体以单价体形式存在;结合GISH技术的分析,证实该杂种是由A、B和C 3个染色体组组成。因此该杂种是栽培稻和小粒野生稻的天然杂交种。     

利用野生稻选育水稻恢复系研究

为了利用野生稻优良基因选育强优势的水稻恢复系,从野生稻资源中筛选出抗性强、具有较好农艺性状且恢复能力强的野生稻,与传统优良恢复系远缘杂交,后代适当复交,采用“大群体、多世代”的系谱法处理杂交后代。经过17 a（1980—1997）的选育,获得了测25、测253、测258、测1012等4个优良恢复系。至2006年,用这些恢复系配组育成的14个杂交稻组合通过了省级以上品种审定,累计推广面积达693.3万hm^2。     

Molecular Cytogenetic Analysis of Spontaneous Interspecific Hybrid Between Oryza sativa and Oryza minuta

Genomic in situ hybridization (GISH) is a powerful tool to characterize parental chromosomes in interspecific hybrids, including the behaviour of autosynapsis and chromosome paidng. It was used to distinguish the chromosomes of Oryza sativa from wild species in a spontaneous interspecific hybdd and to investigate the chromosome pairing at metaphase I in meiosis of the hybdd in this study. The hybrid was a triploid with 36 chromosomes according to the chromosome nurnber investigated in mitosis of root tips. During metaphase I of meiosis in the hybrid, less chromosome pairing was observed and most of the chromosomes existed as univalent. Based on GISH and FISH (Fluorescent in situ hybridization) analyses, the chromosomes of the hybrid were composed of genomes A, B and C. Thus, it was believed that the hybrid was the result of natural hybridization between cultivated rice and wild species O. minuta which was planted in experimental fields.     

非AA型野生稻资源在水稻育种中的利用

非AA型野生稻涵盖B、C、D、E、F、G、H、J、K等九大基因组,广泛分布于世界各地,具有丰富的遗传多样性,是一座天然的水稻基因宝库。综述了非AA型野生稻的种类、优良特性及其在水稻育种中的利用途径和育种成果,指出了目前利用非AA型野生稻存在的主要问题,提出了相应的策略。     

栽培稻种间杂交改良云南粳稻品种研究

为引入非洲栽培稻的有利基因以丰富云南粳稻的遗传基础以达到培育高产、抗病、抗逆云南粳稻品种的目的,利用179个非洲栽培稻品种作母本与6个云南粳稻杂交,并用相应父本回交后形成F1、BC1F1、BC2F1、BC2F2群体,同时对滇粳优1号作轮回亲本的组合在BC2F1中每组合随机用5~10株回交至BC3F1。研究表明,F1及BC1F1的自交结实率为0,种间杂种不育是非洲栽培稻与亚洲栽培稻种间杂交最主要的生殖障碍;但回交至BC2F1自交结实率即达到7.9％, BC3F1的平均结实率为14.6％,在BC2F1选结实率在10％以上的植株自交1次,BC2F2的结实率即为42.8%,变幅15%~80%;表明杂种不育模式符合“单位点孢子体 配子体互作不育”。在BC2F2群体中,10.7％的组合的综合表现优于轮回亲本。大规模育种实践表明,通过两次回交,再自交2~3代,种间杂种不育的障碍基本可得到克服,并可引入非洲栽培稻的有利基因。     

同源四倍体水稻与非洲栽培稻杂交的后效性研究

利用亚洲栽培稻中的4份同源四倍体水稻(O.sativa,2n=4x=48)和相应的4份二倍体水稻(O.sativa,2n=2x=24)为母本,以4份非洲栽培稻(O.glaberrima,2n=2x=24)为花粉供体进行远缘杂交后,对其杂种后代的分离动态进行了研究.结果表明,不同倍性的普通栽培稻与非洲栽培稻之间杂交后代的结实率以二倍体普通栽培稻的较高.在配制的32个杂交组合中,其杂种第1代群体均表现出明显的营养生长优势.从群体的生长势来看,杂种第2代群体比杂种第1代群体要弱一些;在杂种第2代群体中,以同源四倍体水稻为母本的杂交组合的分离现象比以二倍体水稻为母本的杂交组合的分离现象更明显.在各杂交组合的第3代群体中,从植株的株叶形态和生育期来看,株系间的差异和株系内的变异依然很明显,变异频率更宽,变异种类更多.在普通栽培稻与非洲栽培稻的杂交组合中,育性变异、生长势变异、株叶形态变异、染色体变异和结实性变异等是较易发现的变异现象.     

Photosynthesis,Metabolite Composition and Anatomical Structure of Oryza sativa and Two Wild Relatives,O.grandiglumis and O.alta

Photosynthesis, enzyme activities and metabolite pools associated with primary carbon metabolism in leaves were studied in O. grandiglumis and O. alta(wild relatives of rice which produce high biomass) versus O. sativa(a japonica cultivar and a indica-japonica hybrid) to assess their potential for identifying traits which might be utilized to enhance rice productivity. The wild relatives had higher rates of photosynthesis on a fresh weight basis, and higher water use efficiency than the O. sativa lines. There were no striking differences in activities of a number of key enzymes in carbon and nitrogen metabolism between the wild relatives and cultivated rice lines. Along with higher rates of photosynthesis on a fresh weight basis, the leaves of the two wild species had higher nitrate content, higher levels of starch, glucose and fructose, and higher levels of organic acids(malate, succinate and acetate), compared to the O. sativa lines. The results suggested that O. grandiglumis and O. alta have differences in physiology and primary metabolism which might be exploited to improve growth and productivity of cultivated rice.     

野生稻有利基因转移研究进展

稻属有22个种,包括20个野生稻种和2个栽培稻种,现已命名AA、 BB、 CC、 BBCC、 CCDD、 EE、 FF、 GG和HHJJ 9个基因组。野生稻是一个重要的有利基因库,包含对各种生物胁迫的抗性和非生物胁迫的耐性基因。就野生稻的有利性状、野生稻有利基因转移研究进展作了概述,并对野生稻有利基因分子标记定位研究,野生稻有利基因转移的遗传机制以及野生稻有利基因利用前景进行了讨论。     

栽培稻和普通野生稻基因组的随机扩增多态性DNA（RAPD）初步分析

用35个随机引物对5个籼稻品种、5个粳稻品种和27份中国普通野生稻进行了RAPD分析。60%以上的引物能在籼稻和粳稻基因组间显示差异;中国普通野生稻与栽培稻的差异主要表现在与籼稻的不同,绝大部分供试野生稻的RAPD带型与粳稻的相同。这说明多数中国普通野生稻偏粳,但也存在偏籼的普通野生稻。     

栽培稻和普通野生稻基因组的随机扩增多态性DNA（RAPD）初步分析

 用35个随机引物对5个籼稻品种、5个粳稻品种和27份中国普通野生稻进行了RAPD分析。60%以上的引物能在籼稻和粳稻基因组间显示差异；中国普通野生稻与栽培稻的差异主要表现在与籼稻的不同，绝大部分供试野生稻的RAPD带型与粳稻的相同。这说明多数中国普通野生稻偏粳，但也存在偏籼的普通野生稻。     

Subspecies specific RAPD markers in rice

The cultivated rice (Oryza sativa L.) is known to contain two major subspecies, indica (O. sativa L. ssp. indica) and japonica (O. sativa L. ssp. japonica). The indica and japonica differentiation resulted in significance of hybrid sterility and hybrid breakdown, which are barriers of gene flow between the two major subgene pools within O. sativa. Traditional classification of indica and japonica germplasm based on isozymes. Here, we report the identification of several random amplified polymorphic DNA (RAPD) markers that have alleles specific in indica or japonica varieties and thus provide a quick and accurate tool to distinguish japonica lines from indica ones.     

栽培稻种间近等基因系杂种育性研究

 为了研究亚洲栽培稻与非洲栽培稻种间杂种不育的遗传基础，以亚洲栽培稻品种WAB56-104为测验种与来自种间回交组合WAB56-104/CG14//WAB56-104///WAB56-104的14个种间近等基因系测交，对亲本及杂种的花粉及小穗育性研究表明，这14个近等基因系带有来自非洲栽培稻品种CG14的3个互不等位的配子消除位点和2个互不等位的花粉不育基因位点, 其中至少有2个配子消除位点未曾报道过。     

Development and Identification of Novel Rice Blast Resistant Sources and Their Characterization Using Molecular Markers

To develop and characterize introgression lines for leaf and neck blast resistance, 326 introgression lines were developed using various accessions of six different AA genome wild species in the genetic background of elite Indian varieties like PR114 and Pusa 44 and were screened for blast resistance. Stringent phenotyping coupled with genotyping using gene based markers led to the identification of four resistant introgression lines, which showed promising resistance and do not possess any of the tested genes. Furthermore, multi-location screening confirmed the field resistance of the four introgression lines to both leaf and neck blast. Molecular characterization of these introgression lines using genome-wide simple sequence repeat markers revealed the presence of small percentage of wild Oryza genome introgrssion. So these lines can be used for mapping and identification of novel leaf and neck blast resistance genes. Thus, these four introgression lines can be considered as new genetic resources for blast resistance.     

Recent Advances in Development of Herbicide Resistant Transgenic Hybrid Rice in China

In addition to weed control in direct seeding field of hybrid rice, herbicide resistance genes were used by Chinese scientists to increase and identify the purity of hybrid seeds, and to realize the mechanization of hybrid seed production. The elite restorer lines, such as Minghui 63, R752, T461, R402, D68 and E32 were transformed directly with herbicide resistance genes, in which D68 and E32 are restorer lines of two-line system and the others are of three-line system. Because almost all of important restorer lines are indica varieties and are recalcitrant in transformation, many herbicide resistant near-isogenic restorer lines were developed by sexual hybridization of indica and japonica varieties and backcross with indica restorer lines later, such as Ce 64, Minghui 63, Teqing, Milyang 46, R402 and 9311, in which 9311 is a restorer line of two-line system. The elite photoperiod-sensitive/thermo-sensitive genic male sterile lines, such as Pei'ai 64S, P88S, 4008S and 7001S, were transformed with herbicide resistance genes. A few herbicide resistant male sterile lines were developed through sexual hybridization and subsequently systemic selection, such as Bar1259S, Bar2172S, 05Z221A and 05Z227A. With the employment of herbicide resistant male sterile lines or herbicide resistant restorer lines, a few herbicide resistant hybrid rice combinations were developed, such as Xiang 125S/Bar 68-1 and Pei'ai 64S/Bar 9311. Based on herbicide resistance, the research was marching on to investigate the parental lines of hybrid rice with insect resistance, drought tolerance, etc.     

RFLP and SSR mapping of a new gene for brown planthopper resistance introgressed from O. Eichingeri into cultivated rice(O. Sativa L.)

Nine brown planthopper(BPH) resistance genes have been registered so far, but of them only Bph1, bph2, Bph3, bph4, Bph9,and other three unregistered genes Bph10(t), Bph(t), bph(t) were located on chromosome 3, 4, 10, and 12, respectively, by using traditional and molecular mapping methods. To use the genes for BPH resistance in rice breeding and production, interspecific hybrids between cultivated rice and accessions of O. eichingeri (2n=24, CC), a wild rice species from Africa, with strong resistance to BPH and whitebacked planthopper were produced.     

对国际热带农业研究所收集的稻属种的柱头外露性状的研究（英文）

 为筛选柱头高度外露的稻种资源用于培育柱头外露率高的新雄性不育系,提高杂交稻制种产量,我们在位于尼日利亚伊巴丹市的国际热带农业研究所对非洲稻种资源,包括二个栽培种、三个野生种及一个杂草类型,共2065份种质进行柱头外露性状的观察。结果表明。每穗柱头外露率高(≥%)的种质的百分数从高到低依次为:斑点野生稻(100%)>长药野生稻(85.7%)>非洲栽培稻(54.9%).>巴蒂野生稻(34.8%)>杂草型 stapfii(20%)>亚洲栽培稻(1%)。在1787份亚洲栽培稻中筛选出18个柱头高度外露的种质可考虑作为培育异交率高的水稻雄性不育系的亲本。本文还分析讨论了柱头外露种质的遗传及其地理分布。     

我国三种野生稻及其与栽培稻种间杂种外稃表面显微特征的比较观察

 用扫描电镜对栽培稻的两个籼型品种（Oryza sativa subsp. indica）、普通野生稻（O．rufipogon）、药用野生稻（O. officinalis）、疣粒野生稻（O. meyeriana）及野生稻与栽培稻的种间杂种F₁的外稃表面显微特征进行了比较研究，观察到外稃表面的显微特征有明显的种间差异，并初步概述了三种野生稻的乳突特征。栽培稻与野生稻的种间杂种外稃显微特征受亲本影响，其中乳突座间距、列宽主要受野生稻亲本影响；底座以上的峰突特征如峰距、峰数则表现为栽培稻亲本的特征；乳突分布密度表现为超亲现象。     

"热大99W"序列旱稻新品系农艺特征与抗旱特性的研究

海南山栏稻原种与水稻常规品种杂交,Ｆ２或Ｆ３单株再与水稻雄性不育恢复系杂交,其后代又与雄性不育系再杂交,在四交Ｆ６代进行单株选择,Ｆ７代进行株系选择,Ｆ８代对入选的９个品系进行农艺性状比较、产量构成分析和抗旱生理指标测验。结果表明其中３个品系具有良好的农蕊性状和较高的产量潜力（产量可超过４５００ｋｇ／ｈｍ＾２）,同时表现较强的抗旱性。从而获得兼备水稻理想株型和山栏稻抗旱性的丰产旱稻新品系,为进一步培育优良旱稻新品种奠定了重要基础,并对稻作抗旱育种的技术路线进行了有益的探讨。     

利用轮回选择法创造粳稻三系恢复系的研究

利用8份光温敏核不育粳稻材料及28份北方寒冷稻作区优良粳稻品种(系)作为原始亲本开展轮回选择育种,育成了吉粳85、吉524、E180和E385等4个具有三系恢复基因的粳型恢复系。这些恢复系性状稳定,恢复度好,测交F1代产量优势明显,表明轮回选择为粳稻恢复系选育提供了一条新的技术途径,并使三系杂交稻在北方寒冷稻作区的大面积推广成为可能。