A new dominant earliness character of CMS line Zaoxian A and its application value in rice (Oryza sativa L.)

Summary A distant cross between a maintainer Zhenshan 97B and an early maturing F₂ palnt of O. longistaminata x O. rufipogon was made in 1985, and a new CMS line Zaoxian A was bred in 1989 through continuous backcross of new maintainer plants derived from the distant cross to the leading CMS line Zhenshan 97A. Several experiments were carried out in Sichuan during 1990–1992, to analyze the inheritance of earliness of Zaoxian A and its application value to hybrid rice production. The results showed that Zaoxian A was as early-maturing as Zhenshan 97A, the earliness of Zaoxian A was incompletely dominant to the lateness of restorer lines, and was different from the earliness of Zhenshan 97A which was suppressed by the lateness of restorer lines. The F₁ hybrids between Zaoxian A and late maturing restorers combined the early maturity and high yielding capacity, and significantly outyielded the provincial and national checks with same or longer growth duration, because the larger genetic distance between early and late maturing ecotypes remained unchanged and the new earliness could express in F₁ generation. Therefore, the new dominant earliness character of Zaoxian A could enhance the regional and seasonal adaptability of rice. It is also valuable to hybrid rice production and the formation of new cropping systems with high yielding capacity and high economical profit.     

乙烯与水稻细胞质雄性不育的关系

从幼穗发育的IV到VII期,水稻细胞质雄性不育系(珍汕97A)幼穗和叶片的ACC含量和乙烯释放速率均高于其保持系(珍汕97B)。外施乙烯释放剂乙烯利使保持系花粉可育度明显下降;外施ACC合成酶抑制剂AVG引起两系幼穗ACC含量和乙烯释放速率下降,并使不育系花粉育性得以部分恢复,而在外施AVG的同时再施以乙烯利则AVG的恢复作用消失。     

<Emphasis Type="Italic">Rf4</Emphasis> has minor effects on the fertility restoration of wild abortive-type cytoplasmic male sterile <Emphasis Type="Italic">japonica</Emphasis> (<Emphasis Type="Italic">Oryza sativa</Emphasis>) lines

Wild abortive (WA)-type cytoplasmic male sterility (CMS) has been exclusively used for breeding three-line hybrid indica rice, but it has not been applied for generating japonica hybrids because of the difficulties related to breeding japonica restorer lines. Determining whether the major restorer-of-fertility (Rf) gene used for indica hybrids can efficiently restore the fertility of WA-type japonica CMS lines may be useful for breeding WA-type japonica restorer lines. In this study, japonica restorer lines for Chinsurah Boro II (BT)-type CMS exhibited varying abilities to restore the fertility of ‘WA-LiuqianxinA’, which is a WA-type japonica CMS line. Additionally, Rf genes for WA-type CMS were identified in the BT-type japonica restorers. Meanwhile, ‘C9083’, which is a BT-type japonica restorer, exhibited a limited ability to restore the fertility of WA-type japonica CMS lines, and a genetic analysis revealed that the fertility restoration was controlled by one locus. The Rf gene was mapped to an approximately 370-kb physical region and was identified as Rf4. Furthermore, Rf gene dosage effects and the temperature influenced the fertility restoration of WA-type japonica CMS lines. This study is the first to confirm that Rf4 has only minor effects on the fertility restoration of WA-type japonica CMS lines. These results may be relevant for the development of WA-type japonica hybrids.     

水稻优良恢复系明恢63两个恢复基因恢复力的单独评价

野败型细胞质雄性不育系统是选配杂交稻组合广泛应用的主要不育细胞质资源，野败型细胞质雄性不育的育性恢复能力由两个恢复基因控制。以前的研究表明，明恢63具有2个恢复基因Rf3和Rf(μ)，分别位于第1和第10染色体上。为了分别准确估计这两个恢复基因的遗传效应，根据分子标记基因型，从珍汕97／明恢63衍生的241个F9重组自交系群体中选择两个自交系R124和R1183，它们分别含有单个恢复基因Rf3和Rf(M)，将R124和R1183与珍汕97A杂交，分别得到F1A和F1B，再自交得到F2A和F2B。在武汉和海南分别考察F1的育性，F1A的自然结实率海南和武汉分别为53．4％和60．2％，F1B的自然结实率海南和武汉分别为70．5％和75．7％。而珍汕97A／明恢63的杂种汕优63结实率为81．4％。F2A和F2B群体育性分离均符合1个主基因1：3的孟德尔期望分离比，表明，R124和R1183分别只含有一个恢复基因Rf3和Rf(M)。Rf(M)的效应较大，恢复力强，它单独几乎可以使育性恢复正常。利用标记辅助选择方法，转移两个恢复基因可以快速选育优良恢复系。     

Characterization of CMS and maintainer lines in indica rice (Oryza sativa L.) based on RAPD marker analysis

Total DNA from WA type CMS lines: Zhenshan 97 A, Longtepu A and theirmaintainers Zhenshan 97 B, Longtepu B wasextracted by CTAB method. One hundredprimers were used for screening RAPDmarkers to distinguish CMS line (A) andmaintainer (B) plants at seedling stage.Results showed that under the conditions of37 ^°C annealing temperature and1.5 mM MgCl₂ concentration, in Zhenshan97 A, Longtepu A there was a 1600 bp DNAfragment in product amplified by primerOPA12, while in Zhenshan 97 B, and LongtepuB no 1600 bp fragment was found. The 1600 bpfragment was also found in DA type CMS lineXieqingzao A, but was absent in XieqingzaoB. Also in the restorer line, Minghui 63the 1600 bp fragment was absent. In F₁and F₂ generation of Zhenshan97A/Minghui 63, all plants investigated hadthe 1600 bp fragment. When mitochondrial DNA(mtDNA) was isolated from the three CMS (A)and their B lines and amplified by OPA12,results showed that the 1600 fragment wasfound in all the three A lines and wasabsent in the three B lines. In DA typeXieqingzao A, two other fragments (700 bp,1000 bp) were also found except the 1600 bp.These results indicate that the 1600 bpfragment derived from CMS mitochondrial DNAcan be used as a RAPD marker to distinguishA and B plants at seedling stage, and thefragments (700 bp, 1000 bp) can be used todistinguish WA and DA cytoplasms.     

Cytoplasmic Systems in Different Male-Sterile Lines of Rice

In order to characterize the cytoplasmic system in seven cytoplasmic-genic male-sterile lines (CMS; A lines) of rice, viz., V 20A, ‘Zhenshan 97A’, IR 46831A, ‘Madhu A’ (cms-WA), ‘Yar-Ai-Zhao A’ (cms-Gam), ‘Pankhari 203A’ (cms-TN) and Wu 10A (cms-bo) and their isonuclear maintainers (B lines), all possible crosses were made between CMS lines and maintainers (A × B) as well as between the maintainers themselves (B × B). Based on F₁ pollen and spikelet fertility the CMS lines V 20A, ‘Zhenshan 97A’, IR 46831 A, ‘Madhu’ A possessing cms-WA cytoplasm were found to be genetically different from ‘Pankhari 203A’ (cms-TN), Wu 10A (cms- bo) and ‘Yar-Ai-Zhao A’ (cms-Gam) cytoplasms. Cms-bo and cms-TN cytoplasms appeared to be identical. Since the cytoplasms of the A lines are different from those of the B lines, the nuclear genes operating to cause the sterility might also be different in (A × B) and (B × B) crosses.     

水稻体细胞无性系雄性不育突变

对5个类型的水稻不育系进行了幼穗培养, 在红源A、 包源A和W6154s中, 共获得了10例雄 性不育变异株, 水稻花粉败育可分为无花粉、 典败、 圆败和染败四种类型。 发现了不育 花粉败育类型之间可以相互转换现象。 对雄性不育变异株用一批现有CMS不育系的保持系和恢复系进行测交和回交, 有的变异株其 恢保关系发生了变化,     

几个水稻不育系对白叶枯病的抗性

测定了８对不育系（Ａ）和保持系（Ｂ）以及一些杂交稻组合对６个小种的４０株白叶枯病菌的抗性，比较了不同类型不育系对６个小种群的抗性差异。结果表明，冈型、印尼水田谷型和大多数野败型不育系的抗性很差，ＢＴ型的抗性较高。菌株Ａｈ２８对冈４６Ａ和野败珍汕９７Ａ的致病力强。比较了６个恢复系（Ｃ）和８个杂交组合对不同小种的抗性程度。结果显示，杂交稻的抗病性主要受父本（恢复系）核基因的控制，但同时又受不育胞质的影     

Inheritance of root traits and phosphorus uptake in common bean (Phaseolus vulgaris L.) under limited soil phosphorus supply

Heterosis is an important way to improve yield and quality for many crops. Hybrid rice and hybrid maize contributed to enhanced productivity which is essential to supply enough food for the increasing world population. The success of hybrid rice in China has led to a continuous interest in hybrid wheat, even when most research on hybrid wheat has been discontinued in other countries for various reasons including low heterosis and high seed production costs. The Timopheevii cytoplasmic male sterile system is ideal for producing hybrid wheat seeds when fertility restoration lines with strong fertility restoration ability are available. To develop PCR-based molecular markers for use in marker-assisted selection of fertility restorer lines, two F₂ populations derived from crosses R18/ND36 and R9034/ND36 were used to map fertility restoration genes in the two elite fertility restorer lines (R-lines) R18 and R9034. Over 678 SSR markers were analyzed, and markers closely linked to fertility restoration genes were identified. Using SSR markers, a major fertility restoration gene, Rf3, was located on the 1B chromosome in both populations. This gene was partially dominant in conferring fertility restoration in the two restorer lines. SSR markers Xbarc207, Xgwm131, and Xbarc61 are close to this gene. These markers may be useful in marker-assisted selection of new restorer lines with T. timopheevii cytoplasm. Two minor QTL conferring fertility restoration were also identified on chromosomes 5A (in R18) and 7D (in R9034) in two R-lines.     

Genetics of fertility restoration of ‘Wild Abortive’ cytoplasmic male sterility in rice,Oryza sativa L.

Summary Genetics of fertility restoration in six varieties and breeding lines of rice was studied in Wild Abortive cytoplasmic genetic male sterility system using cytoplasmic male sterile lines V 20 A and IR 54752 A. Fertility evaluation of the plants in F₂ and testcross populations of the crosses of V 20 A with PR 103, PR 106 and PAU 502-94-1, and IR 54752 A with PAU 1124-36-1 and PAU 1126-1-1 revealed that fertility restoration in PR 103, PR 106, PAU 502-94-1, PAU 1124-36-1 and PAU 1126-1-1 was controlled by two independently segregating dominant genes. The two genes appeared to have additive effects; one of them being stronger than the other in imparting fertility restoration. Data on spikelet fertility of the plants in F₂ and testcross populations of V 20 A/UPR 82-1-1 cross showed that fertility restoration in UPR 82-1-1 was controlled by two independently segregating dominant genes which exhibited recessive epistatic interaction.

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稻瘟病菌致病毒素的活性测定及其影响条件

稻瘟病菌９０－２菌株是从大田水稻雄性不育细胞质（ＣＭＳ）上分离的对野败型（Ｗ）ＣＭＳ专化致病的生理小种。研究表明,该菌株产生的毒素在致病过程中起着一定作用。本试验测定了此菌株在不同ＰＨ培养基中培养对毒素产生的影响、毒素的热稳定性及ＰＨ值变化对毒素活性的影响等。离体叶片法测定毒素对Ｗ珍汕９７Ａ、９７Ｂ叶绿素总含量的影响和对Ｗ珍汕９７Ａ、９７Ｂ呼吸作用的影响,初步测定了粗毒素的致病作用。用根冠细胞法测     

Diversity among sources of cytoplasmic male sterility in sunflower (Helianthus annuus L.)

Summary Ten cytoplasmic male sterile (CMS) sunflower (Helianthus annuus L.) lines were crossed with nine maintainer or male fertility restorer lines in a diallel crossing scheme. Based on fertility restoration of the F₁ generation, CMS lines were divided into four groups. At least two new sources of CMS, CMS PET2 and CMS GIG1, were found to be potentially useful for commercial production of hybrids. Environment had an influence on fertility restoration of one CMS line, CMS MAX1. Effective restoration of male fertility for CMS RIG1, CMS ANN2, and CMS ANN3 was not found.     

Identification of the Rf gene conferring fertility restoration of the CMS Dian-type 1 in rice by using simple sequence repeat markers and advanced inbred lines of restorer and maintainer

Cytoplasmic male sterility of Dian‐type 1 (CMS‐D1) was developed 30 years ago in Yunnan. A major gene conferring fertility restoration for the CMS‐D1 system was detected by microsatellite markers in advanced inbred lines consisting of 196 maintainers and 62 restorers developed in breeding programmes of hybrid rice involving the CMS‐D1 system. The gene was mapped between two simple sequence repeat markers, OSR33 and RM228, on chromosome 10, and was temporarily designated as Rf‐D1(t). The genetic distances of the gene to the two microsatellite markers were 3.4 and 5.0 cM, respectively. This linkage was confirmed by using an F2 population derived from a cross between a CMS‐D1 line and a restorer. This study also demonstrated that using OSR33 was reliable and efficient for identification of restoring lines in hybrid rice breeding with the CMS‐D1 system.     

滇型水稻细胞质雄性不育恢复基因Rf-D1（t）的克隆与遗传特性分析

CMS/Rf测交F1结实率与花粉可育率检测表明,Ansanbyeo和南34对三种不同细胞质来源的粳稻不育系(CMS-DT1,CMS-BT和CMS-HL)都有较强的恢复力。根据已公布的水稻基因组序列,在水稻恢复基因定位区段内设计引物,确定出一对与两个滇型CMS的恢复系Ansanbyeo和南34恢复基因紧密连锁的分子标记引物M43804和M43558,首次克隆了滇型恢复基因Rf-D1(t),编码16个PPR蛋白。序列比对表明,该基因与BT型恢复基因Rf-1相似度达99%,两个恢复基因之间在ORF区仅存在一个碱基差异,即Rf-D1(t)第1149bp位的A变成Rf-1的C,并产生一个氨基酸的改编即K(赖氨酸)变成N(天冬酰胺)。该差异处于一个PPR结构域中,暗示该氨基酸是恢复基因的关键位点之一,它的改变可能影响对水稻CMS育性恢复力的变化。     

Comparative genetic analysis and molecular mapping of fertility restoration genes for WA,Dissi, and Gambiaca cytoplasmic male sterility systems in rice

The genetic relationship among three cytoplasmic male sterility (CMS) systems, consisting of WA, Dissi, and Gambiaca, was studied. The results showed that the maintainers of one CMS system can also maintain sterility in other cytoplasmic backgrounds. The F₁ plants derived from crosses involving A and R lines of the respective cytoplasm and their cross-combination with other CMS systems showed similar pollen and spikelet fertility values, indicating that similar biological processes govern fertility restoration in these three CMS systems. The results from an inheritance study showed that the pollen fertility restoration in all three CMS systems was governed by two independent and dominant genes with classical duplicate gene action. Three F₂ populations, generated from the crosses between the parents of good-performing rice hybrids, that possess WA, Dissi, and Gambiaca CMS cytoplasm, were used to map the Rf genes. For the WA-CMS system, Rf3 was located at a distance of 2.8 cM from RM490 on chromosome 1 and Rf4 was located at 1.6 cM from RM1108 on chromosome 10. For the Dissi-CMS system, Rf3 was located on chromosome 1 at 1.9 cM from RM7466 and Rf4 on chromosome 10 was located at 2.3 cM from RM6100. The effect of Rf3 on pollen fertility appeared to be stronger than the effect of Rf4. In the Gambiaca-CMS system, only one major locus was mapped on chromosome 1 at 2.1 cM from RM576. These studies have led to the development of marker-assisted selection (MAS) for selecting putative restorer lines, new approaches to alloplasmic line breeding, and the transfer of Rf genes into adapted cultivars through a backcrossing program in an active hybrid rice breeding program.     

广谱抗稻瘟病基因d12的遗传分析及分子标记辅助选择应用

本研究利用一个广谱抗稻瘟病基因d12（来源于武育粳2号）,通过分子标记辅助选择改良珍汕97B抗稻瘟病性。首先利用以珍汕97B为背景构建一个包含236个单株的d12近等基因系BC2F2群体,通过遗传分析,将抗稻瘟病基因d12定位于水稻第12染色体的遗传距离为2.7cM的2个SSR标记RM27792-RM28089之间。QTL分析结果表明,在分蘖期Ⅰ（TL58,播种后第58天考察的叶瘟）和分蘖期Ⅱ（TL75,播种后第75天考察的叶瘟）检测到的d12的LOD值和VAR值（遗传方差/表型方差）分别为：31.7、47.1%以及24.1、37.9%,d12的加性效应和显性效应分别为1.2608、-1.0475以及0.7326、-0.7689;当水稻进入抽穗期（HL98,播种后第98天考察的叶瘟）时,检测不到d12。由此可见,d12对稻瘟病抗性随着水稻的分蘖进程可能由强到弱,当进入生殖生长时期对稻瘟病的抗性没有了贡献。这可以表明d12对稻瘟病的抗性受到发育时期的影响。以上结果可能对稻瘟病持久抗性的育种和受发育影响的抗病性的理解有非常重要的意义。     

Development of new cytoplasmic source of male sterile lines in rice for shallow lowland

Two shallow lowland male sterile lines, MotiA and PadminiAwith Miz.4 cytoplasmic source were developed throughintervarietal hybridization and recurrent backcrossing withtheir respective parents. In all probability, MotiA and PadminiA of Miz.4 source may be genetically different from the Wild abortive CMS source (V.20A). These two CMS lines are semitall in stature, photosensitive, of late duration in flowering with easy fertility restoration ability, and thus could be useful for developing hybrid rice suitable for shallow lowland areas.     

东乡野生稻细胞质雄性不育育性恢复基因的遗传分析及应用

细胞质雄性不育及其恢复系统在杂交水稻生产中必不可少,而从野生稻中鉴定、发掘细胞质雄性不育恢复源对促进杂交水稻的发展产生深远的影响。为了发掘东乡野生稻的育性恢复基因,应用协青早A/(协青早B//协青早B/东乡野生稻BC1F10)和中9A/(协青早B//协青早B/东乡野生稻BC1F10)两套测交群体,开展东乡野生稻细胞质雄性不育育性恢复经典遗传学研究。结果表明:东乡野生稻对矮败型(CMS-DA)和印尼水田谷败型(CMS-IA)的育性恢复表现为质量-数量性状,东乡野生稻对矮败型(CMS-DA)和印尼水田谷败型(CMS-IA)的育性恢复的控制存在主效恢复基因,同时还受到微效基因的影响。此外,还就东野恢复基因发掘及其在杂交水稻育种的生产应用进行了探讨。     

新质源CMS-FA杂交稻系统的亲本资源筛选

用新质源雄性不育系金农1A(CMS-FA)作母本, 分别与来自10个国家和国内13个省份的220个水稻品种组配成杂交种, 考察F₁代的花粉染色率、套袋结实率和自然结实率。在F₁代中, 当这3项育性指标均≤10%时, 显示父本品种具有雄性不育保持能力, 因而将其划分为保持系资源; 当3项育性指标均≥80%时, 显示父本品种具有雄性不育恢复能力, 将其划分为恢复系资源; 此外的其他父本品种, 即3项育性指标中任何一项指标>10%或<80%, 既不能作为保持系, 也不能作为恢复系, 被划分为非杂交稻亲本资源。在220个水稻品种中, 可作为金农1A保持系的有122个, 占55.5%; 未发现恢复系亲本; 非杂交稻亲本品种有98个, 占44.5%。CMS-FA型的杂交稻亲本资源利用率为55.5%。对照野败型不育系珍汕97A(CMS-WA)的保持系亲本品种有44个, 占20.0%; 恢复系亲本品种42个, 占19.1%; 非杂交稻亲本品种134个, 占60.9%。CMS-WA型的杂交稻亲本资源利用率为39.1%。CMS-FA系统比CMS-WA系统的亲本稻种资源利用率高16.4个百分点, 尤其是保持系资源利用率高35.5个百分点(近1.8倍)。国外品种的育性普遍低于国内品种。