Genetic Analysis and Primary Mapping of pms4, a Photoperiod-Sensitive Genic Male Sterility Gene in Rice (Oryza sativa)

To understand the genetic characteristics of a new photoperiod-sensitive genic male sterile line Mian 9S, some reciprocal crosses were made between Mian 9S and six indica rice materials, Yangdao 6, Luhui 602, Shuihui 527, Mianhui 725, Fuhui 838 and Yixiang 1B. Genetic analysis results suggested that the photoperiod-sensitive genic male sterility （PGMS） of Mian 9S was controlled by a single recessive nuclear gene. Thus, the F2 population derived from the cross of Yangdao 6/Mian 9S was used to map the PGMS gene in Mian 9S. By using SSR markers, the PGMS gene of Mian 9S was mapped on one side of the markers, RM6659 and RM1305, on rice chromosome 4, with the genetic distances of 3.0 cM and 3.5 cM, respectively. The gene was a novel PGMS gene and designated tentatively as pms4. In addition, the application of the pms4 gene was discussed.

Improving Blast Resistance of a Thermo-Sensitive Genic Male Sterile Rice Line GD-8S by Molecular Marker-Assisted Selection

The broad-spectrum blast resistance gene Pi-1, from donor line BL122, was introduced into a thermo-sensitive genic male sterile rice line GD-8S, which possessed good grain quality but high susceptibility to rice blast, by using backcross breeding and molecular marker-assisted selection. Five elite improved male sterile lines, RGD8S-1, RGD8S-2, RGD8S-3, RGD8S-4 and RGD8S-5, were selected based on the results of molecular marker analysis, spikelet sterility, recovery rate of genetic background and agronomic traits. Thirty-three representative blast isolates collected from Guangdong Province, China were used to inoculate the improved lines and the original line GD-8S artificially. The resistance frequencies of the improved lines ranged from 76.47% to 100%, much higher than that of the original line GD-8S （9.09%）. On the agronomic characters, there were no significant differences between the improved lines and GD-8S except for flag leaf length and panicle number per plant. The improved lines could be used for breeding hybrid rice with high blast resistance.

New Temperature Sensitive Genic Male Sterile Lines with Better Outcrossing Ability for Production of Two-Line Hybrid Rice

An investigation was carried out with three newly developed temperature sensitive genic male sterile （TGMS） lines for their floral traits, seed production potential and outcrossing ability in ten cross combinations. In the TGMS lines, fertile pollens had an average diameter of 0.89 mm while the sterile pollens was with 0.02 mm diameter.TS-29-150GY produced the biggest fertile pollens with 0.92 mm and other two lines produced relatively smaller pollens with 0.91 and 0.85 ram. Pollen fertility during the fertility reversion period was an average of 60.7%. TS-29-150GY had the maximum of 66.9% spikelet fertility whereas other two lines （TNAU18S and TNAU60S） had relatively lower spikelet fertility of 27.8% and 26.7%, respectively. Average of 17.00 g of seed yield was obtained in the TGMS lines during the fertility reversion period. TS-29- 150GY had the highest value of 21.20 g of seed yield while TNAU18S and TNAU60S produced 16.6 g and 13.2 g of seed yield, respectively. The low seed production ability of these three TGMS lines was attributed only to the environmental conditions prevailing during the period. All three TGMS lines had considerable outcrossing potential of 41.2%, 24.6% and 25.0%, respectively. The cross combinations viz. TNAU18S/IET21508 （36 g/plant）, TNAU18S/IET21044 （13 g/plant）, TNAU18S/IET21009 （26.5 g/plant）, TNAU60S/CB-09-106 （26.2 g/plant）, TNAU60S/IET21009 （14 g/plant） and TS29-150-GY/DRR 3306 （39.2 g/plant） showed perfect synchronization with acceptable hybrid seed yield, indicating suitability of TGMS system under Indian condition. Based on the outcrossing related traits viz. panicle exertion, angle of glume opening, stigma length and pollen size, TNAU18S was identified as the best, followed by TS-29-150GY.

Inducing fertility restoration in the genic male sterile line of rice with chemical regulators

For the first time, the fertility of rice genic male sterile line was partially restored with the application of chemical regulators at Hainan Rice Breeding Nursery on Mar 1993. A single panicle of the rice plant could bear as many as 27 grains. The chemical agent that could modulate the growth of the rice plants of genic male sterile line was developed by Prof ZHOU Guangqia and his colleagues at the Biology Institute, Hunan Teachers University, China.

Mapping of a gene for photoperiod-sensitive genic male sterility in Nongken 58s on chromosome 5 of rice

A photoperiod-sensitive genic male sterile (PGMS) rice was found in 1973 as a spontaneous mutant of Nongken 58, a japonica variety. Pollen fertility of Nongken 58s (N58s) is completely sterile when grown under long-day conditions, whereas fertile under short-day conditions. This PGMS was found to be controlled by one or two recessive gene(s), of which one gene(pms)was linked to a marker gene(d-1) on chromosome 5. In order to identify a more precise location of the pms, we analyzed the populations of BCFand BCFof N58s//N58s/KL211(v-10, virescent) and N58s//N58s/KL520 (gh-1, gold hull). The marker genes v-10 and gh-1 are located on the flanking region of d-1. The F, plants of two crosses were fertile. The number of fertile and sterile individuals in BCFfit

Thoughts and Practice on Some Problems about Research and Application of Two-Line Hybrid Rice

The main problems about research and application of two-line hybrid rice were reviewed, including the confusing nomenclature and male sterile lines classification, the unclear characteristics of photoperiod and temperature responses and the unsuitable site selection for male sterile line and hybrid dce seed production. In order to efficiently and accurately use dual-purpose genic male sterile lines, four types, including PTGMS （photo-thermo-sensitive genic male sterile rice）, TGMS （thermo-sensitive genic male sterile rice）, reverse PTGMS and reverse TGMS, were proposed. A new idea for explaining the mechanism of sterility in dual-purpose hybrid rice was proposed. The transition from sterile to fertile was involved in the cooperative regulation of major-effect sterile genes and photoperiod and/or temperature sensitive ones. The minor-effect genes with accumulative effect on sterility were important factors that affected the critical temperature of sterility transfer. In order to make better use of dual-purpose lines, the characterization of responses to photoperiod and temperature of PTGMS should be made and the identification method for the characterization of photoperiod and temperature responses of PTGMS should also be put forward. The optimal ecological site for seed production could be determined according to the historical climate data and the requirements for the meteorological conditions during the different periods of seed production.

籼型特色水稻两系不育系红17S的选育

红17S是福建省南平市农业科学研究所以广占63S为母本与南平当地优质特色红米美人红杂交,后又与籼型两系不育系K12S复交,经福建建阳及海南三亚等地充分利用自然生态条件,4 a 8代培育成的特色红米温敏核不育系,2022年通过福建省农作物品种审定。总结了红17S的选育过程、配组应用及配套繁殖、制种技术。

Selection of Submergence Tolerant Homozygous Line by STS Marker and Twice Submergence Stress

One sequence tagged site marker Subl-1 and twice submergence stress method were used in selection of submergence tolerant homozygous line from Sub-lBS, a submergence tolerant, bentazon sensitive and photoperiod-sensitive and/or thermo-sensitive genic male sterile line that developed by our laboratory. The results revealed that the original Sub-lBS was heterozygous in SublA-1 locus even though it was identical in almost all of agronomical traits and the segregation of SublA-1 was in accordance with Mendelian law based on chi-square test. And then the original Sub-IBS was divided into two groups： one was ofSublA-1 introgression and the other was not; and the two groups were tested by twice submergence stress method. After the first submergence stress that lasted for 12 d, the average plant heights were significant difference at the 1% level between the two groups. After recovery for 10 d, the second submergence stress sustained for 18 d was carried on; and the group with SublA-1 gene was found apparently tolerant than the other group in submergence tolerance.

水稻籼型光温敏核不育系福7112S的选育及应用

籼型光温敏核不育系福7112S是以1892S为母本与优质自育材料R0564杂交,采用系谱法选育而成的。该不育系育性稳定、败育彻底、株型紧凑、抗性较好、米质较优,2019年通过安徽省农作物品种审定委员会组织的技术鉴定。本文介绍了福7112S的选育过程,阐述了其主要的特征特性和育性表现,分析了其配组应用,总结了繁殖制种技术,以期为福7112S的推广与应用提供参考。

节水抗旱稻光温敏雄性核不育系沪旱82S的选育与利用

沪旱82S是上海市农业生物基因中心利用沪旱3S(沪旱1S∕青四矮)和沪旱5S(沪旱1S∕黄华占)杂交,经上海和海南等多年异地交叉筛选,育成的光温敏雄性核不育系。其具有不育性稳定、不育起点温度较低、抗病性好、抗旱性强、稻米品质优(达部标3级)等特性,2018年10月通过了上海市品种审定委员会的田间鉴定。利用该不育系选配的两系节水抗旱稻品种‘旱两优8200’通过2021年国家审定;配组的‘旱两优8208’分别通过广西壮族自治区和江西省审定,2023年通过国家审定。

优质籼型水稻光温敏核不育系‘7-163S’特征特性及其基因型解析

为了制定合理的育种计划,对籼型水稻光温敏核不育系‘7-163S’特征特性及基因型进行解析。以‘7-163S’及其配制组合或品种为试验材料,对主要农艺性状进行分析,使用基因组测序和RiceNavi数据库解析‘7-163S’的基因型。结果表明,‘7-163S’农艺性状优异,可繁性好,育性起点温度低、中抗稻瘟病、抗白叶枯病。已育成4个品种或组合,均表现出生育期适中、优质、丰产性好等特点。基因型分析表明‘7-163S’含有稻瘟病、白叶枯病、褐飞虱等抗性等位基因,以及低垩白、高氮肥利用效率、耐冷等优异等位基因。然而,其缺乏广谱抗稻瘟病基因Pi2、Pi9和Pigm、广谱抗白叶枯病基因Xa23、香味基因fgr及镉低积累基因OsCd1和OsNRAMP5等。将基因型与表型结合,可为基因聚合增强‘7-163S’抗性和新品种选育提供理论支撑。

籼型水稻温敏核不育系虬S的选育

虬S是福建省农业科学院水稻研究所以P88S为母本与常规稻广东三抗为父本杂交,通过福建沙县与海南三亚两地穿梭,经6 a 12代的定向培育成的籼型水稻温敏核不育系,具有米质优、外露率高、抗稻瘟、繁制种产量高等特点,2020年通过福建省农作物品种审定委员会审定。

优质光温敏两系不育系邦S的选育与应用

[目的]开展异交特性好、综合性状优良的光温敏两系不育系选育,以培育高产优质两系杂交稻。[方法]采用光温敏两系不育种质华6S为母本和三系保持系种质9946B杂交,经4年7代的系谱法选育,育成了植株矮壮、株型紧凑、株叶形态好、熟期适中、米质优、抗性好的感温型两系不育系邦S,并分析了主要特征特性及其配合力。[结果]光温敏两系不育系邦S不育性稳定,临界温度<23℃;籽粒细长,谷粒长11.2 mm,长宽比达4.0;异交特性好,总外露率平均62.8%,其中双边外露率48.7%。邦S配合力好,先后配组出邦两优908、邦两优香占等7个高产、优质的两系杂交稻组合,并通过国家级或省级审定。[结论]光温敏两系不育系邦S不育性稳定,农艺性状优良,稻米品质优,繁殖系数高,杂种一代优势强,应用前景广泛。

水稻OsGMS2基因的鉴定及其核不育系种子繁殖体系构建

雄性不育是作物杂种优势利用的基础。本研究在籼稻93-1160Co-γ辐射诱变突变体库中鉴定了一个普通核雄性不育突变体osgms2。突变体雄性彻底败育,雌性育性正常,其他农艺性状与野生型一致。遗传分析表明雄性不育稳定遗传且为单基因隐性突变,通过与明恢63构建遗传群体将突变基因精细定位于水稻4号染色体长臂的分子标记S3b和4826之间86kb物理区间内。通过测序分析发现定位区间内一编码类成束阿拉伯半乳聚糖蛋白的基因LOC_Os04g48490编码区第118位至126位缺失连续9个碱基,导致氨基酸整码突变。OsGMS2与已报道的OsFLA1为同一基因,但是突变位点不同的新等位突变。粳稻中花11背景下的基因敲除和遗传互补实验证实了该基因的功能。实时荧光定量PCR(qPCR)表达分析模式显示,该基因在水稻各组织均有表达,但在花期和乳熟期种子表达量较高。蛋白同源比对分析发现,该蛋白序列保守,可能在不同物种中发挥重要功能。通过创建OsGMS2-T保持系成功实现了普通核不育系的繁殖。osgms2突变体的发现和基因鉴定为水稻普通核雄性不育研究及杂种优势利用提供了新的材料。

光敏核不育水稻的光温反应研究 Ⅲ.减数分裂期温度对两个籼稻光敏不育系育性转换的影响

在人工控制条件下研究了在15小时长光照下减数分裂期的不同温度(23.3～30.3℃)对籼稻光敏不育系W6154S和5460S育性转换的影响。结果表明,温度对育性的影响因温度的高低及处理持续时间长短而异,不同的材料对温度的反应不同。5460S从不育转为可育的临界温度在26.4℃左右,而W6154S在处理温度范围内均出现自交结实现象,表明供试的W6154S株系育性转换的临界温度可能超过30.3℃。提出了深入研究影响籼稻光敏不育系育性转换的临界温度的建议。

一种紫色水稻的遗传及其在光敏不育系育种中应用的研究

研究表明，本院获得的一种紫色水稻的植株色遗传受控于C、A、Pl3个独立基因座位上显性基因的互补作用，另有一独立的显性基因对Pl基因的表达起抑制作用．由于该抑制基因在籼稻中的高频率存在，因而，紫稻与一般绿稻品种杂交F1多表现为绿株．紫稻光敏不育（株）系的不育性表达和配合力表现，均可达到与普通光敏不育系相似的水平．本文还讨论了选育籼型紫稻光敏不育系设想的可行性．

利用分子标记辅助选择改良温敏核不育系GD-8S的稻瘟病抗性

以含有广谱稻瘟病抗性基因Pi-1的籼稻材料BL122为供体,优质感病温敏核不育系GD-8S为受体,通过杂交、多次回交和自交结合分子标记辅助选择技术,将Pi-1基因导入GD-8S中。综合目标基因的分子检测、育性镜检、田间农艺性状表现以及遗传背景的回复率,筛选获得5个改良株系RGD8S-1、RGD8S-2、RGD8S-3、RGD8S-4和RGD8S-5。采用广东省具有代表性的33个菌株进行人工接种抗性鉴定,5个改良株系的抗性频率为75.76%～100.00%,而对照仅为9.09%。农艺性状分析表明,除剑叶长和每株穗数外,其余性状改良株系与对照无显著差异。这些改良株系可用于进一步测配选育高抗稻瘟病杂交稻新组合。

温敏核不育水稻育性对低温持续时间的敏感性差异比较研究

培矮 6 4S、810S、株 1S、陆 18S、72 9S、139S、康 2 0 1S、179S、香 12 5S等是一类高温条件下不育、低温条件下可育的高温敏型核不育水稻 ,它们的临界不育温度为 2 3～ 2 4℃左右 ;go5 4 3S是一类高温条件下可育、低温条件下不育的低温敏感核不育水稻 ,其临界不育温度为 2 9 5℃。分别在自然长日 (光长 14 2～ 13 7h)、高温 (日均气温 2 9 0～ 34 1℃ )条件下和短日 (光长 13 0～ 12 4h)、较低气温 (日均气温 2 3 9～ 2 8 1℃ )条件下对处于育性敏感期的温敏核不育水稻进行 1～ 6d的冷水 (2 1 5℃ 2 0 5℃ )处理 ,研究不同温敏核不育水稻育性对低温持续时间的敏感性差异。结果表明 :株 1S和陆 18S经 6d低温处理表现为稳定不育 ,对低温反应钝感 ,杂交制种最为安全 ;72 9S、139S、康 2 0 1S在长日、高温阶段经 5d处理表现为不育 ,在短日、较低气温阶段经 4d处理开始转为可育 ,对低温反应较钝感 ;培矮 6 4S和 810S在长日、高温阶段经 4d处理 ,在短日、较低气温阶段经 2d处理开始转为可育 ,对低温反应较敏感 ;179S、香 12 5S在长日、高温阶段经 3d处理 ,在短日、较低气温阶段经 2d处理就会出现可染花粉和自交结实 ,对低温反应敏感 ,杂交制种风险大 ;短暂低温和高温都会引起go5 4 3S的育性发生变化 。

水稻核不育系SE21S的选育与利用

以农垦 5 8S衍生系 16 4S为核不育基因供体 ,与引进的 IRRI系统 192份优良品种自由串粉 ,产生大群体F1 、 F2 ,在生态压力下选择不育起点温度低的单株。定时选择 ,育成具有光补性能的核不育系 SE2 1S。经杂种优势和配合力测定 ,选出两优 2 16 3和两优 2 186等系列强优组合。制种试验表明 ,SE2 1S具有良好的制种性状。SE2 1S与香稻品种配组 ,育成两优 2 12 0 1等系列组合 ,与 173等优良恢复系配组 ,产量与米质优势明显。 SE2

应用分子标记辅助选择培育抗稻白叶枯病光敏核不育系3418S

分子标记辅助选择 (MAS)因其对目标基因的快速准确选择为回交育种提供有效工具。本研究以回交转育为基础 ,逐代用分子标记检测导入广谱抗白叶枯病基因 X a2 1,在保持光敏核不育系 3418S原有优良性状和稳定育性的基础上 ,增强其抗白叶枯病的能力。育成抗白叶枯病的籼型光敏核不育系 3418S。其抗性达到了 IRBB2 1的抗性水平 ,且保持了 3418S的优良经济性状和明显的光敏核不育特性。