Research on Theories and Techniques of Irrigation for Safeguarding Seed Production of Two-Line Hybrid Rice

By inducing frequency, intensity and duration of lower temperature in the middle and last ten-day periods in August in the rice-growing areas of southern China, increasing temperature for safe seed production was defined as 2℃. During the sensitive period of fertility, characters of panicle height and canopy structure of TGMS rice, Pei＇ai64S, were measured. Results showed that temperature changes caused by irrigation in fields were below 40 cm of rice plant, and heating effect was significant at 20 cm when the temperature was increased by 3.1 ℃. For the present study, the following irrigation techniques were put forth： the water depth of 15-20 cm, current water used, irrigating after 17：00 and bailing at 10：00 in sunny or cloudy weather, irrigating on whole day, in shady or rainy weather, increasing inflows and outflows in large fields. In the present experiment, pollen fertility and self-fertilized seed setting rate accepted that the techniques were feasible and effective for against lower temperature and safeguarding seed production of two-line hybrid rice.

Feasibility Analysis and Policy Recommendations for Production of Hybrid Rice Seed in Foreign Countries

In the economic new normal,production of hybrid rice seed in foreign countries is the necessity for reducing farmland area occupied by seed production,for ensuring national grain security,realizing cost reducing and quality improving of hybrid rice seed,strengthening competitive power at international market,guiding seed industry of China to go out,building transnational seed groups with core competitive power,establishing close relationship with developing countries,promoting the construction of One Belt One Road strategy,serving overall situation of diplomacy,and setting up excellent international image. It is feasible to produce hybrid seed in foreign countries considering( i) high overall national strength of China,( ii) rapid and healthy growth of China's seed industry and increasingly mature hybrid rice seed production technologies,( iii) excellent climatic conditions of foreign host countries of seed production,and( iv) low land and labor price of foreign host countries of seed production. However,there are social and policy risks,technology and trade barrier risks,market,production,and other risks for production of hybrid rice seed in foreign countries. In view of these,it came up with recommendations,including allowing delivering parent seeds of hybrid rice to foreign countries,allowing delivering hybrid rice seed to China,solving the problem of " opening in protection,and protection in opening",and formulating a package of support policies.

High-yield Production Techniques of High-quality and Early Maturity Hybrid Rice Xiangzaoyou 2017

Xiangzaoyou 2017 is an excellent early maturing variety bred from the combination of Neixiang 3A and the self-fertile restorer QN 2017 by Qiannan Institute of Agricultural Sciences of Guizhou Province,and it has been approved by the Guizhou Crop Variety Approval Committee( Approval No.: Qianshendao 2006001).In order to promote its application in production,the research on the seed production techniques of Xiangzaoyou 2017 was carried out,and the key technical points of high-yield seed production of Xiangzaoyou 2017 were put forward.

Practices and Prospects of Super Hybrid Rice Breeding

The great progress in super rice breeding both in China and other countries has been made in recent years. However, there were three main problems in super rice breeding： 1） the super rice varieties were still rare; 2） most super rice varieties exhibited narrow adaptability; and 3） current breeding theories emphasized too much on the rice growth model, but they were unpractical in guidance for rice breeding. According to the authors＇ experience on the rice breeding, the breeding strategies including three steps （super parent breeding, super hybrid rice breeding and super hybrid rice seed production） were proposed, and the objectives of each step and the key technologies to achieve the goals were elucidated in detail. The super parent of hybrid rice should exhibit excellent performance in all agronomic traits, with the yield or sink capacity reached the level of the hybrid rice control in regional trials. The super hybrid rice combination should meet the following criteria： good rice quality, wide adaptation, lodging resistance, resistance to main insects and diseases, and the yield exceeded above 8% over the control varieties in the national and provincial regional trials. To achieve the goal, the technical strategies, such as selecting optimal combination of the parents, increasing selection pressure, paying more attention to harmony of ideal plant type, excellent physiological traits and all the agronomic traits, should be emphasized. The yield of seed production should reach 3.75 t/ha and 5.25 t/ha for the super hybrid rice combinations derived from early-season and middle-season types of male sterile lines, respectively. The main technologies for raising seed production yield included selecting optimum seed production site, using the male sterile line with large sink capacity and good outcrossing characteristics, and improving the amount of the pollen by intensive cultivation of the male parent. According to the technologies of the three-step breeding on super hybrid rice, two super rice parents, including a male parent 996 and a thermo（photo）-genic male sterile [T（P）GMS] line C815S, were bred. Furthermore, a super early hybrid rice combination, Luliangyou 996, which could be used as a double-season early rice variety in middle and lower reaches of the Yangtze River, China, was bred by using the super rice varlet3, 996 as the male parent, and several hybrid rice combinations with higher yield than control variety in regional trials both of Hunan Province and state were bred with the T（P）GMS line C815S as the female parent.

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.

Breeding and Seed Production Techniques of New Aromatic Danxiangyouzhenliang Rice Variety with Good Quality and High Yield

Danxiangyouzhenliang rice is a high-quality rice variety derived from the hybrid breeding of Danxiang 12A and Xianghuixiangmiao R133.Its unique temperature-sensitive three-line characteristics endow it with significant advantages of high and stable yield,and its rice fragrance is exquisite and its taste is delicate.Danxiangyouzhenliang rice showed good resistance to rice blast and bacterial blight.On June 10,2021,Danxiangyouzhenliang rice passed the Guangxi Crop Variety Approval(Guishendao 2021074).Danxiangyouzhenliang rice is suitable to be planted as early and late rice in southern,central and northern Guangxi.This study summarized the breeding process and high-yielding seed production techniques of Danxiangyouzhenliang rice,in order to provide useful reference for rice breeders and growers.

Identification of a major quantitative trait locus and its candidate underlying genetic variation for rice stigma exsertion rate

Stigma exsertion in male sterile lines of hybrid rice is important for seed yield.In the present study, ZS616 [Oryza sativa subsp.Xian(indica)], a male sterile line with a stigma exsertion rate(SER) as high as 94.5%, was crossed to DS552, a japonica line with almost no exserted stigmas.F3 plants with extremely low and high SER were sequenced to identify SER-associated quantitative trait loci(QTL).A major QTL for SER, qSER-3.1, was identified along with other QTL on chromosome 3 in a 3.9 Mb region.A total of 307 nonsynonymous single-nucleotide polymorphisms(SNPs) and 27 frame-shift insertion/deletions(InDels)differentiating ZS616 and DS552 were identified in the region containing qSER-3.1.Most SNPs(294) and InDels(25) were excluded after further analysis because they were shared by ZS616 and low(<2.0%) SER accessions in the Huazhong Agricultural University(HAU) core rice collection.Association analysis using the full HAU collection identified a 17-bp InDel in OS03 G0689400 as the most likely causal genetic variant underlying qSER-3.1.ZS616-type accessions(n = 54, with the 17-bp insertion) in the HAU collection had minimum(16.5%)and mean(39.6%) SERs significantly greater than those(n = 424) without the insertion(with minimum and mean SERs of 0.2% and 20.6%, respectively).Thus, this study identified a major QTL for stigma exsertion and revealed the mutation in a candidate gene for the QTL.

海南两系杂交稻制种适宜区域与时段选择

掌握两系杂交稻在海南制种的气象灾害风险,是科学合理安排两系杂交稻制种生长期的重要依据。针对两系杂交水稻制种过程中的3个关键阶段(育性敏感安全期、抽穗扬花授粉安全期和灌浆安全期)的气象灾害概率进行分析,通过数据分析和实例验证得出各地区制种的安全时段,以及需重点考虑的气象灾害。海南两系杂交水稻育性敏感安全期可安排在3月上旬至4月中旬,三亚、陵水地区从3月上旬开始;乐东、东方、昌江从3月下旬至4月上旬开始;临高在4月中旬至下旬左右,不同界限温度变化略有先后。各地花期的阴雨天气较为随机且概率较小;临高、昌江地区制种重点关注灌浆安全期干热风等危害,提早播种。目前海南水稻制种区域和时段合理,可根据不育系材料不育起点温度阈值和耐受低温时间长短,适当调整播种时段。

福建两系杂交稻制种安全高产的精细气候适宜性区划

利用福建省67个国家气象观测站1971-2020年气象资料以及地理信息资料、两系杂交稻制种基地调查资料,构建了两系杂交稻制种育性转换敏感期气候风险模型与风险等级指标、扬花授粉期天气综合危害指数模型与等级指标两个安全期气候区划指标,选择不育系育性转换起点温度23℃开展研究,基于两系杂交稻制种气候适宜性分区等级标准,采用多层复合方法,开展基于GIS的福建省两系杂交稻制种安全高产精细气候适宜性区划。结果表明:育性敏感期安排在7月上旬-下旬、7月中旬-8月上旬,扬花授粉期安排在8月上旬-中旬,适宜区分布在福建北部、西南部等县市海拔300m以下的区域,次适宜区分布在福建北部、西南部等县市海拔300-500m的区域;育性敏感期安排在7月下旬-8月中旬、8月上旬-下旬,扬花授粉期8月下旬-9月上旬,适宜区分布在福建北部、西南部等县市海拔400m以下的区域,次适宜区分布在福建北部、西南部等县市海拔400-500m的区域;育性敏感期安排在7月上旬-8月下旬,扬花授粉期安排在8月上旬-9月上旬,低适宜区分布在海拔500-1000m的区域,不适宜区分布在海拔1000m以上区域。

优质高产籼粳杂交稻嘉丰优3号的选育及制种技术

嘉丰优3号是嘉兴市农业科学研究院联合中国水稻研究所、浙江可得丰种业有限公司,以嘉禾112A(长粒型粳稻三系不育系)为母本与G1143(中籼迟熟型恢复系)为父本选育的三系杂交水稻新组合。该组合具有高产、优质、中抗稻瘟病等优势,于2021年4月通过浙江审定(浙审稻2021019),2021—2023年先后通过了江西省[(赣)引种〔2021〕第001号]、安徽省(皖引稻2021066)、福建省[(闽)引种〔2022〕第1号]、湖北省(鄂引种2022055)的引种备案,适宜在长江中下游地区作中稻种植。文章介绍了嘉丰优3号的选育过程、特征特性、高产栽培及制种技术等。

两系杂交水稻新组合徽两优9192高产制种技术

徽两优9192是合肥丰乐种业股份有限公司与安徽省农业科学院水稻研究所共同选育的籼型两系杂交水稻新品种,2018年通过国家审定,具有丰产性良好、株型好、生育期适中、抗性好等特点,适宜在湖北省(武陵山区除外)、湖南省(武陵山区除外)、江西省、安徽省、江苏省的长江流域稻区以及浙江省中稻区、福建省北部稻区、河南省南部稻区的稻瘟病轻发区作一季中稻种植。根据徽两优9192的亲本特性及制种地区福建省建宁县亚热带季风气候特点,从选择制种区域、田间管理等方面介绍徽两优9192的制种技术,以期为该品种大面积推广种植提供参考依据。

两系杂交水稻新组合两优5078高产制种技术

两优5078是合肥丰乐种业股份有限公司与安徽省农业科学院水稻研究所共同选育的籼型两系杂交水稻新品种,具有株型好、产量高、适口性好等优点,适合在长江中下游作一季中稻种植,2019年通过国家审定。该文简述了该品种的亲本来源、特征特性及制种技术要点。

杂交水稻中浙优26特征特性及制种技术

中浙优26是浙江勿忘农种业股份有限公司、中国水稻研究所利用中浙2A和F1436配组育成的优质杂交水稻新品种,2020年分别通过国家审定和广西壮族自治区审定。浙江龙游县五谷香种业有限公司于2019年引种试验种植,田间表现出丰产性好、优质、耐肥抗倒、对白叶枯病和稻瘟病有较强抗性等特点。同时在龙游开展了2 a的中浙优26制种工作。根据在浙江龙游种植的田间表现和制种实践,结合亲本的特征特性,提出适合中浙优26在浙西的安全高产制种技术。

杂交晚籼稻新组合乐优97的选育及栽培制种技术

乐优97是由合肥丰乐种业股份有限公司利用自育的三系不育系409A与恢复系R977杂交选育而成的高产、优质、抗倒杂交晚籼稻新组合,于2022年通过了国家农作物品种审定委员会审定。本文详细介绍了乐优97的选育过程和特征特性,并总结了乐优97优质高产栽培技术及其制种技术关键要点,以期为该产品的大规模推广种植提供参考。

两系杂交水稻组合Q两优851制种技术

Q两优851是利用自育不育系全151S和自育优质恢复系YR851配组育成的两系杂交籼稻组合,2019和2020年分别通过长江中下游和长江上游审定。本文分析了该组合亲本的特征特性、不育系的选育过程,基于近几年栽培制种实践,总结了该组合高产安全制种技术,为水稻制种工作提供参考。

高产三系杂交中稻荃优9的选育及栽培制种技术

荃优9是长沙碧盈农业科技有限公司与安徽荃银高科种业股份有限公司合作选育的籼型三系杂交中稻迟熟组合,以籼型细胞质雄性不育系荃9311A为母本、R1833为父本配组选育而成,具有产量高、生育期适中、广适性、抗倒伏等特点。2022年通过湖南省农作物品种审定。介绍了荃优9选育的具体过程,以及该品种在区域试验中农艺性状表现,并对其丰产栽培技术和高产制种技术进行了探究,以期为推广应用提供数据支撑。

两系杂交水稻新组合F两优658选育及高产栽培技术

F两优658是安徽赛诺种业有限公司利用两系不育系F168S与恢复系R658配组并经过多年多点比较试验选育而成的两系杂交水稻新组合。该组合株型紧凑,株高适中,丰产性好,适宜在长江上游地区种植。2022年F两优658通过国家农作物品种审定委员会审定,审定编号为国审稻20220052。本文详细阐述了F两优658的选育过程、高产栽培技术及其种子生产技术,以期为水稻种植户提供参考。

杂交粳稻申优28高产制种和栽培技术分析

申优28是利用不育系申21A和恢复系申恢26-28组成的杂交粳稻品种。本文介绍了申优28品种的特征特性,研究了其全程机械化高效制种技术,包括选种、控制播期、调控花期、机械割叶、机械辅助授粉、收割及烘干等操作技术,为杂交水稻生产制种提供技术指导。该品种具有早熟、高产、米质优且抗病性强等综合优势。为充分发挥申优28产量潜力,从适时播种、肥料运筹、水浆管理和适宜收获等方面总结了其高产栽培技术,为该品种示范推广提供参考。

杂交水稻制种基地建设评价实证分析——以福建省建宁县等4个国家级杂交水稻制种大县为例

为保障粮食和重要农产品稳定安全供给,确保“中国粮”主要用“中国种”,就必须保证有数量充足、品质优良的种源,需要依托基地建设产出高质量种源。近十年来,以三明市为核心的福建省杂交水稻制种基地规模逐步增大,2022年落实杂交水稻制种总面积3.13万hm2,占全国总面积的28.6%。本文以三明市建宁县、宁化县、泰宁县、尤溪县等4个国家级杂交水稻制种大县为样本,利用“制种基地建设评价分析系统(简称:制种基地评价系统)V1.0”,科学评价4个基地县杂交水稻制种产业发展情况,借此深入分析福建省杂交水稻制种产业发展面临的主要问题和下一步举措,为该省建设现代化种业基地提供参考。

优质高产籼粳杂交稻嘉禾优7245的选育及制种技术

嘉禾优7245是中国水稻研究所联合嘉兴市农业科学研究院等多家单位,以嘉禾212A(长粒型粳稻三系不育系)为母本与中恢7245(中籼迟熟型恢复系)为父本选育的三系杂交水稻新组合。该组合具有高产、优质、抗倒伏等优势,于2017年7月通过国家审定(国审稻20170064),2020—2022年先后通过了广西壮族自治区(桂审稻2020220号)、广西壮族自治区晚稻(桂审稻2022093号)、江西省(赣审稻20210016)的品种审定,2022年通过福建省:(闽)引种〔2022〕第1号的引种备案,适宜在长江中下游地区作中、晚稻种植。文章介绍了嘉禾优7245的选育过程、特征特性、高产栽培及制种技术等。