Rice yield is a complex quantitative trait. Although a lot of genes for yield have been cloned, their genetic basis remains unknown. In the present study, a set of chromosome segment substitution line population (CSSL) was developed, derived from the indica variety Huanghuazhan as the recipient parent and the Aus variety N22 as the donor parent, and a high-density bin map containing 609 bins was constructed by resequencing. The CSSL population comprised 155 families with an average background recovery rate of 93.02%. Nine yield-related traits, including plant height, panicle number, panicle length, primary branch number, spikelet number per panicle, grain number per panicle, seed setting rate, 1000-grain weight, and grain yield per plant, were evaluated across four environments. The results showed significant differences in yield-related traits between the two parents across four environments. All nine traits showed continuous distribution with transgressive segregation. Spikelet number per panicle, grain number per panicle and 1000-grain weight showed strong correlations with each other, whereas panicle number had weak correlations with them. A total of 80 main-effect quantitative trait loci (QTLs) affecting yield-related traits were identified, among which 13 QTLs were repeatedly detected in multiple environments, 45 QTLs were located in 8 pleiotropic QTL regions, and 47 QTLs showed significant interactions with environments. In addition, 260 pairs of epistatic QTLs underlying yield-related traits were identified, of which 2 pairs stably expressed across different environments, and 11 pairs controlled more than two traits. These findings provide a theoretical basis for clarifying the genetic differentiation between indica and Aus and cloning yield-related genes, and offer valuable gene resources for molecular breeding of high-yield rice varieties.

再生稻具有较好的外观品质.为解析再生稻外观品质的遗传基础,本研究利用籼稻明恢63和粳稻02428构建的双向导入系为材料,连续两年在湖北荆州考察了双向导入系头季和再生季的外观品质.结果表明,明恢63头季和再生季的外观品质均显著优于02428,双向导入系的所有性状均表现为连续分布.同一性状在头季和再生季间表现为显著正相关,同一季节内不同性状间也表现出显著的相关性,其中粒宽对外观品质的影响最大.结合双向导入系已有的4568个Bin的高密度基因型数据,共定位到57个影响再生稻外观品质的数量性状点位(QTL),位于全部12条染色体上.其中25个QTL在两年间稳定表达,17个QTL在两个遗传背景下被重复鉴定到.此外,第3号染色体16.28～17.33 Mb、第5号染色体3.35～4.28 Mb、第7号染色体24.68～25.46 Mb和第11号染色体6.19～6.97 Mb这4个区间同时影响4个以上性状,来自明恢63的等位基因在这4个区间均可提高外观品质.最后,利用分离群体验证了第11号染色体6.19～6.97 Mb具有真实性.本研究结果为分子育种改良再生稻的外观品质提供了遗传基础.

为解析再生稻蒸煮食味品质的遗传基础,本研究连续两年考察了以籼稻(Indica)'明恢63'和粳稻(Japonica)'02428'构建的双向导入系的头季和再生季的蒸煮食味品质.结果表明,'明恢63'的头季直链淀粉含量(amylose content in the first season,FAC)和头季碱消值(alkali spread value in the first season,FASV)与'02428'有显著差异,其再生季胶稠度(gel consistency in the ratoon season,RGC)与再生季碱消值(alkali spread value in the ratoon season,RASV)与'02428'有显著差异,最终'明恢63'的直链淀粉含量变化率(amylose content ratio,ACR)和碱消值变化率(alkali spread value ratio,ASVR)与'02428'有显著差异.双向导入系的所有性状均表现为连续分布,同一性状在两季间表现出显著正相关.结合双向导入系高密度基因型数据,共定位到30个影响再生稻蒸煮食味品质的数量性状位点(quantitative trait locus,QTL),其中7个QTL在两年间稳定表达,1个QTL在头季和再生季被重复鉴定到,5个QTL在两个遗传背景下稳定表达.最后,利用分离群体验证了第11号染色体6.19～6.97 Mb的真实性.本研究结果为分子育种改良再生稻的蒸煮食味品质提供了基因资源.

以2018-2020年度国家武陵山区中籼组区域试验和生产试验资料为主要依据,通过方差分析和高稳系数分析等方法,对三系杂交水稻新品种九优83与对照品种瑞优399进行对比分析.结果表明,九优83丰产性较好,在2018年和2019年两年区域试验中平均产量较对照增产5.27％,2020年生产试验平均产量较对照增产1.20％;稳产性好,两年区域试验平均高稳系数较对照高5.4％,生产试验高稳系数较对照高0.21％;适应性较广,两年区域试验平均适应度达到60％,较对照高20％,生产试验适应度与对照相当.九优83综合抗性强,经抗性鉴定,稻瘟病抗性为抗级,纹枯病为感,稻曲病为轻发;九优83耐低温性鉴定为中间型.九优83稻米品质综合评定为部标普通级.九优83是一个丰产稳产性好,适应性广,综合抗病性强,尤其对稻瘟病抗病能力强的三系杂交中稻组合,适宜在我国湖北、湖南、贵州、重庆等4省(市)所辖的武陵山区海拔 800 m以下稻区作一季中稻种植.

荃9优117是长江大学主要粮食作物产业化湖北省协同创新中心、中国农业科学院深圳农业基因组研究所和安徽荃银高科种业股份有限公司以荃9311A为母本,以长恢117为父本配组育成的迟熟三系杂交中籼新组合.该组合具有米质优、高产稳产、抗稻瘟病、综合农艺性状优良等特点,2021年通过湖北省农作物品种审定委员会审定.

Ratooning ability is a key factor that influences ratoon rice yield, in the area where light and temperature are not enough for second season rice. In the present study, an introgression line population derived from Minghui 63 as the recipient parent and 02428 as the donor parent was developed, and a high-density bin map containing 4568 bins was constructed. Nine ratooning-ability-related traits were measured, including maximum tiller number, panicle number, and grain yield per plant in the first season and ratoon season, as well as three secondary traits, maximum tiller number ratio, panicle number ratio, and grain yield ratio. A total of 22 main-effect QTLs were identified and explained for 3.26–18.63% of the phenotypic variations in the introgression line population. Three genomic regions, including 14.12–14.65 Mb on chromosome 5, 4.64–5.76 Mb on chromosome 8, and 10.64–15.52 Mb on chromosome 11, were identified to simultaneously control different ratooning-ability-related traits. Among them, qRA5 in the region of 14.12–14.65 Mb on chromosome 5 was validated for its pleiotropic effects on maximum tiller number and panicle number in the first season, as well as its maximum tiller number ratio, panicle number ratio, and grain yield ratio. Moreover, qRA5 was independent of genetic background and delimited into a 311.16 kb region by a substitution mapping approach. These results will help us better understand the genetic basis of rice ratooning ability and provide a valuable gene resource for breeding high-yield ratoon rice varieties.

稻瘟病是水稻(Oryzasativa L.)生产中最重要的病害之一,选育抗稻瘟病的水稻品种是防治稻瘟病最经济有效的方法.本研究通过连续回交结合分子标记辅助选择,将抗稻瘟病基因Pi2导入到高产优质晚粳品种'长农粳1号'中,改良'长农粳1号'的稻瘟病抗性.改良系的背景回复率为94.36％,仅在第6染色体有一个导入片段.'长农粳1号'改良系的稻瘟病抗性为中感,显著优于'长农粳1号'.此外,'长农粳1号'改良系的生育期显著缩短,产量显著下降,品质显著改变.研究结果将为利用分子标记辅助选择改良粳稻的稻瘟病抗性提供科学依据和种质资源.

杂交水稻种子生产虚拟仿真实验分为10大模块,包括父母本播差期计算、父母本群体结构建立和培管、花期预测及调节、异交授粉和收获等内容.全程再现了杂交水稻种子规模化生产全过程.通过人机交互,将原本断续的实验片段连续起来,使学生在短时间内掌握杂交水稻种子生产的全部技术.同时也避免了实体实验中由于气候等不可预知因素而导致实验无法重复的结果.极大地提高了学生的学习兴趣和效率,培养学生的创新能力.在农学专业的实验教学和种业企业的培训中有较好的实用价值.

Cadmium (Cd) is a toxic heavy metal which has been threatening food security worldwide. In the present study, two sets of reciprocal introgression lines were used to dissect the genetic basis of Cd tolerance at seedling stage. Although the two parents had no significantly difference on Cd tolerance, the introgression progenies showed large variations. A total of 15 main-QTL (M-QTL) and 53 digenic epistatic QTL pairs (E-QTL) were detected for plant height, leaf length, leaf width and root length under Cd stress condition, each explaining 2.48-31.55% of phenotypic variations. E-QTL had larger effects than M-QTL for most traits, suggesting that E-QTL was the main genetic component for Cd tolerance at seedling stage. No common QTL, either M-QTL or E-QTL, was identified independent of background, indicated that both M-QTL and E-QTL were highly sensitive to genetic background. Two pleiotropic QTL in the regions of 13.31-15.56 Mb on chromosome 2 and 7.34-7.59 Mb on chromosome 11 were detected in the two backgrounds respectively, and further validated their effects on three traits by two introgression lines, indicated that they were both genetic true. Our results will give valuable QTL for improving Cd tolerance at seedling stage by molecular breeding.

高温热害严重威胁中稻生产,对其产量、品质和育性等多方面都有较大影响.为给湖北省水稻品种审定与推广应用提供科学依据,同时挖掘出耐热的优异水稻种质资源供育种利用,本研究利用江汉平原地区田间与玻璃温室的高温环境,对湖北省近年参试的中稻新品种进行抽穗开花期耐热性鉴定.结果 表明:参试材料总体耐热性较好,在耐热性较强至强的品种中常规品种(系)和两系杂交稻组合占比相当,而三系杂交稻组合占比次之.本试验共鉴定筛选出耐热性强且优于耐热对照丰两优4号的品种20份,其中有粤禾丝苗、润珠香占、S532、楚糯3号和利丰占等5份常规品种(系),既可以作耐热性种质资源进行育种利用,也可优先审定后在热害常发稻区作耐热品种推广应用;荃优133、荃优晶占和荃优锦禾等5份三系杂交水稻品种,C两优300、全两优5号和恩两优454等10份两系杂交水稻品种,可在同等条件优先审定后在热害常发稻区作耐热品种推广应用,其亲本或亲本之一通过进一步鉴定,可能从中筛选出优异耐热性种质资源材料.另外,还鉴定出特优559、华浙优1534和中广优2号等32份品种耐热性较弱至弱,建议在审定时要特别谨慎.

长农优231是长江大学主要粮食作物产业化湖北省协同创新中心以不育系长农2A与早熟抗稻瘟病恢复系长恢31配组育成的早熟三系杂交中籼新组合.该组合具有米质优、抗稻瘟病、丰产性好、成熟期早、综合农艺性状优良等特点,2019年8月通过湖北省农作物品种审定委员会审定.

剑叶是水稻主要的源器官,剑叶大小与产量呈极显著的正相关,揭示剑叶大小和单株产量的遗传基础对于选育株型适宜的水稻高产品种具有重要意义.本研究以来源广泛、多样性丰富的1016份全球水稻核心种质资源为材料,在湖北荆州连续两年考察了种质资源的剑叶大小和单株产量.结果 显示,剑叶长、宽、面积和单株产量在两年变异丰富,受环境影响大;剑叶长、宽和面积与单株产量相关性程度较低,说明这些性状的遗传基础不同.利用4.8M高密度SNP基因型数据进行全基因组关联分析,共定位到31个影响水稻剑叶相关性状和单株产量的QTL,其中1个QTL(qFLW4)在两年均定位到,3个位点同时影响多个性状(qFLW4和qFLA4、qFLL6和qFLA6、qFLL10.1和qFLA10).结合候选区间单倍型分析和生物信息学分析,鉴定到7个候选基因和10个有利等位基因.研究结果为克隆水稻剑叶性状新基因和通过分子标记辅助选择配置不同剑叶相关基因塑造理想株型提供基因资源.

苗期冷害是一种影响水稻群体建成和生长发育的延迟性冷害,最终导致水稻减产.筛选苗期耐冷性强的种质资源可以为水稻耐冷育种提供亲本资源.本研究采用3 000份全球水稻核心种质资源中的1 542份在人工气候箱进行苗期耐冷鉴定及评价,以存活率为评价指标.发现种质资源苗期耐冷性变异非常丰富,筛选出存活率80％以上的苗期耐冷资源材料73份,其中籼稻9份,温带粳稻47份,热带粳稻4份,粳稻混合型8份,籼粳中间型和香稻类型各1份,籼粳混合型3份,Ⅺ-B、Ⅺ-2和亚热带粳稻中未筛选到苗期耐冷材料.耐冷材料主要集中在温带粳稻中,但亦有部分籼稻材料表现出较强的耐冷性.多数苗期耐冷资源材料的综合农艺性状较差,结合株高、生育期性状等筛选出14份半矮秆和生育期适中的强耐冷性材料,可作为水稻苗期耐冷育种亲本应用.对利用种质资源开展苗期耐冷基因挖掘和选育全生育期耐冷品种进行了讨论.本研究初步阐明了水稻耐冷种质资源的分布,为水稻耐冷育种提供了优异的供体亲本材料.

Grain shape is a very important goal in the rice breeding program nowadays. Underlying the genetic basis of grain shape would largely speed the breeding process. In the present study, a diverse panel of 1016 rice accessions from 70 countries and areas worldwide were evaluated for their grain shapes. There were large variations for all three grain shape traits, including grain length, grain width and length to width ratio, and they had significantly positive or negative correlations with each other. Besides, high positive correlations were found between two experimental years. Genome-wide association mapping strategy was conducted to identify QTL for grain shape using 509219 high quality SNP genotypes and grain shape traits. A total of 70 QTL were identified in all chromosomes. Among them, 16 QTL were found on chromosome 1, 2, 3, 5, 7, 9 and 11 expressed in both years. Eight genomic regions on chromosome 1, 3, 4, 5, 7 and 9 had pleiotropic effects on two or three traits. Four genomic regions on chromosome 3, 5, 6 and 7 were identified in both year and controlled more than two traits. Besides, 25 QTL on all chromosomes except chromosome 8, 10 and 12 had large effect on the traits. In conclusion, these results helped us better understand the genetic basis of rice grain shape and provide valuable gene resources for improving rice grain for desired shape. (C) 2020 Friends Science Publishers

鉴定玉米引种备案品种对主要病害的抗性表现,为湖北省玉米引种备案提供依据,在湖北省鹤峰县燕子镇设病圃对18个引种备案品种(含对照)进行自然诱发鉴定.结果 表明:璐玉13号和Q玉318对灰斑病抗性差,建议不予引种;正大659和显玉509对纹枯病抗性较差,9级病株率高达20％,对产量影响较大,建议谨慎引种,并在生产中注意加强药剂防治;金都玉2号、正大659、正大999、显玉509和康农1号对穗腐病抗性较差,正大999和康农1号对弯孢叶斑病抗性较差,以及显玉509穗萌较重的问题,在引种生产中都应高度重视.

为评选出适宜湖北利川南坪种植的水稻新品种,对参加2015～2016年湖北省恩施州早熟中稻区试的水稻新品种在利川南坪优质稻基地进行了试验筛选和综合评价,结果表明,闽香优683和绵7优恩66经两年试验,在产量、抗性、熟期等方面综合表现较好,可在该基地加快示范种植;新参试品种长农优231和中100A/R65综合表现好,可在2017年继续进行试验筛选;其他品种表现不突出.

Excellent rice germplasm is the precondition of rice breeding. In this paper, 1 219 worldwide rice germplasm introduced from Chinese Academy of Agricultural Sciences was evaluated its adoptability in Jingzhou City and screened for high yield germplasm. The results showed that the yield and its related traits varied largely.Among them,panicle length and yield per plant had large varia-tion, while heading date, flag leaf width, number of primary branch, seed setting rate and 1 000 grain weight had small variation. Through screening 539 germplasm were adopted the ecological condition in Jingzhou, and 100 were high yield germplasm. Among them 24 were big panicle type,3 were big grain type and 23 were high seed setting rate type,respectively. They can provide valuable resources in high yield breeding of rice.

The fungus Magnaporthe oryzae threatens the rice production of Kongyu 131 (KY131), a leading japonica variety in Northeast China. In this study, two rice lines, KP1 and KP2-Hd1, were obtained by introgressing the blast resistance genes Pi1 and Pi2 into KY131, respectively. However, both lines headed later than KY131. RICE60K SNP array analysis showed that Hd1 closely linked to Pi2 was introgressed into KP2-Hd1, and the linkage drag of Hd1 was broken by recombination. On the other hand, no known flowering genes were introgressed into KP1. Gene diagnosis by resequencing six flowering genes showed that KP1 carried functional Hd16 and Ghd8 alleles. Due to its suppression role in heading under long-day conditions, Ghd8 was chosen as the target for gene editing to disrupt its function. Four sgRNAs targeting different sites within Ghd8 were utilized to induce large-deletion mutations, which were easy to detect via agarose gel electrophoresis. All the ghd8-mutated KP1 lines were resistant to rice blast disease and headed earlier than the control KP1, even than KY131, under natural long-day conditions, which ensures its growth in Northeast China. This study confirmed that a combination of gene diagnosis and targeted gene editing is a highly efficient way to quickly eliminate undesired traits in a breeding line.

Rice yield is a complex trait that is the major target in rice breeding program. In the present study, two sets of introgression line populations derived from three parents were used to dissect the genetic basis of yield-related traits, explore the genetic background effect on QTL detection and mine pleiotropic QTL for yield-related traits.. Among the three parents, IR75862 was the common donor parent, and Ce258 and Zhongguangxiang1 were two recipient parents. The two introgression line populations were evaluated for yield-related traits in the summer of 2012 at Jingzhou, China. Combined with genotype of the introgression lines, 35 QTLs were detected in all 12 chromosomes except chromosome 5 for eight yield-related traits, including plant height, panicle number per plant, panicle length, filled grain number per panicle, spikelet number per panicle, seed setting rate, thousand grain weight and grain yield per plant, which explained 6.36. - 36.37% of phenotypic variances. No common QTL was detected in the two backgrounds, and seven chromosome regions on chromosomes 2, 3, 4, 6 and 10 had pleiotropic effects on two or more traits, indicating large genetic background effect on expression of QTLs for yield-related traits. Total of 19 (54%) QTLs including newly identified QTLs, qGY3, qFGN10.2 and qSN10 with IR75862 alleles increased yield-related traits. Therefore, it's possible to develop new super rice varieties through introgressing or pyramiding the IR75862 alleles at the pleiotropic QTLs (qPL2.1 and qPL6.1) and novel QTLs (qGY3, qFGN10.2 and qSN10) into Ce258 and Zhongguangxiang1 by marker-assisted selection. (c) 2018 Friends Science Publishers

惠34S系武汉惠华三农种业有限公司用广占63S为母本与海南地方品种小白稻杂交后经过多代选育而成的籼型光温敏核不育系,具有不育性稳定、不育起点温度低、异交结实率高、米质优、抗病性好、配合力强等特点.2012年通过安徽省科技厅鉴定,目前已有5个杂交组合通过国家或省级审定.