Background Hybrid rice plays a pivotal role in ensuring global food security, yet the weak multiple resistance of restorer lines remains a major bottleneck limiting the stability and environmental sustainability of hybrid varieties. The elite restorer line R202 possesses desirable combining ability and good grain quality, but it is chronically susceptible to bacterial blight, blast, brown planthopper (BPH), and herbicides. Single-trait improvements have proven insufficient to meet the demands of modern intensive rice production. Results In this study, we employed backcross breeding combined with marker-assisted selection to introgress the broad-spectrum bacterial blight resistance gene Xa23 , the blast resistance gene Pigm , the brown plant hopper resistance (BPH) gene Bph6 , and the acetolactate synthase (ALS) inhibiting herbicide resistance gene ALS W548M into the R202 genetic background. After BC 4 F 2 generations coupled with stringent foreground selection, we successfully developed the novel restorer line R4202. The hybrid combination 1892S/R4202, derived from R4202, was evaluated under artificial inoculation and (or) natural field infection conditions. Results demonstrated that R4202 and its hybrid exhibited high resistance to both bacterial blight and blast, moderate-to-high resistance to BPH, and good tolerance to ALS-inhibiting herbicides. Multi-location field yield trials showed that R4202 and its hybrid achieved synergistic stacking of these multiple resistances without incurring any significant yield and grain quality penalty; grain yields remained comparable to those of the recurrent parent R202 and its hybrid (with no statistically significant difference, 0.214 < P value < 0.910). Conclusion Collectively, R4202 is a novel restorer line that integrates resistances to bacterial blight, blast, BPH, and ALS-inhibiting herbicides, while simultaneously retaining good eating quality and high yield potential. This germplasm provides valuable genetic resources for breeding green, low-input, high-quality hybrid rice varieties

Introduction:Nitrogen is a crucial nutrient for crop growth, yet its utilization efficiency is generally low, leading to resource waste and serious environmental problems. Future agricultural sustainability requires improved crop NUE. In this study, we investigated the functions of the rice transcription factors OsNIGT2 and OsNIGT3 in nitrate uptake under high-nitrogen conditions. Methods:Hydroponic experiments and field tests were conducted to investigate the effects of OsNIGT2 and OsNIGT3 on physiological phenotypes and nitrogen use efficiency. Transcriptome analysis was used to explore the genome-wide transcriptional landscape of the two genes in response to nitrate availability. DNA affinity purification sequencing (DAP-seq) was employed to identify genomic sites bound by OsNIGT2, subsequently, yeast one-hybrid and transient expression assays verified the regulatory effects of OsNIGT2 and OsNIGT3 on key genes. Results:The double mutants of OsNIGT2 and OsNIGT3 presented significantly greater dry weights, nitrogen contents, total amino acid contents, and nitrate levels than the WT, whereas the single mutants presented no significant differences. These findings indicate the functional redundancy of OsNIGT2 and OsNIGT3 in regulating nitrogen uptake and assimilation. OsNIGT2 and OsNIGT3 act as transcriptional repressors, negatively regulating the expression of nitrogen absorption-related genes. Furthermore, DAP-seq identified potential targets bound by OsNIGT2, highlighting its role in the expression of several nitrogen and phosphorus utilization-related genes. Additionally, field tests shown that OsNIGT2 and OsNIGT3 knockout promotes both grain yield and NUE. This study provides potential genetic targets for improving yield and NUE in rice and other crops, laying a significant foundation for future crop improvement.

Developing genotypes with high-nitrogen use efficiency is a prerequisite for achieving sustainable agriculture and high yields. In this study, both physiological and metabolic analyses were performed to evaluate the NUE (nitrogen use efficiency) of two elite indica rice cultivars: OM052 and Huanghuazhan (HHZ). The pNUE and gNUE of OM052 were higher than HHZ under three N conditions, and significant (p < 0.05) especially under both LN and MN conditions. The contents of soluble sugar and malate were significantly different between OM052 and HHZ under LN and HN conditions. The GDH activity in OM052 was significantly high than that in HHZ under HN condition. Metabolic analyses showed that 136 and 142 differentially accumulating metabolites were identified between OM052 and HHZ under LN and HN conditions, respectively. KEGG analysis showed that ‘aminoacyl-tRNA biosynthesis’ was also the most significant enriched in LN_OM052 vs. LN_ HHZ and ‘Glyoxylate and dicarboxylate metabolism’ and ‘citrate cycle’ were the most significantly enriched in HN_OM052 vs. HN_ HHZ. The contents of four metabolites (cis-aconitate, isocitrate, fumarate, and malate) involved in the TCA cycle were significantly upregulated in HN condition compared with LN condition, regardless of OM052 and HHZ. Taken together, the results of our study revealed the physiological and metabolic differences underlying the OM052 and HHZ and provide new insights into coordinating C and N metabolism and improving the NUE of rice.

Liangyou 1976,derived from the self-bred two-line male sterile line 191S and high-quality medium-maturing indica male parent R076,is a new two-line medium-maturing indica hybrid rice combination developed by the Rice Research Institute of Anhui Academy of Agricultural Sciences.It was approved by Anhui Provincial Crop Variety Appraisal Committee in July 2020.In two years of the regional trials,the combination get matured in about 136 days and yielded 10.54 t/hm2 on average,6.18％higher than that of the control Ⅱ You 838.Its grain quality is good,reaching the 2nd class of quality standards of indica rice issued by the Ministry of Agriculture.It is suitable for planting as single-cropping medium rice in Anhui Province.

7011S系安徽省农业科学院水稻研究所以生产上广泛使用的籼型两系不育系1892S为母本,与抗稻瘟病材料谷梅4号杂交、自交,经5年7代选育而成的籼型温敏核不育系.该不育系具有株型适中、叶色深绿、分蘖力较强、茎秆较粗、不育起点温度低、异交结实率高、配合力强及广适等特性,2019年8月通过安徽省农作物品种审定委员会鉴定.以7011S为母本、R202为父本配制的两系杂交籼稻新组合两优7002具有优质、高产、抗逆特点,于2022年通过国家农作物品种审定委员会审定.

504S系安徽省农业科学院水稻研究所以籼型两系不育系1892S为母本,以自育三系保持系65B(丰8B/早籼M057)为父本,经5年8代选择育成的优质籼型温敏核不育系.该不育系具有株型紧凑、叶色深绿、分蘖力强、不育起点温度低、异交结实率较高、配合力强等特性,2013年8月通过安徽省农作物品种审定委员会鉴定.利用504S所配制的两系杂交籼稻新组合两优5078和两优5077具有优质、高产、抗逆的特点,分别于2019年和2020年通过国家农作物品种审定委员会审定.

6022S系安徽省农业科学院水稻研究所以1892S为母本,与6M022(3M178/9311 F6)杂交、自交,经5年7代选择育成的籼型光温敏核不育系.该不育系株型紧凑,分蘖力强,抗倒伏性好,不育起点温度低,异交结实率高,配合力强.2019年8月通过安徽省农作物品种审定委员会的鉴定.6022S所配组合表现出熟期适中,株高较矮,粒型较好,抗倒伏,高产优质等特点.

191S系安徽省农业科学院水稻研究所以1892S为母本,与2M191(蜀恢527/9311 F6)杂交,经5 a 7代选择育成的籼型两系不育系.该不育系叶色较深,叶片内卷,株型紧凑,分蘖力中等,茎秆较粗,抗倒伏性好,不育起点温度低,异交结实率高.2015年8月通过安徽省农作物品种审定委员会鉴定.以191S为母本所配制的优质、高产籼型两系杂交稻新组合两优1976和两优1999分别于2020年通过安徽省品种审定委员会审定.

Rice production relies on large amounts of synthetic nitrogen fertilizer to meet crop nutritional demands. However, the current fertilizer use efficiency is poor, with an average of 30–50% of total applied nitrogen (N) recovered in grains. Consequently, optimizing N availability and N use efficiency (NUE) has become a major target for rice yield improvement, and looking for quantitative trait loci (QTL) associated with NUE can provide useful information for developing nitrogen efficient rice genotypes. The present study aims to identify QTLs associated with NUE and its two components, agronomic NUE (agNUE) and grain nitrogen increase rate (GIR). A recombinant inbred line population (RIL) derived from a cross between Nipponbare and OM052, consisting of 159 F3 individuals was developed and cultivated in low-N (8 kg N/0.67 ha, N8) and high-N (18 kg N/0.67 ha, N18) conditions. Specific length amplified fragment sequencing (SLAF) was used to genotype the RILs and construct a high-density linkage map spanning 1587.70 cM, consisting 2707 SLAF markers with an average interval of 0.59 cM between adjacent marker loci. QTL analysis confirmed four significant QTLs distributed among chromosome 1, 6, and 11, with the proportion of phenotypic variance explained by each QTL ranging from 2.96 to 11.11% and LOD scores from 1.67 to 3.75. Functional annotation of genes located within the QTL intervals revealed NUE putative candidate genes. Overall, the QTLs identified in this study contribute information that could be useful for NUE improvement in rice.

为了进一步明确江淮区域气候变化对两熟制粮食作物物候期及周年光温水资源分配与利用的影响,以安徽省12个农业气象观察站1992-2013年气象数据、作物生长发育期数据与产量数据为基础,采用线性趋势、相关分析、回归分析等方法,分析不同区域不同熟制作物物侯期变化趋势,以及气候变化对积温、辐射和降水资源分配与利用的影响.结果表明,1992-2013年沿淮淮北冬小麦-大豆种植模式,冬小麦播种期提前趋势显著(P＜0.05),平均每10 a提前3.03 d,成熟期变化不显著,全生育期平均每10 a增加3.54 d;大豆播种期和开花期则显著推迟(P＜0.05),平均每10 a推迟3.06 d和0.86 d,全生育期平均每10 a减少3.65 d.江淮冬小麦-一季稻模式,水稻播种期、抽穗期和成熟期均显著提前(P＜0.05),平均每10 a分别提前5.12 d、3.87 d和2.92 d,全生育增加2.2d;小麦有同样的变化趋势,全生育期表现为每10a缩短0.8d.沿江江南双季早稻物候期变化不明显,全生育期每10a缩短0.6d;晚稻平均每10a播种期推迟1.14d,抽穗期与成熟期分别提前0.71 d和6.85 d,成熟期提前趋势显著(P＜0.01),全生育期每10 a缩短5.17 d.沿淮淮北冬小麦与江淮一季稻以及沿江早稻和晚稻生长季积温呈增加趋势,大豆与江淮冬小麦积温减少.沿淮淮北与江淮冬小麦及沿江早稻和晚稻生长季辐射呈增加趋势,大豆与一季稻则表现为减少.不同种植模式第1季作物冬小麦和早稻的降水均有减少趋势,而第2季作物大豆、一季稻和晚稻则呈增加趋势.冬小麦-一季稻种植模式周年光温水生产效率最高.线性回归分析表明,积温和辐射与沿淮淮北冬小麦和沿江双季稻的产量均呈显著线性正相关(P＜0.05),光温是提高其产量的主要限制因子.江淮一季稻积温过高和降水过多也限制产量提升.气候变化改变了两熟制粮食作物物侯期,进一步影响了光温水气候资源的分配与利用效率.通过改良品种、改变播栽时间、提高抗逆性等适应措施,可以在一定程度上抵消气候变化对作物生长的不利影响.

研究了安徽沿江平原稻区不同播期对稻麦周年产量、生育期及温光资源利用的影响,以为科学选用稻麦模式适宜水稻品种类型提供参考.结果表明,播期对不同类型水稻产量影响大小表现为迟熟中籼>中熟中粳>早熟晚粳>迟熟中粳>中熟晚粳;随播期推迟,迟熟中籼、早熟晚粳和中熟晚粳水稻产量均显著下降,播期对中熟中粳、迟熟中粳产量的影响则不明显.不同类型水稻品种与适播期春小麦接茬周年产量高低表现为"迟熟中籼稻-春小麦">"中熟晚粳稻-春小麦">"迟熟中粳稻-春小麦">"早熟晚粳稻-春小麦">"中熟中粳稻-春小麦".在稻麦不同种植模式中,5月20日前播种的"迟熟中籼稻-春小麦"模式周年温光资源利用效率最高,较目前6月9日播种的"早熟晚粳稻-春小麦"模式的周年温光生产效率提高16.26％以上、周年光能利用效率提高18.06％以上.

为筛选适宜安徽沿江麦茬稻机械直播水稻品种,并明确节水灌溉技术与一次性施用控释肥对机械直播水稻产量的影响,设置不同类型水稻品种机条播大区筛选试验、节水灌溉与常规漫灌的对比试验和控释肥试验.结果表明,不同类型水稻品种机械直播均能安全齐穗,产量以天优华占最高,为710.04 kg·(667 m2)-1,其次为南粳9108.适宜沿江机械直播水稻品种类型以中熟中籼和迟熟中粳为主,全生育期平均在135 d左右.节水灌溉较常规漫灌节约用水87 m3·(667 m2)-1,节水15.8％,产量增加40.9 kg·(667 m2)-1,增产5.9％.相较于常规施肥,控释肥一次性基施,节约纯氮33.9％,产量增加2.9 kg·(667 m2)-1,节约人工、肥料费101.1元·(667m2)-1.

为明确安徽中籼稻米品质变化趋势及关键影响因子,基于农业农村部食用稻品种品质最新标准,利用加速遗传算法的投影寻踪模型初步建立了中籼稻米品质综合评价函数,并对2009-2019年安徽省中籼稻综合品质变化趋势及其关键影响因子进行分析.结果 表明,安徽中籼稻米综合品质整体呈显著上升趋势,投影寻踪模型分析结果与参试组合各年实际检测的优质米所占比例变化趋势基本一致,在通过审定品种中三级以上优质米所占比例的变化趋势也证实这一规律.稻米在整精米率、垩白粒率、垩白度等品质指标上的显著进步,促进了综合品质的提升.垩白粒率、垩白度和直链淀粉含量是影响安徽中籼型稻米综合品质的关键因子.降低垩白粒率和垩白度、保持中等直链淀粉含量及提高整精米率仍是安徽未来品质育种的主攻方向,同时也要注意碱消值性状的改良.

以市场上大面积应用的杂交水稻及常规籼型水稻为材料,通过设置不同氮肥水平,研究其对不同基因型水稻产量和氮素利用效率的影响.结果表明:水稻主要经济性状的变异系数表现为低氮处理>正常施氮处理>不施氮处理,低氮水平下变异系数为20.89％—121.37％.水稻单株产量随施氮量的增加而提高.对筛选出的双高效型(第I象限)水稻品种'XY52'IIY52'9311'JLYHZ'LY391'进行回归分析,发现'IIY52'的产量潜力最高,'XY52'节氮能力最强.对双高效型品种进行氮素籽粒生产效率筛选,发现'XY52'IIY52'LY391'为高产氮高效型水稻品种.研究结果可为氮高效水稻品种评价与高产高效栽培提供依据.

两优531是安徽省农业科学院水稻研究所用自育的籼型温敏不育系5308S与恢复系R131杂交配组育成的两系杂交中籼新组合,具有米质优、高产、抗病、适应性广等特点.2018年9月通过国家农作物品种审定委员会审定,适宜在长江中下游地区作中稻栽培.

为分析苗期不同氮浓度对中籼水稻品种物质重和氮利用率的影响.笔者以近来大面积应用的水稻品种为材料,在6个氮水平下测定苗期物质重与氮利用率等数据并进行分析.结果表明,随着氮浓度的增加,水稻品种苗期物质重呈现抛物线变化趋势.中籼水稻品种均在氮浓度1.5 mol/L时物质重积累达到最大值,中籼水稻品种苗期最佳水培氮浓度为1.5 mol/L.'黄华占'(HHZ)与'两优671'(LY671)表现出较强的耐低氮能力.在正常供氮1.00～1.50 mol/L时,'OM052'、'协优52'(XY52)均表现出较高的氮利用率.根干重、根冠比均与氮利用率呈极显著正相关,可以作为氮高效品种苗期评价参考指标.

为了解施氮量对不同品种水稻(Oryza sativa L.)氮素利用、光合效率及碳氮代谢的影响,以不同品种的水稻品种RH 003和wp 6为供试品种,氮肥运筹按基肥(50％)、分蘖肥(20％)和穗肥(30％)3次施用,通过设置4个施氮水平(N用量设0,120,195,270 kg·hm-2)的田间小区试验,研究氮素水平对水稻产量和氮素利用效率的影响,并探讨氮素水平下水稻碳氮代谢关键酶活性的变化.结果表明,2个水稻品种的子粒产量随施氮量增加而显著增加,施氮后,2个品种剑叶的长度和宽度都大幅增长.从产量构成因子来看,在一定范围内,施氮肥增产主要是提高了品种的有效穗数和每穗粒数.随施氮量增加,植株地上部干质量显著增加,2个品种的氮肥农学利用效率和氮肥偏因素生产力却逐渐降低,在120或195 kg·hm-2处理下,更有利于水稻品种获得最高的氮肥生理利用效率和氮素收获指数;与对照(0 kg·hm-2)相比,随施氮量增加,2个品种蔗糖合成酶活性变化幅度不大,而硝酸还原酶活性则表现了先增后降的变化趋势,显著高于对照处理,且在120 kg·hm-2处理下,硝酸还原酶活性达最大.

[Objective] To research the physiological differences of different varieties of waterlogging-tolerant rice (Oryza sativa L.) to submergence during tillering period.[Method] Four different varieties of waterlogging-tolerant rice (FR13A,9311,IR64,OM052) were used as the experimental materials,submergence treatments for 2,4,5,7 d and a subsequent recovery for 3 and 5 d were conducted.Effects of different degrees of submergence on the growth and physiological indexes of rice during tillering period were investigated.[Result] The content of chlorophyll and shoot relative water content were decreased;root-shoot ratio increased;the root length decreased gradually,the activities of superoxide dismutase (SOD),peroxidase (POD),catalase (CAT) activity,as well as malondialdehyde (MDA) content,were induced and increased subsequently.Compared with the control,the activities of superoxide dismutase (SOD),peroxidase (POD) and catalase (CAT),as well as malondialdehyde (MDA) content,of OM052 rised by 50.0％ and 25.8％ and 50.5％ and 17.9％ on the 4th day of treatment,respectively.Mter submergence for 5 d,only OM052 and FR13A survived,which were tolerant varieties.[Conclusion] 5 d might be the turning point for evaluating submergence tolerance at tillering stage,and 0M052 had relatively good waterlogging tolerance in certain degree.

[目的]研究水稻穗部叶绿体发育的分子机制.[方法]本文以籼型恢复系RH003的自然突变体wp6为研究材料,从农艺性状、稻米品质和叶绿素含量比较了突变体和野生型,并以突变体与日本晴、9311杂交构建F2群体来研究wp6的遗传模式.[结果]突变体整株叶片呈绿色,抽穗期至成熟期,穗部白色,穗轴和小梗为绿色.与野生型相比,wp6的生育期、株高、有效穗数、每穗总粒以及每穗实粒略高,而wp6的结实率(66.85％)则远低于野生型RH003的82.40％.成熟期米质分析表明,突变体的外观品质和蒸煮食味比野生型略差.苗期突变体和野生型叶片叶绿素含量差异不大,抽穗期时突变体白穗性状是由于叶绿素a含量低所致.对wp6与正常叶色品种杂交F1、F2代的遗传分析表明,该性状受1对隐性核基因调控.[结论]该研究为wp6基因的定位、克隆和功能研究奠定基础,也为水稻标记性状育种提供新的资源.

从育种方法、技术路线、选育原理和选育过程等方面阐述了杂交中籼稻新品种两优671的选育经过,总结其品种特征特性及产量表现,以期为该品种的推广应用提供参考.