Suitable growing zone and yield potential for late-maturity type of Yongyou japonica/indica hybrid rice in the lower reaches of Yangtze River, China

Late-maturity type of Yongyou japonica/indica hybrids series （LMYS） have shown great yield potential, and are being widely planted in the lower reaches of Yangtze River, China. Knowledge about suitable growing zone and evaluation of yield advantage is of practicall importance for LMYS in this region. Fifteen LMYS, two high-yielding inbred japonica check varieties （CK-J） and two high-yielding hybrid indica check varieties （CK-I） were grown at Xinghua （119.57°E, 33.05°N） of Lixiahe region, Yangzhou （119.25°E, 32.30°N）of Yanjiang region, Changshu （120.46°E, 31.41°N）of Taihu Lake region, and Ningbo （121.31°E, 29.45°N） of Ningshao Plain in 2013 and 2014. The results showed that maturity dates of the 15 were later than the secure maturity date at Xinghua and 6, 14 and 15 LMYS were mature before the secure maturity date at Yangzhou, Changshu and Ningbo, respectively. One variety was identified as high-yielding variety among LMYS （HYYS） at Yangzhou, 8 HYYS in 201：3 and 9 HYYS in 2014 at Changshu, 9 HYYS at Ningbo. HYYS here referred to the variety among LMYS that was mature before the secure maturity date and had at least 8% higher grain yield than both CK-J and CK-I at each experimental site. Grain yield of HYYS at each experimental site was about 12.0 t ha-1 or higher, and was significantly higher than CK varieties. High yield of HYYS was mainly attributed to larger sink size due to more spikelets per panicle. Plant height of HYYS was about 140 cm, and was significantly higher than check varieties. Significant positive correlations were recorded between duration from heading to maturity stage and grain yield, and also between whole growth periods and grain yield. HYYS had obvious advantage over check varieties in biomass accumulation and leaf area duration from heading to maturity stage. Comprehensive consideration about safe matudty and yield performance of LMYS at each experimental site, Taihu Lake region （representative site Changshu） and Ningshao Plain （representative site Ningbo） were thought suitable growing zones for LMYS in the lower reaches of Yangtze River. The main factors underlying high yield ofHYYS were larger sink size, higher plant height, longer duration from heading to maturity stage and whole growth periods, and higher biomass accumulation and leaf area duration during grain filling stage.

Yield and Quality Performance of Japonica Rice Varieties Grown in the Late Season in a Double Rice Cropping System of China

Meeting the demand for high-quality japonica rice is a major challenge facing China's grain security. In the present study, a two-year field experiment was conducted to investigate the yield, quality, and profitability of japonica rice varieties(including hybrids and inbreds) grown in the late season as compared with local elite indica hybrids in a double rice cropping system of China where indicas are traditionally planted. Indica hybrids had significantly longer vegetative(from sowing to heading) and total(from sowing to maturity) growth durations than japonicas in both2011 and 2012, while reproductive growth duration(from heading to maturity) was longer for indica hybrids than for japonicas in 2011 but not in 2012. Indica hybrids produced higher grain yield than japonicas in 2011, but with no significant differences in 2012. Japonicas had higher brown rice, milled rice, and head rice percentages than indicas, but had lower gelatinization temperature and amylose content,while with no significant differences in gel consistency and protein content. Indica hybrids tended to have lower chalky grain percentage and chalkiness degree than japonicas, though the differences were not statistically significant due to large genotypic variations. The net returns were 16.1% and 9.9% greater for indica hybrids than for japonica hybrids and japonica inbreds in 2011, with only 3.8% and 1.3% in2012, respectively. Thus, our results suggest that replacing indicas with japonica varieties as late rice may not be feasible at the present site unless locally adapted japonica varieties are developed.

Effects of Nitrogen Level and High Temperature Stress on Yield, SPAD Value and Soluble Sugar Content of Early Rice Ganxin 203

This study aimed to investigate the combined effects of nitrogen level （high and ordinary） and high temperature stress （37 ℃, 4 d） at the late panicle ini- tiation stage on yield, SPAD value and soluble sugar content of Ganxin 203, an early rice cultivar. The results showed that under both high and ordinary nitrogen levels, high temperature stress reduced the seed-setting rate, yield per stem, SPAD value and soluble sugar content of Ganxin 203; under both high and ordinary tem- peratures, high nitrogen level increased the seed-setting rate, yield per stem and soluble sugar content of Ganxin 203; the seed-setting rate, yield per stem and yield per plant of Ganxin 203 under high temperature and high nitrogen level were higher than those under high temperature and ordinary nitrogen level. It suggests that ap- propriate high nitrogen level contributes to weakening the negative effects of high temperature stress on rice yield.

Comparison of agronomic performance between inter-sub-specific hybrid and inbred japonica rice under different mechanical transplanting methods

Mechanical transplanting has been applied to rice cultivation to save labor costs and ease labor shortages in Asian countries, especially in China. However, little information is available related to the characteristics of agronomic performance when comparing inter-sub-specific hybrid rice(IHR) and inbred japonica rice(IJR) under mechanical transplanting method. In 2013 and 2014, field experiments were conducted using IHR(Yongyou 2640) and IJR(Wuyunjing 24) under two cultivation patterns, that is, pot seedlings mechanically transplanted(PS) and carpet seedlings mechanically transplanted(CS). Grain yield, yield components, leaf area index(LAI), leaf area duration(LAD), aboveground biomass, crop growth rate(CGR), nitrogen(N) uptake, and N accumulation were investigated. When compared with CS, PS displayed significantly increased grain yield for both varieties because the larger sink size allowed higher N accumulation from panicle initiation to maturity. Moreover, total aboveground biomass under PS increased significantly compared with that under CS; that is, higher photosynthetic productivity resulted from a greater LAI and higher LAD during the grain filling stage. Higher N absorption capacity in the middle and late growth periods resulted in significantly enhanced total N uptake under PS. When compared with IJR for both treatments, IHR generated 75.2% more grain yield. However, the characteristics creating high yield of IHR were different from those of IJR. Greater aboveground biomass production as well as higher N uptake and accumulation created higher grain yield in IHR than in IJR. These results suggest higher yield could be achieved using PS with IHR, attributing to exploit both yield superiority and productive potential.

Breeding of New Japonica-indica Hybrid Rice Combination Chunyou 284

Chunyou 284 is a medium- japonica hybrid combination,as well as an indica-japonica subspecific hyrbid with super-high yield,which was developed from Chunjiang 23A,a thermo-sensitive CMS line with very early anthesis time,and C84,an indica-japonica intermediate type restorer line with wide compatibility.This combination has the advantages of high yield potential,early maturity,excellent comprehensive agronomic traits and wide adaptability.It was approved by Jiangsu Provincial Crop Variety Approval Committee in June,2018.The breeding process,main characteristics,cultivation techniques and seed production points of the combination were introduced.

Correlation,Regression and Path Analysis between Yield Traits and Yield of Yongyou No.9

[Objective] The research aimed to understand the high and efficiency technique in intersubspecific hybrid rice Yongyou No.9.[Method] We conducted the correlation analysis,regression analysis and path analysis of intersubspecific hybrid rice Yongyou No.9 based on the data of its ear,grain and weight at different yield levels.[Result]The performance of ear,grain and weight in Yongyou No.9 showed significant difference among different yield levels.The enhancement of effective ears would restrain the number of per ear total grains.It was found that the direct contributions of main economic traits to yield were determined to be per ear total grainseffective earseed setting rate1 000-grain weight.[Conclusion]The high-yield and effective cultivation techniques were suggested as follows：on the basis of certain effective ear number,grain number per ear should be mainly focused with a consideration to 1 000-grain weight.

植物生长调节剂对优质粳稻产量、品质与光合特性的影响

为探究植物生长调节剂对优质粳稻光合特性、产量与品质的影响,以绥粳18、垦稻12和三江6为试验材料,研究剑叶展开期喷施脱落酸(ABA)、6-苄氨基腺嘌呤(6-BA)、己酸二乙氨基乙醇酯(DA-6)、亚精胺(Spd)、3-吲哚丁酸(IBA)、3,5-二硝基水杨酸(SA)、油菜素内酯(BL)、玉米素(ZT)、三十烷醇(TRIA)、茉莉酸甲酯(MeJA)和N6-呋喃甲基腺嘌呤(KT)对水稻产量、品质和光合特性的影响。结果表明:与对照(CK)相比,喷施BL提高了抽穗后水稻干物质积累和茎鞘物质转运能力,增加了每穗粒重、千粒重、结实率和粒叶比,两年平均增产7.61%;喷施6-BA有利于延长抽穗期至蜡熟期绿叶面积持续期,改善抽穗后光合特性,增加每穗粒数、每穗粒重、千粒重和粒叶比,两年平均增产6.40%;而喷施DA-6、ZT、ABA、Spd、IBA、SA和KT的增产效果存在品种和年份间稳定性差异。在品质上,喷施DA-6和ZT提高了精米率和整精米率,改善了稻米外观品质。综上,剑叶展开期喷施BL和6-BA有利于供试品种增产,而喷施DA-6和ZT则更有利于稳产或增产前提下提质。

超高产优质早熟籼粳杂交稻浙优915的选育与栽培技术

高产与优质是水稻产业的关键性目标,然而这2个性状存在明显的矛盾,运用常规育种技术在同一品种上集聚2个性状非常困难。本研究团队采用分子育种技术与籼粳杂种优势利用方法相结合,成功选育出超高产优质早熟籼粳杂交稻浙优915。该品种在区域试验和生产试验中,表现出超高产潜力。稻米品质符合食用稻部标三等,评价指标中除碱消值外,其余指标符合部标一等。全生育期为146.5~156.5 d,比嘉优5号早熟0.3~0.9 d。2023年通过国家品种审定,适宜在浙江、上海、安徽、湖北、苏南等南方粳稻种植区推广应用。根据浙优915品种特性,提出提高有效穗数和增加每穗粒数的关键性高产栽培技术。

长江下游地区味优高产协同粳稻的品种特性

【目的】探明长江下游地区味优高产协同粳稻品种共性农艺与生理特征,为实现区域稻米产量和品质协同提升提供理论依据和技术支撑。【方法】于2018年和2022年,分别采用14个和13个常规粳稻品种开展品种筛选试验,系统比较不同品种的产量及构成、食味品质及质构特性,以及生物量、茎鞘非结构性碳水化合物(NSC)、群体光合势(LAD)等农艺与生理指标的差异。【结果】品种间的食味值和产量具有较大变幅,为此,按食味值和产量进行聚类,将不同水稻品种分为味中低产(ML)、味中高产(MH)和味优高产(GH)3种类型。GH类型品种2年的平均食味值和产量分别为68.5和10.2 t·hm^(-2),较MH和ML综合提高食味值6.8%、产量14.6%。从产量和品质性状的表现来看,与MH和ML相比,GH类型品种表现最高的结实率和口感得分。从生物量积累的过程来看,GH类型品种增加了灌浆初期的干物质积累比例,表现最高的抽穗-抽穗后15d的干物质积累。进一步分析此阶段干物质积累成因发现,GH类型品种在稳定增加LAD的同时,显著增加了茎鞘中NSC的转运率。相关性分析表明,水稻结实率与口感得分、抽穗-抽穗后15 d的干物质积累和LAD及NSC转运率均呈极显著正相关关系。【结论】在保持较高的抽穗-抽穗后15 d LAD(100.4 m^(2)·m^(-2)·d)的同时,进一步提高灌浆期茎鞘NSC的转运率(79.9%)促进灌浆启动,增加抽穗-抽穗后15 d干物质积累(3.6 t·hm^(-2)),提高水稻结实率(95.4%)和口感(9.6),是该区域味优高产协同水稻品种的共性特征。此外,研发以提高灌浆期NSC转运量和抽穗期植株茎鞘NSC积累为目标的水肥管理技术,有望进一步发挥上述味优高产协同品种的产量和食味品质潜力。

浙江省粳稻品种的演替研究综述

浙江省作为我国经济较为发达的地区,较早地开展了水稻新品种选育研究。浙江省种植的品种基本涵盖了各种水稻类型,其中粳稻是主要的种植类型,尤其是晚粳稻。虽然自杂交水稻出现后,常规水稻面积占比日益减小,但由于晚粳稻兼顾产量和品质,在生产上仍具有不可替代的地位。对晚粳稻产量影响最大的4个因素进行分析,发现可以通过增加穗粒数和有效穗数以及千粒重来提高产量。除了产量的提高之外,稻米品质也成为了晚粳稻育种的主要目标,因此,现在的育种工作已经将米质作为重要育种目标。本文主要通过对浙江省近20 a通过审定的晚粳稻品种进行生育期、产量、品质、抗病性等方面的分析,总结浙江省粳稻品种的性状变化,以期为浙江省的粳稻育种工作提供参考依据。

浙江省9个晚粳稻代表品种的农艺性状分析

分析浙江省历年审定的9个晚粳稻代表性品种的农艺性状及农艺性状和产量之间的关系,可以了解各农艺性状对产量的影响,以及探索浙江省晚粳稻品种审定的规律。研究选取9个历年审定晚粳稻品种中表现较好,具有代表性的品种,采用催芽后撒播移栽到大田的方式,测量株高、茎粗、分蘖、剑叶长、剑叶宽、叶绿素含量等农艺性状。剑叶宽和茎粗是各农艺性状中对产量影响最大的2个因素,2010—2019年的3个品种茎粗和剑叶宽为3个时间段中最大的,由此可以看出,茎粗和剑叶宽是农艺性状中对晚粳稻品种产量影响最大的,且浙江省育种研究者也一直在提升晚粳稻的茎粗和剑叶宽。

优质高产晚粳新品种稼粳86的选育与应用

稼粳86系安庆市稼元农业科技有限公司和安徽省农业科学院水稻所选育的双季晚粳新品种,具有适应性广、优质、高产的特征,2021年通过安徽省农作物品种审定委员会审定,适宜在安徽省一季粳稻和双季晚粳稻区示范推广。介绍了稼粳86的亲本来源及选育过程,总结了其特征特性及栽培技术,以期为该品种的示范推广提供相应参考。

寒地水稻开花期多雨寡照复合逆境灾损评估指标

黑龙江省是中国优质粳稻生产核心种植区,开花期多雨寡照复合发生,严重影响寒地水稻结实率和产量。为了保障国内优质稻米的供应及国家粮食安全,本研究旨在构建一个针对多雨寡照复合发生的判识指标,并定量评估其对产量的损失。通过整合气象数据、水稻生育期信息、产量资料以及历史灾情记录,运用多层灰色关联分析法探究致灾因子、作物产量结构与相对气象产量之间的灰色映射关系。据此,建立了寒地水稻多雨寡照复合指数(RSCI)和一个描述复合逆境与产量损失率关联度的模型。利用K-均值聚类分析方法和历史典型灾害年份数据确定了灾害的临界值和等级,进而形成了评估多雨寡照复合发生导致产量损失的评估指标体系。本研究明确了寒地水稻在不同等级(轻度、中度、重度)多雨寡照条件下的临界阈值和相应的产量损失率,历史灾情验证显示多雨寡照判识率达到100%,产量损失率判识准确率超过80%。在1958—2021年间,全省水稻不同程度多雨寡照的发生频率呈轻度高于中度高于重度的趋势,且北部农区的发生频率高于南部农区。该研究成功构建了一套多雨寡照复合发生的判识指标,为定量化评估产量损失提供了重要的技术支撑。

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。

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。

硅肥对优质晚稻抗倒伏特性及产量的影响

以优质晚稻桃优香占、玉针香为供试材料,设置4种施硅肥处理,分别记为CK、T1、T2、T3,对应施硅肥量分别为0、75、150、225 kg/hm^(2),进行大田试验,研究不同处理下优质晚稻成熟期植株茎秆抗倒伏特性、养分含量以及产量的差异。结果表明:与不施硅肥相比,T2、T3处理下茎秆基部节间折断弯矩显著增加,桃优香占的增幅为8.96%~11.11%,玉针香的增幅为13.02%~16.29%;2个晚稻品种的基部节间倒伏指数较不施硅肥处理的显著降低,桃优香占的降低12.02%~19.51%,玉针香的降低12.68%~22.31%;施用硅肥能改善上3叶形态,提高茎中的硅含量,桃优香占的提高2.01%~23.27%,玉针香的提高1.19%~11.33%;此外,施硅肥可提高水稻产量,以T1的增产效果最好,桃优香占和玉针香T1的实际产量较CK的分别增加6.81%和11.95%。考虑本试验在当季并未发生实质性倒伏,结合产量和成本效应,建议桃优香占和玉针香的施硅肥量为75 kg/hm^(2)。

穗分化末期-灌浆初期干旱胁迫对优质食味粳稻根系形态和叶片光合特性的影响

【目的】研究穗分化末期至灌浆初期土壤干旱对优质食味粳稻根系形态生理与叶片光合特性的影响,为水稻抗旱栽培提供理论参考。【方法】以南粳9108和丰粳1606为供试材料,分别在穗分化末期至籽粒灌浆初期20 d(BAH)、穗分化末期10 d(BH)与灌浆初期10 d(AH)设置轻度干旱(LD,ψsoil=−20±5 kPa)、重度干旱(SD,ψsoil=−40±5 kPa)及常规水分(CK)处理。【结果】1)在处理结束当天、处理结束后10 d、穗后30 d与成熟期,根长、根表面积、根体积、根尖数、根干质量与根系活力均表现为SD<LD<CK,根冠比呈相反趋势。在处理结束时,BAH时段SD、LD均与CK差异显著,除根冠比外,BH、AH时段SD与CK差异显著,LD与CK无显著差异。处理结束后10 d、穗后30 d与成熟期,BAH时期SD与CK差异显著,除根尖数外LD与CK差异不显著,BH时期SD根系部分指标与CK差异显著,AH时期水分处理间无显著差异。2)在处理结束时、处理结束后10 d、穗后30 d与成熟期,剑叶净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、胞间CO_(2)浓度(Ci)、最大光化学效率(Fv/Fm)、光化学猝灭系数(qp)均表现为SD<LD<CK,非光化学猝灭系数(NPQ)呈相反趋势。在处理结束时,BAH时段SD、LD各指标均与CK差异显著,除Ci外SD、LD间差异也显著,BH、AH时段SD各指标均与CK差异显著,LD与CK差异不显著。在处理结束后10 d、穗后30 d与成熟期,BAH时段SD与CK差异显著,LD与CK差异多不显著,BH时段SD的Pn、Tr、Fv/Fm较CK差异显著,而AH时段各指标在水分处理间差异多数不显著。3)三处理时段下各胁迫处理间产量均表现为SD<LD<CK,BAH、BH时段不同水分处理间差异显著,AH时段LD、CK间无显著差异,但二者均与SD差异显著。【结论】BAH时期轻度干旱、重度干旱均会抑制根系生长与叶片光合能力,显著降低产量,其中轻度干旱影响较小。BH时期土壤重度干旱时,根、叶形态生理指标在处理结束后难以恢复至对照水平,AH时期轻度干旱、重度干旱处理各指标在处理结束后能较快恢复。可见,在穗分化末期至灌浆初期,水稻根系和叶片生长对穗分化末期干旱胁迫更为敏感。

优质食味香型粳稻徽香粳977选育及栽培技术

徽香粳977是以镇稻14号为母本,武香粳14号为父本选育的粳稻品种,2022年通过品种审定。本文分析了徽香粳977选育过程、农艺性状特征、生产上的表现及主要栽培技术要点。徽香粳977具有优质食味、高产、大穗、综合性状优和适应性广等优点,适宜安徽单季晚粳、双季晚粳稻区种植;其高产栽培技术原则是稳基础、争足穗、攻大穗、提高粒重和结实率,以获取较高的品质和产量。研究结果为该品种的推广应用提供参考。

稻茬晚播油菜栽培技术研究进展

中国稻茬油菜种植区域主要在长江流域冬油菜区,近些年来稻茬油菜的单产不断提高,种植面积也稳中有升,为中国的油料安全做出了重要贡献。然而,随着长江流域冬油菜区水稻中晚熟品种轻简化栽培技术的推广应用,水稻成熟期大幅度推迟,导致油菜冬前生长时间进一步压缩,油菜晚播与过晚播面积逐年增大,严重制约了油菜的生产潜力。在长江流域稻油两熟区,油菜晚播现象尤为突出,已成为诸多学者广泛关注的热点问题。通过对油菜晚播现状以及相关高产限制因素的分析,致力于找出晚播油菜生产中的重要问题。通过对油菜晚播现状的分析,提高稻油轮作区油菜籽粒质量和产量。提倡运用先进的栽培技术减轻油菜晚播的影响,为促进未来油菜产业的蓬勃发展提供理论参考。

连作晚稻品种生长特性及产量比较

针对连作晚稻季节紧、产量低的问题,比较6个高产杂交稻品种的生长特性和产量。结果表明,甬优59、华中优9326、嘉丰优2号和甬优31每667 m^(2)产量分别较对照品种甬优1540提高12.0%、14.0%、15.4%和16.4%。嘉丰优2号和华中优9326产量较对照品种增产的主要原因是每穗粒数和千粒重提高,甬优31和甬优59产量较甬优1540增产的主要原因是每穗粒数提高。供试品种的生育期较对照品种延长1~6 d。生产上可根据早晚稻品种的生育期进行搭配,选用生长期适宜的杂交稻品种作连作晚稻机插种植。