生态环境对籼粳交后代株型特性和产量构成的影响

 以两个籼粳稻杂交F2群体（F2 A：晚轮422/沈农265;F2 B：泸恢99/沈农265）为试材,在四川和辽宁同年种植,研究生态环境对株型特性、产量构成及其相互关系的影响。结果表明,生态环境对株型特性和产量构成因素具有较为明显的影响。从四川到辽宁,株高和穗弯曲度显著提高,而穗长、剑叶长、剑叶宽及剑叶张角则表现出降低趋势。在辽宁,有效穗数、千粒重、结实率以及产量均显著高于四川,每穗粒数则显著低于四川。千粒重、结实率和产量表现为Cw（长剑叶、弯穗）> Cz（长剑叶、直穗） > Dw（短剑叶、弯穗） > Dz（短剑叶、直穗）,穗数和每穗粒数以Dz最低,Cz和Cw较高。剑叶长与产量构成因素间的相关性均未达到显著水平,而剑叶宽与每穗粒数均呈显著或极显著正相关,在辽宁,剑叶宽与结实率呈显著负相关。穗弯曲度只在四川分别与结实率及产量显著或极显著正相关,在辽宁则表现为与大多数产量构成因素相关不显著。     

水稻顶部三叶与穗重的关系及其QTL分析

 摘要: 对水稻汕优63重组自交系群体顶部3张叶片的长、宽、重和单穗重等10个性状进行了相关分析和QTL定位。穗重与9个叶片性状存在极显著的正相关，其中与倒2叶重的相关系数最大，剑叶重次之。所有性状在重组自交系群体中均存在双向超亲分离，接近正态分布。共检测到44个主效QTL和43对双位点互作影响上述10个性状。主效QTL分布于水稻的除第8染色体外的其余11条染色体上，贡献率介于3.19%~26.23%；互作分布于水稻的12条染色体上，贡献率变幅为2.03%~8.93%。第2染色体的R2510-RM211标记区间同时检测到控制单穗重和倒2叶重的QTL，该QTL对超级稻株型育种具有应用价值。     

不同类型亲本的杂交粳稻产量性状比较

收集不同熟期、不同类型的BT型粳稻不育系(保持系)和恢复系,对亲本分别按不同性状进行聚类,比较分析不同类型亲本配组杂种后代的性状表现,结果表明:1)不同类型亲本配组,杂种的性状一般表现为中间类型;2)亲本的抽穗期、株高对杂种单株穗数、每穗总粒数、每穗实粒数、单株产量、单株颖花量等多数产量性状无明显影响。亲本的穗粒结构对杂种的穗粒构成有明显影响,多穗型亲本间配组,杂种每穗总粒数及单株颖花量、产量潜力均较小;大穗型亲本间配组,杂种每穗总粒数及单株颖花量、产量潜力均较大;3)以多穗型不育系与大穗型恢复系配组,产量较高,是现有亲本配制杂交粳稻一种较好的配组方式;4)直立穗不育系与弯曲穗恢复系配组,杂种单株颖花量最多,产量潜力最大,而且株叶形态较好,如筛选到结实率高的组合,该配组方式的杂种具有较高的增产潜力。     

水稻回交群体剑叶性状综合评价及QTL定位

【目的】通过对水稻剑叶性状的综合评价,明确剑叶相关性状间及与6个农艺性状的关系。检测剑叶相关性状的QTL,为优良株型品种选育,剑叶性状基因的精细定位和克隆奠定基础。【方法】以日本优质粳稻品种越光和葡萄牙粳稻地方种Bertone构建的回交群体两个世代为实验材料,利用BC₃F₁群体基因型构建遗传连锁图谱;测定亲本和BC₃F₂群体各株系剑叶SPAD、剑叶长、剑叶宽,计算剑叶长宽比、剑叶面积;利用隶属函数和标准差系数赋予权重法获得剑叶性状综合评价值(D值),分析其与6个农艺性状间的关系。分别利用单标记分析(SPA)和区间作图(IM)检测水稻剑叶相关性状QTL。【结果】在抽穗灌浆期,两亲本剑叶SPAD值呈现先升高后降低的动态变化。BC₃F₂群体的5个剑叶相关性状变异丰富,总体表现趋向轮回亲本越光。4个剑叶形态性状间相关性均达到极显著水平,与剑叶SPAD的相关性不显著。主成分和逐步线性回归分析表明剑叶宽、剑叶SPAD、剑叶长、剑叶面积是影响剑叶综合评价值(D值)的主要因子。高D值株系的株高、穗长、茎基粗和单株产量均极显著高于低D值株系,两者的分蘖数和有效穗数差异不显著。共检测到18个控制剑叶性状的QTL,分布在水稻第1、4、7和8染色体上,贡献率分布范围为4.00%~28.00%(SPA)和3.41%~27.00%(IM),除qFLSPAD1之外的17个QTL增效基因均来自Bertone。在第8染色体上的RM22720-RM404区间发现1个QTL簇,含6个主效QTL,分别为qFLL8.1、qFLL8.2、qFLA8.1、qFLA8.2、qD8.1和qD8.2。【结论】获得了剑叶宽、剑叶SPAD、剑叶长和剑叶面积4个评价剑叶性状的关键指标;明确了剑叶性状与单株产量之间的正相关关系;检测到18个剑叶相关性状QTL,位于第8染色体RM22720-RM404区间的QTL簇,是影响剑叶性状的1个重要染色体区域。     

秸秆还田下适宜施氮量提高机插稻南粳9108产量和群体质量

为探明秸秆还田条件下机插稻适宜施氮量,阐明机插稻产量和高质量群体形成对氮肥响应的特点,在大田秸秆全量还田条件下,以优质食味水稻南粳9108为材料,设置0、135.0、202.5、270.0、337.5、405.0 kg/hm²等6种施氮水平,研究氮肥用量对机插稻产量及其构成和群体质量的影响。结果表明,随着施氮量增加,机插稻产量先增加后减少,以施氮量为270 kg/hm²产量最高。产量提高的主要原因是较高的群体颖花量,在施氮量为270 kg/hm² 条件下,机插稻群体颖花量达最大值。机插稻单位面积穗数随着施氮量增加而增加,每穗粒数先增后减,而结实率和千粒重表现为递减趋势。随着氮肥用量增加,机插稻分蘖中期、拔节期、抽穗期和成熟期的茎蘖数、叶面积指数、光合势和干物质积累量均呈递增趋势,而抽穗后干物质积累量、成穗率、有效叶面积率、高效叶面积率和粒叶比呈先增后降的趋势。因此,秸秆还田后适当增加施氮量利于提高机插稻产量,优化群体质量。     

不同时期弱光胁迫对晚稻不同耐弱光品种源库特征及叶片保护酶活性的影响

目的 本研究旨在明确弱光胁迫下不同弱光耐性品种在源库特征及叶片保护酶活性变化方面的差异,揭示其耐弱光胁迫的机制,为双季稻高产稳产新品种的选育及抗逆栽培提供理论指导。方法 以2个对弱光胁迫耐性存在显著差异的晚稻品种为材料,通过设置不同时期的遮光处理,研究弱光胁迫时期对晚稻不同耐性品种的源库特征及叶片保护酶活性的影响。结果 结果表明,不同时期弱光胁迫对晚稻生长有重要影响,分蘖期弱光胁迫下晚稻分蘖数、每穗粒数及总颖花量减少,叶面积下降,产量降低;幼穗分化期弱光胁迫下晚稻分蘖数和每穗粒数减少,总颖花量、叶面积、结实率均下降,产量降低;灌浆期弱光胁迫下水稻叶片净同化率降低,结实率和千粒重下降,产量降低。不同时期弱光胁迫对晚稻产量的影响表现为灌浆期>幼穗分化期>分蘖期。结论 耐弱光胁迫型品种能通过增加叶片的长宽度减少叶面积的下降,叶片含氮量保持相对稳定,叶片中SOD、CAT等保护酶活性保持在较高水平,POD活性保持相对稳定,叶片净同化率下降幅度小,在弱光胁迫下实现“强源”,减产率相对较低。弱光胁迫下具有较强的叶面积补偿能力和适宜氮含量以及较高的保护酶活性是水稻耐弱光胁迫的重要机制。     

Genetic architecture, inter-relationship and selection criteria for yield improvement in rice (Oryza sativa L.)

This study has been conducted to determine the extent of genetic association between yield of Rice (Oryza sativa L.) and its components. The present experiment was carried out with 40 Rice (Oryza sativa L.) genotypes which were evaluated in a randomized block design with 3 replications during wet season of 2007 and 2008. Results showed that sufficient amount of variability was found in the entire gene pool for all traits studied. Higher magnitude of genotypic and phenotypic coefficients of variation was recorded for seed yield, harvest index, biological yield, number of spikelets per panicle, flag leaf length, plant height and number of tillers indicates that these characters are least influence by environment. High heritability coupled with high genetic advance as percent of mean was registered for seed yield, harvest index, number of spikelets per panicle, biological yield and flag leaf length, suggesting preponderance of additive gene action in the expression of these characters. Grain yield was significantly and positively associated with harvest index, number of tillers per hill, number of panicle per plant, panicle length, number of spikelet's per panicle and test weight at both genotypic and phenotypic levels. Path coefficient analysis revealed that harvest index, biological yield, number of tillers per hill, panicle length, number of spikelets per panicle, plant height and test weight had direct positive effect on seed yield, indicating these are the main contributors to yield. From this study it may be concluded that harvest index, number of tillers per hill, panicle length and number of spikelet per panicle and test weight are the most important characters that contributed directly to yield. Thus, these characters may serve selection criteria for improving genetic potential of rice.     

稻曲病发病程度与水稻株型的相关性

采用6个对稻曲病抗感程度不同的水稻品种(组合),调查稻曲病发病率、严重度并计算损失率。同时测量一次枝梗数、二次枝梗数及着粒密度等穗部性状,并考察剑叶角度、剑叶长和株高等株型性状。将结果进行相关性分析,认为稻曲病的发生存在着显著的品种间差异,发病率与穗部性状关系密切,相关性大小为着粒密度>每穗粒数>二次枝梗数,发病率与穗长、剑叶角度、穗弯曲度、剑叶长度呈极显著或显著的负相关。提出在株型育种中应注意选择一次枝梗数较多的偏散穗、长弯穗型,避免选用二次枝梗数过多的资源。     

小麦品种宁7840突变体农艺性状和赤霉病抗性解析

为了解突变体与野生型小麦的农艺性状、产量和抗性差异,以高抗赤霉病小麦品种宁7840及其23个甲磺酸乙酯(EMS)诱导的纯合突变体(Mu4)作为材料,研究其分蘖数、株高、叶绿素含量、千粒重、小穗数、穗粒数及赤霉病抗性等12个指标的差异。结果表明,除叶长、分蘖数和小穗数在突变体与野生型之间无显著差异外,其余9个性状在野生型与部分突变体之间有显著差异。N8和N16两个突变体表现高感赤霉病;N16突变体的叶宽、SPAD值、千粒重和粒宽显著优于野生型,其株高显著低于野生型。赤霉病病小穗率与叶长显著负相关,叶长可作为筛选小麦赤霉病抗性品系的间接指标;叶宽和粒宽可作为筛选小麦产量性状的重要指标。基于12个性状的聚类分析,将24个小麦材料聚为3类,其中第I类在产量性状方面优于其他两类。     

水氮管理对不同氮效率水稻根系性状、氮素吸收利用及产量的影响

【目的】探究水氮管理措施对不同氮效率水稻根系构型、氮素吸收利用和产量形成的影响,以及根系性状特征与氮素吸收利用和产量关系。【方法】试验采用三因素裂裂区设计,主区为2个不同氮效率水稻品种德香4103(氮高效型)和宜香3724(氮低效型),裂区设置"常规灌溉"和"控制性交替灌溉"2种水分管理方式,裂裂区为SPAD指导施肥、优化施肥以及农民习惯施肥3种施氮模式,运用岭回归分析方法探究根系构型与氮素吸收利用和产量的关系。【结果】水稻抽穗期根系性状、产量、每穗粒数、千粒重及总颖花量均存在显著的基因型差异。氮高效品种德香4103每穗粒数多,群体库容量大,产量较氮低效品种宜香3724高0.24%~11.31%;控制性交替灌溉有利于水稻千粒重的增长,常规灌溉则对水稻有效穗数、每穗粒数及群体颖花量提高更为有利;SPAD指导施肥和优化施肥处理能够提高水稻有效穗数和每穗粒数,扩大群体颖花量以保证其对农民习惯施肥的产量优势;由于水氮互作效应的存在,控制性交替灌溉下施氮处理与空白处理水稻千粒重的差距比常规灌溉的大幅降低,使得控制性交替灌溉下施用氮肥的增产效果更佳。德香4103的氮肥生理利用率较宜香3724平均高8.69%,常规灌溉下水稻氮积累量较高,控制性交替灌溉下氮肥回收率、农学利用率、生理利用率均较优;与农民习惯施肥处理相比,SPAD指导施肥与优化施肥模式更有利于水稻氮素吸收利用效率的提高。拔节期、抽穗期和成熟期水稻根系构型与产量岭回归方程的决定系数范围为0.4198~0.9028,其中,抽穗期根系性状与产量关系最为密切,氮高效和氮低效品种的决定系数均超过0.9。在拔节期,水稻细分枝根长对产量影响最大;在抽穗期,氮高效和氮低效品种存在差异,前者是粗分枝根长,后者是细分枝根表面积对产量影响最大;在成熟期,不定根长与产量关系最为密切。水稻抽穗期根系构型对氮积累量变化的解释程度较高,岭回归方程决定系数均接近0.7。就水氮管理措施而言,氮高效和氮低效水稻均应采用常规灌溉配套SPAD指导施肥或控制性交替灌溉结合优化施肥来实现产量的提高。【结论】水稻抽穗期根系构型与产量、氮积累量关系密切,采用合理的水氮管理措施能够实现水稻产量和氮素吸收利用效率的同步提高。     

Pre-anthesis non-structural carbohydrate reserve in the stem enhances the sink strength of inferior spikelets during grain filling of rice

Sink strength plays an important role in grain filling of cereals but how it is related to the pre-anthesis non-structural carbohydrate (NSC) reserves is not clear. This study investigated if and how an increase in NSC reserves could enhance sink strength, and consequently improve grain filling of later-flowering inferior spikelets (in contrast to the earlier flowering superior spikelets) for rice varieties with large panicles. Two “super” rice varieties (the recently bred high-yielding rice) and two New Plant Type (NPT, named in IRRI for the extra-large panicle) rice lines were compared with two elite inbred varieties under field-grown conditions. Three nitrogen (N) treatments, applied at the stages of panicle initiation, spikelet differentiation or both, were adopted with no N application during the mid-season as control. Both super rice and NPT rice showed a greater yield capacity as a result of a larger panicle than the elite inbred rice. However, a lower percentage of filled grains limited the realization of higher yield potential in super rice and especially in NPT rice, due to their lower grain filling rate and the smaller grain weight of their inferior spikelets. The low grain filling rate and small grain weight of inferior spikelets are mainly attributed to a poor sink strength as a result of small sink size (small number of endosperm cells) and low sink activity, e.g. low activities of sucrose synthase (SuSase) and adenosine diphosphoglucose pyrophosphorylase (AGPase). The amounts of NSC in the stem and NSC per spikelet at the heading time are significantly and positively correlated with sink strength (number of endosperm cells and activities of SuSase and AGPase), grain filling rate, and grain weight of inferior spikelets. Nitrogen application at the spikelet differentiation stage significantly increased, whereas N application at the panicle initiation or at both panicle initiation and spikelet differentiation stages, significantly reduced, NSC per spikelet at the heading time, sink strength, grain filling rate, and grain weight of inferior spikelets in super rice. The results suggest that pre-anthesis NSC reserves in the stem are closely associated with the sink strength during grain filling of rice, and N application at the spikelet differentiation stage would be a good practice to increase pre-anthesis NSC reserves, and consequently to enhance sink strength for rice varieties with large panicles, such as super rice varieties.     

用培矮64S/日本晴F2群体对水稻6个农艺性状的QTL定位

 用水稻测序品种培矮64S和日本晴配组建立了由180个单株组成的F2群体，构建了含137个SSR标记的连锁遗传图谱，对水稻的分蘖数、有效分蘖数、分蘖率、株高、剑叶长和穗长等6个相关农艺性状进行了QTL定位分析。共检测到14个QTL，分布在第1、2、4、5、6、7染色体的11个区间。检测到1个控制株高的主效QTL(qPH1 2),位于第1染色体，其表型贡献率为24.0%；1个控制剑叶长的主效QTL(qFL4）,位于第4染色体，其表型贡献率为30.5%。对所定位QTL的价值、QTL在染色体上的区域分布等进行了探讨。     

利用染色体片段置换系群体检测水稻叶片形态QTL

 水稻叶片的形态改良是水稻株型育种和产量育种的重要目标之一。以9311/日本晴染色体片段置换系（CSSLs）群体为材料,定位了上3叶叶片长、宽、叶面积共9个性状QTL,分析了叶片性状与产量性状之间的相关性,同时定位了主穗重及产量构成因素（颖花数、千粒重、结实率）相关QTL。结果表明,CSSLs群体的叶片性状之间存在显著或极显著相关性;叶片性状与主穗重呈显著或极显著正相关,与主穗颖花数呈极显著正相关;叶片形态多数性状与结实率、千粒重没有显著相关性。两年共定位到20个叶片性状QTL,分布于第1、3、4、5、6、9、11共7条染色体的10个区间,贡献率为3.82%~14.61%,其中贡献率大于10%有6个,多个QTL成簇分布在相同区间,3个QTL在两年间重复检测到,8个QTL为前人未报道的新位点。两年共检测到16个与控制主穗产量相关的QTL,分布于第1、2、3、5、7、8、10共7条染色体13个区间,其中有7个主穗产量相关QTL所在5个区间与叶片形态14个QTL所在区间一致。     

不同年份水稻产量性状的QTL分析

分别于2005年和2006年利用热研2号（粳稻）和密阳23（籼稻）为亲本构建的含111个家系的F6和F7重组自交系群体,对单株穗数、每穗颖花数、每穗实粒数、结实率、千粒重和单株产量6个性状进行了QTL分析。两年共检测到分布于7条染色体上的19个QTL,其中2005年检测到10个,2006年检测到14个,两年相同的QTL 5个。大多数性状之间具有显著的表型相关性,相关性较强的性状之间具有较多共同或紧密连锁的QTL。检测到3个控制产量性状的QTL区域存在一因多效或紧密连锁,其中第8染色体上RM5556-RM331区域两年同时检测到控制每穗颖花数、每穗实粒数以及单株产量的QTL。这些QTL为通过分子标记辅助选择提高水稻产量提供了有用信息。     

黑龙江省第二积温带水稻产量性状分析

为明确黑龙江省第二积温带水稻高产育种目标,分析了黑龙江省第二积温带30个水稻品种的产量性状及其相关关系。结果表明,对水稻产量影响较大的第一主因子为每穗粒数,第二主因子为剑叶宽,第三主因子为千粒重,第四主因子为穗长,第五主因子为结实率,第六主因子为株高。在今后高产育种工作中,应将改良水稻株型及提高每穗粒数作为工作基础。     

吉林省47年来粳稻品种遗传改良过程中某些农艺性状的变化

对吉林省1958-2005年间育成的25个粳稻品种的产量及农艺性状的研究结果表明,随着粳稻品种的改良,产量呈线性增加。根据回归方程计算,产量由1958年的6 198.68 kg/hm2增加至2005年的12 682.8 kg/hm2,平均每年增加137.96 kg/hm2,增长率为2.23%。每穗粒数、结实率、单穗重和总穗数随育成年代推移显著增加,并与产量呈正相关,其中每穗粒数与产量的相关系数最大（r=0.85**）。株高随育成年代推移显著降低,茎叶夹角显著减小,灌浆期叶面积指数增加,抽穗期推迟。结果表明,产量的增加主要与品种改良过程中总库容的扩大有关,其中每穗粒数的增加是关键。     

Agronomic Performance of F1 Hybrids of Rice (Oryza sativa L.) in Japonica-Indica Crosses

Summary

Generally F₁ hybrids from crosses between japonica and indica rice show variable degrees of sterility. Previous studies revealed that among the indica rice, the Aus type has sexual affinity with japonica cultivars giving higher fertility in F₁ hybrids. Therefore, we made an effort to obtain higher grain yield by producing F₁ hybrids between japonica and Aus-type indica. A field experiment was conducted to investigate the heterosis in these F₁ hybrids for dry matter accumulation, spikelet fertility, yield and yield attributes, to find cross combinations with higher grain yield, and examined the relationships of grain yield with some agronomic characters. F₁ hybrids flowered earlier than their parent cultivars. Heterosis for dry matter accumulation was positive at the panicle initiation stage, at heading and at maturity. The average heterosis for number of panicles, grain and straw yield per plant, number of spikelets per panicle and 1000-grain weight was positive. A few F₁ hybrids showed positive heterosis for number of filled grains per panicle, spikelet fertility and harvest index; but the average heterosis for these traits was negative. Among the yield components, a higher number of panicles per plant and higher number of spikelet per panicle contributed to higher grain yield in F₁ hybrids. A significant and positive relationship existed between spikelet fertility and grain yield per plant. The higher grain yield was attributed to higher dry matter production rather than higher harvest index in F₁ hybrids, although low spikelet fertility limited yield potential in some F₁ hybrids.     

Parental Selection in Rice Cultivar Improvement

The evaluation of rice (Oryza sativa L.) cultivars assists breeders in identifying useful trait relationships and in selecting parents as donors of specific traits. This study was conducted to compare long-grain rice cultivars using genotype × trait (GT) biplot analysis and determine potential donors of traits related to grain yield and quality. Seventeen cultivars in the 2005 and 2006 Uniform Regional Rice Nursery in Beaumont, Texas, USA were analyzed for 20 traits using GT biplot analysis. The GT biplots showed the diversity among cultivars with regards to yield-related traits. Cultivars recommended as donor parents were: Trenasse, Spring, Presidio, and Cocodrie for high grain yield and head rice rate; Trenasse and Presidio for semi-dwarfness; Banks for tall plant height; Wells for high flag leaf area, panicle weight, and number and mass of filled grains per panicle; Hidalgo for high tiller density; Francis for high number of spikelets per panicle; Spring and Trenasse for short flowering duration; Cheniere for more days to heading and maturity and Spring for less days; and Spring and Hidalgo for high grain weight. Breeders can use these cultivars with specific traits to increase grain yield and quality.     

不同燕麦基因型源库关系对穗粒数形成过程的影响

为了解燕麦穗粒数形成过程与源、库特征之间的关系，连续两年以10个不同来源、熟期、穗型、株型、小穗数的燕麦品种为试验材料，测定三叶期至拔节期的幼穗分化阶段及抽穗期源库特征，采用方差分析、聚类分析、逐步回归分析等方法，分析不同燕麦基因型源库特征及对穗粒数形成过程的影响。结果表明，燕麦穗粒数形成过程存在基因型差异，幼穗分化较好品种的穗粒数较全部品种平均值高11.22%~65.43%；幼穗分化较好品种的光合势、干物质量、粒数叶比、收获指数显著高于幼穗分化较差品种，其中粒数叶比和收获指数是影响穗粒数形成的主要因素，粒数叶比和收获指数较全部品种平均值分别高0.99%~68.74%和0.85%~13.80%。综上所述，源库协调是燕麦幼穗分化良好的生理基础，可通过提高光合势和干物质量达到增源的目的，进而提高穗粒数。     

籼粳交重组自交系群体主要农艺性状分析

采用方差分析、相关分析和多元逐步回归分析等方法对籼粳交（Lemont×特青）构建的一套包括265个重组自交系（RIL）群体(F14)的株高、生育期、产量和产量构成因子等10个重要农艺性状进行了研究。结果表明,除株高和有效穗以外,8个农艺性状在双亲之间均存在显著或极显著差异。各性状在RIL群体中呈连续变异,分布频率大致接近正态分布,同时存在双向超亲分离现象。单株产量与结实率、粒数和株高呈极显著相关;除千粒重外,所有性状均与株高具有相关性。对单株产量作用大的性状依次为结实率、有效穗、每穗粒数和千粒重,这4个性状解释了单株产量90.7%的变异。另外还对6份优良株系进行了评价。这些结果可为水稻数量性状基因定位分析提供有用的信息,也为水稻育种改良提供理论依据。