不同库容量常规籼稻品种物质生产与分配的基本特征

 在群体水培条件下,以国内外不同年代育成的常规籼稻代表品种（2001年为88个、2002年为122个）为材料,测定干物质量（包括根系）、产量及其构成因素等,采用组内最小平方和动态聚类方法将供试品种按库容量从低到高依次分为A、B、C、D、E、F 6类,研究了各类品种物质生产与分配的基本特点。结果表明： 1）供试品种间库容量的差异很大,库容量最大的品种是最小品种的426倍(2001)和818倍（2002）。A、B、C、D、E、F类品种的平均库容量,2001年分别为42637、64253、77096、90373、106432、121390 g/m2,2002年分别为35936、57411、76498、96243、120011、145559 g/m2; 2）大库容类型品种生物产量、抽穗前干物质生产量、结实期干物质生产量显著大于小库容类型品种; 3）大库容类型品种成熟期分配到根系、茎鞘叶中的干物质比例较小,分配到穗中的干物质比例较大,经济系数较高;4）大库容类型品种抽穗期单位干物质库容量较大,结实期单位干物质库容量较小;5）从品种演变角度来看,生物产量对库容量的影响大于经济系数,抽穗期干物质生产量、抽穗期干物质形成库容的效率对库容量的作用大于结实期同类指标。     

优质晚籼稻产量性状的相关性分析及高产育种方向

采用方差分析、简单相关分析、逐步回归分析、通径分析及聚类分析，对４０个优质晚籼稻品种的单株产量及１０个产量性状进行了分析研究。结果表明：所分析的１１个性状在不同品种间存在极显著差异；这１１个性状间存在着相互制约和相互促进的关系；对单株产量的正向线性效应达显著以上统计水平的性状，根据其相对重要性的大小依次为每穗实粒数、单株有效穗数、千粒重和每穗一次枝梗数。在现有优质晚籼稻品种性状水平的基础上，开展优质晚籼稻的高产育种，应当把增加每穗实粒数作为主要方向，即重点打破单株有效穗数与每穗实粒数的负相关，着重提高每穗实粒数，其次是提高单株有效穗数，同时兼顾适当提高千粒重；在提高每穗实粒数的选育中必须着重把每穗一次枝梗数多作为选择指标。     

杂交水稻新组合全优2689的产量结构分析

通过对全优2689的产量结构进行分析,结果表明:应用简单相关分析,有效穗数、株高、穗长、每穗总粒数、结实率、千粒重等各因子与产量的相关性均不显著;而应用偏相关分析和通径分析,6个因子中有效穗数、穗长、每穗总粒数和千粒重等4个因子对产量的影响均达到极显著水平,其中有效穗数、每穗总粒数和千粒重的影响是正效应,穗长的影响是负效应.在栽培中应主攻每穗总粒数,注意追施穗肥,增加一次枝梗和二次枝梗上的粒数及着粒密度,从而增加每穗总粒数,同时协调好每穗总粒数、有效穗数、千粒重三者之间的关系,充分发挥该品种的增产潜力.     

寒地粳稻不同穗重类型产量因子初探

以松06-307、东农416、合选99-7、龙粳26、垦稻12、青系102、龙盾02-72、龙粳18、合选99-1作为供试品种(系),按照穗重将其分为三种类型:即轻穗型、中穗型、重穗型。分析不同穗重类型产量因子。结果表明:寒地不同穗重类型品种粳稻的一、二次枝梗的平均粒数较稳定,一次枝梗的粒数稳定在5~6粒;二次枝梗的粒数在3粒,是比较稳定的遗传性状。结实率轻穗型中穗型重穗型,二次枝梗的结实率与整体结实率呈线性正相关。不同穗重类型的一、二次枝梗千粒重差值却有显著差异,重穗型差值最大,轻穗型最小。     

中国东北粳稻与日本粳稻产量差异及原因分析

【目的】随着籼粳稻杂交理想株型创造与超高产育种理论的应用,我国东北地区培育出大量高产粳稻品种,逐渐取代曾经占据主导地位的日本典型粳稻。本研究旨在通过分析中国东北粳稻与日本粳稻形态、遗传和产量的差异及原因,研究籼粳杂交对东北粳稻改良的影响。【方法】利用InDel和SSILP亚种特异性分子标记、程氏指数、维管束数目比分析比较中国东北与日本粳稻的籼粳成分和属性及与产量结构的关系。【结果】东北粳稻育成品种产量比日本典型粳稻高15.79%,每穗粒数多15.22%,粳型基因频率极显著低于日本粳稻。按程氏指数分类标准,东北粳稻籼粳类型是偏粳型。相关分析结果表明,籼型基因频率与穗数极显著负相关,与每穗粒数极显著正相关,且与一、二次枝梗数及其粒数正相关。【结论】东北粳稻籼型基因频率增加导致穗数减少,每穗粒数增加,同时将结实率和千粒重维持在较稳定水平是东北粳稻品种获得高产的关键。     

不同产量水平粳稻品种间比较

对高、中、低产粳稻品种的株高、穗长、有效穗、颖花数、结实率、千粒重、一次枝梗数、二次枝梗数、一次枝梗粒数、二次枝梗粒数、生物产量进行比较,认为高产、中产、低产品种在颖花数、结实率、一次枝梗数、二次枝梗数、一次枝梗粒数、二次枝梗粒数、生物产量和有效穗数上存在差异,表现为高产品种较高,中产品种次之,低产品种最低,有效穗数表现相反趋势。另外,不论是高产品种还是低产品种,结实率均随颖花数的增加而变小,在相同颖花数量条件下,高产品种的结实率普遍高于低产品种。     

不同外源物质及喷施时期对滩涂水稻穗部性状、产量及品质的影响

以南粳5055为供试品种,于2021年在江苏滩涂地区（土壤盐分1.11～1.26 g/kg）开展田间试验,研究不同外源物质及喷施时期（2次：分蘖期、孕穗期和3次：分蘖期、孕穗期、灌浆期）对滩涂水稻穗部性状及产量、品质的影响。试验设置7个处理,即喷施清水（CK）、禾稼春喷施2次（L1-2）、碧护喷施2次（L2-2）、萘乙酸喷施2次（L3-2）、禾稼春喷施3次（L1-3）、碧护喷施3次（L2-3）和萘乙酸喷施3次（L3-3）。结果表明,喷施外源物质具有提高水稻产量的效果,与CK相比,L2-2、L2-3、L3-2和L3-3分别显著提高产量17.69%、17.80%、11.62%和13.42%,L1-2和L1-3则分别提高产量6.66%和7.09%,但差异不显著;喷施外源物质对稻米品质影响不大。喷施外源物质对水稻有效穗数和结实率均没有明显影响,但显著增加实粒数;L1-2、L2-2、L1-3和L3-3处理显著增加每穗粒数,L2-2和L2-3处理显著增加千粒重。喷施外源物质对水稻一次枝梗的枝梗数、总粒数、实粒数和结实率没有显著影响,而对二次枝梗的枝梗数、总粒数、实粒数及结实率均有不同程度的增加效果...     

不同产量水平粳稻品种间比较

对高、中、低产粳稻品种的株高、穗长、有效穗、颖花数、结实率、千粒重、一次枝梗数、二次枝梗数、一次枝梗粒数、二次枝梗粒数、生物产量进行比较，认为高产、中产、低产品种在颖花数、结实率、一次枝梗数、二次枝梗数、一次枝梗粒数、二次枝梗粒数、生物产量和有效穗数上存在差异，表现为高产品种较高，中产品种次之，低产品种最低，有效穗数表现相反趋势。另外，不论是高产品种还是低产品种，结实率均随颖花数的增加而变小，在相同颖花数量条件下，高产品种的结实率普遍高于低产品种。     

机直播杂交籼稻结实期物质转运与不同粒位米质的关系

选用8个杂交籼稻品种为试验材料,比较机直播不同品种间结实期物质转运、产量及穗部不同粒位（强、弱势粒,一次、二次枝梗,上、中、下部）米质的差异,并探讨结实期物质转运与不同粒位米质的关系,为机直播杂交籼稻品种筛选提供理论依据。结果表明,具有较高的颖花数和千粒重,且结实期具有较高的茎鞘和叶片物质输出与转换率,是机直播高产品种的主要特征。强势粒、一次枝梗籽粒垩白度和垩白粒率均低于弱势粒及二次枝梗籽粒,食味值均高于弱势粒及二次枝梗籽粒;穗上部籽粒米质特征均不同程度高于穗中部和下部籽粒,但穗中部和下部籽粒米质特征品种间存在差异;宜香优2115不同粒位食味值均不同程度高于其他品种。相关分析表明,结实期茎鞘物质输出率及转换率与不同粒位垩白均存在显著或极显著负相关（r=-0.66^*~-0.85^**）,与不同粒位食味值呈显著或极显著正相关（r=0.67^*~0.86^**）。提高机直播杂交籼稻结实期茎鞘物质转运率及转换率可改善不同粒位籽粒食味品质,宜香优2115作机直播在产量及米质上综合表现好,尤其在食味品质方面优势明显,适宜作为机直播水稻品种应用。     

稻米品质与水稻部分生育性状的相关研究

对水稻的经济性状和穗部性状与稻米品质性状进行相关分析,结果表明:出糙率与生育天数和株高有较大的负相关;垩白大小与生育天数呈正相关,与单株的生物产量和谷重呈负相关;粒宽与生育天数、株高和单株草重有较大的负相关,与单株谷重有较大的正相关;胶稠度与生育天数和株高有较大的正相关。糙米率与千粒重呈显著正相关;垩白率与每穗实粒数呈显著的负相关,与结实率、秕粒数、一次枝梗数呈显著的正相关;垩白大小与穗数、每穗实粒数、二次枝梗数呈显著正相关,与千粒重、结实率、每穗秕粒数呈显著的负相关性;垩白度与每穗实粒数、千粒重呈显著负相关,与每穗秕粒数、二次枝梗数、一次枝梗数呈显著的正相关;透明度与穗数、秕粒、结实率、实粒、千粒重都有较大的相关性。各穗部性状与直链淀粉含量和胶稠度的相关性不显著。回归分析表明,品质性状与水稻的其它性状间有着复杂的线性关系。     

Identification of quantitative trait loci for panicle structure and grain filling using a cross between indica- and japonica-type high-yielding rice cultivars

ABSTRACT

To enhance the yield potential of rice by breeding, it is important to reveal the genetic factors affecting yield components in high-yielding cultivars. Quantitative trait loci (QTL) analysis for panicle structure and spikelet weight as an index of grain filling was conducted using recombinant inbred lines (RILs) derived from a cross between an indica-dominant high-yielding cultivar, Takanari, and a japonica-dominant high-yielding cultivar, Momiroman in 2012 and 2013 in eastern Japan. The grain-filling ability of Takanari is reported to be better than that of Momiroman. Since grain filling is generally better near the tip of the panicle and decreases as the number of branches from the rachis increases, we classified whole panicles into upper and lower side panicles and spikelets into primary, secondary, and tertiary spikelets according to the number of branches from the rachis. On chromosomes 1, 4, and 6, QTLs regulating the number of spikelets per panicle and panicle structure were detected and were most likely identical to GN1a, SPIKE, and APO1, respectively, which has been previously reported as QTLs regulating the number of spikelets per panicle. Takanari produced much heavier secondary and tertiary spikelets than Momiroman on the lower side panicle. On chromosome 5, novel QTLs regulating spikelet weight were detected. The Takanari allele enhanced secondary and tertiary spikelet weight on the lower side panicle. These results indicate that it may be possible to enhance sink capacity and translocation of source with a combination of novel QTLs detected on chromosome 5 and GN1, APO1, and SPIKE.     

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.     

Proteins and Carbohydrates in Developing Rice Panicles with Different Numbers of Spikelets: —Cultivar difference and the effect of nitrogen topdressing—

Abstract

Proteins and carbohydrates in developing rice panicles were analyzed to see whether these parameters control spikelet number in rice. Two rice cultivars and 2 levels of nitrogen topdressing were used to obtain panicles with different numbers of spikelets. A japonica rice cultivar, Nipponbare, with topdressing (H) had 1.8 times more spikelets per panicle than that without topdressing (L). Moreover, the number of spikelets per panicle in an indica rice cultivar, Takanari, without topdressing was 2.7 times larger than that in Nipponbare-L. Panicles with more spikelets (LP) in Nipponbare-H and Takanari-L showed slower growth than those with few spikelets (SP) in Nippanbare-L in an early stage. LP, however, increased markedly in size thereafter, eventually exceeding SP, in length and fresh weight. Soluble protein content was higher in LP than SP in an early stage, but this difference was hardly detected in a late stage. No clear difference was observed in sugars or starch between LP and SP. Analysis of soluble and insoluble proteins by SDS-polyacrylamide gel electrophoresis showed that bands corresponding to insoluble proteins with a molecular weight about 42 kDa were present at higher intensities in LP than in SP. These results suggest that the spikelet number in rice is controlled by the soluble protein content in an early stage and insoluble proteins with a molecular weight of 42 kDa during panicle development, but not by the carbohydrates in developing panicles.     

甬优系列籼粳杂交稻中熟高产品系的株型特征

以甬优系列籼粳杂交稻中熟类型品系为试材,常规粳稻宁粳3号和武运粳29、杂交籼稻丰两优香1号和新两优6380为对照,比较各类型在穗部特征、叶片形态以及茎秆特性上的差异。结果表明,1)依据甬优系列籼粳杂交稻两年中的产量表现,将其分成高产品系(产量>10.5 t/hm²)和中产品系(产量<10.5 t/hm²)。两年中,甬优系列籼粳杂交稻高产品系为甬优2638、甬优2640、甬优1610、甬优1612和甬优1640,中产品系为甬优1851、甬优1852、甬优7753、甬优1763和甬优 5854。产量构成因素方面,不同类型品种单株穗数、结实率和千粒重以常规粳稻最高,每穗粒数以高产品系最高。2)穗长以杂交籼稻最高,单穗重和着粒密度以高产品系最高;除穗下部二次枝粳籽粒数以杂交籼稻最高外,穗部其余5部位籽粒数均以高产品系、中产品系显著高于常规粳稻和杂交籼稻,且籽粒数以上部二次枝粳和中部二次枝粳的增加最为明显。3)上三叶的叶长和叶宽为中产品系>杂交籼稻>高产品系>常规粳稻,高产品系上三叶的卷曲率高于对应的中产品系;上部第1、2叶的叶基角和披垂角以高产品系最低。4)高产品系株高为118.7cm,高于常规粳稻(96.6cm),低于杂交籼稻(132.9cm)和中产品系(144.1cm);上部第1、2、3节间长度以中产品系最高、常规粳稻最低;穗长与穗下节间长占株高比例、穗下节间占秆长比例均以高产品系最低。单茎干质量、单茎鞘干质量、茎秆单位节间干质量以高产品系最高。提出了甬优籼粳交中熟高产品系的株型选育指标及配套高产栽培措施。     

机插方式和密度对不同穗型水稻品种产量及其构成的影响

为探明不同机插方式下水稻适用穗型和适宜栽插规格,阐明不同机插方式下不同穗型水稻品种产量形成特征,选用大、中和小穗型各2个品种为试验材料,设置钵苗机插(行距33cm)、行距30cm毯苗机插和行距25cm毯苗机插3种机插方式(记为A、B、C),研究机插方式和密度对不同穗型水稻品种产量及其形成和穗部性状的影响。钵苗机插设置3种株距,分别为12cm、14cm和16cm(记为1、2、3),2种行距毯苗机插设置5种株距,分别为10cm、11.7cm、13.3cm、14.8cm、16cm(记为1、2、3、4、5)。研究结果表明:1)钵苗机插,随着密度降低,大穗型品种产量呈先增后减,以A2最高;中、小穗型品种产量呈递减趋势,以A1最高。毯苗机插,随着密度降低,大穗型品种B方式产量呈先增后减,以B4最高,C方式呈递增趋势,以C5最高;中穗型品种B和C方式产量均呈先增后减,分别以B3和C4最高;小穗型品种B方式产量呈递减趋势,以B1最高,C方式呈先增后减,以C2最高。同一密度下,钵苗机插产量显著高于毯苗机插,增产幅度表现为大穗型中穗型小穗型,2种行距毯苗机插差异不显著。对2种行距毯苗机插而言,同一株距下,大穗型品种B方式产量高于C方式;中穗型品种株距为10cm、11.7cm、13.3cm,B方式产量高,而株距为14.8cm、16cm,C方式产量高;小穗型品种除株距为10cm外,C方式较B方式具有增产优势。2)随着密度降低,不同机插方式下不同穗型品种单位面积穗数减少,每穗粒数增加,群体颖花量变化趋势与产量一致,结实率和千粒重变化不一。同一密度下,不同机插方式间单位面积穗数相当,钵苗机插每穗粒数显著高于毯苗机插,每穗粒数增幅表现为大穗型中穗型小穗型,结实率和千粒重差异不显著。对2种行距毯苗机插而言,同一株距下,B方式单位面积穗数少于C方式,而每穗粒数则相反。3)随着密度降低,不同机插方式下不同穗型品种穗长、着粒密度、单穗质量、一次枝梗数、一次枝梗粒数、二次枝梗数和二次枝梗粒数呈增加趋势,一、二次枝梗数比值和一、二次枝梗粒数比值呈减少趋势。同一密度下,钵苗机插穗长、着粒密度、单穗质量、一次枝梗数、一次枝梗粒数、二次枝梗数和二次枝梗粒数高于毯苗机插。因此,钵苗机插应用大穗型品种宜适当降低密度,充分发挥大穗优势,提高群体颖花量而高产;中、小穗型品种宜采用高密度栽插,增加穗数以获得高产。毯苗机插应用大穗型品种宜采用行距30cm,适当增加株距,依靠扩大穗型而高产;中穗型品种宜采用行距30cm,配置中等密度,协调穗粒结构而提高群体颖花量;小穗型宜采用行距25cm,适当减少株距,通过显著增加穗数以获得高产。     

杂交晚稻穗粒结构观察分析

对多个两系和三系杂交晚稻新组合的穗总粒、一次枝梗、二次枝梗、结实率和空秕率等穗粒性状进行了观察分析，指出了穗粒主要性状差异主要来源于组合本身，一次枝梗性状较稳定，二次枝梗受营养和环境条件影响较明显。从而为新组合的选育及高产栽培提供了依据。     

Response of Spikelet Number per Panicle in Rice Cultivars to Three Transplanting Densities

Abstract

Spikelet number per panicle (SPP), differentiated spikelet number per panicle (D-SPP), and preflowering aborted spikelet number per panicle (A-SPP) were examined in five rice cultivars at three planting densities (HD; high, MD; medium, LD; low planting density) in the field condition. Rice plants at LD produced a higher panicle number per plant but lower panicle number per unit area, accompanied by higher D-SPP and SPP, on average. A-SPP and the ratio of A-SPP to D-SPP (%A) showedno consistent trends. There was a broader range of D-SPP values at LD than at HD because of larger D-SPP in higher order panicles (panicles with a higher spikelet number). D-SPP was smaller in lower order panicles in all cultivars and years, whereas %A increased. D-SPP and SPP of each panicle were positively correlated with tiller size (tiller height, leaf area, and neck internode diameter). Spikelet production efficiency for D-SPP or for SPP (spikelet number per leaf area) of each tiller was higher in IR65564-44-51 (NPT65) and Akihikari than in the other cultivars, indicating a greater capacity of tillers to produce spikelets or support spikelet growth. In each cultivar except NPT65, spikelet production efficiency for D-SPP increased as panicle order decreased, whereas spikelet production efficiency for SPP remained constant or decreased. This finding indicates that irrespective of planting density, lower order panicles produce more spikelets than they can afford physiologically, but they were regulated downward to a nearly constant value in four cultivars. In NPT65 different from other cultivars, spikelet production efficiency for D-SPP was lower in lower order panicles.     

亚种间杂交稻大穗形成机理研究I．颖花的形成特点

比较了亚种间杂交稻赣化７号与品种间杂交稻汕优６３的枝梗和颖花的分化及发育特性，分析了颖花的分化、发育及一、二次枝梗对大穗形成的作用，提出了增加颖花数的主攻方向。     

水稻半矮秆基因sdl对农艺性状的影响

比较了从７份半矮秆品种８／高秆品种的Ｂ７Ｆ２中分离的高矮秆近等基因系，ｓｄｌ基因抑制了节间伸长，从基部到倒第１节及穗长分别为高秆的３８．２％、２６．０％、４０．８％、７１．１％和９２．６％，缩短程度逐步减轻。ｓｄｌ基因还可促进有效穗数、结实率和收获指数的提高而使矮秆类型的产量潜力高于高秆类型，但ｓｄｌ工基因并不影响抽穗天数、每穗粒数和干粒重。对ｓｄｌ基因的多效性以及秆高和穗数的关系进行了讨论。