国审杂交籼稻组合的稻米品质分析

分析了2003—2013年通过国审的378份杂交籼稻的主要米质性状表现以及各米质指标间的相关性。结果表明,杂交早籼稻的垩白、整精米率和胶稠度在11 a间均有明显改善,但其米质性状仍然差于杂交中、晚籼;垩白性状仍是今后杂交籼稻米质改良的重点。垩白度和垩白粒率与整精米率、胶稠度和长宽比呈负相关,与直链淀粉含量呈正相关;低直链淀粉含量品种的平均垩白度和垩白粒率均显著低于中高直链淀粉含量品种,而其胶稠度和长宽比则高于中高直链淀粉含量品种;降低直链淀粉含量有利于改良垩白和胶稠度,适当增加籼稻的长宽比有利于降低垩白。     

不同直链淀粉含量籼稻食味品质与其他品质性状的关系

以12个中等直链淀粉含量的软米和8个高直链淀粉含量的硬米为研究材料,分析了两类稻米食味品质与其他品质性状的关系。结果表明,直链淀粉含量低的软米食味优于直链淀粉含量高的硬米;硬米食味值与整精米率呈显著负相关,与粒长和粒型呈显著正相关,软米食味与外观品质和加工品质的相关性不显著;硬米和软米食味值与胶稠度分别呈极显著和显著正相关,与蛋白质含量呈显著和极显著负相关;硬米食味值与RVA谱相关性不显著,软米食味值与崩解值和最高黏度呈极显著正相关,与消减值呈极显著负相关。在今后的稻米食味品质评价工作中,应根据不同直链淀粉含量进行分类,再有针对性地选择相应食味品质指标进行测定,以便能更加准确地评价不同类型稻米的食味品质。     

杂交籼稻外观品质性状与食味品质性状典型相关分析

为了明确稻米外观品质与食味品质的关系,甄选合适的评价指标,为培育外观品质与食味品质综合优良的杂交籼稻品种提供理论参考,以8个不育系与25个恢复系配制的200个杂交籼稻组合为材料,采用简单相关和典型相关分析研究了稻米外观品质性状与食味品质性状的相关关系。结果表明,直链淀粉含量与粒宽、垩白度、垩白粒率呈显著正相关,与长宽比显著负相关;米饭食味综合评分与粒长、长宽比显著正相关,与粒宽显著负相关。典型相关分析得到相关系数达显著水平的两对典型相关变量,累计贡献值为91.329%。在第一对典型变线性组合构成中,U₁和V₁分别以长宽比、直链淀粉含量的权重较大;在第二对典型变线性组合构成中,U₂和V₂分别以粒长、食味综合评分的权重较大。     

施氮时期对扬稻6号颖果发育及稻米品质的影响

通过盆栽试验研究了相同施氮量下不同施氮时期（分蘖期和孕穗期）对扬稻6号颖果发育及稻米品质的影响。与对照相比,增施氮肥（尿素）特别是孕穗肥能显著提高稻米精米率、整精米率、蛋白质含量,降低垩白粒率和直链淀粉含量;在分蘖期和孕穗期施氮肥能明显影响颖果发育,提高粒重,而后者的效果更为明显;在颖果发育过程中不同时期增施氮肥能显著降低颖果的总淀粉和直链淀粉含量,但对支链淀粉含量影响较小;不同时期增施氮肥特别是孕穗肥对淀粉体和蛋白质体的发育及结构均有显著影响,能显著改变籽粒中不同部位特别是腹部淀粉体和蛋白质的分布、数目和形状。与对照相比,淀粉体和蛋白质体的排列更紧密、相互间空隙较少、数量增加、密度增大,淀粉体形状多数呈晶状体。     

不同生态地点下稻米外观品质性状的QTL定位分析

 利用两个已测序品种93 11和日本晴为亲本,采取单粒传法创建由190个家系组成的重组自交系群体,并构建了包含178个SSR、CAP和STS标记的遗传连锁图谱。采用复合区间作图方法,在3个不同生态地点(陵水、合肥和怀远)对垩白(垩白率、垩白大小、垩白度)、粒形(粒长、粒宽、长宽比)等6个外观品质的数量性状基因座（QTL)进行了定位分析。共定位到39个QTL,单个性状QTL数目在6~7个,说明垩白和粒形是多基因控制的数量性状。8个QTL可在2个以上地点检测到,其中,两个垩白度相关QTL qCD 1、qCD 3(贡献率分别为288%、321%)在3个地点同时检测到;11个QTL具有一因多效性,单个QTL位点控制的性状为2~6个,如第3染色体RM16-RM143区段控制垩白率、垩白大小、垩白度、粒长、粒宽和长宽比等6个性状。比较3个地点的检测结果,发现外观品质性状的QTL定位都受环境影响,但不同性状受影响的程度不同。长宽比和垩白度受环境影响较小,粒宽受环境影响较大。     

华南籼稻稻米品质性状早晚季间变化规律探讨

目前 ,华南双季稻作区种植的常规稻品种大多数都是早晚兼用型品种 ,不少生产上应用的杂交组合也属早晚兼用型。早晚兼用型品种 (组合 )在早晚季种植时稻米品质会有所不同 ,普遍的经验认为晚季稻米的食味品质优于早季 ,但对于稻米蒸煮、外观、碾米、食味等具体品质指标在早晚季的变化尚缺乏深入的量化研究。本文采用国家优质稻谷标准ＧＢ／Ｔ１７８９１-１９９９,测定并分析了９个华南籼稻品种 (组合 )在６个试点早晚两季种植的稻谷样品的品质指标 ,试图揭示华南籼稻品种 (组合 )早晚季品质变化的规律 ,讨论了新国标的可操作性。一、材料与方…     

华南籼稻新品种（组合）早季品质性状的综合分析和讨论

采用国家优质稻谷标准GB／T17891－1999对广东省早季不同稻作区种植的同一套不同质量档次新品种（组合）进行品质测定，品质性状方差分析结果表明：出糙率、整精米率、不完善粒的地点效应达极显著水平；垩白粒度、垩白度、直链淀粉含量、食味品质、胶稠度、粒型的地点效应不显著。综合分析了广东省新品种（组合）品质性状的现状，讨论了加权法定级的合理性，初步提出了广东省优质稻质量标准意见。     

稻米淀粉RVA谱特征与品质性状的相关性

 通过对106份水稻材料稻米外观品质、蒸煮品质和RVA谱特征值的测定,研究了淀粉黏滞性（RVA谱）特征值与各项品质指标的相关关系。RVA谱特征值与外观品质中的垩白率关系最为密切,其中垩白率与崩解值(BDV)和消减值(SBV)的相关系数分别为-0.43**和0.40**;RVA谱特征值与低直链淀粉含量(AC)品种和糯稻品种的蒸煮品质指标呈显著或极显著相关,与中高直链淀粉含量品种的指标相关性不显著,特别是高直链淀粉含量品种的AC与RVA谱特征值相关性均不显著,而糯稻品种的AC与RVA谱特征值（BDV和 SBV除外）的相关系数均在0.85以上。由此认为,水稻品种的AC越低,AC与RVA谱特征值的关系越密切。     

氮肥后移对杂交籼稻产量及不同粒位稻米垩白与食味品质的影响

以低垩白高食味品种宜香优2115和高垩白低食味品种F优498为材料,在施氮量150 kg/hm²条件下,研究了3 种氮肥运筹方式（基肥:蘖肥:穗肥分别为5:3:2、3:3:4、3:1:6,分别记为N1、N2 N3）和不施氮（N0）对杂交籼稻产量及不同粒位稻米垩白性状和食味品质的影响,并探讨了不同粒位稻米垩白性状与食味品质的关系。结果表明,品种、氮肥运筹对产量、氮肥农学利用效率及不同粒位稻米垩白性状及食味值均存在显著影响。参试2个品种产量及氮肥利用效率均以N2处理最高,实现了产量及氮肥利用效率的协同提高;同时能进一步降低宜香优2115不同粒位的垩白性状、提高相应粒位食味值;而F优498的食味值以N1处理为宜,可改善其不同粒位稻米品质。进一步分析发现,垩白度和垩白粒率强势粒低于弱势粒、一次枝梗上的籽粒低于二次枝梗上的籽粒、穗上部籽粒低于穗中部和下部籽粒,而食味值则强势粒高于弱势粒、一次枝梗上的籽粒高于二次枝梗上的籽粒、穗上部籽粒高于穗中部和下部籽粒。相关分析表明,稻米垩白性状与食味值呈显著或极显著相关（r=-0.706^*~-0.937^**）,降低稻米垩白是提高食味品质的主要途径。     

两个籼稻品种垩白对稻米蒸煮食味与营养品质的影响

以冈优527(杂交籼稻)和窄叶青8号(常规籼稻)为材料,研究垩白对稻米蒸煮食味品质及营养品质的影响。与非垩白米相比,冈优527垩白米的直链淀粉含量极显著升高,最终黏度、消减值、回复值显著升高,胶稠度、峰值黏度、崩解值显著降低,RVA谱的其余指标无显著变化。窄叶青8号垩白米与非垩白米的上述各指标间无显著差异。窄叶青8号垩白米的粗蛋白含量显著低于非垩白米,而冈优527垩白米的粗蛋白含量与非垩白米相比无显著变化。2个品种垩白米的清蛋白、球蛋白、醇溶蛋白、赖氨酸含量与非垩白米间无显著差异, 但谷蛋白含量显著低于非垩白米。     

Caryopsis Development and Main Quality Characteristics in Different indica Rice Varieties

A comparison on the caryopsis development, rice quality characteristics and the size, shape, structure of the endosperm amyloplasts （starch granules） between two indica rice varieties was made, The main quality traits in Yangdao 6 were better than those in Xiangzaoxian 33; In the early period after fertilization the dry matter in Yangdao 6 was accumulated more slowly than that in Xiangzaoxian 33 but faster in the later period, and the starch was accumulated strongly in the later period; There were two kinds of amyloplasts： single and compound amyloplasts, being 4.4 um and 9.5 um in diameter on average with the range of 2.4-8.0 um and 5.7-19.5 um, respectively. In the case of Xiangzaoxian 33, most of the single amyloplasts were elliptic or round with loose arrangement and great difference in size, and the coefficient of variation was high. While in the Yangdao 6, most of the amyloplasts were single, well developed, polyhedral, crystalline and compactly arranged, and the coefficient of variation was low. The amyloplasts in the dorsal region of endosperm were developed better than those in the ventral and central regions. The chalkiness in the endosperm resulted from badly-developed and loose-arranged starch granules, which was closely relevant to the transport of filling materials.     

Effects of Nitrogen Application Time on Caryopsis Development and Grain Quality of Rice Variety Yangdao 6

A pot experiment was conducted to study the effects of different nitrogen application time(during the tillering or the booting stages)with the same nitrogen rates on the caryopsis development and grain quality of rice variety Yangdao 6.The increased nitrogen fertilizer(urea),especially applied during the booting stage,could evidently increase the milled rice rate,head rice rate and protein content in rice grains compared with the control(no nitrogen application),and decrease chalky grain rate and amylose content.Moreover,the increased nitrogen fertilizer significantly affected the caryopsis development and enhanced the grain weight when nitrogen applied during the tillering and the booting stages,especially during the booting stage.During caryopsis development the increased nitrogen fertilizer applied during the tillering and booting stages could obviously decrease the total starch and amylose contents,but not obviously for the amylopectin content in rice grain.Increased topdressing of nitrogen fertilizer,especially applied during the booting stage,had significant effect on the development and structures of amyloplasts and proteinoplasts.That is,it could change the distribution,number and shape of amyloplasts and proteinoplasts in the endosperm cells especially in grain abdomen.Compared with the control the arrangements of amyloplasts and proteinoplasts were closer,with more numbers,higher density and less interspaces each ohter.Furthermore,most amyloplasts showed polyhedron under the increased nitrogen fertilizer level.     

不同粒型中籼杂交稻组合稻米品质及相关性分析

通过米粒粒型分类,对2013-2014年通过四川省审定的36个中籼杂交水稻组合的主要品质性状进行了分析,并研究了品质性状指标间的相关关系。结果表明,36个组合中只有2个组合的稻米品质指标全部达国颁优质稻谷标准3级以上,这2个组合的米粒长宽比都在2.9以上;在单个品质性状指标中,这些组合优质达标率(达到国颁优质稻谷标准3级以上)最高的是糙米率,其次是胶稠度,第三是整精米率,达标率较低的是垩白粒率和垩白度。长米粒型组合垩白粒率和垩白度优质达标率均为16.67%,中米粒型组合分别为0和14.29%,短米粒型组合分别为10.00%和0。垩白粒率和垩白度是中籼杂交稻组合稻米品质提升的主要障碍因子。品质性状相关分析结果:垩白粒率和垩白度与米粒长宽比呈极显著负相关,与直链淀粉含量呈极显著正相关;在长米粒型组合中,垩白粒率、垩白度与直链淀粉含量显著或极显著正相关;在中米粒型组合中,垩白粒率、垩白度与米粒长宽比显著或极显著负相关,与直链淀粉含量极显著正相关;在短米粒型组合中,垩白粒率和垩白度与其他主要品质性状相关性均不显著。建议在遗传改良中籼杂交稻垩白粒率和垩白度时可以从粒型着手,选择米粒粒型偏长、容重大、无裂纹、近圆柱形的材料和组合。     

四个不同粒重水稻品种颖果发育的比较

 以粒重差异较大的4个水稻品种为供试材料,采用树脂切片、酶解胚乳细胞和显微观察等方法,比较研究了品种间在颖果生长、胚乳细胞增殖、果皮和胚乳结构等方面的差异,探讨了影响颖果生长的因素。 大粒品种颖果发育时间较小粒品种长,其胚乳细胞数、胚乳干质量及单个胚乳细胞平均干质量均高于小粒品种。在粒重相近的情况下,籼稻颖果发育和淀粉积累快于粳稻。与小粒品种相比,大粒品种子房壁细胞中淀粉粒多,子房壁细胞生长的持续时间长,果皮及背部维管束衰亡迟。 小粒品种胚乳外层细胞在花后7 d已转化成糊粉层细胞,大粒品种胚乳外层细胞要在花后10 d才转化成糊粉层细胞。 大粒品种的库容大和生理活性期长是其颖果能显著增大的生理原因。     

Structural and Histochemical Characterization of Developing Rice Caryopsis

The development of pericarp, seed coat, starchy endosperm and aleurone of the rice caryopsis was investigated, histochemically and structurally, from the time of flowering to maturity. The results showed that during its growth, the maximum length of the caryopsis was attained first, followed by width and then thickness. Histochemical examination of the caryopsis showed that starch was mainly accumulated in the endosperm, but the endosperm showed no metabolic activity, while embryo and pericarp contained a few starch grains, and embryo and aleurone were strongly active. Aleuronic cells contained many aleurone grains and spherosomes, and aleurone in the dorsal region developed earlier and contained more layers of cells. Amyloplasts in endosperm contained many starch granules and were spherical at early stages but polyhedric at late stages. The protein bodies appeared later than amyloplasts, and the number of protein bodies in subaleurone was greater than those in the starchy endosperm. The white-belly portion of endosperm might be relative to the status of amyloplast development.     

Comparison of Grain Quality Characteristics Between F1 Hybrids and Their Parents in Indica Hybrid Rice

Sixteen widespread elite indica parents including seven CMS lines and nine restorer lines, and their 63 F1 hybrids were chosen to compare the eleven traits of grain quality. Overall results showed that the frequency of negative over-dominance, dominance and partial dominance was much higher than that of positive ones and heterosis, indicating that the values of F1 hybrids were generally lower than the means of their parents in quality characteristics. There existed apparent disparity in grain quality performance among F1 hybrids varied with the traits. The characteristics of chalky area percentage, chalky grain percentage, gel consistency and head rice recovery had a great variation in all kinds of tested heterosis indices including the mid-parent heterosis index, over high-value parent heterosis index and over low-value parent heterosis index, which suggested that special attention should be paid to the selection of F1 hybrids in these traits in breeding. The mean values of F1 hybrids were significantly lower than those of their higher parents in all the traits but close to or significantly lower than those of their mid-parent values except for kernel length and amylose content; and significantly higher than those of their lower parents except for brown rice recovery, milled rice recovery and gel consistency.     

中籼水稻品种改良过程中米质和根系特征对灌溉方式的响应

【目的】研究不同灌溉方式下中籼水稻品种的稻米品质与根系特征。【方法】以江苏省近80年来各阶段具有代表性的中籼水稻品种为试验材料,全生育期设置干湿交替灌溉(AWD)和常规灌溉(CI)处理。在矮秆、半矮秆常规稻和半矮秆杂交稻中各选择2个水分利用效率(WUE)存在明显差异的品种进行稻米品质和根系特征分析。【结果】无论是在AWD还是CI下,各类型品种的产量和WUE均随品种改良逐渐提高。与CI相比,AWD显著增加了产量和水分利用效率。在AWD下,各类型品种(矮秆品种、半矮秆品种、半矮秆杂交稻)的产量分别为6.96 t/hm²、8.71 t/hm²和10.14 t/hm²,WUE分别为1.30 kg/m³、1.62 kg/m³和1.91 kg/m³。各类型品种的精米率、整精米率、蛋白质含量、淀粉溶解度与膨胀度、根干质量、根冠比、根系氧化力、根系总吸收表面积和活跃吸收表面积、根系伤流液中玉米素和玉米素核苷以及脱落酸含量随品种改良显著提高。与CI相比,AWD改善了稻米的加工和外观品质及根系形态生理特征,提高了稻米淀粉的峰值黏度、热浆黏度、最终黏度和崩解值,降低了淀粉的消减值和相对结晶度。相关分析表明,产量、WUE及稻米品质均与根系生长密切相关。【结论】现代半矮秆品种尤其杂交稻在全生育期干湿交替灌溉条件下可获得较高的产量和水分利用效率以及较优的稻米品质,这与根系形态和生理特征的改善密切相关。     

优质籼稻桂华占、八桂香花后干物质积累与转运及灌浆的动态特征

 以品质优良、较好、较差的桂华占、八桂香、珍桂矮（CK）3个籼稻品种为材料,研究了优质稻花后干物质积累、运转与籽粒生长的动态特征及相互关系。结果表明,优质籼稻品种花后单株叶片和茎鞘干物质量大,花后叶片干物质的转运率和转运速率较对照高,但茎鞘的花后运转与对照的差异较小。3个水稻品种籽粒干质量的动态均可用Richards方程进行模拟,但优质品种的灌浆启动快、活跃灌浆期长、最大灌浆速率小。花后茎叶干物质的再运转占籽粒干质量的1/5~1/3,其中优质品种花后叶的再运转对籽粒生长的贡献是对照的1.5~2.0倍。相关分析表明,花后叶的干物质运转与籽粒生长的关系密切,因此,单株叶片干质量大、花后运转率高可能是优质水稻品质形成的重要生理原因之一。     

不同海拔高度对稻米品质性状的影响

对10个杂交稻组合在同一生态区5个不同海拔高度12个品质性状的变异特点进行了研究.结果表明,不同品质性状在不同海拔高度的变异存在很大差异,糙米率、精米率、粒长相对稳定,各组合平均变异系数仅为0.75%,0.60%和3.16%;而垩白度、垩白粒率波动较大,各组合平均变异系数高达92.28%和66.54%.通过聚类分析,可根据稻米品质性状在不同海拔高度的变异系数大小划分为3种类型,第1种是对气候条件变化最敏感的生态敏感型,如垩白度、垩白粒率,第2种是对气候条件变化反应迟钝的生态迟钝型,如糙米率、精米率、粒长,第3种是介于二者之间的中间型.随海拔升高,灌浆结实时间延长,整精米率增大,垩白度、垩白粒率变小,说明高海拔有利于改善稻米品质.