6-苄氨基嘌呤对水稻灌浆成熟期籽粒氮代谢及蒸煮食味品质的影响

选用两个品质不同的粳稻品种,研究在抽穗期喷洒6 苄氨基嘌呤（6 BA）对灌浆成熟期籽粒氮代谢及蒸煮食味品质的影响。 抽穗后随灌浆进程籽粒谷氨酰胺合成酶活性逐渐增加,达到峰值后又逐渐下降,呈单峰曲线变化,且抽穗后20 d 的酶活性最高;蛋白质含量高的品种灌浆前期籽粒谷氨酰胺合成酶活性高于蛋白质含量低的品种;与未喷6 BA对照相比,抽穗期喷洒6 BA供试品种的味度值、最高黏度、崩解值、可溶性蛋白含量等均有不同程度的提高,籽粒谷氨酰胺合成酶活性和消减值降低,但蛋白质和直链淀粉含量变化很小。     

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。     

稻米食味品质对结实期温度的响应研究进展

综述了稻米食味品质对结实期温度的响应特征及稻米食味品质与直链淀粉、支链淀粉和蛋白质含量的关系,并从籽粒灌浆过程中淀粉与蛋白质合成代谢角度阐明了水稻食味品质对结实期温度响应的生理基础,最后展望了结实期温度胁迫对稻米食味品质影响的研究方向。     

Relationship Between Variation in Activities of Key Enzymes Related to Starch Synthesis During Grain Filling Period and Quality of Eating and Cooking in Rice

Eating or cooking quality is one of the important quality of rice. Amylose content, RVA properties and taste meter value are three important indexes for evaluating cooking and eating quality of rice, which are determined by the chemical and physical com- …     

High Temperature at Grain-filling Stage Affects Nitrogen Metabolism Enzyme Activities in Grains and Grain Nutritional Quality in Rice

Rice plants would more frequently suffer from high temperature (HT) stress at the grain-filling stage in future. A japonica rice variety Koshihikari and an indica rice variety IR72 were used to study the effect of high temperature on dynamic changes of glutamine synthetase (GS) activity, glutamate synthase (GOGAT) activity, glutamic oxalo-acetic transminase (GOT) activity, glutamate pyruvate transminase (GPT) activity in grains and grain nutritional quality at the grain-filling stage. Under HT, the activiti...     

Effects of Low Light on Agronomic and Physiological Characteristics of Rice Including Grain Yield and Quality

Light intensity is one of the most important environmental factors that determine the basic characteristics of rice development. However, continuously cloudy weather or rainfall, especially during the grain-filling stage, induces a significant loss in yield and results in poor grain quality. Stress caused by low light often creates severe meteorological disasters in some rice-growing regions worldwide. This review was based on our previous research and related research regarding the effects of low light on rice growth, yield and quality as well as the formation of grain, and mainly reviewed the physiological metabolism of rice plants, including characteristics of photosynthesis, activities of antioxidant enzymes in rice leaves and key enzymes involved in starch synthesis in grains, as well as the translocations of carbohydrate and nitrogen. These characteristics include various grain yield and rice quality components （milling and appearance as well as cooking, eating and nutritional qualities） under different rates of shading imposed at the vegetative or reproductive stages of rice plants. Furthermore, we discussed why grain yield and quality are reduced under the low light environment. Next, we summarized the need for future research that emphasizes methods can effectively improve rice grain yield and quality under low light stress. These research findings can provide a beneficial reference for rice cultivation management and breeding program in low light environments.     

水稻灌浆过程中籽粒淀粉合成关键酶活性与蒸煮食味品质

选用稻米蒸煮食味品质有显著差异的4个粳稻品种,对水稻籽粒灌浆过程中淀粉合成关键酶的活性变化及其与蒸煮食味品质关系进行了研究。 不同品质类型的品种间籽粒直链淀粉和支链淀粉含量在灌浆前、中后期表现出差异,这种差异主要表现在灌浆不同时期淀粉积累速率上。籽粒灌浆过程中,不同品质类型的品种中ADPG焦磷酸化酶和可溶性淀粉合成酶活性出现峰值的时间无差异,但淀粉分支酶活性出现峰值的时间,劣质品种明显早于优质品种,而且优质品种灌浆中、后期仍然保持较高水平的酶活性。ADPG焦磷酸化酶、可溶性淀粉合成酶、淀粉分支酶的活性与直链淀粉含量、支链淀粉含量、味度值、RVA谱特性间的相关性和程度因灌浆时期不同而发生变化。在整个灌浆过程中,可溶性淀粉合成酶活性与味度值间的相关均不显著,但灌浆前期和中、后期的ADPG焦磷酸化酶和淀粉分支酶的活性与味度值间呈显著或极显著相关。选择灌浆前期酶活性低或灌浆后期酶活性高的材料,将有利于提高稻米蒸煮食味品质。     

Effect of Temperature at Grain Filling Stage on Activities of Key Enzymes Related to Starch Synthesis and Grain Quality of Rice

Three japonica rice varieties with different cooking and eating quality were grown at high temperature in the greenhouse and natural field. Effects of temperature at the grain filling stage on these varieties were investigated in terms of the activities of key enzymes related to starch synthesis and cooking and eating quality of rice grain. The high temperature at the grain filling stage increased protein content, and decreased amylose content and taste meter value of rice; inferior grain quality varieties showed a greater magnitude of the increase or decrease than the superior ones. Reaction of rapid visco analyser profiles to the temperature varied with rice varieties. The activities of adenosine diphosphoglucose pyrophosphoryiase （AGPP）, soluble starch synthase （SSS） and starch branching enzyme （SBE） gradually increased to a peak value, and thereafter declined as grain filling progressed. Enzyme activities in different varieties differed in a same filling stage, and also in the time when the enzyme activity reached a maximum. AGPP and SSS were insensitive to the environmental temperature, but SBE was comparatively sensitive to the temperature, and its activity declined when temperature was too high or too low.     

不同施氮水平下水稻穗上不同部位籽粒的蒸煮与营养品质变化

以中熟籼稻扬稻6号和中熟粳稻武育粳3号为材料,研究了不同施肥水平下稻米蒸煮及营养品质在穗上不同粒位籽粒间的差异及其分布特点。 总体而言,穗下部一、二次枝梗籽粒的胶稠度较低,直链淀粉含量较高;穗中、上部一、二次枝梗的胶稠度较高,直链淀粉含量较低。在同一个枝梗上,二次枝梗上早开花的第1粒的胶稠度最高,穗子中、上部一次枝梗迟开花的第2粒的直链淀粉含量较高。扬稻6号穗中部一次枝梗籽粒的粗蛋白含量较低,穗上、下部枝梗上籽粒的粗蛋白含量较高;而武育粳3号一次枝梗和二次枝梗籽粒的粗蛋白含量在穗上、中、下三部位间无明显差异。从不施氮到少量施氮（120 kg/hm2）,稻米的胶稠度和粗蛋白含量增加,直链淀粉含量降低。但从少量施氮（120 kg/hm2）到中等施氮（240 kg/hm2）,稻米的胶稠度降低,直链淀粉和粗蛋白含量有不同程度增加。     

灌浆结实期弱光对水稻产量、生理及品质的影响

试验研究了灌浆结实期水稻群体光照强度的变化规律以及弱光对生物产量与物质分配和群体光合速率及生理变化的影响。结果表明,群体内的相对光照变化相对环境光照出现滞后性。在抽穗后水稻群体光照的垂直分布中群体中上部差异较大,群体下部差异较小。水稻在抽穗后光照强度降至对照的80％时,单株产量、生物产量、粒重、结实率和成熟后的谷草比都没有显著的变化;但当光照强度降至对照崎的60％时,则上述指标显著降低;当光照强度降至对照的20％时,植株几乎停止了生长。随着光照的减少,干物质在茎叶和穗中的积累量都有所下降,会出现负积累量,而干物质在叶和茎鞘中的分配比率增加,在穗中的比率减少：除对粒型外,弱光照对其他品质指标造成显著影响,其中垩白指标受影响最为显著：气孔导度和蒸腾速率也随着光照的减弱而减小。     

不同类型水稻品种稻米蛋白质含量与蒸煮食味品质的关系及后期氮肥的效应

目的 为揭示不同类型水稻品种稻米蛋白质含量与其蒸煮食味品质间的关系及其对不同后期施氮水平的响应。方法 以3个常规籼稻品种和3个常规粳稻品种为供试材料,在抽穗期实施不同氮肥水平的处理,分析稻米蛋白质及其组分含量与蒸煮食味品质的关系。结果 不论籼粳亚种,后期氮素肥料均显著增加了稻米蛋白质含量,品种对氮素的反应存在明显不同,但肥料处理效应大于品种间差异。随着后期氮肥水平的提高,稻米中四种蛋白组分含量也显著增加,以醇溶蛋白和谷蛋白对氮肥的施用反应较大;直链淀粉含量有所下降,胶稠度显著变短;淀粉糊化特征值中最高黏度、热浆黏度、崩解值和最终黏度下降,而回复值、消减值呈上升趋势;食味值显著下降。相关分析显示,籼﹑粳稻总蛋白质含量与胶稠度呈极显著负相关;籼稻蛋白质含量与食味值(r=-0.975^**)﹑最高黏度呈极显著负相关,与崩解值呈负相关,与回复值﹑消减值呈正相关或显著正相关;粳稻蛋白质含量与食味值(r=-0.923^**)和崩解值呈极显著负相关,与最高黏度呈显著负相关,与回复值﹑消减值的关系和籼稻基本相同。籼、粳稻食味值均与球蛋白、醇溶蛋白和谷蛋白显著负相关,与清蛋白(即比例最小的组分)的关系,籼稻呈极显著负相关,而粳稻相关性未达显著。结论 后期氮肥水平的增加显著提高稻米蛋白质及其组分含量。稻米蛋白质含量的增加,显著劣化稻米蒸煮品质和适口性。四种蛋白组分的增加均会不同程度地劣化稻米食味,其中,尤以球蛋白和醇溶蛋白的负效应较为显著,谷蛋白对食味的负效应也不可忽视,在籼稻品种中表现更明显。     

Effects of Chalkiness on Cooking,Eating and Nutritional Qualities of Rice in Two indica Varieties

An experiment was conducted to investigate the effects of chalkiness on cooking, eating and nutrition qualities of rice using Gangyou 527 (indica hybrid rice) and Zhaiyeqing 8 (conventional indica rice) as materials. Compared with the milled rice without chalkiness, amylose content, final viscosity, setback and consistence increased significantly, while gel consistence, peak viscosity and breakdown decreased remarkably and other RVA values did not have significant changes in the chalky rice of Gangyou 527. The differences in the above indices between the chalky and non-chalky rice was not remarkable in Zhaiyeqing 8. The crude protein content of chalky rice in Zhaiyeqing 8 was significantly lower than that of non-chalky rice, but there was no remarkable change between the chalky and non-chalky rice in Gangyou 527. Glutelin content fell significantly, and albumin, globulin, prolamine and lysine contents did not change significantly in chalky rice compared with non-chalky rice in the two varieties.     

不同类型水稻品种稻米蛋白质含量与蒸煮食味品质的关系及后期氮肥的效应

【目的】为揭示不同类型水稻品种稻米蛋白质含量与其蒸煮食味品质间的关系及其对不同后期施氮水平的响应。【方法】以3个常规籼稻品种和3个常规粳稻品种为供试材料，在抽穗期实施不同氮肥水平的处理，分 析稻米蛋白质及其组分含量与蒸煮食味品质的关系。【结果】不论籼粳亚种，后期氮素肥料均显著增加了稻米蛋白质含量，品种对氮素的反应存在明显不同，但肥料处理效应大于品种间差异。随着后期氮肥水平的提高，稻米中四种蛋白组分含量也显著增加，以醇溶蛋白和谷蛋白对氮肥的施用反应较大；直链淀粉含量有所下降，胶稠度显著变短；淀粉糊化特征值中最高黏度、热浆黏度、崩解值和最终黏度下降，而回复值、消减值呈上升趋势；食味值显著下降。相关分析显示，籼﹑粳稻总蛋白质含量与胶稠度呈极显著负相关；籼稻蛋白质含量与食味值(r=?0.975**)﹑最高黏度呈极显著负相关，与崩解值呈负相关，与回复值﹑消减值呈正相关或显著正相关；粳稻蛋白质含量与食味值(r=?0.923**)和崩解值呈极显著负相关，与最高黏度呈显著负相关，与回复值﹑消减值的关系和籼稻基本相同。籼、粳稻食味值均与球蛋白、醇溶蛋白和谷蛋白显著负相关，与清蛋白(即比例最小的组分)的关系，籼稻呈极显著负相关，而粳稻相关性未达显著。【结论】后期氮肥水平的增加显著提高稻米蛋白质及其组分含量。稻米蛋白质含量的增加，显著劣化稻米蒸煮品质和适口性。四种蛋白组分的增加均会不同程度地劣化稻米食味，其中，尤以球蛋白和醇溶蛋白的负效应较为显著，谷蛋白对食味的负效应也不可忽视，在籼稻品种中表现更明显。     

灌浆成熟期温度对水稻籽粒淀粉合成关键酶活性及品质的影响

 选用蒸煮食味品质不同的3个粳稻品种，利用温室高温和自然常温，研究了灌浆成熟期温度对水稻籽粒淀粉合成关键酶活性及蒸煮食味品质的影响。结果表明，灌浆成熟期高温条件下，水稻籽粒蛋白质含量提高，直链淀粉含量和味度值降低，劣质品种提高或降低的程度大于优质品种；RVA谱特性对灌浆成熟期温度的反应因品种和特性而异；灌浆过程中，籽粒ADPG焦磷酸化酶、可溶性淀粉合成酶和淀粉分支酶活性随灌浆进程，酶活性逐渐增加，达到峰值以后，酶活性又逐渐下降，呈单峰曲线，但不同品种酶活性达到峰值的时间和同一时期的酶活性大小有差异；ADPG焦磷酸化酶和可溶性淀粉合成酶的活性表现对温度的影响反应较为迟钝，而淀粉分支酶活性表现对温度变化的反应较为敏感，温度过高过低都降低该酶活性。     

水稻灌浆成熟期籽粒谷氨酰胺合成酶活性变化及其与稻米品质关系的初步研究

 选用稻米蒸煮食味品质有显著差异的4个粳稻品种，通过盆栽试验对水稻灌浆成熟期籽粒谷氨酰胺合成酶活性变化及其与稻米蒸煮食味品质关系进行了初步研究。结果表明，水稻灌浆过程中籽粒谷氨酰胺合成酶活性随灌浆进程逐渐增加，达到峰值后又逐渐下降，呈单峰曲线变化；抽穗15 d以前蛋白质含量高的品种谷氨酰胺合成酶活性大于蛋白质含量低的品种，而以后与之相反；灌浆前期，籽粒谷氨酰胺合成酶活性与味度值、最高黏度、崩解值间呈负相关，灌浆中、后期呈正相关，而与籽粒最终蛋白质含量和黏滞峰消减值在灌浆前期呈正相关，灌浆中、后期呈负相关，而且相关程度随灌浆时段而发生变化；抽穗后15~20 d是籽粒谷氨酰胺合成酶活性与味度值、RVA谱特性间的相关性质发生变化的转折时期。     

Changes in Activities of Glutamine Synthetase during Grain Filling and Their Relation to Rice Quality

Four japonica rice varieties differed in cooking and eating qualities were used in a pot experiment to study the relationship between the activities of glutamine synthetase during grain filling and rice quality. The activities of glutamine synthetase gradually increased and then declined as a single peak curve in the course of grain filling. The 15th day after heading was a turning point, before which the enzymatic activities in the inferior rice varieties with high protein content were higher than those in the superior rice varietie with low protein content, and after which it was converse. The activity of glutamine synthetase in grain was correlated with the taste meter value, peak viscosity and breakdown negatively at the early stage of grain filling whereas positively at the middle and late stages. Moreover, it was correlated with the protein content of rice grain and setback positively at the early stage and negatively at the middle and late stages. The correlation degree varied with the course of grain filling. From 15 days to 20 days after heading was a critical stage, in which the direction of correlation between the activity of glutamine synthetase and taste meter value and RVA properties of rice changed.     

结实期干湿交替处理对稻米品质的影响及其生理机制

 以扬稻6号和武育粳3号为材料,研究了结实期干 湿交替处理对稻米品质的影响及其机理。结果表明,结实期轻度干 湿交替处理改善了稻米的加工品质和外观品质,提高了米粉的崩解值,降低了消减值,而重度干 湿交替处理结果则相反。轻度干 湿交替处理还提高了籽粒中蔗糖合酶(SuSase)、ADP葡萄糖焦磷酸化酶(ADPGase)、可溶性淀粉合酶(SSSase)和淀粉分支酶(Q酶)的活性。重度干 湿交替处理则降低上述酶类的活性。上述酶类活性与稻米主要品质指标显著相关。根系伤流中1 氨基环丙烷 1 羧酸（ACC,乙烯合成前体）浓度、籽粒中ACC浓度和乙烯释放速率在轻度干 湿交替处理条件下均明显降低,而在重度干 湿交替处理条件下则明显提高。根系伤流中ACC浓度、籽粒中ACC浓度和乙烯释放速率与SuSase、ADPGase、SSSase和Q酶活性呈显著或极显著负相关。灌浆结实期土壤水分处理改变了根系ACC浓度,影响了籽粒乙烯释放速率和ACC浓度,进而影响籽粒蔗糖 淀粉代谢途径关键酶的活性,最终影响了稻米品质的形成。     

灌浆结实期不同时段温度对水稻结实与稻米品质的影响

利用人工气候箱在水稻灌浆结实期不同时段进行温度试验,研究温度对水稻结实与稻米品质的影响。结果表明,灌浆结实期40℃高温处理后籽粒结实率显著降低,粒重下降,外观品质和食味品质变差。不同水稻品种对灌浆结实期温度的响应表现不一致。在试验条件下,华粳1号开花受精的敏感温度为35℃,而特优559开花、灌浆结实的最适温度为30℃,该温度处理结实率、粒重较高,外观品质以及食味品质较优。此外,灌浆结实期不同时段的高温对水稻结实与稻米品质的影响也存在显著差异：结实率对高温最敏感的时期是开花后1~5 d,粒重对高温最敏感的时期是开花后11~20 d;而温度对稻米品质影响最大的时期主要在花后16~20 d,25 d后温度处理影响较小。因此,灌浆前期适宜的温度条件对水稻优质栽培意义重大。