Low Light During Grain Filling Stage Deteriorates Rice Cooking Quality,but not Nutritional Value

To investigate the effect of low light (LL, 50% natural light) during grain filling (GF) stage on rice transamination, amino acid (AA) accumulation, nutritional value, and cooking quality in three different rice genotypes, transaminase activities and AA levels in grains during GF stage and the traits that significantly affected rice quality (physical appearance, cooking quality, and nutritional value) were analyzed. LL did not disturb transamination in rice grains during GF stage, as minimal impact was found on alanine and aspartate transaminase activities. Nevertheless, most AAs in caryopses, including lysine and threonine, increased in response to LL, except for sulfur-containing AAs. These results suggest that AA metabolism and accumulation in rice grains were rarely suppressed by LL during GF stage. Rice nutritional ingredients at harvest, such as major protein components including glutelin and most important essential amino acids (EAAs) including lysine and threonine, increased significantly in response to LL, whereas most protein and EAA ratios were rarely affected. However, LL markedly affected physical appearance of rice grains by reducing brown rice rate, milled rice rate, and 1000-grain weight and increasing the chalkiness rate. In addition, cooking qualities decreased in response to LL, while breakdown values and amylose levels decreased and setback values increased. We concluded that LL during GF stage decreased the cooking quality of rice, but could potentially improve the nutritional value of rice.     

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.     

喷施“双酸肥”对水稻作用效果的初步研究

 在田间和盆栽试验中分别于水稻孕穗期、抽穗期和秧苗三叶期用富含核苷酸和氨基酸的双酸肥（DAF）喷施水稻,结果表明：DAF对水稻叶片叶绿素的形成和光合作用、呼吸酶活性和ATP形成、氮素的吸收与同化、DNA和RNA的合成、根系吸收能力、孕穗期茎鞘贮存性碳水化合物的积累及抽穗后向穗部的转移均有明显的促进作用,最终导致水稻产量的增加和谷粒蛋白质含量的提高。     

江淮杂交中籼水稻品质性状基因型与播期互作的AMMI模型分析

为明确杂交中籼水稻在江淮地区种植的适宜播期,提高稻米品质,选用3个杂交中籼水稻品种(系)分5个播期,利用AMMI模型对其营养食味品质性状(糊化温度、胶稠度、直链淀粉含量、蛋白质含量)进行了稳定性和适应性分析。结果表明,糊化温度、胶稠度、直链淀粉含量、蛋白质含量4项指标在基因型间、播期间及基因型×播期互作间的方差均达到极显著水平,这4项指标的交互效应主成分值(IPCA)差异也达到显著水平;穗期(抽穗至成熟期)平均气温较高、累计日照时数长、气温日较差大,有利于杂交中籼水稻品质的提高;3个参试品种(系)营养食味品质稳定性表现为新两优6号两优1128丰两优4号,5个播期对杂交中籼水稻品质影响表现为4月20日5月10日5月20日4月30日5月30日。     

施氮量和灌溉方式的交互作用对东北粳稻稻米品质的影响

【目的】探讨不同灌溉方式和氮肥对水稻品质的影响及其互作效应。【方法】以常规粳稻沈稻47和杂交粳稻粳优586为材料，进行防雨棚盆栽试验，设置浅水层灌溉、浅湿灌溉、轻干湿交替灌溉和重干湿交替灌溉4种灌溉方式及正常施氮(normal nitrogen, NN, 180 kg/hm2)和高氮(high nitrogen, HN, 220 kg/hm2)2种氮肥水平，研究不同肥水处理对稻米品质的影响。【结果】灌溉方式和施氮量对稻米品质有明显的互作效应，在正常施氮和高氮水平下，稻米的加工品质、外观品质、营养品质和蒸煮食味品质均以轻干湿交替灌溉为佳。正常施氮水平下，重干湿交替灌溉下稻米的整精米率、胶稠度、最高黏度和崩解值低于浅水层灌溉，而其垩白度、垩白粒率、直链淀粉含量及消减值却高于浅水层灌溉。高氮水平下，重干湿交替灌溉处理的加工品质、外观品质、营养品质和蒸煮食味品质优于浅水层灌溉，但二者间差异不显著。灌溉方式对氨基酸的影响因施氮量和品种的不同而存在差异。常规施氮水平下，轻干湿交替灌溉显著提高了稻米的总氨基酸含量；高氮水平下，重干湿交替灌溉显著提高了沈稻47的氨基酸总量，而粳优586总氨基酸含量则在轻干湿交替灌溉处理下取得较高值，必需氨基酸和非必需氨基酸含量与总氨基酸含量趋势一致。【结论】轻干湿交替灌溉方式可以改善稻米品质。在本研究条件下，沈稻47和粳优586分别以轻干湿交替灌溉和施氮量为180 kg/hm2和施氮量为220 kg/hm2时，米质较好。     

施氮量和灌溉方式的交互作用对东北粳稻稻米品质的影响

[目的]探讨不同灌溉方式和氮肥对水稻品质的影响及其互作效应。[方法]以常规粳稻沈稻47和杂交粳稻粳优 586 为材料,进行防雨棚盆栽试验,设置浅水层灌溉、浅湿灌溉、轻干湿交替灌溉和重干湿交替灌溉4种灌溉方式及正常施氮(normal nitrogen, NN, 180 kg/hm^2)和高氮(high nitrogen, HN, 220 kg/hm^2)2种氮肥水平,研究不同肥水处理对稻米品质的影响。[结果]灌溉方式和施氮量对稻米品质有明显的互作效应,在正常施氮和高氮水平下,稻米的加工品质、外观品质、营养品质和蒸煮食味品质均以轻干湿交替灌溉为佳。正常施氮水平下,重干湿交替灌溉下稻米的整精米率、胶稠度、最高黏度和崩解值低于浅水层灌溉,而其垩白度、垩白粒率、直链淀粉含量及消减值却高于浅水层灌溉。高氮水平下,重干湿交替灌溉处理的加工品质、外观品质、营养品质和蒸煮食味品质优于浅水层灌溉,但二者间差异不显著。灌溉方式对氨基酸的影响因施氮量和品种的不同而存在差异。常规施氮水平下,轻干湿交替灌溉显著提高了稻米的总氨基酸含量;高氮水平下,重干湿交替灌溉显著提高了沈稻47的氨基酸总量,而粳优586总氨基酸含量则在轻干湿交替灌溉处理下取得较高值,必需氨基酸和非必需氨基酸含量与总氨基酸含量趋势一致。[结论]轻干湿交替灌溉方式可以改善稻米品质。在本研究条件下,沈稻 47和粳优586分别以轻干湿交替灌溉和施氮量为180 kg/hm^2和施氮量为220 kg/hm^2时,米质较好。     

优良食味水稻品种籽粒蛋白质积累特征及其对氮素水平的响应

【目的】探讨优良食味水稻品种的籽粒蛋白质积累特征及其对氮素水平的响应。【方法】以食味值不同的常规粳稻和杂交稻为材料,在结实期设置不同氮素施用水平处理,分析不同类型品种在不同氮素水平下的蒸煮食味品质及其与稻米蛋白质及其组分含量的关系。进一步分析各品种在不同氮素水平下稻穗不同部位的氨基酸含量及籽粒蛋白质含量在结实期的动态变化,总结优良食味水稻品种的籽粒蛋白质积累特征及其对氮素水平的响应特征。【结果】优良食味水稻品种籽粒蛋白质含量较低,且随着氮素水平的增加而上升;优良食味水稻崩解值较高,消减值较低;蒸煮食味品质受氮素水平影响较小。优良食味水稻品种蛋白组分含量较低,且稻米蛋白质含量与食味品质呈显著负相关。在常规粳稻中,稻米食味值与清蛋白、球蛋白和醇溶蛋白含量均显著负相关;在杂交稻中,稻米食味值与醇溶蛋白和谷蛋白含量显著负相关。优良食味水稻品种籽粒充实过程中游离氨基酸含量较低,并呈现较低水平的蛋白质积累。而食味较差品种灌浆期籽粒的氨基酸含量较高,成熟籽粒蛋白质含量也较高,且氮素供应水平提升其籽粒蛋白质含量的效应更为显著。【结论】优良食味水稻品种的籽粒蛋白质含量较低,与其充实过程中蛋白质积累水平较低有紧密关系,且受氮素水平影响较小。     

矿质元素对稻米品质影响研究进展

水稻是世界上重要的粮食作物,稻米品质是水稻遗传特性与生长环境、栽培技术互作的结果,矿质元素对稻米品质的形成具有重要作用。本文综述了不同矿质元素对稻米品质的影响,分别总结了大量元素、中量元素和微量元素对稻米品质的不同影响。受多种因素影响,同一矿质元素对稻米品质影响的研究结果不尽相同;矿质元素对稻米品质的影响存在品种间和不同稻米品质间差异,而且在稻米品质形成过程中,不同矿质元素起的作用及作用程度也不尽相同;矿质元素对稻米品质的影响具有多向性,且不同矿质元素间存在一定的互作关系,施用中很难兼顾到稻米品质的每一个指标。生产中应根据实际情况,因地制宜、适时适量、合理运筹,最大程度提高稻米的整体品质。     

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。     

花后不同时段低温对籼粳杂交稻稻米品质性状的影响

【目的】花后低温是影响米质的首要生态因子。为明确花后低温对甬优品种稻米品质性状及淀粉RVA谱特性的影响,【方法】以籼粳杂交稻甬优17号、甬优538和杂交籼稻中浙优1号、常规粳稻浙粳88为材料,采用盆栽试验,通过人工气候箱于水稻花后0-15d(前期)、15-30d(中期)和30d-成熟(后期)分别进行20℃、17℃和14℃的低温处理。【结果】花后低温显著影响供试品种整精米率、垩白度、胶稠度、直链淀粉含量及蛋白质,使甬优品种淀粉RVA谱特征值峰值黏度、热浆黏度、冷胶黏度、崩解值降低,回复值和消减值升高。花后前期低温对稻米加工品质影响最大,而花后中、后期低温对外观品质、蒸煮食味品质和营养品质影响最大,且甬优17号比甬优538对低温更敏感。花后低温对稻米品质影响明显,低温处理影响因品种类型、品质指标及处理时段而异。【结论】生产中应基于品种特性综合考虑稻米各品质指标,在结实期采取相应的米质调优栽培措施,充分发挥籼粳杂交稻品种的品质潜力。     

盐碱地区水稻食味值及其与品质性状的关系

以辽宁省盐碱地利用研究所提供的65个水稻品系为试材,分析了这些水稻品系食味值的总体表现,及食味值与各品质性状的关系。结果表明,各参试品系品质普遍较好,但品系间各品质性状有一定差异;各参试品系食味值在60.44~84.00之间,品系间差异显著,并接近正态分布;食味值与垩白粒率、垩白度呈极显著正相关,与精米率、直链淀粉含量和蛋白质含量呈极显著负相关,与长宽比呈显著负相关。因此,在品种选育过程中,应选择直链淀粉含量和蛋白质含量相对较低,籽粒长宽比较小的品种,这样可以提高食味值。但是,食味值的提高会增加稻米的垩白粒率和垩白度。     

Effects of Phosphorus on Grain Quality of Upland and Paddy Rice under Different Cultivation

We investigated how upland and paddy japonica rice responded to phosphorous(P) fertilizer under two cultivation methods.The upland rice Zhonghan 3 and the paddy rice Yangfujing 8 were both grown under moist cultivation(MC,control) and bare dry cultivation(DC) with three P levels,low(LP,45 kg/hm2),normal(NP,90 kg/hm2) and high(HP,135 kg/hm2).As P level increased,grain yields of both upland and paddy rice increased under DC.There were no significant differences in grain yields between HP and NP for either rice,although upland rice slightly increased and paddy rice slightly decreased in grain yield.Under DC at LP,Zhonghan 3 showed a higher head milled rice rate and better appearance,cooking and eating qualities than at HP or NP.Yangfujing 8 was similar to Zhonghan 3 except that Yangfujing 8 had better appearance quality at NP.Under MC,Zhonghan 3 had a higher head milled rice rate at LP and better cooking and eating qualities at NP.Yangfujing 8 was similar to Zhonghan 3 except in appearance quality.DC improved head milled rice rate and appearance quality of both upland and paddy rice,and cooking and nutrient qualities of paddy rice.Compared with paddy rice,upland rice had better processing,nutrient and eating qualities.The results suggest that upland and paddy rice respond differently to cultivation method and phosphorus level.     

Differential responses to high temperature during maturation in heat-stress-tolerant cultivars of Japonica rice

High-temperature stress during the grain-filling stage reduces grain quality of rice, and this is a serious problem in Japan, especially in the Kyushu region. To solve this problem, various heat-tolerant cultivars have been bred, such as ‘Nikomaru’, ‘Kumasannochikara’, ‘Genkitsukushi’, ‘Sagabiyori’, and ‘Otentosodachi’. When cultivated under high temperature after flowering, these heat-tolerant cultivars had lower percentages of chalky grains than in the heat-sensitive cultivar ‘Hinohikari’. All the heat-tolerant cultivars markedly decreased the nonstructural carbohydrate content in the stem under the high temperature compared to control condition during early grain-filling stage, which is considered to be a common trait of heat tolerance. Notably, ‘Sagabiyori’, ‘Genkitsukushi’, and ‘Nikomaru’ maintained a nucellar epidermis at 17 days after flowering (DAF) under high temperature, whereas the nucellar epidermis disappeared in ‘Hinohikari’. In addition, the expression of AGPS2b, thought to be a rate-limiting enzyme in starch synthesis, in ‘Kumasannochikara’, ‘Otentosodachi’, and ‘Nikomaru’ did not decrease under high temperature, whereas ‘Hinohikari’, ‘Sagabiyori’, and ‘Genkitsukushi’ could not maintain expression of the gene at 17 DAF. Moreover, the expression of Amy3E, a starch-degradation-related gene considered to induce grain chalkiness, in ‘Kumasannochikara’ at 17 DAF was not increased by high temperature. These results suggest that the heat-stress-tolerant cultivars have various mechanisms for dealing with high-temperature stress.     

播期和地点对不同生态类型粳稻稻米品质性状的影响

 以不同生态类型的5个粳稻品种为材料,在江苏省选择5个不同纬度地点,通过分期播种试验研究稻米品质性状的差异,探讨不同地点和不同播期对稻米加工、外观、蒸煮食味和营养品质的影响。结果表明,13个品质性状在地点、播期及品种间的差异均达到了极显著水平,多数性状品种间变异最大,地点次之,播期影响最小。不同品质性状在不同纬度的变化趋势不同,稻米加工品质随纬度的升高呈改善趋势,粒长、粒宽和长宽比在不同纬度间的变化较小,直链淀粉含量、糊化温度、胶稠度和食味值呈北高南低的趋势,垩白率、垩白度和蛋白质含量则呈现南高北低的趋势,食味品质随纬度的升高有提高趋势。随播期的推迟,加工品质、直链淀粉含量、糊化温度、蛋白质含量均有提高的趋势,粒长和长宽比增加,粒宽减小,胶稠度降低,垩白率和垩白度在不同播期之间存在显著差异,但变幅不大,过早或过迟播种食味值均有降低趋势。不同性状对地点和播期的反应不同,糙米率、粒宽、粒长、长宽比和精米率受影响较小,而垩白率和垩白度受影响较大,整精米率、糊化温度、蛋白质含量、直链淀粉含量、胶稠度和食味值居两者之间。不同品种不同品质性状在地点和播期间的稳定性不同,南粳46的品质性状综合表现最好,但受地点和播期的影响较大。     

浙江省“八五”早籼稻区试品种(系)品质、农艺性状研究

 探讨了浙江省“八五”早籼区试品种品质、农艺性状进展趋势。结果表明,“八五”参试品种较“七五”参试品种品质有极显著提高,而且有着生育期缩短、有效穗数减少、穗型增大趋势,迟熟组尤为明显。分析“八五”参试品种各项品质性状表现,参试品种品质仍不理想,大多数品种整精米率、垩白率、垩白面积、粒型表现欠佳。剖析待改良品质的各效应方差分量发现,除整精米率品种×年份互作效应高于品种效应以外,其余品质性状均以品种效应为主。     

开放式增温对华南双季稻稻米品质的影响

【目的】华南双季稻区是我国优质籼稻的主产区之一,研究气候变暖对华南双季稻稻米品质的影响具有重要意义,【方法】采用稻田开放式主动增温系统对早稻(合丰丝苗,2020年;粤禾丝苗,2021年)和晚稻(粤禾丝苗,2020和2021年)进行全生育期昼夜不间断增温处理,分析增温对早、晚稻加工、外观、营养和食味品质的影响。【结果】与不增温处理相比,增温(早稻,1.5～1.8℃;晚稻1.9～2.0℃)对早、晚稻糙米率均无显著影响。增温条件下,早稻精米率和整精米率均显著降低,而晚稻精米率和整精米率无显著变化。增温对垩白粒率和垩白度的影响在早、晚稻之间呈相反趋势;增温显著提高早稻垩白粒率和垩白度,而降低晚稻垩白粒率。增温条件下,早、晚稻直链淀粉含量均显著降低,而蛋白质含量呈升高趋势。此外,增温提高早、晚稻稻米峰值黏度和米饭黏性,降低其消减值及晚稻糊化温度和米饭硬度。相关分析表明,增温条件下,早、晚稻糊化特性和米饭质构的改变主要与直链淀粉含量的降低有关。【结论】增温导致早稻加工和外观品质变差,而有利于改善其营养和食味品质。增温条件下,晚稻外观、营养和食味品质均有改善。     

我国稻米品质标准及检测技术创新概述

稻米品质是决定其市场价值和商品价值的重要属性.本文简述了我国稻米品质标准的现状;探讨了稻米品质评价包括的五个方面:加工品质、外观品质、蒸煮品质、食味品质及营养品质;介绍了稻米品质检测技术的创新进展.     

双季优质稻产量和品质形成对开放式主动增温的响应

目的 水稻是我国最重要的口粮作物。明确气候变暖对双季优质稻产量和稻米品质的影响对我国粮食安全至关重要。方法 采用稻田开放式远红外主动增温系统,早稻以金早47(常规籼稻)、两优287(杂交籼稻),晚稻以象牙香珍(常规籼稻)、万象优华占(杂交籼稻)和甬优5550(杂交粳稻)为材料,设置全生育期增温和全生育期不增温2个处理,分别测定双季优质稻的产量、产量构成和稻米品质。结果 与不增温相比,全生育期増温(1.3℃ ~1.6℃)对早晚籼稻产量影响不显著,但晚粳稻产量显著下降,降幅为10.2%,主要是因为其每穗粒数下降。全生育期增温降低了早晚稻株高;早稻生育期缩短了3~4 d,而晚稻生育期无明显变化。全生育期增温下,双季优质稻米垩白粒率和垩白度显著增加,早稻两优287出糙率和整精米率及晚粳甬优5550整精米率显著提高;同时,晚稻蛋白质含量提高,但晚粳直链淀粉含量降低,而早稻蛋白质和直链淀粉含量无明显变化;此外,稻米RVA谱特征值因季别和品种而异。结论 全生育期增温对优质晚粳稻产量影响大于籼稻,不利于外观品质的保优,但有利于改善优质稻米加工品质,对晚稻营养品质和食味品质的影响也大于早稻。     

云南粳型特色软米食味品质性状稳定性分析

将5个低直链淀粉含量的软米品种(系)种植在4个不同海拔生态点,利用AMMI模型对食味品质性状(直链淀粉含量、胶稠度、碱消值和蛋白质含量)进行了稳定性分析,并以食味品质性状的表型值、AMMI分析的前两位主成分值及相应的稳定性参数(Di)为指标,对品种(系)食味品质及其稳定性进行评价。结果显示,直链淀粉含量、胶稠度和蛋白质含量3项指标在基因型间、环境间及基因型×环境互作间的方差达到显著或极显著水平,此3项指标的交互效应主成分值(IPCA)差异也显著。综合考虑3项指标的表现,5个软米品种(系)食味品质稳定性依次为银光云粳20号云粳优4号YH6H559。影响食味品质稳定性的主要环境气候因子是海拔和日平均气温。综合考虑供试品种(系)的产量水平、食味品质及其稳定性,银光和云粳20号可作为改良稻米食味品质(特别是降低直链淀粉含量)及其稳定性的亲本。     

结实期土壤水分和氮素营养对水稻产量与品质的交互影响

杂交籼稻汕优63和粳稻武育粳3号种植于土培池,于始穗期进行0N（0 g/m2）、NN（中氮,4.5 g/m2 ）和HN（高氮,9.0 g/m2）3种施氮量处理,于抽穗后7 d至成熟期设置了WW（保持浅水层）、MD（轻度落干,土壤水势保持-25 kPa）和SD（重度落干,土壤水势保持-50 kPa）3种土壤水分处理,研究了结实期土壤水分和氮素营养对水稻产量与品质的交互影响。在各施氮水平下,产量、糙米率、精米率和整精米率均以MD处理最高,垩白粒率和垩白度均以MD处理最低。在0N下,SD处理降低了产量、碾磨品质、外观品质和食味品质;在MN或HN下,SD处理的产量、碾磨品质、外观品质和食味品质与WW的差异不显著或显著优于WW。说明土壤水分和氮素营养对水稻产量和品质的影响存在着明显的互作效应,结实期土壤水势为-25 kPa、粒肥的施氮量为45 kg/hm2,稻米的品质较优、产量最高。