Protein utilization of pigmented and nonpigmented brown and milled rices by rats

The protein of pigmented brown rices had similar lysine content as that of nonpigmented brown rices, but it was less digestible in rats. Because of higher biological value, only the purple rice, but not red rice, had lower net protein utilization than two nonpigmented rices. Milling, which removed bran-polish and reduced pigment and phenolic content, improved the digestibility of the pigmented rices.     

Comparative Protein Digestibility in Growing Rats of Cooked Rice and Protein Properties of Indica and Japonica Milled Rices

College,Laguna, Philippines.Received 1 ABSTRACT Eight indica and japonica milled rices with low amylose content and low starch gelatinisation temperature were analysed for cooked rice energy and N balance in growing rats and for protein properties. Digestible energy values were similar. Japonica rices Koshihikari and Sasanishiki had higher true digestibility (TD) and net protein utilisation in rats than indica rices IR24 and PR23383-15. Similar results were obtained from in vitro proteolysis. High TD of cooked rices was not significantly correlated with low prolamin content in raw rice and with low waxy gene product (protein bound to starch granule) but was significantly correlated with low cysteine content in protein and with low denatured prolamin content in cooked rice. In two pairs of cooked waxy milled rices, which are devoid of waxy gene product, japonica rice still tended to show higher rat TD and in vitro protein digestibility than indica rice, consistent with lower cysteine content in japonica protein.     

Variability in contents of thiamine and riboflavin in brown rice,crude oil in brown rice and bran-polish,and silicon in hull of IR rices

Among 30 IR varieties, variety had greater effect on thiamine content of brown rice than season. Both season and variety affected riboflavin content. Purple- and red-pericarped Philippines rices had higher riboflavin and crude protein contents than IR rices. Crude oil contents of brown rice and bran-polish of 19 IR rices were significantly affected by variety, but only brown rice oil content was significantly affected by season. Bran-polish of waxy rice IR29 had the highest oil content. Silicon content of hull of 16 IR rices showed significant variation due to variety and season and tended to be higher in the dry season crop. Variety rankings in nutrient composition were not consistent for the two crops. The levels of nutrients of IR rices were within the range of values reported for other rices.     

Effect of salinity on yield and 2-acetyl-1-pyrroline content in the grains of three fragrant rice cultivars (Oryza sativa L.) in Camargue (France)

Aromatic quality of rice grains is known to vary greatly with environmental factors and cultivation methods. Among the environmental factors, soil salinity is thought to have a positive impact on the content of 2-acetyl-1-pyrroline (2AP) in grains, the key volatile compound of rice aroma. This study compared 2AP content in grains of three improved fragrant rice (Oryza sativa L.) varieties grown in two fields, differing mainly in their soil salinity level. The impact of salinity on yield and main yield components was also investigated to understand the relationship between aromatic quality and yield build-up. Soil salinity was monitored by measuring the electrical conductivity (EC) of soil solution samples extracted every week. 2AP content in grains was determined by a newly developed stable isotope dilution method involving solid-phase microextraction (SPME) and GC MS/MS analysis. The results showed an increase of 2AP content in grains with salinity for the three varieties. The relationship between 2AP and mean EC of the crop fitted a single model for the three varieties (R² = 0.728). In contrast, the impact of salinity on yield and yield components differed greatly between the three varieties. One variety appeared to be very sensitive to salt stress, with significant yield loss up to 40%, while the two other varieties proved to be resistant to the salinity levels experienced by the plants, with no significant yield loss or even higher yields in saline conditions. Nevertheless, the three varieties presented a significant negative correlation between 1000 grain weight (TGW) and the mean EC of the crop, and between TGW and 2AP content. It was concluded that the increase of 2AP content with salinity resulted partially from a 2AP concentration mechanism in smaller size grains. The direct effect of salinity on 2AP synthesis through stimulation of the proline metabolism is further discussed.     

盐逆境对水稻产量、光合特性及品质的影响

【目的】江苏沿海滩涂种植水稻是促进盐土脱盐改良和开发利用滩涂的主要技术之一,研究盐逆境对水稻产量、光合特性和稻米品质的影响,可为发展滩涂种稻提供参考和理论依据。【方法】以耐盐性较好的通粳981、盐稻12、盐稻10号和南粳5055等4个粳稻品种为材料,设置非盐逆境(S₀, 电导率0.207 dS/m)和逆境(S₁,电导率1.112 dS/m)2个处理,分别测定产量及其构成因素、光合参数、稻米品质和淀粉黏滞特性。【结果】与非盐逆境相比,盐逆境下水稻产量显著下降,仅为非逆境的40.5%,单位面积穗数差异不显著,每穗粒数和千粒重显著减少;光合速率、胞间CO₂浓度显著下降,而气孔导度和蒸腾速率差异不显著;稻米加工品质显著下降,外观品质变化不大,直链淀粉含量显著下降,蛋白质含量显著增加;峰值黏度、热浆黏度、最终黏度、崩解值和回复值均未发生显著的变化,消减值和起始糊化温度显著增高。【结论】盐逆境对水稻产量、光合参数、稻米品质等均有不利的影响,可在盐逆境对产量、品质影响的关键时期孕穗期和灌浆结实期采取措施缓解盐逆境的危害。     

盐逆境对水稻产量、光合特性及品质的影响

【目的】江苏沿海滩涂种植水稻是促进盐土脱盐改良和开发利用滩涂的主要技术之一,研究盐逆境对水稻产量、光合特性和稻米品质的影响,可为发展滩涂种稻提供参考和理论依据。【方法】以耐盐性较好的通粳981、盐稻12、盐稻10号和南粳5055等4个粳稻品种为材料,设置非盐逆境(S0,电导率0.207 d S/m)和逆境(S1,电导率1.112 d S/m)2个处理,分别测定产量及其构成因素、光合参数、稻米品质和淀粉黏滞特性。【结果】与非盐逆境相比,盐逆境下水稻产量显著下降,仅为非逆境的40.5%,单位面积穗数差异不显著,每穗粒数和千粒重显著减少;光合速率、胞间CO2浓度显著下降,而气孔导度和蒸腾速率差异不显著;稻米加工品质显著下降,外观品质变化不大,直链淀粉含量显著下降,蛋白质含量显著增加;峰值黏度、热浆黏度、最终黏度、崩解值和回复值均未发生显著的变化,消减值和起始糊化温度显著增高。【结论】盐逆境对水稻产量、光合参数、稻米品质等均有不利的影响,可在盐逆境对产量、品质影响的关键时期孕穗期和灌浆结实期采取措施缓解盐逆境的危害。     

Effects of Soil Salinity and Alkalinity on Grain Quality of Tolerant,Semi-Tolerant and Sensitive Rice Genotypes

Soil salinity and alkalinity adversely affects the productivity and grain quality of rice.The grain quality of 19 rice genotypes characterized as salt tolerant (T),semi-tolerant (ST) and sensitive (S) was assessed in lysimeters containing saline and highly alkaline soils.Head rice recovery was reduced by salinity stress whereas it was not affected by alkalinity stress.The ratio of length to width (grain dimensions) was significantly reduced in the T genotype even at low electrical conductivity (EC,4 mS/cm) and alkalinity (pH 9.5),whereas in the ST genotype,it was significantly reduced at high salinity (EC 8 mS/cm).There was no significant effect of any levels of salinity or alkalinity on grain dimensions in the S genotype.Amylose content was significantly reduced in T and ST groups even at low EC (4 mS/cm) and alkalinity (pH 9.5) and the effect in the S genotype was only at high salinity.Starch content showed significant reduction at high salinity and alkalinity (EC 8 mS/cm and pH 9.8) in the T and ST genotypes and no significant effect was observed in the S genotype.The effect of both levels of salinity (EC 4 and 8 mS/cm) and high alkalinity (pH 9.8) on gel consistency was observed only in the S genotype.The tolerant genotypes IR36 under high salinity,and CSR10 and CSR11 under alkali stress showed less reduction in amylose content.The T genotype BR4-10,and ST genotypes CSR30,CSR29 and CSR13 showed better gel consistency under saline and alkali stress.Amylose content was affected even at low salinity stress and thus important to be considered in breeding rice for salt tolerance.Overall,the grain quality of T and ST genotypes was less affected by saline and alkali stress compared to S ones.     

不同直链淀粉含量软米品种品质性状的比较

【目的】具有较低直链淀粉含量（5%～12%）的优良食味软米在国内市场上广受消费者欢迎,然而不同软米品种间稻米品质表现差异较大,造成这种差异的原因尚未明确。因此,有必要深入研究不同类型软米理化品质的差异及其成因。【方法】选取了江苏地区具有显著品质差异的4个软米品种、2个糯稻品种和2个常规品种（均为粳稻品种）为对象,对其稻米理化品质和淀粉结构进行了系统的比较分析。【结果】测序结果表明,软米品种南粳5055和南粳9108携带Wxmp等位基因,而软米品种香软玉和武香粳113携带跟2个常规粳稻品种相同的Wxb等位基因。品质分析表明,香软玉和武香粳113稻米较另两个软米品种中的直链淀粉含量更低,籽粒胚乳透明度更差;4个软米类稻米胚乳淀粉粒内部存在明显的孔隙,并且稻米胚乳越不透明,孔隙越明显;较低直链淀粉含量的软米食味表现更佳,这可能与低直链淀粉含量稻米具有更低的冷胶黏度、较大的崩解值和较小的消减值有关。淀粉精细结构测定表明,与常规粳稻米相比,软米的直链淀粉组分占比较低,而支链淀粉短链组分占比较高。【结论】目前江苏地区软米品种间存在显著的遗传和理化品质特性的差异,这为新型软米品种的培育和优异基因的克...     

Natural Biodiversity for Salinity and Alkalinity Tolerance in Scented Rice Cultivar Kalanamak

Abstract

Soil salinity and alkalinity are a widespread problem in a number of rice (Oryza sativa L.) growing countries, particularly in South Asia. Kalanamak is one of the finest quality traditional scented rices of India. Tolerance of 40 lines of Kalanamak was evaluated at pH 4.5, 7.0 and 8.9, under in vitro conditions, both in the absence and presence of 70 mM NaCl and also in Usar soil in the field at a different pH. Different lines exhibited wide variability in their sensitivity to pH and/or salt, both under in vitro and in vivo conditions. In vitro, adverse effect of salt was more pronounced at high pH (8.9). Most of the lines that showed salt tolerance relative to root and/or shoot growth at high pH under in vitro conditions, e.g., 3119, 3120, 3120-1, 3126, 3128, 3130, 3131, 3216, 3216-1, 3222, 3256, 3278 and 3319 performed well in Usar soil in the field even at pH 9-9.5. Two high quality, panicle blast-resistant and relatively salt-tolerant lines (3119 and 3131) yielded equally well or better than coarse grain cultivar Narendra Usar-2 recommended for the cultivation on Usar soil. In a multilocation field trial, Kalanamak 3119 yielded well on alkaline, coastal saline and inland saline soils. This line holds great potential for cultivation on Usar soil.     

不同属性特征基质对早稻秧苗耐低温的影响

[目的]早稻育秧过程中易遭受低温冷害,引起水稻减产.因此,有必要研究不同类型的基质对早稻秧苗耐低温的影响.[方法]以水稻田自然表层土为对照,采用两种代表性基质(无土基质和发酵基质)培育早稻秧苗,在水稻出芽6 d后进行不同低温处理,3 d后测定水稻的基本理化性质指标和基因表达,明确不同基质对早稻秧苗耐低温胁迫的调节作用....     

不同产地香米微量元素含量差异及吸收富集特征研究

对特种水稻“江永香稻”的根、茎、米与土壤中的 11种微量元素含量进行了分析。结果表明 ,江永香稻茎、根对 Mn,As,Zn等元素富集能力特别强 ,对 Pb元素富集能力次之 ;江永香米对 Zn,Mn等元素吸收能力强 ,因此香米的 Zn,Mn含量均比普通稻米的高     

Effects of Different Nitrogen Fertilizer Levels and Native Soil Properties on Rice Grain Fe, Zn and Protein Contents

Deposition of protein and metal ions (Fe, Zn) in rice grains is a complex polygenic trait showing considerable environmental effect. To analyze the effect of nitrogen application levels and native soil properties on rice grain protein, iron (Fe) and zinc (Zn) contents, 32 rice genotypes were grown at three different locations each under 80 and 120 kg/hm2 nitrogen fertilizer applications. In treatments with nitrogen fertilizer application, the brown rice grain protein content (GPC) increased significantly (1.1% to 7.0%) under higher nitrogen fertilizer application (120 kg/hm2) whereas grain Fe/Zn contents showed non-significant effect of nitrogen application level, thus suggesting that the rate of uptake and translocation of macro-elements does not influence the uptake and translocation of micro-elements. The pH, organic matter content and inherent Fe/Zn levels of native soil showed significant effects on grain Fe and Zn contents of all the rice genotypes. Grain Zn content of almost all the tested rice genotypes was found to increase at Location III having loamy soil texture, neutral pH value (pH 6.83) and higher organic matter content than the other two locations (Locations I and II), indicating significant influence of native soil properties on brown rice grain Zn content while grain Fe content showed significant genotype × environment interaction effect. Genotypic difference was found to be the most significant factor to affect grain Fe/Zn contents in all the tested rice genotypes, indicating that although native soil properties influence phyto-availability of micronutrients and consequently influencing absorption, translocation and grain deposition of Fe/Zn ions, yet genetic makeup of a plant determines its response to varied soil conditions and other external factors. Two indica rice genotypes R-RF-31 (27.62 μg/g grain Zn content and 7.80% GPC) and R1033-968-2-1 (30.05 μg/g grain Zn content and 8.47% GPC) were identified as high grain Zn and moderate GPC rice genotypes. These results indicate that soil property and organic matter content increase the availability of Fe and Zn in rhizosphere, which in turn enhances the uptake, translocation and redistribution of Fe/Zn into rice grains.     

香米品质与微量元素含量特征关系的研究

采用“江永香稻”与、香稻80－66”两个香稻品种，在香稻产地与非产地同时进行大田试验，对其稻米、灌溉水与土壤中的11种微量元素含量与稻米品质各项指标进行了分析。结果表明：不同产地同一品种稻米品质与不同品种稻米品质存在明显差异；江永香米的Zn,Mn,Cr含量均比普通稻米及香稻80－66的含量高，香稻80－66香米中Zn含量也较普通稻米高。香米产地香米香味长期不退化，可能与灌溉水中Zn元素含量较高有关。     

稻蟹共作模式生态效应研究进展

主要从土壤、水环境和杂草防控三个方面,对目前我国稻蟹共作模式下田间生态的研究现状进行了总结与分析.提出了几种目前比较常见的稻蟹共作模式,即有机稻蟹和常规稻蟹两种普遍模式.分析了稻蟹共作对土壤理化性质、土壤酶活性和根际微生物区系的影响.养蟹稻田可以显著降低土壤容重,而总孔隙度及全氮、全磷、碱解氮、有效磷、速效钾和土壤有机质含量都显著增加;显著提高0~10 cm土壤脲酶、蛋白酶、脱氢酶以及过氧化氢酶的活性;土壤根际微生物以细菌为主要菌群,氨化细菌、反硝化细菌、嫌气性纤维素分解菌、好气性自生固氮菌、亚硝酸细菌数量显著高于单作水稻;与常规稻蟹相比,有机稻蟹的土壤性状表现更好.稻蟹模式下浮游动植物的多样性和生物量显著低于单作水稻,而水体中溶解氧(DO)明显偏低,硝酸盐、磷酸盐含量显著高于不养蟹稻田.稻田养蟹能够显著抑制稻田4种优势杂草的密度,对于稻田杂草的防控效果明显.     

A study of biodiversity of flavonoid content in the rice caryopsis evidencing simultaneous accumulation of anthocyanins and proanthocyanidins in a black-grained genotype

Rice genotypes with pigmented caryopses have received increased attention because of their antioxidant properties. Previous works evidenced that the kernel of red rice is characterized by the presence of proanthocyanidins, whereas black rice is characterized by the presence of anthocyanins. In the present study, the total antioxidant capacity (TAC) and the polyphenol content of the caryopsis were evaluated on a set of Italian rice varieties (three white, two black and five red ones). The pigmented rices, on average, had a TAC four times higher than the white ones. As expected, red-grained genotypes contained no detectable anthocyanins and one black rice contained no detectable proanthocyanidins. However, the black-grained cv. Artemide had large amounts of both proanthocyanidins and anthocyanins. This genotype was also characterized by the highest TAC and polyphenol content: its TAC was about twice the TAC of the other pigmented rices, and it had a polyphenol content 2–3 times the content found in the other pigmented rices. Pigmented genotypes are confirmed to be very interesting to breed rice for high polyphenol content and TAC. Furthermore, the possibility to select for genotypes accumulating both anthocyanins and proanthocyanidins provides a way to substantially increase the polyphenol content and TAC of the rice caryopsis.     

水稻种植对陕北盐碱地土壤理化性质的影响及耐盐碱水稻品种筛选

为明确种植水稻对陕北盐碱地土壤理化性质的影响,并筛选适宜陕北地区种植的耐盐渍水稻品种,进一步探索陕北盐碱地改良利用方式,以陕西省定边县堆子梁镇营盘梁村土地开发项目为契机,开展大田试验。结果表明,水稻种植可以显著改善盐碱地表层（0~20 cm）土壤的理化性质,表层土壤pH值和含盐量较未种植水稻前分别降低5.7%和25.5%,全氮、有效磷、速效钾和有机质含量则分别提高117.3%、45.9%、27.7%和67.3%。另外,种植不同水稻品种对盐碱地土壤酸碱度和含盐量影响基本无差异,但对表层土壤养分含量影响存在一定差异,水稻收获后,种植东稻4号的土壤全氮、有效磷含量最高,种植宁粳28的土壤有机质含量最高。隆优619产量较宁粳28、东稻4号分别提高4.96%和42.78%。     

施氮量对超级杂交稻产量和稻米品质的影响

为探明超级杂交稻在成都平原的适宜施氮量,达到高产与优质协同,以超级杂交稻德优4727、普通杂交稻川优6203和常规稻五山丝苗为材料,于2016年在四川德阳进行大田试验,设置4个施氮量(0、120、165、210 kg/hm~2,分别记作N0、N120、N165、N210),研究施氮量对水稻产量和稻米品质的影响。结果表明,超级杂交稻产量随施氮量的增加呈先增加后下降的趋势,以N165处理最高;普通杂交稻和常规稻产量随施氮量的增加而增加,以N210处理最高,但与N165处理差异不显著。糙米率、整精米率、蛋白质含量随施氮量的增加而提高;垩白粒率、垩白度对氮肥的响应因品种而异。除普通杂交稻胶稠度外,施氮量对胶稠度和直链淀粉含量的影响不显著。品种间产量和品质均存在显著差异。与普通杂交稻和常规稻相比,超级杂交稻产量显著增加,增产优势主要表现在粒重上。超级杂交稻糙米率、垩白粒率、垩白度、胶稠度显著高于常规稻,直链淀粉含量和蛋白质含量低于常规稻;超级杂交稻整精米率显著高于普通杂交稻,但与常规稻相当。考虑产量和品质两因素,本试验条件下超级杂交稻选择纯N用量165 kg/hm~2,可实现产量和品质的协同提高。     

The influence of milling on the nutritive value of flour from cereal grains. 4. Rice

Brown and milled rices were prepared from rough rice, and the nutritive value of the rices was studied by chemical analyses and in balance experiments with growing rats. The concentration of essential nutrients decreased with the degree of milling, but the energy density of brown and milled rices was similar. In the highly refined white rice the protein content was reduced to 86% and the mineral content to 23% of corresponding levels in brown rice. The zinc concentration was halved. The amino acid composition was rather unaffected by the degree of milling, but the lysine concentration was slightly lower in white rice than in brown rice. Milling was accompanied by an increase in true protein digestibility and a corresponding decrease in biological value. Thus net protein utilization of the different rices was remarkably uniform. A total of 33% of the utilizable protein and 22% of the digestible energy in brown rice was removed during milling. Rats fed rough, brown and lightly milled rices were unable to maintain their femur zinc concentration; deposition of calcium and phosphorus also appeared to be affected. Factors present in the outer part of the rice kernel interfere strongly with zinc utilization. Phytate and/or fibre are not solely responsible for this effect. Unless rice was milled into highly refined white rice, zinc status of rats was adversely affected. The results suggest that zinc might be a limiting factor in rice-based diets.     

Spatial variability in the growth of direct-seeded rainfed lowland rice (Oryza sativa L.) in northeast Thailand

Large within-field variation in rice growth often causes production loss in broadcast-seeded (BC) rainfed lowland rice. The spatial variability of direct-seeded rainfed lowland rice was evaluated in 2004, 2005, and 2007 in on-station experiments at Ubon Ratchathani, northeast Thailand, in relation to soil water content and weed infestation, by adopting semivariogram and block kriging, including comparisons among BC with harrowing (BCH; no weeding), BC with no harrowing (BCNH; no weeding), and row-seeded (RS; interrow weeding once) fields. BCH and BCNH were also compared in 11 farmers’ fields in 2006 and 2007, to assess the effect of harrowing on rice growth and weed infestation. During most of the rice growing periods, flooded and non-flooded portions existed simultaneously in the fields, with different proportions among years and among seeding methods in the on-station experiment. BCH and BCNH rice had large within-field variation in seedling density, heading date, shoot dry matter, grain yield, harvest index, panicle density, and filled spikelet per panicle, as well as in weed infestation, measured by a quick visual estimation. Many of the measured variables (except mean soil water content in RS in 2007, seedling density in BCH in 2005 and 2007, shoot dry matter in BCH and BCNH in 2007, and panicle density in BCH in 2007) were spatially dependent (i.e., data from nearby locations were most similar) by geostatistical analysis. Analysis of correlations using the 420 data sets of BCH plots in 2005 and BCH, BCNH, and RS plots in 2007 revealed a positive correlation between soil water content and grain yield and negative correlations between weed infestation and soil water content and grain yield. Compared with BCH, in 2007 BCNH had much lower grain yield because of lower soil water content after establishment and more weed infestation. BCH had higher grain yield than BCNH in weedy fields in the farmers’ fields experiment. RS with interrow weeding resulted in a smaller coefficient of variation, smaller sill value, and higher grain yield than BCH, due to less weed infestation and a higher proportion of flooded water. These results indicated that reducing the spatial variability in rice growth requires careful field preparation, such as harrowing to level the soil surface and to reduce the uneven distribution of standing water and the variability in soil water content, combined with effective crop and weed management (i.e., harrowing and row-seeding). This is the first study that examined spatial variability in the growth of direct-seeded rice as a function of soil water content and weed infestation in a rainfed lowland environment.     

杂草稻和栽培稻氮代谢对镉胁迫反应的差异

在水培条件下,以杂草稻和粳稻越光为材料,研究了Cd胁迫对水稻氮吸收和氮代谢酶活性的影响。Cd处理设0、01、10和50 μmol/L 4个水平,以硝酸铵为氮源。结果表明,两种水稻的植株Cd含量和积累量均随溶液Cd处理水平的提高而显著增加,但增加程度两水稻材料存在着明显的差异,在较高Cd水平（10和50 μmol/L）下,杂草稻根系Cd含量和积累量低于越光,但地上部呈相反的趋势,表明杂草稻根系吸收的Cd转运至地上部的量高于越光,揭示出杂草稻地上部具有较强的解毒能力。植株氮含量、积累量以及氮代谢有关酶,如硝酸还原酶、谷草转氨酶和谷丙转氨酶等活性随着Cd处理水平的提高而下降,但Cd胁迫对这些参数的抑制程度两水稻材料之间存在着明显差异,总体上对杂草稻的抑制作用较弱。表明杂草稻对Cd的耐性要强于越光,且几种氮代谢酶活性变化与Cd耐性存在着一定的相关。