Selection of Rice Genotypes for Salinity Tolerance Through Morpho-Biochemical Assessment

The present study reported the morpho-biochemical evaluation of 15 selected rice genotypes for salt tolerance at the seedling stage. Growth parameters including shoot length, root length, plant biomass, plant turgid weight, plant dry weight along with relative water content were measured after exposure to saline solution （with electrical conductivity value of 12 dS/m）. Genotypes, showing significant differential responses towards salinity in the fields, were assessed through 14 salinity-linked morpho-biochemical attributes, measured at 14 d after exposure of seedling in saline nutrient solution. Relative water content, chlorophyll a/b, peroxidase activity and plant biomass were identified as potential indicators of salt tolerance. Principal component analysis and successive Hierarchical clustering using Euclidean distance revealed that Talmugur, Gheus, Ghunsi, Langalmura, Sabitapalui, and Sholerpona were promising genotypes for further breeding programmes in rice. The maximum Euclidean distance was plotted between Thavallakanan and Talmugur （7.49）, followed by Thavallakanan and Langalmura （6.82）, indicating these combinations may be exploited as parental lines in hybridization programmes to develop salinity tolerant variety.     

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。     

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.     

Genetic Polymorphism of Wx Gene and Its Correlation with Main Grain Quality Characteristics in Rice

The allelic variation of the Wx gene in 50 non-glutinous rice varieties (lines) was analyzed by using the microsatellite marker RM190 [for (CT)n simple sequence repeat (SSR)] and cleaved amplified polymorphic sequence(CAPS) marker 484/W2R-ACCⅠ[for G/T single nucleotide polymorphism (SNP)]. Six homozygous (CT)n types, namely (CT)20, (CT)19, (CT)18, (CT)17, (CT)16, (CT)14, (CT)11 and (CT)10, and a heterozygous genotype (CT)11/(CT)18 were detected for RM190, of which (CT)11 and (CT)18 were predominant. Two homozygous Wx genotypes (G/G and T/T) and one heterozygous (G/T) were detected using 484/W2R-ACCⅠ . Most of the materials with a RM190 of (CT)11 were G/G for SNP of 484/W2R-ACC I, while T/T for SNP was predominantly appeared in materials with (CT)18. The materials tested could be grouped into 10 categories using the two markers together. Results indicated that 59.3% variance of amylose content was attributed to the polymorphism of Wx gene revealed by RM190, while 56.1% and 24.6% of the variances in amylose content and gel consistency were respectively to the polymorphism of Wx gene revealed by 484/W2R-ACC I. Furthermore, with both SSR and CAPS markers, 72.4% of the variance in amylose content could be explained. In addition, the application prospects of the two markers in breeding were also discussed.     

稻米直链淀粉含量和胶稠度对高温耐性的QTL分析

利用由98个家系组成的Nipponbare/Kasalath//Nipponbare回交重组自交系群体,以直链淀粉含量耐热指数（高温下直链淀粉含量/适温下直链淀粉含量×100）和胶稠度耐热指数（高温下胶稠度/适温下胶稠度×100）为评价指标,采用混合线性模型的QTL定位方法,在南昌和南京两个试验地点对水稻蒸煮食用品质性状的高温耐性QTL进行了检测。两个性状在两个试验地点共检测到9个QTLs,其中直链淀粉含量高温耐性QTL 3个,胶稠度高温耐性QTL 6个。两个性状中共有3个QTLs在两个地点同时被检测到。其中位于第6染色体上与Wx基因相同的染色体区域和第8染色体G1073-R727区域分别是控制直链淀粉含量和胶稠度高温耐性的重要区域。     

弱光胁迫对不同基因型水稻稻米淀粉RVA谱特征值及直链淀粉含量的影响

以Ⅱ优498、冈优188、冈优527、川香9838、冈优906为材料,研究了弱光胁迫对稻米淀粉RVA谱特征值及直链淀粉含量的影响。结果表明,返青分蘖期和孕穗期遮荫均影响了淀粉RVA谱特征值及直链淀粉含量,孕穗期遮荫影响程度高于返青分蘖期。随着光照强度的减弱,最高黏度、最终黏度、崩解值降低,而消减值增加,直链淀粉含量在弱光下表现为返青分蘖期增加,孕穗期减少的趋势。不同基因型稻米淀粉RVA谱特征值对弱光的反应不同,Ⅱ优498、冈优906经遮荫处理后RVA谱特征值与对照差异不显著,而其余3个品种遮荫处理的RVA谱特征值与对照差异显著。冈优527、冈优188和川香9838的直链淀粉含量对弱光较敏感。综合淀粉RVA谱特征值和直链淀粉含量,Ⅱ优498和冈优906受弱光影响较小,较适应四川弱光寡照环境条件。     

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.     

Effects of Different Nitrogen Fertilizer Levels on Fe, Mn, Cu and Zn Concentrations in Shoot and Grain Quality in Rice （Oryza sativa）

In a pot experiment, effects of N fertilizer application on the concentrations of Fe, Mn, Cu and Zn in shoot of rice and the quality of brown rice were studied. In the treatments with N fertilizer application, the concentrations of Fe, Mn, Cu and Zn in most parts of rice shoot increased compared with control (no N fertilizer application). This indicated that the transportation ability of microelements from root to shoot in rice was improved with N fertilizer application. Effect of N fertilizer on IR68144 was similar to that of on IR64, but the concentrations of the microelements in plant differed, suggesting that the characteristic expression of the two rice genotypes was not controlled by the amount of N fertilizer supplied. The concentrations of those microelements in brown rice increased at first and then decreased with increasing N fertilizer application, reaching the highest at 160 kg/ha, at which the Fe, Mn, Cu and Zn concentrations in brown rice increased by 28.96%, 41.34%, 58.31% and 16.0% for IR64, and by 22.16%, 13.75%, 8.75% and 20.21% for IR68144 compared with control, respectively. Moreover, N fertilizer promoted the accumulation of protein, decreased the accumulation of amylose in grain, and enhanced gel consistency of brown rice. These results indicate that appropriate N fertilizer management could increase micronutrient contents in grain and improve nutrition quality of rice.     

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...     

Variability in Grain Quality Characters of Upland Rice of Assam,India

The grain quality of 100 upland/ahu rice genotypes from Assam,India was assessed.The characteristics measured were grain length,grain width,cooked grain length,cooked grain width,grain elongation ratio after cooking,grain widening ratio after cooking,alkali spreading value,gel consistency,as well as starch,amylose,amylopectin and total soluble sugar contents.Considerable genetic variability among the 100 rice genotypes was observed for the characteristics under study.Analysis of variance revealed highly sig...     

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。     

CPPU和PP333对杂交稻3个淀粉合成酶活性和米质的影响

在抽穗期和抽穗期后12d对两系杂交水稻培杂青珍喷施CPPU[N-(2-氯－4－吡啶基）－N'－苯基脲]和PP333（多效唑）溶液。结果发现，CPPU和PP333能提高籽粒的可溶性淀粉合成酶（SSS）、结合性淀粉合成酶（GBSS）和淀粉分支酶（SBE）活性，其增加以SSS和SBE明显高于GBSS，而GBSS活性具有相对的稳定性。同时，能提高精米率、整精米率和胶稠度，而降低垩白粒率、垩白度和直链淀粉含量，有利于改良米质。其中，以抽穗期用质量浓度为10mg/L的PP333溶液喷60ml/m^2 抽穗期后12d用质量浓度为2mg/L的CPPU溶液喷施75ml/m^2的处理对促进SSS、SBE和GBSS活性提高与改良品质的作用最大。     

花后水稻穗部夜间远红外增温处理对稻米品质的影响

 以武育粳3号为材料,在开放环境下使用远红外加热器对水稻穗部进行增温处理,研究了灌浆结实期穗部日间或夜间增温对稻米品质的影响。结果表明,夜间增温降低了糙米率、精米率和整精米率,增加了垩白发生,降低了稻米的加工品质和外观品质,与日间增温影响一致。夜间增温提高了稻米蛋白质含量,与日间增温相似,但夜间增温有降低稻米直链淀粉含量的趋势,与日间增温相反。夜间增温处理淀粉结构与日间增温差异较分明,尤其是胚乳腹部,夜间增温胚乳腹部的淀粉粒个体较大,棱角分明,排列紧密;而日间增温淀粉体较小,呈圆形和椭圆形,但数量较多。夜间增温对淀粉相对结晶度的影响与日间增温相似,但夜间增温增幅较小。总体来说,灌浆结实期夜间增温对稻米的加工品质、外观品质、营养品质影响与日间增温一致,对蒸煮食味品质和淀粉结构的影响与日间增温存在很大的差异,且夜间增温对稻米品质的影响程度整体上小于日间增温。     

Management of Soil Salinity and Alkalinity Problems in India

SUMMARY

Like the problem of salt-affected soils afflicting many other countries with arid and semi-arid climates, these lands occupy about 8.6 M ha in India out of which 3.5 M ha are in canal commands, commonly referred to as man made or wet deserts. Starting from the early systematic work of Dr. Leather about a century ago, real impetus to development and application of reclamation technologies has occurred in the post independence period, especially the seventies. Salt-affected soils are grouped into saline and alkali/sodic soils on the considerations of soil management and crop responses. Out of the 3.4 M ha of alkali lands in Indo-Gangetic Plains, about 1.0 M ha has been reclaimed by the hydro-chemical technology. Application of amendments like gypsum, equivalent to 50% gypsum requirement, to the surface 15-cm soil only was enough to start cropping with rice. Light and frequent irrigation are ideal for upland crops. Application of higher doses of nitrogen in splits to compensate for volatilization losses, organic matter additions through green manure to increase reclaiming action, skipping phosphorus application in the initial years and the application of zinc to each crop were some of the emerging recommendations. Application of low-grade pyrites also gave encouraging results in calcareous soils. Feasibility of drainage has been successfully demonstrated in 1980s for the quicker rehabilitation of saline and waterlogged soils. Provision for subsurface drains at 1.5–2.0 m depth and 50–75 m spacing in alluvial soils and 12–24 m interval in vertisol was sufficient for facilitating growing crops within 2–3 years on lands lying barren for considerable period. However, technological, economic, social, and political considerations are the major bottlenecks for large-scale amelioration of saline soils, in addition to the safer disposal of drainage waters. Strategies worked out for successful crop production on saline soils after drainage include initial leaching management (minimizing water requirement for leaching by synchronizing with monsoon rains, etc.), proper selection of crops/cultivars, irrigation (method, controlled frequency for enhancing water-table contribution, canal water use during the initial stages including presowing for conjunctive use with drainage waters) and cultural practices (furrow planting, increasing seed rate and fertility management). Some of the future issues for combating salinity and also preventing further land degradations in India are also highlighted.     

同源四倍体和二倍体水稻Wx基因与淀粉品质的遗传关系

用Wx 基因的(CT)n微卫星标记和切割的扩增产物多态性序列(cleaved amplified polymorphic sequence, CAPS)分子标记PCR Acc Ⅰ 对40份同源四倍体和14份二倍体水稻Wx基因型进行研究。利用484/485引物检测,Wx基因呈 Wx1、Wx2和Wx3 3种多态性;而用PCR Acc Ⅰ检测,Wx基因表现为G 型和T 型。同时,在测定稻米直链淀粉含量（AC）、胶稠度（GC）和糊化温度（GT）的基础上探讨它们与Wx基因的关系,结果表明AC、GC与Wx基因密切相关,GT与Wx基因相关不显著。综合分析表明,同源四倍体水稻中,92.0%的Wx1基因型材料为G 型,而Wx2基因型村料和800%的Wx3基因型材料为T 型。统计分析表明,Wx基因(CT)n微卫星标记检测与PCR Acc Ⅰ 分子标记检测的相关系数为0842,呈极显著正相关。     

Effects on Grain and Malting Quality of Genes Altering Barley Starch Composition

In this study inbred barley lines carrying waxy and/or high amylose genes were obtained from a cross between Waxy Hector and a breeders» line BE285 (high amylose Glacier×Midas) and assessed for malting quality. Inbred lines were assayed and classified as having none, one or both genes. After malting, waxy lines had a slightly lower hot water extract than normal starch lines. Large effects were demonstrated for both grain nitrogen content and hot water extract in high amylose lines and, particularly, in lines with both genes. Endosperm modification during malting was reduced by both starch mutations. Electron microscopy showed that the phenotype with both genes was characterised by a highly compacted endosperm. During malting, this structure was extremely resistant to modification.     

Cause of varietal difference in insulin and glucose responses to ingested rice

Combined data on four rices differing in amylose content suggested that difference in the response or the increase in blood plasma insulin and glucose in man to ingested rice was a result of difference in Amylograph cooked paste consistency and amylose content rather than to difference in starch lipids and starch gelatinization temperature.     

Effects of Weak Light on Starch Accumulation and Starch Synthesis Enzyme Activities in Rice at the Grain Filling Stage

Photosynthetic product in rice plant is transported to grains mainly in the form of sucrose. Sucrose in the grains eventually becomes starch through a series of enzymatic reactions [1-2]. The starch weight accounts for 90% of the brown rice [3-4], so the course of the rice grain filling is the biochemical process in which starch is mainly formed, and the factor of light is indispensable at the course. Much research has been conducted to study the influence of the light on the grain starch synt…     

稻谷碎米淀粉性能改良研究初报

试验采用6种不同处理方法对碎米淀粉性能改良作了初步的探讨和研究,结果表明:碎米放置在温度42℃、湿度88%的老化箱内进行人工加速老化11d后,胶稠度由原来的44.67mm下降为33.33mm,胶稠度显著降低,但该方法是否适用于米粉加工还有待在生产实践中进一步验证。     

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。