Effect of Milling and Parboiling Processes on Arsenic Species Distribution in Rice Grains

This study identified the role of milling and parboiling on arsenic (As) content and its species in large numbers of rice samples. Total As contents were 108 ± 33 μg/kg in polished rice grains (PR), 159 ± 46 μg/kg in unpolished rice grains (UR), 145 ± 42 μg/kg in parboiled polished rice grains (PPR) and 145 ± 44 μg/kg in parboiled unpolished rice grains (PUR). The percentages of inorganic As (iAs) were 66% ± 8% in PR and from 72% to 77% in other grain categories. The polishing process reduced the As content in the rice grains, removing outer part of the UR with high amount of As, whereas the parboiling technique transferred the semimetal content within the grain. Total As and iAs contents were not significantly different in UR, PPR and PUR, homogenizing its distribution inside the grains. The results allowed to understand how different operations affect As fate and its chemical forms in grains.     

含水量变化对米粒裂纹形成的影响与调控

稻米水分含量变化是引起籽粒裂纹发生、影响整米率的主要因素。潮湿米粒的快速干燥,干燥籽粒的浸水或回潮均会带来严重的裂纹。干燥后润谷可以减少裂纹的发生。生产、加工、贮藏过程中可通过合理处理稻米水分含量减少裂纹发生,提高碾米品质。     

Effects of Continuous Steaming on Milling Characteristics of Two Indica Rice Varieties

Parboiling improves milling characteristics of rice in a positive manner,which has been found to influence consumers demand and acceptability.A laboratory model of continuous steaming unit was fabricated and tested with two indica rice varieties,fine (ADT39) and coarse (CO43) rice,at three different soaking temperatures (50,60 and 70 ℃) for 4 h and five residence times of steaming (1.0,1.5,2.0,2.5 and 3.0 min).The effects of continuous steaming on milling characteristics of rice were studied and compared with the values obtained from the control experiment (open steaming process under laboratory conditions).The favourable conditions for continuous parboiling of the fine variety ADT39 were identified as soaking at 70 ℃ for 4 h and 3.0 min residence time of steaming.These conditions showed head rice outturn of 74.0%.The favourable processing conditions for the coarse variety CO43 were found to be 4 h of soaking at 60 ℃ and steaming of 3.0 min residence time,and at these conditions the head rice outturn was 73.9%.     

Relationship Between Degree of Starch Gelatinization and Quality Attributes of Parboiled Rice During Steaming

Paddy rice samples were parboiled by soaking at 65 °C for 180 min and steaming at 96 °C for 2–10 min, and then dried to achieve the final moisture content of 11% ± 1%. The degree of starch gelatinization(DSG) and several quality attributes(head rice yield(HRY), color value and hardness) of parboiled rice were measured. Results showed that DSG(46.8%–77.9%), color value(18.08–19.04) and hardness(118.6–219.2 N) all increased following steaming. In contrast, the HRY increased(64.8%–67.1%) for steaming times between 2–4 min but decreased(67.1%–65.0%) for steaming times between 4–10 min. Linear relations between DSG and color value(R~2 = 0.87), and DSG and hardness(R~2 = 0.88) were observed. The suitable DSG of parboiled rice leading to the highest HRY was found to be 62.5%, obtained following 4 min of steaming.     

不同生育时期干旱胁迫对水稻产量与碾米品质的影响

以粳稻品种农大3号为材料,利用盆栽的方式人工控制土壤水分(水势),研究了不同生育时期干旱胁迫对水稻产量及碾米品质的影响。各时期干旱均导致产量下降,其敏感程度依次为：孕穗中期（抽穗前11~20 d）>孕穗后期（抽穗前1~10 d）>分蘖中期（移栽后11~20 d）>孕穗前期（抽穗前21~30 d）>分蘖初期（移栽后1~10 d）>分蘖后期（移栽后21~30 d）>乳熟期（抽穗后31~40 d）>抽穗开花期（抽穗后1~10 d）>灌浆期（抽穗后21~30 d）>蜡熟期（抽穗后41~50 d）。抽穗前干旱胁迫的敏感时期主要是孕穗中期、孕穗后期和分蘖中期。抽穗后,抽穗到乳熟期均较蜡熟期对干旱敏感,但对土壤水分变化较抽穗前迟钝。抽穗前干旱胁迫对糙米率和精米率影响最大的时期为孕穗中期,其次为孕穗后期。灌浆期到蜡熟期干旱胁迫,糙米率和精米率明显下降,抽穗后11~40 d干旱胁迫对整精米率的影响最大,其次为抽穗前1~20 d,其他时期干旱虽对整精米率有一定影响,但影响较小。     

直立与弯曲穗型水稻穗上不同部位籽粒碾磨品质的比较

以直立穗型和弯曲穗型水稻材料为对象,研究了穗上不同部位和不同粒位籽粒在碾米品质上的差异。弯曲穗型材料整穗籽粒的糙米率、精米率及整精米率以及粒重均高于直立穗型材料,其中整精米率差异达到显著水平。总体而言,在稻穗的同一部位,两穗型材料一次枝梗籽粒的糙米率、精米率、整精米率和粒重均高于二次枝梗的籽粒;一次枝梗上以第2 或第3粒位籽粒的糙米率、精米率和整精米率较高,第1 粒位籽粒的较低;穗上同一部位二次枝梗籽粒的碾米品质在两穗型材料间的差异大于一次枝梗,而穗型与其排序并无直接关系;两穗型材料籽粒粒重在穗上的分布与排序基本一致。因此,可以通过育种选择来改良直立穗型材料的碾磨品质。     

北方粳稻留胚米碾磨工艺的研究

以东北地区大面积种植的水稻品种为材料,以碾米工艺中碾磨时间、碾米辊目数、碾米辊转速以及米粒长宽比等因素作为试验工艺参数,采用二次旋转正交组合试验设计,利用响应面和回归方程进行分析,研究了经碾磨的留胚米的白度和留胚率在各参数影响下的变化规律。结果表明,碾米辊目数是影响留胚米的白度和留胚率的主要因素,碾米辊转速、碾磨时间次之;米粒长宽比越大,留胚米白度增加越高,但留胚率逐渐降低;碾磨的最佳工艺为碾磨时间6 min、米粒长宽比1.79、碾米辊目数46#、碾米辊转速830 r/min。     

基质含水量对机插水稻秧苗素质及产量的影响

为了探明机插育秧基质的最佳含水量,以江早361为试验材料,探讨了基质4种水分含量(W1,40%;W2,60%;W3,80%;W4,100%)对早稻(E)和晚稻(L)秧苗素质和大田产量的影响。结果表明,基质含水量对秧苗素质和产量均有显著影响。在早季,EW2处理产量最高,比其他3个处理增产4.9%~5.9%,差异显著;EW2处理叶龄比EW1和EW4增加7.0%,差异显著;EW2处理苗高比EW3和EW4分别增加10.2%和10.7%,差异显著;EW2处理单株茎叶质量比其他3个处理增加6.8%~13.3%,差异显著。相关分析可知,早稻产量与每穗粒数呈显著正相关。在晚季,LW2处理产量最高,比LW1和LW4处理分别增加13.2%和10.4%,差异显著;随着基质含水量的增加,晚稻叶龄、苗高、茎基宽和单株茎叶质量均是先增加后减少,均以LW2处理最大,4个指标最高值比最低值分别增加7.4%、13.3%、13.0%、14.8%。相关分析可知,晚稻产量与千粒重呈显著负相关。可见,在本试验条件下,基质含水量为60%时有利于提高机插稻秧苗素质,进而提高机插稻产量。     

食用稻品质评价标准发展及其对稻米品质改善的影响

食用稻品质评价标准在增强我国人民稻米品质意识、促进我国稻米品质改良工作中起到了积极的作用。为全面了解我国优质食用稻品质评价标准的发展及其在水稻品质改良中的实际作用,本文比较了我国不同时期优质食用稻的品质评价标准,并结合我国稻米优质率情况进行了分析讨论,以期为我国“十四五”时期优质稻新品种培育和产业发展提供参考。     

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。     

稻米直链淀粉和蛋白质含量对糙米重与外观品质性状间遗传相关性的影响

利用7个籼型不育系和5个籼型恢复系按不完全双列杂交方式配制杂交组合,采用包括胚乳、细胞质和母体植株基因效应的非条件和条件分析方法,研究了稻米直链淀粉和蛋白质含量对糙米重、稻米外观品质性状间遗传相关性的影响。结果表明,糙米重与稻米直链淀粉含量、蛋白质含量之间存在着显著或极显著的相关性,可以利用条件分析的方法排除直链淀粉含量或蛋白质含量对糙米重的影响,进而深入分析糙米重与稻米外观品质性状间存在的真实遗传相关性。条件分析结果表明,直链淀粉含量的表现会增大糙米重与糙米长、糙米宽、糙米厚间的基因型相关性,降低糙米重与糙米长宽比、糙米长厚比间的基因型相关性;蛋白质含量的表现除了对糙米重与糙米长厚比间的遗传相关性影响不大外,其他与直链淀粉含量的表现相反。不同遗传体系的条件相关分量表明,当排除了直链淀粉含量或蛋白质含量对糙米重的影响后,糙米重与外观品质成对性状间的条件相关分量会产生与非条件分析结果明显不同的变化,其中以细胞质主效应相关、母体加性主效应相关以及相应的环境互作相关等尤为明显。     

中日水稻品种杂交后代的株型性状与产量和品质的关系

以东北地区最具代表性的水稻品种辽粳5号(直立穗型)与日本著名的优质米品种秋田小町(弯曲穗型)杂交后采用单粒传法构建的F9重组自交系群体(以下简称RIL群体)为试材,研究中日水稻品种杂交后代株型性状的变化规律及其与稻米产量和品质的关系,结果表明,来自中日水稻杂交的RIL群体的株型性状、产量和米质性状均发生了分离和重组。株高、倒3、4节长和剑叶基角与产量呈显著正相关。植株越高、颈穗弯曲程度越大、倒3叶越窄长的株系,稻米的加工品质和外观品质越好。食味值与绝大多数株型性状的相关性未达显著水平,仅与倒3片叶的宽、二次枝梗数、着粒密度呈极显著负相关。产量与米质的相关分析表明,产量越高,整精米率就越高,但食味越差。中日水稻品种杂交后代的株型性状与产量和米质性状密切相关。尽管产量与食味很难统一,但RIL群体中仍然有极小部分产量高食味也好的株系,它们的主要株型特征是具有较长的穗长和较长的倒1节间长。     

精度对稻米品质的影响

 以5个中至长粒形的籼稻品种为材料,研究了碾米精度对稻米品质的影响。结果表明,精度对以精米为对象的各项米质指标的影响十分显著,其中精度与精米的白度、胶稠度、糊化温度及直链淀粉含量等米质指标成正相关,而与精米的整米率、长宽比以及蛋白质含量等米质指标成负相关。     

水稻杂种后代籽粒直链淀粉含量选择与品质和产量性状的关系

 选用4个稻米直链淀粉含量有显著差异的粳稻品种配制两个杂交组合（系选1号×通769和东农423×藤系180）,研究其杂交后代籽粒直链淀粉含量选择对品质和产量性状的影响。结果表明,籽粒直链淀粉含量选择对杂种后代蒸煮食味品质和产量相关性状有不同程度的影响,其影响程度因杂交组合及性状不同而异;在蒸煮食味品质性状中,淀粉黏滞性谱的崩解值和消减值受直链淀粉含量选择的影响较大,而在产量相关性状中抽穗期、单株有效穗数、结实率、单株粒重等受直链淀粉含量选择的影响相对较大;通过直链淀粉含量的连续定向选择可以从杂种后代中分出直链淀粉含量不同的后代,粳稻杂种后代低直链淀粉含量的定向选择效果优于高直链淀粉含量的选择效果,更容易得到超低亲的变异类型;直链淀粉含量的选择对杂种后代产量性状的影响较复杂,存在有利或不利的影响,低直链淀粉含量的选择将会导致单株粒重的下降。     

稻作方式对优质食味品种南粳9108的产量、品质及效益的影响

以南粳9108为试验材料,研究了不同稻作方式对优质稻品种产量、品质及效益的影响。结果表明,不同稻作方式实收单产由高到低依次为钵苗机插、毯苗机插、稻鸭共作和稻虾共作;整精米率由高到低依次为稻鸭共作、稻虾共作、钵苗机插和毯苗机插,垩白粒率及垩白度表现为钵苗机插最高、稻鸭共作最低,稻田综合种养模式稻米的外观品质表现较好。稻田综合种养模式降低了南粳9108稻米的蛋白质含量和直链淀粉含量,适当提高了稻米的胶稠度,稻米RVA特征谱表现出消减值降低和崩解值提高,改善了蒸煮食味品质。经济效益由高到低依次为稻虾共作、稻鸭共作、钵苗机插、毯苗机插,综合种养模式的效益明显高于单一种稻模式。     

基于不同分析策略的杂交稻米碾磨品质的分子预测

 糙米率、精米率和整精米率是决定稻米碾磨品质的重要性状,在育种中对其进行有效预测具有十分重要的意义。用9个不育系与9个恢复系及其所配制的81个双列水稻杂交组合为材料,利用有多态性的174对SSR标记筛选与F1糙米率、精米率和整精米率相关的阳性位点和增效位点,分别用二组法和三组法对F1碾磨品质性状值进行预测。结果表明：1）采用二组法,利用增效位点对糙米率、精米率和整精米的预测相关系数分别为0.553（P<0.01）、0613（P<0.01）和0.772（P<001）,预测效果明显优于阳性位点;2）利用增效位点,固定不育系进行预测,3个碾磨品质性状的相关系数与显著性水平明显高于固定恢复系的结果,表明不育系对碾磨品质的影响大于恢复系;3）固定不育系时三组法预测杂交稻米糙米率、精米率和整精米率杂种优势的相关系数依次为0.466（P<0.05）、0.564（P<001）与0.688（P<0.01）,比二组法分别降低了177%、8.0%和10.9%,固定恢复系时两种方法预测效果基本一致;4）对于水稻碾磨品质的分子预测,固定不育系的预测效果最佳,二组法的预测效果显著优于三组法。在3个碾磨品质指标中,整精米率预测效果最好,其次为精米率,糙米率较差。     

水稻籽粒不同部位植酸含量及其与稻米品质的相关性

 选用13个不同类型的水稻品种,对其籽粒不同部位植酸含量品种间差异及与稻米主要品质性状间的相关性进行了分析。结果表明,供试13个水稻品种米糠、糙米、颖壳、精米的植酸含量平均值分别为48.51、9.77、1.40和0.91 mg/g,而且不同水稻品种间籽粒不同部位的植酸含量存在极显著差异。在籽粒中,米糠中植酸积累最多,其次是精米,颖壳最少。米糠中植酸含量与糙米和颖壳中植酸含量呈极显著正相关。糙米和米糠中植酸含量与稻米蛋白质含量均呈显著的负相关,与千粒重均呈显著正相关。     

保墒旱育秧对不同类型水稻品种的增产作用

不同类型水稻品种保墒旱育秧试验结果表明,保墒旱育秧较常规旱育秧有一定的增产优势。增产原因在于保墒旱育秧播种早、播量低、秧苗素质好、分蘖能力强,早育早插延长了有效分蘖期,有效分蘖增加,从而获得更多的收获穗数,最终实现高产。     

抗倒酯对北方优质稻抗倒伏能力、产量和米质的影响

[目的]研究抗倒酯对优质稻抗倒伏能力及产量与米质的影响.[方法]以优质稻品种丰锦和沈农09001为试材,在分蘖期、拔节初期、孕穗期叶面喷施不同浓度(0、90、180和360 mg/L,1200 L/hm2)的抗倒酯,以倒伏指数、抗折力以及抗推力作为评价植株抗倒伏能力的指标,研究抗倒酯对优质稻抗倒伏能力及产量和米质的影响...     

Influence of Crop Nutrition on Grain Yield, Seed Quality and Water Productivity under Two Rice Cultivation Systems

The system of rice intensification (SRI) is reported to have advantages like lower seed requirement,less pest attack,shorter crop duration,higher water use efficiency and the ability to withstand higher degree of moisture stress than traditional method of rice cultivation.With this background,SRI was compared with traditional transplanting technique at Indian Agricultural Research Institute,New Delhi,India during two wet seasons (2009-2011).In the experiment laid out in a factorial randomized block design,two methods of rice cultivation [conventional transplanting (CT) and SRI] and two rice varieties (Pusa Basmati 1 and Pusa 44) were used under seven crop nutrition treatments,viz.T 1,120 kg/hm2 N,26.2 kg/hm2 P and 33 kg/hm2 K;T 2,20 t/hm2 farmyard manure (FYM);T 3,10 t/hm2 FYM+ 60 kg/hm2 N;T 4,5 t/hm2 FYM+ 90 kg/hm2 N;T 5,5 t/hm2 FYM+ 60 kg/hm2 N+ 1.5 kg/hm2 blue green algae (BGA);T 6,5 t/hm2 FYM+ 60 kg/hm2 N+ 1.0 t/hm2 Azolla,and T 7,N 0 P 0 K 0 (control,no NPK application) to study the effect on seed quality,yield and water use.In SRI,soil was kept at saturated moisture condition throughout vegetative phase and thin layer of water (2-3 cm) was maintained during the reproductive phase of rice,however,in CT,standing water was maintained in crop growing season.Results revealed that CT and SRI gave statistically at par grain yield but straw yield was significantly higher in CT as compared to SRI.Seed quality was superior in SRI as compared to CT.Integrated nutrient management (INM) resulted in higher plant height with longer leaves than chemical fertilizer alone in both the rice varieties.Grain yield attributes such as number of effective tillers per hill,panicle length and panicle weight of rice in both the varieties were significantly higher in INM as compared to chemical fertilizer alone.Grain yields of both the varieties were the highest in INM followed by the recommended doses of chemical fertilizer.The grain yield and its attributes of Pusa 44 were significantly higher than those of Pusa Basmati 1.The seed quality parameters like germination rate and vigor index as well as N uptake and soil organic carbon content were higher in INM than those in chemical fertilizer alone.CT rice used higher amount of water than SRI,with water saving of 37.6% to 34.5% in SRI.Significantly higher water productivity was recorded in SRI as compared to CT rice.