Effect of proton beam irradiation on germination, seedling growth, and pasting properties of starch in rice

This study was carried out to determine the pretreatment effect of proton beam irradiation on germination and pasting properties of starches in two rices. Mature and healthy seeds irradiated with 10 doses (0, 50, 100, 200, 300, 400, 500, 600, 700, and 800 Gy) for determination of LD50 and characteristics of germination were recorded at 14 days after irradiation. The rice seeds irradiated with five doses (0, 50, 100, 200, and 300 Gy) were used to evaluate the irradiation effects of pasting properties of starches. It showed that a lower survival rate in germinated rice seeds was observed above 300 Gy showing 31 and 35% in Ilpum and Hanmaum, respectively. The higher plant height and root length were also recorded in 50 and 100 Gy. Amylose content in proton beam irradiated with 50, 100, 200, and 300 Gy was significantly decreased in two rice cultivars. Peak viscosity, hot peak viscosity, cooling peak viscosity, and setback viscosity decreased with increasing proton beam dose levels. The degree of crystallinity was significantly increased with increasing proton beam dose levels. Consequently, it might be deduced that proton beam irradiation causes changes of starch properties affecting crystalline regions of starch granules, especially at high dosage irradiation.     

Pasting properties of colored rice starch by ball-mill treatment

Physically modified rice starch by ball-mill is important for making good quality bread, noodles, and several processed foods. The production of rice flour was done by ball-mill in an industrial scale. The effects of ball-mill treatment on the physicochemical properties of rice starch were investigated. The gel pasting properties of Joseongheugchal employed to ball-mill treatment showed that pasting time was 0.44 min shorter than that of the control and it also decreased peak viscosity (PKV), hot peak viscosity (HPV), and cold paste viscosity (CPV). In Hongjinju rice, RVA (rapid visco analyzer) pasting trace was characterized with high peak viscosity (3,448 RVU: rapid visco unit), and cold paste viscosity (2,975 RVU), also with high breakdown viscosity (1,597 RVU). The onset, peak, and conclusion gelatinization temperatures of ball-milled Josengheugchal rice starch were 57.4, 64.2, and 76.5°C, respectively, which were significantly higher than those of the control. The parameters of DSC (Differential scanning calorimetry) of ball-milled Hongjinju rice were 57.9, 65.1, and 77.3°C, respectively. The mean particle size of starch in both Josengheugchal and Hongjinju by ball-milling was decreased. The distribution of mean particle size in ball-milled rice starch was smaller in Josengheugchal than in Hongjinju compared to the native starch. As rice grains were ball-milled, the regions of amorphism were becoming larger and larger at the expense of crystalline regions, and diffraction peak patterns were decreased commonly in two colored rice cultivars. The ¹³C FT-solid state NMR patterns of starches showed dramatic chemical shifts of the ¹³C resonances by ball-milled treatment.     

Starch properties of native foxtail millet, Setaria italica Beauv.

Properties of foxtail millet (Setaria italica Beauv.) starches have been studied. Amylose content ranged between 3.3 and 11.4%. Starch content was from 67.5 to 68.7%. The onset temperature (To) of all samples ranged from 66.4 to 69.6°C, peak temperature (Tp) ranged 71.0 to 74.2°C, and their gelatinization enthalpy varied from 0.44 to 8.22 J/g, respectively. A highest gelatinization temperature was obtained for Bongseongjaerae (69.6°C). The enthalpy of the gelatinization (Δ H _gel ) was highest in Andongjaerae. The highest peak, highest breakdown, very high final viscosity, and very low setback were noted in Jucheonjaerae. The starch granule sizes ranged 10.1–25.0 in length and 4.7–12.5μm in diameter. X-ray diffraction angles indicated that all starch samples possess a typical A-type crystallinity.     

施氮量对机插粳型超级稻主要米质性状及淀粉RVA谱特征的影响

以粳型超级稻常规品种南粳44和杂交品种常优1号为材料,在机械插秧条件下,研究施氮量（0、90、180、270、360 kg/hm2）对粳型超级稻主要米质性状及淀粉粘滞谱（RVA谱）特征的影响。结果表明：施氮量对两个品种的稻米加工品质、营养品质、蒸煮食味品质及淀粉RVA谱3个曲线峰值的影响达到显著或极显著水平,对淀粉RVA谱其他特征参数的影响因不同品种而异;常优1号的外观品质指标（垩白粒率和垩白度）对氮肥施用量的反应较南粳44表现敏感,增加施氮量使杂交粳稻外观品质变差。随施氮量的增加,两个品种的糙米率、精米率、整精米、精米蛋白质含量呈增加趋势,而稻米的直链淀粉含量、食味值和淀粉RVA谱曲线峰值（峰值黏度、热浆黏度和冷胶黏度）呈现下降趋势。表明增施氮肥在提高粳型超级稻加工和营养品质的同时,降低了稻米食味品质,并使稻米淀粉粘性变劣。     

Differences in Starch Characteristics of Rice Strains Having Different Sensitivities to Maturation Temperatures

The amylose synthesis in rice with Wx^b is affected by environmental temperature during seed development. We previously isolated a mutant candidate (coi) in which amylose synthesis is insensitive to a cool temperature. Here, the effects of maturation temperature (21 °C vs. 28 °C) on the starch characteristics of coi and its original strain 76‐3/T65 were studied. Amylose contents and gelatinization properties of 76‐3/T65 were affected by maturation temperatures, while coi was less affected. The amylopectin chain length distributions were almost the same between the two strains maturated at both temperatures. Gelatinization onset (T_o), peak (T_p), conclusion temperatures (T_c) and enthalpies (ΔH) decreased with environmental temperatures, and T_p, T_c and ΔH of coi at 21 °C were significantly higher than those of 76‐3/T65. Thus, the coi mutant, less affected by maturation temperature than that of 76‐3/T65, may be a useful strain in understanding biochemical and genetic starch biosynthesis response to slight changes in temperature.     

不同生态条件下籼稻米饭质地和淀粉RVA谱的特性

研究了6个籼稻品种在大范围不同的生态环境条件下,米饭质地和淀粉RVA特征谱的变化。结果表明,供试样品的米饭质地指标硬度和黏度存在极显著环境主效应,环境与品种互作效应在硬度、黏附性和黏度3个性状中均极显著。6项RVA特征值（峰值黏度、热浆黏度、最终黏度、崩解值、消减值和回复值）均存在极显著环境主效应;环境与品种互作效应在上述性状中,均极显著;且生态条件对RVA谱的影响因品种不同而异。6个试验点中,米饭质地指标黏附性的变异系数最小;RVA的热浆黏度、最终黏度、峰值黏度、崩解值和回复值以及米饭质地的硬度、黏度值的变异系数较小;RVA的消减值的变异系数最大。     

Genetic region responsible for the differences of starch properties in two glutinous rice cultivars in Hokkaido,Japan

Starch properties are major determinants of grain quality and food characteristics in rice (Oryza sativa L.). Control of starch properties will lead to the development of rice cultivars with desirable characteristics. We performed quantitative trait locus analysis and detected a putative region on chromosome 2 associated with phenotypic variation of starch properties in two glutinous rice varieties developed in the Hokkaido region of Japan: ‘Kitayukimochi’, which has a low pasting temperature and creates soft rice cakes, and ‘Shirokumamochi’, which has a high pasting temperature and creates hard rice cakes. Starch branching enzyme IIb (SbeIIb) was identified as a candidate gene within the region. Sequence analysis of SbeIIb in parental lines identified two single-nucleotide polymorphisms (SNPs) with non-synonymous mutations in the coding region of the ‘Shirokumamochi’ genotype (SbeIIb^sr). We genotyped over 100 rice cultivars, including 28 rice varieties in the Honshu region of Japan, using the CAPS marker, which was designed using one of the SNPs. However, SbeIIb^sr was not found in rice cultivars in Honshu. Distribution analysis indicated that SbeIIb^sr was introduced to the rice breeding population in Hokkaido from the American variety ‘Cody’ via the Hokkaido cultivar ‘Kitaake’. As a result, SbeIIb^sr was distributed only in progenies of ‘Kitaake’.     

淀粉的糊化与凝胶特性及食用品质研究

不同种类的淀粉具有不同的理化、感官特性,为了实现从原料推断产品的好坏,本研究以市场上常用的各种淀粉原料作为试材,探究谷类淀粉(小麦淀粉、玉米淀粉)、薯类淀粉(马铃薯淀粉、红薯淀粉、木薯淀粉)、豆类淀粉(豌豆淀粉、绿豆淀粉)的基本成分、溶解度、膨胀度、糊化特性、凝胶特性及感官评分等指标。结果表明:豆类淀粉的直链淀粉含量最多,薯类淀粉的直链淀粉含量最低;谷类淀粉的糊化温度相对较高,稳定性最好,薯类淀粉糊化温度最低;马铃薯淀粉的峰值黏度、谷值黏度、最终黏度及回生值最大,豌豆淀粉的峰值黏度最小,玉米淀粉的回生值最小;豆类淀粉的硬度、弹性、咀嚼性及凝胶强度最大,黏度最小;薯类淀粉的黏度最大,硬度、弹性、咀嚼性及凝胶强度最小;豆类淀粉的感官得分最高,薯类淀粉的感官得分最低,其中豌豆淀粉的感官得分最高,为8.14分(满分9分),该产品色泽剔透、质地紧密,弹性好,更为消费者所喜爱。综合各项指标得出豆类淀粉中的豌豆淀粉的糊化凝胶特性及感官指标相对较好,可将其大力开发成凝胶产品。     

鲜食期和成熟期糯玉米粉理化特性的差异

以5个糯玉米品种为材料,研究其鲜食期和成熟期籽粒的理化特性。结果表明,糯玉米粉的最大吸收波长鲜食期和成熟期无显著差异,均表现出典型的糯性特征,禾盛糯1512成熟期的蓝值高于鲜食期,其余品种鲜食期和成熟期无显著差异。成熟期糯玉米粉具有较高的淀粉含量和较低的蛋白质含量。成熟期糯玉米粉的结晶度和膨胀势高于鲜食期,而溶解度和透光率低于鲜食期,但不同品种对收获期的响应不一致。中糯319鲜食期的黏度特性较优,其他4个品种成熟期较优,鲜食期收获的粤彩糯1号不能糊化。差示扫描量热仪结果表明,成熟期收获的糯玉米粉具有较低的转变温度(起始温度、峰值温度、终值温度)、热焓值、峰值指数以及较宽的糊化范围,鲜食期收获的糯玉米粉具有较低的回生值。相关分析表明,最大吸收波长与峰值黏度显著正相关(相关系数为0.63,P<0.05),与糊化温度显著负相关(相关系数为-0.86,P<0.01)。结晶度与糊化温度显著负相关(相关系数为-0.70,P<0.05),与热焓值、峰值指数及回生后的热焓值显著正相关(相关系数分别为0.74,P<0.01;0.62,P<0.05;0.74,P<0.01)。回生值与蓝值、最大吸收波长、结晶度及回生后的热焓值显著正相关(相关系数分别为0.64,P<0.05;0.61,P<0.05;0.69,P<0.05;0.96,P<0.01)。中糯319鲜食期收获具有较高的淀粉含量、结晶度和黏度特征值,适宜作鲜食;粤彩糯1号两个时期的回生值远低于其他品种,适宜制作低回生的食品。     

反义trxs基因导入对不同品质类型小麦产量和品质性状的影响

以转反义trxs基因小麦TY18和TY34及其相应未转基因对照为材料,于2007-2009年通过大田试验系统研究了反义trxs基因导入对两种品质类型小麦籽粒产量性状和加工品质指标的影响。结果表明,4个转基因株系的穗粒数和产量较对照显著提高,反义trxs基因对小麦籽粒淀粉品质有一定的正效应。4个转基因株系的淀粉含量、支链淀粉含量、峰值黏度、低谷黏度、最终黏度均显著提高,直/支比降低。反义trxs基因对小麦籽粒蛋白质品质的影响因品种类型而异,其中弱筋小麦的总蛋白、清蛋白、球蛋白、谷蛋白含量显著减少,醇溶蛋白含量显著增加,面粉的形成时间和稳定时间降低。强筋小麦除清蛋白、醇溶蛋白、谷蛋白含量减少外,面团的粉质和拉伸参数变化不明显。上述结果说明,反义trxs基因导入有利于两种品质类型小麦籽粒淀粉品质的改善,并在一定程度上改善了弱筋小麦的烘焙品质。     

基肥配比和拔节期追氮对糯玉米淀粉胶凝和回生特性的影响

以苏玉糯4号为材料,采用二因素裂区设计,研究了不同基肥配比(纯N 75 kg hm^-2、纯N 75 kg hm^-2+K₂O 70 kg hm^-2、纯N 75 kg hm^-2+P₂O₅ 65 kg hm^-2和纯N 75 kg hm^-2 +P₂O₅ 65 kg hm^-2+K₂O 70 kg hm^-2)和拔节期追氮(0、150和300 kg hm^-2)对糯玉米淀粉胶凝和回生特性的影响。结果表明,淀粉和回生淀粉的起始温度、峰值温度和终值温度虽然受到施肥处理的影响,但总体上变异较小。热焓值受基肥配比影响较小,糊化范围和峰值指数受拔节期追氮量影响较小。在不同基肥配比处理下,糊化范围在基施氮钾时最低,氮磷钾合理配施处理下最高,峰值指数表现和糊化范围相反。在拔节期不同追氮量处理下,热焓值以追氮150 kg hm^-2时最高,追氮300 kg hm^-2或不追氮无显著差异。胶凝淀粉冷藏后发生回生,表现为转变温度、热焓值和峰值指数降低,糊化范围变宽。和仅基施氮相比,增施磷或(和)钾都可降低淀粉的回生值和回生淀粉的热焓值,拔节期追氮处理的这两项指标均劣于不追氮处理。回生值与回生淀粉的热焓值和峰值指数显著正相关,相关系数分别为0.90 (P < 0.01)和0.41 (P < 0.05); 原淀粉的热焓值与峰值指数极显著正相关, 相关系数为0.65 (P < 0.01),与回生淀粉热焓值显著正相关,相关系数0.44 (P < 0.05),与终值温度显著负相关,相关系数-0.41 (P < 0.05)。在本试验条件下,以氮磷钾均衡基施并拔节期追氮150 kg hm^-2时,淀粉胶凝和回生特性较为理想,表现为热焓值较高,回生值较低。     

Assessment of Cold and Heat Tolerance of Winter-grown Canola (Brassica napus L.) Cultivars by Pollen-based Parameters

Winter‐grown canola (Brassica napus L.) production is limited mostly by frost and winter kill in the southern canola‐growing regions of the United States. Tolerance to cold and heat were assessed by studying percentage of pollen viability (PV), in vitro pollen germination (PG) and pollen tube length (PTL) for 12 field‐grown cultivars. Freshly collected pollen from all cultivars were incubated on artificial solid growth media at a constant temperature ranging from 10 to 35 °C at 5 °C interval for 30 h to determine PG and PTL. A modified bilinear model best described the temperature response functions of PG and PTL. Canola cultivars showed significant variability (P < 0.001) for PV (61.3 % to 89.7 %), PG (29.0 % to 48.2 %) and PTL (463 to 931 μm). The average cardinal temperatures, T_min, T_opt and T_max, for PG and PTL were 6.4, 24.3 and 33.7 °C, respectively. Principal component analysis revealed that maximum PG, PTL, T_min and T_opt of both PG and PTL were the most important factors in determining cold tolerance, whereas T_max of PG and PTL, and maximum PG and PTL were more responsible in separating the cultivars for heat tolerance. The canola cultivar, KS3077, was the most cold tolerant with the lowest T_min and the widest temperature adaptability range, and the cultivar Kadore was the most heat tolerant with the highest T_max for the PG. The identified cold‐ and heat‐tolerant cultivars may be useful in canola‐breeding programmes to develop cultivars suitable for a niche environment.     

Effects of Increasing Temperatures on Spikelet Fertility in Different Rice Cultivars based on Temperature Gradient Chamber Experiments

Spikelet sterility in rice (Oryza sativa L.) induced by high temperatures is a major concern given global warming predictions. We studied differences among eight rice cultivars in spikelet fertility at five different temperature levels in temperature gradient chamber (TGC) experiments. Six japonica and two indica cultivars were exposed to high‐temperature gradients in TGCs during the 2005 flowering season. Spikelet sterility increased with temperature in TGCs and differed among cultivars because of both variations in temperature tolerance and timing of heading. The correlation between spikelet fertility of individual panicles and both air temperature and panicle temperature during flowering was analyzed to compare tolerances among cultivars. The temperature (T₇₅) at which spikelet fertility was 75 % of maximum ranged from 34 to 39 °C air temperature and differed significantly among cultivars. Indica varieties had higher T₇₅ values than japonica varieties. The T₇₅ values based on panicle temperature also differed among cultivars, but the difference between indica and japonica varieties were less significant. We concluded that the higher temperature tolerances of indica cultivars in our experiments could be attributed to lower spikelet temperatures, and cultivars with similar spikelet temperatures still had different heat tolerances due to differences in pollination ability.     

Endosperm starch properties in several wheat cultivars preferred for Japanese noodles

To characterize superior genotypes for the white Japanese noodle, endosperm starch properties including amylose content, flour peak viscosity and starch-granule bound Waxy (Wx) proteins were compared using several cultivars preferred for noodle manufacture. Amylose contents from three seasons trials and flour peak viscosity from two seasons trials varied among cultivars. Low amylose content was a common property in the noodle cultivars, whereas a high peak viscosity was not always the case. When the Wx proteins were analyzed by sodium dodecylsulfate polyacrylamide gel electrophoresis, a clear reduction in the amount of low molecular weight protein or a lack of the high molecular weight protein occurred in the noodle cultivars. Segregation of Wx proteins was detectable in a B₁F₁ population, indicating that the Wx protein analysis has a potential as a surrogate of selecting low amylose genotypes in early generations.     

Identification of allelic variations of puroindoline genes controlling grain hardness in wheat using a modified denaturing PAGE

The amount of long chains (LC) of amylopectin in high-amylose rice is thought to be one of the important determinants of its quality when cooked. A wide range of differences in LC content have been reported in rice varieties, which can be clearly divided into four classes based on LC and apparent amylose content: namely, amylose and LC-free, low or medium-amylose and low-LC, high-amylose and medium-LC, high-amylose and high-LC. However, genetic factors controlling LC content have not been fully understood. Here, we performed quantitative trait loci (QTL) analysis of LC content using 157 recombinant inbred lines (RILs) derived from a cross of a low-LC cultivar, Hyogokitanishiki, and a high-LC line, Hokuriku 142. By analyzing randomly selected 15 RILs, it was shown that high LC content (≥11%) was associated with high setback viscosity (≥200 RVU), and that low LC (≤ 3%) was associated with low setback viscosity (≤ 130 RVU), as measured by a Rapid Visco Analyzer. With setback viscosity as an indicator for LC content, QTL analysis was conducted using 60 DNA markers including a CAPS marker that distinguished Wx a and Wx b alleles coding for granule-bound starch synthase I (GBSSI or Wx protein), the enzyme working for amylose biosynthesis. Only one QTL with a peak log of likelihood score at the wx locus was detected, and no line showing setback viscosity corresponding to the medium-LC class appeared. The fact that wx mutants of Hokuriku 142 lacked LC in their rice starch supports the view that the functional Wx allele is indispensable for LC synthesis in addition to amylose synthesis in rice endosperm. We suggest three possible reasons why no line with medium-LC content was observed. First, the locus (loci) responsible for generation of medium-LC may be located very close to the wx locus and not able to be dissected by the population and DNA markers we used. Second, there may be special QTLs for medium-LC cultivars that do not exist in low- or high-LC cultivars. Third, medium-LC cultivars may have an as-yet unidentified Wx allele with lower capability in LC synthesis compared to the Wx allele in high-LC cultivars.     

SEM DSC和RVA在豆类淀粉研究中应用

简要介绍了扫描电镜(SEM)、差示扫描量热(DSC)和快速黏度分析(RVA)技术的基本原理与在豆类淀粉研究中应用。扫描电镜技术可以对豆类淀粉的颗粒表面的形态进行观察,并可以测定淀粉颗粒的直径大小。差示扫描量热技术在淀粉的热力学性质研究上起到举足轻重的作用,通过DSC图谱可以得知淀粉糊化的起始温度(T0)、峰值温度(Tp)、终止温度(Tc)。快速黏度分析技术分析糊化淀粉的黏度是近年来广泛采用的方法之一。从RVA图中可以得到成糊温度、出峰时间、最大黏度、破损值、最小黏度、最终黏度、回复值等参数。     

淀粉和变性淀粉糊化特性的研究

用布拉班德淀粉粘度仪研究了不同的原淀粉和变性淀粉的糊化特性,用成糊温度(PT),热糊粘度(H)、冷糊粘度(C)、和各种粘度差,即破损值或崩解值(P-H)、回值(C-P)、总回值或稠度(C-H)、相对破损值(P-H/C-H)等来表示.这些特性在不同淀粉之间存在明显的差异.淀粉中直链淀粉的含量对淀粉的糊化和老化倾向影响很大.变性处理可以改变原淀粉的糊化特性,例如酯化(或醚化)能使玉米淀粉的成糊温度降低,老化倾向减小,粘度稳定性变差,而交联则使其粘度稳定性增强,能够抵抗酸和剪切力的影响.     

The effect of nitrogen concentration on nitrogen use efficiency and related parameters in cultivated rices (Oryza sativa L. subsp. indica and japonica and O. glaberrima Steud.) in hydroponics

Nitrogen use efficiency (NUE) in cultivated rice has become of utmost importance due to ecological and economical consequences of nitrogen (N) losses. However, detailed information on the components of NUE—physiological, absorption and agronomical NUEs—is lacking. The present study aimed to determine the components of NUE for three cultivars of Asian and African rices [IR64 (Oryza sativa indica), Azucena (O. sativa japonica) and TOG7105 (O. glaberrima)] exposed to a wide range of N supply, from excess to deficiency—from 4× to 1/8× of the standard Yoshida solution (1×). Increasing the N supply to 2× or 4× did not induce much change for most parameters, including tissue N concentrations and pNUE. However, aNUE and agNUE decreased gradually as the N supply increased from 1/2× to 4×. In contrast, lowering the N supply, particularly to 1/4× or 1/8×, induced a significant decrease in most measured parameters, except NUEs. The pNUE increased gradually when lowering the N supply from 1× to 1/8×, while aNUE and agNUE were maximal at 1/2 and/or 1/4× according to the cultivar. In contrast, the F_v/F_m and PSII values remained unchanged. Differences between cultivars were low. However, the O. glaberrima cultivar showed a significantly lower aNUE and agNUE than both O. sativa cultivars under low N supply (1/4 and 1/8×). These results demonstrate that all NUE components were sharply and differentially affected by low N supply, while the PSII remained unaffected. These results are important for determining the cultivar and N supply with the best balance between intensive and sustainable rice cultivation.     

水旱种植下多个品种蒸煮品质和稻米RVA谱的比较性研究

研究了多个品种于水旱种植下稻米RVA谱曲线的变化及其蒸煮和营养品质,结果表明:旱种条件下米粉的RVA谱发生明显的变化,主要表现在最高粘度、崩解值、最终粘度和回复值RVA谱特征值上.根据水、旱种植下稻米淀粉谱的变化特点,将供试品种分为三类,第一类品种是生产上可用于旱作的品种,该类品种旱作下蒸煮和食味品质有变优的趋势,     

Effect of storage time at low temperature on the volatile compound composition of Sevillana and Maravilla raspberries

In this study, the effect of storage time at low temperature on volatile compounds in two cultivars of raspberry, Rubus idaeus L. cv. Sevillana and Maravilla, was determined. A total of 28 compounds were identified in both cultivars and showed quantitative differences between the cultivars. The Sevillana cultivar was richer in volatile compounds than the Maravilla cultivar. β-Ionone had the highest concentration in both cultivars. We observed opposing trends in the volatile compound composition for the cultivars during storage at low temperature, in which ‘Sevillana’ lost compounds and ‘Maravilla’ was enriched. Therefore, storage at low temperature causes important changes in the volatile compound profile of raspberry, particularly the Sevillana cultivar, with significant decreases in C₁₃-norisoprenoids and increases in terpenes. These changes are most likely responsible for the aromatic differences between the cultivars because of the presence of terpenes in ‘Sevillana’ and C₁₃-norisoprenoids in ‘Maravilla’.