Polyamines mediate the effect of post-anthesis soil drying on starch granule size distribution in wheat kernels

Polyamines(PAs) are important endogenous plant growth regulators responding to environmental stress and mediating many physiological processes including grain filling in cereals.This study investigated whether PAs mediate the effect of post-anthesis soil drying on starch granule size distribution,starch content,and weight of superior and inferior kernels of wheat(Triticum aestivum L.).Two wheat cultivars were grown in pots.Three treatments,well-watered(WW),moderate soil drying(MD) and severe soil drying(SD),were imposed from 9 days post-anthesis until maturity.PA levels in kernels and small,medium and large granules were measured.The results showed that superior kernels had much higher free spermidine(Spd) and free spermine(Spm) concentrations,larger volumes of medium starch granules,and smaller-sized large granules than did inferior kernels under all the treatments.Compared to WW,MD significantly increased the concentrations of free Spd and free Spm,activities of soluble starch synthase and granule-bound starch synthase,volume of medium granules,and starch content and kernel weight of inferior kernels,and decreased the size of large granules.SD produced the opposite effect.Application of Spd or Spm to spikes produced effects similar to those of MD,and application of an inhibitor of Spd and Spm synthesis produced effects similar to those of SD.These results suggest that PAs mediate the effect of post-anthesis soil drying on starch biosynthesis in wheat kernels by regulating key enzymes in starch synthesis and that elevated PA levels under MD increase the volume of medium granules and kernel weight of inferior kernels.

Comparison of Starch Granule Size Distribution Between Hard and Soft Wheat Cultivars in Eastern China

Granule size distribution of wheat starch is an important characteristic that can affect its chemical composition and functionality. Two types of wheat cultivars, the hard and soft wheat cultivars, grown at Tai＇an Experimental Station of Shandong Agricultural University, Taian, Shandong, China, were examined in this study. The granule size distribution and amylose contents in wheat grains were studied and compared, and relationships between the properties were identified. A clear bimodal distribution of granule size was shown in all wheat cultivars. Volume distribution of starch granules shows the typical bimodal with peak values in the ranges of 5.6-6.1μm and 20.7-24.9μm, respectively. Also, granule surface area distribution was bimodal with peak values in the ranges of 2.4-3.2μm and 20.7-24.9μm, respectively. Number distribution of granules was a typical population with a peak value in the range of 0.54-1.05μm. Contributions from the granules 〈 2.8μm and 〈 9.9μm to the total volume were in the ranges of 94.2-95.1% and 99.7-99.9% of total number, respectively. Proportions of granules〈2.8μm, 2.8-9.9μm, 9.9-22.8μm, and 22.8-42.8μm were in the ranges of 12.9-14.3%, 28.4-31.1%, 33.5-35.6%, and 19.7-22.7% for hard wheat, and 10.3-13.9%, 26.6-28.1%, 32.7-34.6%, and 24.2-27% for soft wheat. Hard wheat had greater B-type granules （ 〈 9.9μm）, and had fewer granules of 22.8-42.8μm than soft wheat. Amylose content was positively related to volume percentage of granules 22.8-42.8μm, and negatively related to volume percentage of granules 2.8-22.8μm.

QTL mapping of starch granule size in common wheat using recombinant inbred lines derived from a PH82-2/Neixiang188 cross

Starch is a crucial component determining the processing quality of wheat(Triticum aestivum L.)-based products. Wheat starch generally contains A-type and B-type starch granules, having different effects on starch properties and end-use qualities. In the present study, 240 recombinant inbred lines(RILs) derived from a PH82-2/Neixiang 188 cross were grown in Anyang, Henan, China, during three cropping seasons. A-type and B-type granule contents were determined using a laser diffraction particle size analyzer, defined as the percentage of total starch volume. A total of 195 SSR and STS markers were used to construct a genetic map. QTL analysis was performed by composite interval mapping. Three QTL for A-type starch granule content were mapped on chromosomes 1DL, 7BL and 4AL, explaining5.6%, 5.2% and 3.8% of the phenotypic variation, respectively. These results provide useful information for improving starch quality in common wheat.

Exogenous Application of Abscisic Acid or Gibberellin Acid Has Different Effects on Starch Granule Size Distribution in Grains of Wheat

Granule size distribution of wheat starch is an important characteristic that can affect its chemical composition and the functionality of wheat products. Two high-yield winter wheat cultivars were used to evaluate the effects of the application of exogenous ABA or GA during the reproductive phase of the initial grain filling on starch granule size distribution and starch components in grains at maturity. The results indicated that a bimodal curve was found in the volume and surface area distribution of grain starch granules, and a unimodal curve was observed for the number distribution under all treatments. The exogenous ABA resulted in a significant increase in the proportions （both by volume and by surface area） of B-type （〈9.9 Ixm in diameter） starch granules, with a reduction in those of A-type （〉9.9 ~tm） starch granules, while, the exogenous GA3 led to converse effects on size distribution of those starch granules. The exogenous ABA also increased starch, amylose and amylopectin contents at maturity but significantly reduced the ratio of amylose to amylopectin. Application of GA3 significantly reduced starch content, amylopectin content but increased the ratio of amylose to amylopectin. The ratio of amylose to amylopectin showed a significant and negative relationship with the volume proportion of granules 〈9.9 μm, but was positively related to the volume proportion of granules 22.8-42.8 μm.

The Effect of Maize Grain Size on the Physicochemical Properties of Isolated Starch, Crude Maize Flour and Nixtamalized Maize Flours

Usually, the maize cob is formed by grains of medium size. However, the extremes have larger or smaller size grains. The objective of this study was to investigate the influence of grain size from the same hybrid on the physicochemical properties of isolated starch, crude maize flours and nixtamalized maize flours. Two hybrids, one from CIMMyT-Mexico called IMIC-254 and one commercial sample from Monsanto (Puma) were studied. The isolated starch granules from small, medium, and large grains exhibit the same size and distribution. The grain size has influence in the determination of cooking and steeping times;small grains reach these parameters faster than medium and large ones. The hardness of the grain size for both hybrids does not showed statistical differences between them. The starch from small, medium and large grains is mainly composed of amylopectin;this result is confirmed by X-ray diffraction and Megazine analysis. The apparent viscosity of the isolated starches of small grains showed statistically significant higher peak values. According to these results, it is possible to use small, medium, and large grains to obtain products with the same physicochemical properties, by adjusting the cooking and steeping times and Ca2+ content.

丙酸酯化-叔胺化淀粉浆料的制备及其黏附性能

为改善淀粉浆料的黏附性能,以提升淀粉浆料对经纱的上浆质量,以丙酸酐(PA)为酯化剂,二甲氨基氯乙烷盐酸盐(DMC-HCl)为叔胺醚化剂,采用固定PA用量及改变DMC-HCl用量的方式,以水为介质,在弱碱性和低温条件下,对酸解淀粉(AHS)进行丙酸酯化-叔胺化处理,制备出一系列具有不同总取代度的丙酸酯化-叔胺化淀粉(PTAS)。对其进行化学结构表征、元素分析、颗粒形貌观察分析以及取代度测定,并对其与涤纶、涤/棉与棉粗纱间黏附性,以及浆液表面张力进行考察。结果表明:固定PA对AHS质量分数为4.63%、改变DMC-HCl用量为10~40 g,可制备出丙酸酯化程度为0.030、叔胺化程度为0.010~0.035的PTAS样品;化学结构表征与元素分析结合证实了PTAS的成功制备,PTAS颗粒仍保持颗粒态形貌,但部分颗粒表面产生损伤;这种复合变性能够明显改善淀粉对涤纶、棉纤维的黏附性能,提升淀粉浆液的表面活性,表现为PTAS对涤纶、涤/棉及棉3种粗纱的黏合力均明显高于AHS,表面张力明显低于后者;随着PTAS总取代度的增加,其表面张力逐渐降低、黏合力逐渐增大、对棉纤维黏附性的提升优于对涤纶纤维。

种植密度对沿淮玉米籽粒淀粉粒度分布与糊化特性的影响

分析不同种植密度对沿淮玉米籽粒中淀粉粒度分布与糊化特性的影响。以豫单132、京科968等13个玉米杂交品种为材料,设置56 250株/hm^(2)、67 500株/hm^(2)、77 250株/hm^(2)等3个种植密度,分析不同种植密度对玉米籽粒品质、淀粉粒度分布与糊化特性的影响。结果表明,在种植密度56 250~77250株/hm^(2)范围内,随着种植密度的增加,玉米籽粒的蛋白质和脂肪含量呈递减趋势,淀粉含量呈递增趋势,即淀粉/蛋白质比率增加。玉米籽粒大型淀粉粒体积和表面积百分比显著增加,小型淀粉粒却显著降低。增加种植密度后玉米淀粉的峰值黏度、低谷黏度、最终黏度和稀懈值等黏度参数均呈显著升高。相关分析表明,玉米籽粒峰值黏度等黏度参数与小、大型淀粉粒体积百分比呈正相关,与中型淀粉粒体积百分比呈显著或极显著负相关。说明种植密度影响玉米籽粒淀粉粒度分布、淀粉黏度参数和组分含量。

拔节期渍水对软质小麦淀粉粒度分布与糊化特性的影响

为明确拔节期渍水对软质小麦淀粉粒度分布与糊化特性的影响。在大田条件下,于2021—2023年,选用软质小麦品种华成麦1688和荃麦725为试验材料,设对照(CK)和渍水(WL)2种处理,在小麦拔节期进行连续10 d的渍水处理,研究拔节期渍水对软质小麦淀粉粒度分布及黏度参数的影响及其相互关系。结果表明,与对照相比,拔节期渍水胁迫通过降低小麦穗数、穗粒数及千粒重,从而降低小麦产量,籽粒湿面筋含量、蛋白质含量显著降低,淀粉含量显著增加。拔节期渍水胁迫抑制了小麦胚乳B淀粉的产生和生长,使小麦B型淀粉粒体积、表面积及数目百分比显著降低,其中主要影响2.8~10.0μm的淀粉粒;A型淀粉粒体积、表面积百分比显著增加,以影响其中10.0~22.0μm的淀粉粒为主,渍水胁迫对A型淀粉粒数目百分比无显著性影响。渍水胁迫后,面粉峰值黏度、低谷黏度、最终黏度、稀懈值及回升值显著增加。可见,拔节期渍水胁迫改变了小麦淀粉粒度分布,通过降低B型淀粉粒占比,增加A型淀粉粒占比,进而增加峰值黏度等黏度参数,最终影响小麦籽粒品质。

氧化-叔胺化淀粉的制备及其对羊毛低温性能的影响

为提高淀粉在羊毛经纱低温上浆中的应用效果,在碱性条件下,制备氧化玉米淀粉(OCS)并与醚化剂(二甲氨基甲酰氯)反应制备氧化-叔胺化淀粉(OTAS),使用扫描电子显微镜(SEM)和X射线能谱仪(EDS)对其进行了表征分析,并考察了这种变性对淀粉溶解度及其低温粘度及粘度热稳定性、粘附性、羊毛经纱上浆等性能的影响。结果表明,OTAS能有效降低淀粉的低温粘度,提高其低温粘度热稳定性,提高其溶解度及其对羊毛纤维的低温粘合性能,提升淀粉膜的溶胀度、溶解率,缩短水溶时间,降低膜脆性,具有更好的低温浆纱性能。随着取代度增加,OTAS的低温粘度、溶解度及其对羊毛纤维的低温粘附性能均逐渐提升,从而为OTAS在羊毛经纱低温上浆中的应用奠定了基础。

大小粒型藜麦籽粒表型、灌浆特性及淀粉合成酶活性的差异分析

【目的】籽粒大小是影响藜麦产量、商品性和加工特性的重要因素,考察灌浆期大小粒型藜麦籽粒表型、灌浆特性和淀粉合成酶活性的差异,可为大粒型藜麦品种的选育提供理论指导。【方法】选择千粒重大于5.0 g和小于3.0 g的藜麦材料各2份,在青海省农林科学院种质资源创新试验基地进行田间试验,比较自灌浆期始7 d、14 d、21 d和28 d籽粒表型、灌浆特性和淀粉合成酶活性等在大小粒型藜麦间的差异。【结果】(1)大小粒型藜麦籽粒面积、周长、直径、粒长、粒宽表型性状随着生育时期均极显著增大,且粒型间存在显著差异,并以籽粒面积和周长差异最大,大粒型藜麦分别显著高于小粒型藜麦9.12%~11.54%和21.49~23.92%。(2)灌浆期间大粒型藜麦百粒干质量始终显著高于同期小粒型藜麦,平均增幅在21.23%~31.04%;大小粒型藜麦灌浆速率随生育期均先上升后下降,均符合“慢—快—慢”的变化规律,但达到峰值时间和峰高明显不同,大粒型峰值出现早而高,小粒型则低而迟。(3)淀粉分支酶(SBE)、蔗糖合成酶(SS)、可溶性淀粉合成酶(SSS)和ADPG焦磷酸化酶(AGP)在大小粒型藜麦籽粒灌浆期呈现不同的变化趋势,SBE和SS活性表现为小粒型藜麦强于大粒型藜麦,而SSS和AGP活性则表现为大粒型藜麦强于小粒型藜麦。【结论】藜麦籽粒灌浆期间4种淀粉合成酶活性的差异,致使淀粉合成积累量和灌浆速率峰值的不同,进而形成籽粒表型性状的差异,而SSS和AGPase是影响藜麦籽粒大小形成的关键酶。

花后弱光对弱筋小麦淀粉粒度分布与黏度参数的影响

为探讨花后弱光对弱筋小麦淀粉粒度分布与黏度参数的影响,以弱筋小麦品种皖西麦0638、宁麦13为材料,设置开花后(开花期—成熟期)30%遮荫处理,分析了不同处理下弱筋小麦淀粉粒度分布与黏度参数及其相互关系。结果表明,与正常光照相比,花后弱光显著降低小麦穗粒数、千粒重、产量和容重,显著增加籽粒蛋白质含量、湿面筋含量及沉降值;显著降低B型淀粉粒体积、表面积及数目百分比,以影响2.8~10μm淀粉粒为主;增加A型淀粉粒体积、表面积及数目百分比,以影响10~22μm淀粉粒为主;显著降低小麦峰值黏度、低谷黏度、最终黏度、稀懈值及回升值。相关分析表明,弱筋小麦B型淀粉粒体积分布与峰值黏度、低谷黏度、最终黏度、稀懈值和回升值均呈显著正相关,与A型淀粉粒体积分布呈显著负相关。综上,花后弱光降低弱筋小麦产量、B型淀粉粒占比,增加A型淀粉粒占比;显著降低峰值黏度等黏度参数。

多元酯化淀粉在新型纤维品种中的上浆工艺

探讨多元酯化淀粉JF-999的浆料性能,替代PVA用于新型纤维纱线上浆的效果。对比测试JF-999浆料和常规PVA浆料的浆液和浆纱性能,对两种配方的浆纱各项指标分析,以及织造生产效率对比。试验结果表明:JF-999多元酯化淀粉黏度及稳定性较好,与天竹等新型纤维具有良好的亲和性,且黏着力较好;浆纱质量稳定,好轴率较高,具有良好的浆纱增强和减伸效果,布机效率提升明显;易退浆、无污染,完全符合绿色环保要求,可以替代PVA用于新型纤维品种的经纱上浆。

THE ADHESIVE CAPACITY OF STARCH GRAFT COPOLYMERS TO POLYESTER/COTTON FIBER

The advantages of using starch graft copolymers as warp sizes in textile were briefly discussed, and the factors of affecting adhesive capacity to the fiber were analysed. By using eerie ammonium nitrate as an initiator under nitrogen atomosphere, a number of vinyl and/or acrylic monomers such as acrylic acid, acrylamide, methyl acrylate, ethyl acrylate, butyl acrylate, hydroxyethyl acrylate, methyl methacrylate, butyl methacrylate, vinyl acetate and the combinations among them were graft copolymerized respectively onto granular corn starch in aqueous dispersion. The adhesive capacity of these starch graft copolymers to polyester/cotton fibers was evaluated by a slightly sized rovings according to V. K. Aggarwal’s method which measures the breaking strength and elongation of the rovings impregnated with the size paste. The influences of the monomers and their combinations, the grafting technological processes and the pretreatment methods before graft copolymerization upon adhesive capacity have been

DEGREE OF SUBSTITUTION OF THE IONIZED STARCHES AND THEIR ADHESIVE CAPACITY TO POLYESTER / COTTON FIBERS

Adhesive capacity of quaternary ammonium starch and starch phosphate to the polyester / cotton fibers was studied by means roving method for the purpose of improving the sizing performance and decreasing the cost. By introducing different amount of quaternary ammonium or phosphate groups onto starch molecules, the modified starch with a series of defferent degree of substitution was prepared. Therefore the regularity of adhesive capacity, extended property and size-absorbing ability with the change in degree of substitution (DS) was obtained through the researches. The experiments demonstrate that the DS of the two modified starches show a marked influence upon the properties mentioned above. The starch phosphate is superior to quaternary ammonium starch as warp size for polyester / cotton yarns from the viewpoint of adhesive capacity and cost, although both of them are better than natural one. To improve the adhesive capacity to polyester / cotton fibers, DS≥0.027 is necessary for quaternary ammonium

Effects of Early- and Late-Sowing on Starch Accumulation and Associated Enzyme Activities During Grain Filling Stage in Rice

The environmental temperature occurring during the grain filling stage is an important factoraffecting starch synthesis and accumulation in rice. We investigated starch accumulation, amylaseactivity and starch granule size distribution in two low-amylose japonica rice varieties, Nanjing 9108 andFujing 1606, grown in the field at different filling temperatures by manipulating sowing date. The two ricevarieties exhibited similar performances between two sowing dates. Total starch, amylose andamylopectin contents were lower at the early-filling stage of T1 treatment (Early-sowing) compared withthose at the same stage in T2 treatment (Late-sowing). In contrast, at the late-filling stage, when fieldtemperatures were generally decreasing, total starch and amylopectin contents in T1 were highercompared to those in T2. The ideal temperature for strong activity of ADP-glucose pyrophosphorylaseand soluble starch synthase was about 22℃. A higher temperature from the heading to maturity stagesin T1 increased the activities of starch branching enzyme and suppressed the activities of granule boundstarch synthetase and starch debranching enzyme. We found that rice produced larger-sized starchgranules under the T1 treatment. These results suggested that due to the early-sowing date, the hightemperature (30℃) occurring at the early-filling stage hindered starch synthesis and accumulation,however, the lower temperatures (22 ℃) at the late-filling stage allowed starch synthesis and accumulationto return to normal levels.

Emsize CP-L浆料应用实践

Em size CP-L马铃薯变性淀粉具有粘度低、粘着力强、与其他浆料混溶性好等优点,介绍了生产细号高密宽幅织物的浆纱工艺与经验体会。实践证明,应用Em size CP-L浆料浆纱成本低、浆纱质量好、织机效率高。

A plastidic ATP/ADP transporter gene, IbAATP, increases starch and amylose contents and alters starch structure in transgenic sweetpotato

A plastidic adenosine triphosphate（ATP）/adenosine diphosphate（ADP） transporter（AATP） is responsible for importing ATP from the cytosol into plastids. In dicotyledonous plants, increasing ATP supply is a potential way to facilitate anabolic synthesis in heterotrophic plastids. In this study, a gene encoding the AATP protein, named Ib AATP, was isolated from sweetpotato（Ipomoea batatas（L.） Lam.）. Transcripts of Ib AATP were predominantly detected in the storage roots and leaves and were induced by exogenous sucrose and subjected to circadian rhythm. Transient expression of Ib AATP in tobacco and onion epidermal cells revealed the plastidic localization of Ib AATP. The overexpression of Ib AATP in sweetpotato significantly increased the starch and amylose contents and led to enlarged starch granules. The IbA ATP-overexpressing plants showed altered fine structure of amylopectin, which contained an increased proportion of chains with a degree of polymerization（DP） of 10–23 and a reduced number of chains with a DP of 5–9 and 24–40. In addition, starch from the transgenic plants exhibited different pasting properties. The transcript levels of starch biosynthetic genes, including Ib AGP, Ib GBSSI, Ib SSIIV, and Ib SBE, were differentially regulated in the transgenic plants. These results revealed the explicit role of Ib AATP in the starch biosynthesis of sweetpotato and indicated that this gene has the potential to be used to improve starch content and quality in sweetpotato and other plants.

SYNTHESIS AND SIZING PROPERTIES OF GRAFT STARCHES AS WARP SIZING MATERIALS FOR POLYESTER/COTTON BLEND SPUN YARN

Grafting a number of monomers such as acrylic acid, acrylamide, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, butyl methacrylate and vinyl acetate onto granular corn starch was carried out respectively in aqueous dispersion by using cerie ammonium nitrate as an initiator under nitrogen atmosphere. Conversion of monomer, grafting ratio and grafting efficiency were measured by the method of combining the chemical quantitative analysis with the weight. The adhesive power of the starch graft copolymers to polyester/cotton fiber was evaluated by measuring the breaking strength and elongation of the roving impregnated with the paste. The viscosity change of the size paste before and after grafting was studied. The mechanical properties of polyester/cotton fibre yarn sized by the graft starch were tested. The main conclusions are as follows: (1) monomers which were graft coplymerized onto starch have a significant influence upon the viscosity of the size paste; (2) the adhesive power

Effect of Starch Dodecenylsuccinylation on the Adhesion and Film Properties of Dodecenylsuccinylated Starch for Polyester Warp Sizing

A series of dodecenylsuccinylated starches( DSSs) with different degree of substitution( DS) were prepared via the esterification of dodencenylsuccinic anhydride with hydrolyzed cornstarch in aqueous dispersion for investigating the influences of starch dodecenylsuccinylation upon the performances such as apparent viscosity and surface tension of starch paste, film behaviors,and adhesion to fibers for warp sizing. It was found that the dodecenylsuccinylation was able to reduce the surface tension of cooked starch paste and enhance the adhesion of starch to polyester fibers. It was also capable of depressing the brittleness of native starch and improving the mechanical behaviours such as breaking elongation and work-to-break of starch film. Initial increase in DS level of dodecenylsuccinylation enhanced these positive effects,while excessively increasing the level resulted in marked reduction in tensile strength of starch film and significant decrement in reaction efficiency. X-ray diffraction patterns of starch films showed the dodecenylsuccinates derivatized onto the backbones of starch depressed the degree of crystallinity of starch film. Based on the paste behaviors, adhesion, and film properties, the dodecenylsuccinylation level is recommended in a range of 0. 015-0. 025 for sizing polyester warps.

Starch-g-poly (vinyl alcohol) as Compatibilizer for Reducing the Phase Separation Rates of Polyvinyl Alcohol/Cornstarch Pastes

Starch- g-poly(vinyl alcohol) as a compatibilizing agent for reducing the phase separation rates of polyvinyl alcohol/starch pastes has been investigated by blending and dissolving the two polymers in distilled water. The separation rates were quantitatively evaluated by the term of initiul demixing time. The grafted starches, with a series of grafting ratios, were prepared by grafting a number of vinyl acetate onto granular cornstarch in aqueous dispersion and then alcoholating in methanol. It was found that the addition of small amounts of starch- g poly (vinyl alcohol ) in the size compositions can effectively decrease the separation rates of the blended pastes in comparison to pure starch/PVA ones.Moreover, the influence of the grafting ratio, starch content, and PVA variety on the separation rates was also studied.