鲁麦21和济南17胚乳发育过程中淀粉粒的动态变化

 【目的】以2个不同品质类型的小麦品种为供试材料,分析小麦胚乳中淀粉粒的分布特征和变化特点。【方法】选用鲁麦21（弱筋）和济南17（强筋）两个小麦品种,利用激光衍射粒度分析仪研究其胚乳发育过程中淀粉粒的积累动态。【结果】花后不同时期小麦胚乳淀粉粒数目的变化均呈单峰曲线,峰值出现在0.5～1.1μm。花后7 d,A-型淀粉粒已经出现,最大直径20μm;花后10 d,淀粉粒直径范围扩大到30μm;至花后14 d, B-型淀粉粒开始产生;花后21 d又产生了一个新淀粉粒群体,即C-型淀粉粒;花后24～28 d,籽粒中新淀粉粒的产生仍在继续;花后35 d,主要是最小粒径淀粉粒直径的扩大。与强筋小麦济南17相比较,花后7～14 d,弱筋品种鲁麦21胚乳中小于0.6μm的淀粉粒数目百分比较低,大于0.6μm的淀粉粒数目百分比较高,花后17～28 d则相反。【结论】灌浆前期鲁麦21胚乳中淀粉粒的增长速率较快,而灌浆后期新淀粉粒合成能力较强。成熟期,济南17籽粒中的B-型淀粉粒所占体积和表面积百分比较高,而弱筋小麦鲁麦21的A-型淀粉粒体积和表面积百分比较高。     

灌浆期遮光对糯小麦和非糯小麦淀粉组分及理化特性的影响

【目的】揭示灌浆期遮光对糯小麦和非糯小麦籽粒淀粉理化特性影响的差异,探讨籽粒淀粉组分与理化特性的内在联系。【方法】大田条件下,选用非糯小麦品种轮选987和糯小麦品种农大糯50222,分别于灌浆前期(花后1—10 d)、灌浆中期(花后11—20 d)和灌浆后期(花后21—30 d)遮去60%的光合有效辐射处理,以大田自然光强为对照(CK),研究灌浆期遮光对糯小麦和非糯小麦籽粒淀粉组分和理化特性的影响。【结果】灌浆期遮光显著降低小麦籽粒总淀粉、直链淀粉和支链淀粉含量,其中灌浆前期遮光降低幅度最大,而灌浆后期最小,且弱光对轮选987总淀粉含量的影响大于农大糯50222。灌浆期遮光轮选987直/支比值增大;而农大糯50222的直/支比值在灌浆前期和中期遮光后减小,灌浆后期遮光无变化;灌浆前期和后期遮光显著提高轮选987淀粉B型淀粉粒的体积、表面积和数目比例,降低A型淀粉粒的体积、表面积和数目比例,而灌浆中期遮光则呈相反趋势。灌浆期遮光均显著提高了农大糯50222淀粉B型淀粉粒的体积、表面积和数目比例,降低了A型淀粉粒的体积、表面积和数目比例。灌浆期遮光两小麦淀粉的相对结晶度呈降低趋势,遮光对其影响程度随遮光时期的延迟而减小,且农大糯50222淀粉的相对结晶度显著大于轮选987。灌浆前期和灌浆中期遮光降低了轮选987淀粉的峰值黏度、谷值黏度、最终黏度和稀懈值。灌浆各时期遮光均降低了农大糯50222淀粉的上述指标,但仍高于轮选987。相关性分析表明,直链淀粉含量、直支比值与最终黏度、反弹值、峰值黏度、谷值黏度及糊化时间呈显著负相关,支链淀粉含量与其呈显著正相关。B型淀粉粒的体积比例与最终黏度和反弹值呈显著负相关。B型淀粉粒表面积比例和相对结晶度、最终黏度、反弹值、糊化时间呈显著正相关,与糊化温度呈显著负相关。【结论】灌浆期遮光改变了小麦胚乳淀粉组分、粒度分布、相对结晶度及其主要糊化特征参数。小麦胚乳淀粉组分与晶体特性和糊化特性之间均存在明显的相关性,表明遮光影响了小麦淀粉组分,间接影响了其理化特性。     

陕糯1号与非糯小麦西农1330胚乳发育及淀粉形态、粒径分析

【目的】比较分析糯小麦陕糯1号和非糯小麦西农1330胚乳发育及淀粉形态、粒径的差异,为糯性与非糯性小麦的品质改良和开发利用提供理论依据。【方法】选用陕糯1号（糯性）和西农1330（非糯性）2个小麦品种,取发育过程中籽粒（花后5、8、12、15、18、21、25和28 d）液氮速冻后横断,经戊二醛和锇酸固定、磷酸缓冲液漂洗、丙酮梯度脱水、Epon812胶包埋后,采用超薄切片机切成1 μm厚的半薄切片,经1%甲苯胺蓝染色后采用光学显微镜观察胚乳细胞发育。提取2个小麦品种的淀粉粒,将其与成熟期籽粒横断面分别固定在样品台上,经离子溅射镀金后用扫描电镜观察成熟期胚乳结构及淀粉粒形态。采用MASTERSIZER-2000激光粒度仪分析淀粉粒粒径分布特征,每个样品重复3次,测定结果采用DPS统计软件进行数据统计分析,Sigmaplot 12.0作图。【结果】在小麦籽粒发育过程中,陕糯1号胚乳细胞体积大小及增大幅度均小于西农1330,发育早期,二者淀粉粒表面均能被甲苯胺蓝染色,发育中后期,陕糯1号淀粉粒仍能被染色,西农1330淀粉粒则不能被染色。与西农1330相比,陕糯1号胚乳细胞内蛋白基质较少,蛋白质与淀粉粒结合较疏松。陕糯1号B型淀粉粒形态多为不规则的多边形,西农1330B型淀粉粒大多呈圆球形,二者A型淀粉粒形态无明显差异。陕糯1号和西农1330淀粉粒粒径分布存在差异。陕糯1号淀粉粒体积分布呈四峰曲线变化,西农1330则呈双峰曲线变化,二者表面积分布均呈三峰曲线变化,数目分布均呈单峰曲线变化。陕糯1号A 型（>10 μm）淀粉粒体积、表面积百分比均低于西农1330,B型（<10 μm）淀粉粒体积、表面积百分比均高于西农1330,二者A、B型淀粉粒数目百分比无明显差异。陕糯1号中SB型（<1 μm）淀粉粒的体积、表面积、数目占总淀粉粒比例分别比西农1330低1.11%、11.60%和9.28%,LB型（1-10 μm）淀粉粒的体积、表面积、数目占总淀粉粒比例分别比西农1330高8.27%、15.88%、9.27%。陕糯1号具有少量LA（>53 μm）型淀粉粒,而西农1330没有。【结论】在小麦籽粒发育过程中,陕糯1号与西农1330的胚乳发育及淀粉形态存在明显差异。LB型淀粉粒对陕糯1号与西农1330 B型淀粉粒粒径分布影响较大。     

钾肥对玉米胚乳淀粉粒分布及糊化特性的影响

【目的】本文目的是为明确钾素对玉米胚乳淀粉粒分布与糊化特性的影响。【方法】以玉米杂交种郑单958为材料,设置不同钾素水平,即K0、K1、K2、K3(分别施K2O 0、135、270、405 kg/hm2),分析不同钾肥水平下玉米胚乳淀粉粒粒度分布及糊化特性的变化。【结果】不同处理下玉米籽粒淀粉粒体积和表面积分布均呈双峰曲线,数目分布呈单峰曲线。以玉米淀粉粒直径3和18μm为界线,可将玉米籽粒淀粉粒划分为小型淀粉粒(3μm)、中型淀粉粒(3～18μm)和大型淀粉粒( 18μm) 3组。小型淀粉粒组数目占总数大约98%以上,说明玉米胚乳淀粉粒主要由小型淀粉粒组成。随着钾素水平的增加,玉米胚乳 18μm淀粉粒体积与表面积百分比显著减小;而玉米胚乳 18μm淀粉粒数目百分比没有显著变化,可见钾素有利于玉米胚乳淀粉粒个体体积的增大。相关分析表明,淀粉峰值黏度、保持黏度与最终黏度与 18μm淀粉粒体积百分比呈显著正相关。【结论】可见钾肥通过降低玉米胚乳大型淀粉粒比例、降低大型淀粉粒比例,进而影响淀粉糊化特性,即降低了其淀粉峰值黏度、保持黏度与最终黏度等参数。     

不同类型甘薯品种块根淀粉粒粒度的分布特征

 【目的】阐明不同类型甘薯块根淀粉粒粒度的分布特征及其与淀粉品质的关系。【方法】选用6个淀粉型品种、5个食用型品种和1个兼用型品种,研究块根中淀粉粒的体积和数目分布、淀粉粒体积和数目分布与淀粉及其组分含量的相关性。【结果】甘薯块根含有小（粒径＜3.36 µm）、中（粒径3.36—19.76 µm）和大（粒径＞19.76 µm）3种类型淀粉粒,其粒径范围为0.39—55.14 µm。淀粉粒体积和数目都表现为双峰分布,低谷粒径均为3.36 µm;其中,粒径＜3.36 µm的淀粉粒体积占总体积的9.8%—18.5%,而粒径＜3.36 µm的淀粉粒数目占总数目的97.7%—99.1%。与淀粉型品种相比,食用型品种粒径＜3.36 µm的淀粉粒所占体积百分比和粒径＜1.00 µm的淀粉粒所占数目百分比较高。块根总淀粉、直链淀粉和支链淀粉含量与小型和中型淀粉粒的体积百分比呈显著负相关,与大型淀粉粒的体积百分比呈显著正相关;支/直链淀粉比率与小型和中型淀粉粒的体积百分比呈显著正相关,与大型淀粉粒的体积百分比呈显著负相关。【结论】食用型甘薯块根中小型淀粉粒所占比例较高,而淀粉型甘薯块根中大型淀粉粒所占比例较高。     

不同氮素水平下追氮时期对小麦淀粉粒度分布的影响

【目的】分析不同追氮时期对成熟期小麦胚乳淀粉粒粒度分布的影响。【方法】以矮抗58和山农22为材料,在2种氮素水平(N1:120 kg/hm~2,N2:240 kg/hm~2)下设置2个追氮时期(返青期、拔节期)处理,研究小麦籽粒淀粉粒粒度分布的变化。【结果】在同一氮素水平下,两品种拔节期追氮处理籽粒淀粉含量显著低于返青期追氮处理(P0.05),但淀粉积累量显著高于返青期(P0.05)。在N1水平下,与返青期追氮处理相比,拔节期追氮降低了胚乳淀粉粒平均粒径,显著提高B型淀粉粒体积和表面积百分比(P0.05),降低A型淀粉粒体积和表面积百分比;在N2水平下,与返青期追氮处理相比,拔节期追氮显著提高胚乳淀粉粒平均粒径(P0.05),提高了A型淀粉粒体积和表面积百分比,降低B型淀粉粒体积和表面积百分比,两品种表现一致。追氮时期与施氮水平对小麦A、B型淀粉粒数量分布影响不显著(P0.05)。【结论】在施纯氮120kg/hm~2条件下,追氮时期推迟主要通过增加小麦籽粒B型淀粉粒体积百分比,进而有利于籽粒淀粉的积累;在施纯氮240 kg/hm~2条件下,追氮时期推迟主要通过增大淀粉粒个体体积,即A型淀粉粒的体积百分比增加,进而有利于籽粒淀粉的积累。     

不同淀粉含量玉米籽粒淀粉粒度的分布特性

  【目的】 比较不同淀粉含量玉米籽粒淀粉粒度分布特性,及其与籽粒总淀粉、蛋白质含量和容重的相关性。【方法】选用普通型品种农大108、郑单958和高淀粉型品种费玉3号、郑单18,对成熟期玉米籽粒中淀粉粒的体积、数目和表面积分布进行分析测定。【结果】成熟期玉米籽粒胚乳内淀粉粒的粒径分布范围为0.37—31.5μm,以2μm和15μm为界限,将淀粉粒分为小型、中型和大型三类。淀粉粒的体积和表面积分别表现为双峰和三峰分布,淀粉粒的数目表现为单峰分布,其中小淀粉粒组数目占总数的95%左右;高淀粉玉米小淀粉粒组（＜2μm）和中淀粉粒组（2—15μm）所占体积分数显著高于普通型玉米,而在普通型玉米中,大淀粉粒组（＞15μm）所占的数目、体积和表面积百分比相对较高;籽粒总淀粉含量与0.8—2μm,2—10μm和10—15μm的淀粉粒体积百分比均呈正相关,其中与前两者的相关系数达到显著水平,与其它粒径范围的淀粉粒体积百分比呈负相关;蛋白质含量及籽粒容重与所有粒径范围内的淀粉粒体积百分比无明显相关性。【结论】玉米胚乳淀粉粒数目、体积和表面积分别呈单峰、双峰和三峰曲线变化,高淀粉型玉米小、中型淀粉粒组的体积百分比显著高于普通型玉米。     

糯小麦胚乳发育过程中淀粉粒形态变化及A、B型淀粉粒的显微观察

利用扫描电子显微镜对小麦胚乳发育过程中淀粉粒的形态和成熟胚乳中的A、B型淀粉粒进行观察。电子显微镜扫描结果显示,花后5~10d,糯小麦胚乳中可见到一些体积较小的A型淀粉粒,10~15d以A型淀粉粒数量增多和体积增大为主;B型淀粉粒在花后15d已经形成,但此时B型淀粉粒的数量少;花后20d—成熟前B型淀粉粒的数量和体积逐渐增长。糯小麦成熟籽粒胚乳中淀粉粒的直径分布为0.96~34.92μm。与普通小麦相比,糯小麦A型淀粉粒的形状较扁平;表面没有普通小麦光滑;B型淀粉粒的形状比普通小麦更无规则,且更容易发生聚集现象。另外,发现在A型淀粉粒上有许多孔洞;在5 000倍数下观察,发现这些孔洞结构从A型淀粉粒表面一直延伸到其内部。     

糯玉米胚乳发育过程中淀粉粒粒度分布的变化

为明确糯玉米淀粉粒粒度分布形成过程及特征,为糯玉米淀粉品质改良及调控糯玉米淀粉粒粒度提供理论依据,采用激光衍射粒度分析仪测定糯玉米胚乳发育过程中淀粉粒粒径以及体积、表面积和数目分布的变化。结果表明,授粉后10~20 d,糯玉米胚乳淀粉粒粒径下限逐渐减小,粒径上限和平均粒径显著增大;授粉后20d一直到成熟期,粒径各项指标无显著变化。随着胚乳发育,糯玉米胚乳淀粉粒体积和表面积分布均呈现"单峰-双峰-三峰"的动态变化,数目分布始终表现为单峰曲线。以成熟期淀粉粒体积分布三峰曲线的谷值为界线,将糯玉米淀粉粒分为小型(3.519μm)、中型(3.519~7.422μm)和大型(7.422μm)。胚乳发育前期,小型淀粉粒所占体积和表面积百分比呈降低趋势,数目百分比呈增加趋势,中型淀粉粒所占体积、表面积和数目百分比整体上呈降低趋势,而大型淀粉粒则呈增加趋势;淀粉粒的体积、表面积和数目分布均以小型淀粉粒所占比例最高,其次为中型淀粉粒,大型淀粉粒所占比例最低。胚乳发育中后期,不同粒径淀粉粒分布情况均趋于稳定,体积分布以大型淀粉粒为主,而表面积和数目分布以小型淀粉粒为主。因此,胚乳发育前期是糯玉米淀粉粒形成的关键时期,此时期调控淀粉粒粒度分布,可有效改良糯玉米淀粉品质。     

硫肥对小麦籽粒淀粉粒度分布的影响

摘要：为研究施硫对小麦胚乳淀粉粒分布特征的调控效应，以小麦品种烟农19和山农22为材料，研究不同氮素水平条件下，硫肥对胚乳淀粉粒分布特征的影响。结果表明，不同处理小麦籽粒淀粉粒体积、表面积、数目分布分别呈双峰、三峰和单峰曲线分布。在施纯氮120 kg/hm2（低氮水平）条件下下，随施硫量的增加，籽粒B型淀粉粒体积百分比显著降低，A型淀粉粒体积百分比显著升高。在施纯氮240 kg/hm2（适氮水平）条件下，随施硫量的增加，籽粒B型淀粉粒体积百分比先升高后降低，A型淀粉粒体积百分比先降低后升高。在施纯氮120 kg/hm2条件下下，随施硫量的增加，籽粒3.6μm～10μm淀粉粒数目百分比逐渐降低。在施纯氮240 kg/hm2条件下，随施硫量的增加，籽粒3.6μm～10μm淀粉粒数目百分比逐渐提高，S9处理效果下降。在施纯氮120 kg/hm2条件下，随施硫量的提高，小麦籽粒B型淀粉粒的表面积百分比显著降低，A型淀粉粒表面积百分比显著增加；在施纯氮240 kg/hm2条件下，随施硫量的提高，小麦籽粒B型淀粉粒表面积百分比逐渐增加，A型淀粉粒表面积百分比逐渐降低，高硫S9处理施用效果下降。可见，在低氮水平下施硫有利于淀粉粒体积的增大；在适宜氮素水平下施硫有利于3.6-10 μm淀粉粒数目的增加，但过量硫肥施用效果下降。     

Ethylene and Spermidine in Wheat Grains in Relation to Starch Content and Granule Size Distribution Under Water Deficit

Two wheat cultivars （Triticum aestivum L.） were used to evaluate the effects ofpost-anthesis severe water deficit （SD） on starch content and granule size distribution and their relations with ethylene and spermidine （Spd）. Comparison to the well-watered （WW） treatment, SD led to lower Spd and higher 1-aminocylopropane-l-carboxylic acid （ACC） concentrations and ethylene evolution rate （EER） in grains at the critical stage of forming starch granules. Application of Spd or aminoethoxyvinylglycine （AVG） significantly reduced ACC concentration and EER and increased Spd concentration, while ethephon or methylglyoxal-bis （MGBG） had an opposite impact. The volume and surface area distribution of starch granules showed a bimodal curve, while the number distribution exhibited a unimodal curve. SD caused a marked drop in grain weight, grain number and starch content, also led to a significant reduction in the proportion （both by volume and by surface area） of B-type starch granules （〈10 Ixm）, with an increase in those of A-type starch granules （〉10 ~tm）. Application of Spd or AVG increased the proportion （both by volume and by surface area） of B-type starch granules under SD. Correlation analysis suggested that ethylene and Spd showed an antagonism relation in the formation of B-type granules. These results suggested that it would be good for the formation of B-type starch granules to have the physiological traits of higher Spd and lower ACC concentrations and ethylene emission under SD.     

小麦胚乳A、B型淀粉粒理化特性研究

【目的】研究小麦胚乳A、B型淀粉粒对其理化特性的影响。【方法】利用扫描电镜对4个小麦品种籽粒发育不同时期自然断面和分离提纯的A、B型淀粉粒进行观察;用直链、支链淀粉试剂盒对籽粒不同发育时期胚乳中A、B型淀粉粒的直链、支链淀粉含量进行测定;成熟籽粒A、B型淀粉粒膨胀势依据McCormick的方法进行了测定。【结果】小麦胚乳淀粉粒形态出现规则形状和反常态,胚乳淀粉粒中直链淀粉形成早于支链淀粉,但最终积累量支链淀粉大于直链淀粉。供试的4个品种中,B型淀粉粒膨胀势均大于各自A型淀粉粒的膨胀势。【结论】小麦胚乳A型和B型淀粉粒从形态上分为常规型和反常型。成熟小麦胚乳A、B型淀粉粒中,支链淀粉的含量大于直链淀粉,且与总淀粉含量呈正相关趋势。B型淀粉粒的膨胀势大于A型淀粉粒。     

小麦强、弱势籽粒中淀粉粒度分布特征

以2个冬小麦品种鲁麦21和济南17为供试材料,对小麦强、弱势籽粒中淀粉粒的体积、数目和表面积的分布特征进行了研究。结果表明,小麦强、弱势籽粒均含有A(>9.8μm)、B(2.0~9.8μm)、C(<2.0μm)3种类型的淀粉粒,但不同类型淀粉粒的分布状况存在明显差异。在强势籽粒中,淀粉粒的体积和表面积分布均表现为三峰分布,而弱势籽粒中淀粉粒的体积和表面积分布则表现为双峰分布。与弱势粒相比较,强势粒中C型淀粉粒的体积百分比为7.25%~8.01%,表面积百分比为34.88%~37.21%,而弱势粒的体积和表面积百分比分别为5.33%~6.35%和26.31%~33.19%,表明强势粒中C型淀粉粒所占比例较大。强、弱势籽粒中小于0.6μm和0.6~2.0μm范围内的淀粉粒数目存在明显差异,弱势粒中小于0.6μm的淀粉粒所占比例较大,为36.21%~37.41%,而强势粒中0.6~2.0μm范围内的淀粉粒数目较多,为84.38%~87.76%。     

Effects of Shading at Different Stages After Anthesis on Maize Grain Weight and Quality at Cytology Level

The objective of the current study is to investigate the effects of different stages of shading after anthesis on grain weight and quality of maize at cytology level.The shading experiments were conducted in the field from 2005 to 2006,with a common maize cultivar(TY2)as the experimental material.Plants were given stress using horizontal shading net and the light intensity was reduced by 55%.Field-grown maize plants were shaded at 1-14 d(S1),15-28 d(S2),and 29-42 d(S3)after pollination,respectively.Control plants(S0)were grown under natural light.Grain weight,quality,endosperm cell proliferation,cob sugar content,and grain pedicel vascular bundle cross section area were measured.The ultrastructural changes of endosperm cells and endosperm transfer cells were observed after pollination.The result indicated that the grain weight,starch content,endosperm cell number,and volume were declined after shading.On the contrary,the proportion of embryo and endosperm,protein content,and fat content in grain increased.Shading treatments significantly delayed the development of the starch granules and remarkably reduced the endosperm filling status.Among the three treatments.the number of the grain endosperm was the least under shading stress at 1-14 d after pollination.However,the volume of starch granules and the substantiation of endosperm under shading treatment at 15-28 d after pollination were the worst.Compared with the control(natural sunlight without shading),the soluble sugar of maize cob increased significantly,while there was no obvious change in vascular structure of small cluster stalk.The number of protein body in maize endosperm was influenced markedly by low light at different stages after pollination.Low light decreased the volume of the grain endosperm transfer and the cell wall extensions of the basal transfer cells became thinner and shorter under shading treatment than those of the control.Furthermore,the degree of connection and the capacity of the nutrient transport were decreased and the mitochondrion number of the transfer cell was reduced after shading.The change in grain quality after shading was observed due to increase in the proportion of embryo and endosperm.The morphology and functions in endosperm transfer cell and the shortage of energy restricted the nutrient transport greatly with shading at different stages,suggesting that an impeded flux may be one of the important reasons for the reduction of maize grain weight of maize grain at later growth stage under low light condition.     

Effects of high temperature after anthesis on starch granules in grains of wheat (Triticum aestivum L.)

The effect of high temperatures (above 25°C) on starch concentration and the morphology of starch granules in the grains of wheat (Triticum aestivum L.) were studied. Wheat plants of cultivars Yangmai 9 (weak-gluten) and Yangmai 12 (medium-gluten) were treated with high temperatures for 3 days at different times after anthesis. The results showed that the starch concentration of grains given a heat-shock treatment above 30°C were lower than those developing at normal temperature in both cultivars. High temperature lowered starch concentration due to the decrease of amylopectin. Under the same temperature, the effect of heat shock from 6 to 8 days after anthesis (DAA) was the greatest, whereas from 36 to 38 DAA the effect was the least. The effects of high temperatures after anthesis on starch-pasting properties were similar to those on starch concentration, especially after 35-40°C treatments. The size, shape and structure of starch granules in wheat grains (determined by electron microscopy) after heat shock were visibly different from the control. When given heat shock during development, the starch granules in mature wheat grains were ellipsoid in shape and bound loosely with a protein sheath in Yangmai 9, while they were damaged and compressed with fissures in Yangmai 12, indicating the differences in resistance to high temperature between cultivars. Ratios of large (type-A) and small (type-B) starch granules significantly decreased under heat shock, which limited the potential sink size for dry matter deposition in the grain.