夏玉米不同粒位蛋白质组分氮素效应及与子粒脱水的关系研究

从蛋白质粒位差异的角度,以不同自然脱水类型玉米品种为材料,分析不同氮肥运筹处理下不同部位子粒蛋白质组分含量、子粒脱水速率,研究子粒脱水与蛋白质组分和氮素施用的关系。结果表明,脱水速率差异较大的品种总蛋白质存在较大差异,蠡玉16和先玉335总蛋白质含量分别为11.25%、12.16%。增施氮肥蛋白质含量明显增加;增施氮肥主要增加了醇溶蛋白和谷蛋白含量,清蛋白和球蛋白含量影响较小。增施氮肥生理成熟后不同处理间脱水速率存在显著差异;蛋白质组分和脱水速率之间存在密切关系,先玉335生理成熟后不同部位间醇溶蛋白和谷蛋白与脱水速率呈显著或极显著负相关,醇谷比与子粒脱水呈正相关。     

耐低钾基因型水稻成熟期籽粒淀粉与蛋白质含量变化

以2个耐低钾基因型水稻N18,N19和1个低钾敏感型水稻N27为材料,在缺钾条件下,分析耐低钾基因型水稻籽粒在成熟期淀粉含量、蛋白质含量的变化。结果表明：在不施钾肥即缺钾条件下,耐低钾基因型水稻籽粒中总淀粉含量较低钾敏感型的略有增加,且直链淀粉含量占总淀粉含量的比例低于钾敏感型;耐低钾基因型水稻籽粒中可溶性蛋白质含量也较低钾敏感型的高,但是钾元素的含量差异并不明显。     

不同品质类型小麦籽粒蛋白质、淀粉积累过程的基因型差异

对 3个具有不同蛋白质含量的大面积推广小麦品种宁麦 9号 (低蛋白 )、苏麦 6号 (中蛋白 )和重庆面包麦(高蛋白 )籽粒灌浆期蛋白质、淀粉含量的动态变化进行了研究。结果表明 ,(1) 3个品种在籽粒灌浆过程中 ,粒重的增加、籽粒蛋白质、淀粉含量存在极显著的差异 ;(2 ) 3个品种在开花后 2 2 d前经历了淀粉含量的快速增加、蛋白质含量下降期 ;(3)三个品种在整个灌浆至乳熟阶段淀粉持续积累 ,至花后 37d仍有较高的积累速率 ;重庆面包麦乳熟期(开花后 32 d之后 )蛋白质积累较宁麦 9号和苏麦 6号快 ,而宁麦 9号乳熟期蛋白质积累几乎停止     

冬小麦品种粒重和淀粉特性的穗粒位差异分析

为给小麦品质育种和栽培调控提供理论参考,通过田间试验,分析了3个冬小麦品种粒重和淀粉特性的穗粒位（分别用G1、G2、G3表示第1~3小籽位）差异。结果表明,小麦粒重表现为中部和下部穗位粒重高于上部穗位,上部穗位不同粒位则表现为G1>G2>G3,中部和下部穗位的不同粒位表现为G2>G1>G3,表明中部和下部穗位的第2粒位籽粒对穗粒重的贡献较大。豫麦2号和周麦18以上部穗位的直链淀粉含量最高,而郑育麦9987则以中部穗位直链淀粉含量最高;三个品种不同穗粒位籽粒直链淀粉以G3粒位含量最高。淀粉峰值黏度、稀懈值在不同穗位之间表现为上部穗位>中部（下部）穗位,不同粒位表现为G3粒位最高,表明G3粒位籽粒对淀粉糊化参数的改善有较大作用。在育种和栽培调控中,可以根据专用小麦品质特性,通过适当调控产量构成要素来改善品质和增加产量。     

水稻强弱势籽粒核酸和蛋白质代谢差异

以两系杂交稻两优培九和培两优500为试验材料,对强弱势粒核酸和蛋白质含量进行了测定。水稻抽穗当天,强势粒单位质量子房中总RNA、mRNA含量都高于弱势粒,蛋白质含量却低于弱势粒。抽穗后第5天,强势粒单位质量子房中总RNA含量仍然高于弱势粒,mRNA含量两者差异不大,蛋白质含量依然低于弱势粒。不论是强势粒还是弱势粒,从抽穗到开花后第5天,其总RNA、mRNA和蛋白质单粒含量都有显著的增加,且各时期强势粒都高于弱势粒。抽穗当天强势粒有两条特异蛋白质带出现,而弱势粒没有,抽穗后第5天弱势粒才出现其中的一条。这说明强势粒与籽粒灌浆有关的基因表达比弱势粒早,强度高。     

两种穗型粳稻穗内粒间直链淀粉含量变异与粒位分布特征

以6个直穗型和4个弯穗型粳稻品种为材料,对两者在相同栽培条件下的穗内粒间直链淀粉含量变异及其频数分布、粒位特征进行了比较分析。结果表明：水稻穗型虽然与品种间的直链淀粉含量高低无直接关系,但对其穗内不同籽粒间的直链淀粉含量差异存在着较大的影响;直穗型粳稻品种单一稻穗内直链淀粉含量的粒间差异明显大于弯穗型品种,其直链淀粉含量的粒间变异系数与离散程度均高于后者;同一稻穗内不同籽粒间的直链淀粉含量变化与其相应的粒位有关,两种穗型粳稻品种均表现为穗顶部籽粒的直链淀粉含量相对较高、穗基部籽粒的直链淀粉含量相对较低这一基本趋势。但与弯穗型粳稻品种相比,直穗型粳稻品种大量低直链淀粉含量籽粒产生的部位是在其稻穗的中部,而不仅仅局限在稻穗基部的3个枝梗上。     

小麦光合器官对不同穗位和粒位粒重及蛋白质含量的影响

为探明小麦叶片与非叶光合器官对不同穗位和粒位籽粒发育的影响,以济麦22为试验材料,开花期设置剪叶、包穗、包茎等7种处理,分析了不同处理下不同穗位和粒位粒数、粒重和蛋白质含量的差异。结果表明,小麦穗对穗上部和下部弱势粒数影响显著,与叶片共同作用对穗上部强势粒数及穗中部和下部粒数,以及与茎和叶片共同作用对穗上部粒数、穗中部和下部弱势粒数均影响显著;穗对不同穗位强势粒重和穗上部弱势粒重影响显著,旗叶对穗中部和下部强势粒重、穗上部和中部强势粒重及穗下部粒重影响显著;包穗、剪旗叶和剪倒二叶处理显著提高穗上部强势粒及穗中部和下部籽粒蛋白质含量;剪倒三叶和剪倒四叶+剪倒五叶处理显著提高穗下部强势粒蛋白质含量;同一穗位的强势粒蛋白质含量大于弱势粒,不同穗位籽粒的平均蛋白质含量表现为穗下部穗中部穗上部;同一穗位的弱势粒蛋白质含量变异系数大于强势粒,穗上部的籽粒蛋白质含量变异系数大于穗中部和下部。因此,建议小麦育种中应注重穗光合选择,适当增加小穗排数,减少高穗位粒数,可能是提高小麦产量潜力和改善品质的重要途径。     

小麦花后籽粒抗性淀粉含量累积动态分析

为了给小麦抗性淀粉(Resistant starch,RS)的生物合成调控提供依据,以3个抗性淀粉含量差异较大的春小麦品种新春24、安农9912和E28为材料,分别测定其花后6、9、12、15、18、21、24、27、30 d籽粒中的抗性淀粉含量,并进行了净遗传增量的估算.结果表明,三个品种的抗性淀粉含量在籽粒灌浆期均呈现双峰曲线变化.新春24籽粒的抗性淀粉含量在花后15d达到第一个累积高峰,而安农9912和E28籽粒的抗性淀粉含量在花后18 d后才达到第一个累积高峰(其中E28的峰值最高),花后30 d安农9912和新春24再次达到第二个累积高峰.通过各时期籽粒抗性淀粉含量净遗传增量的变化可以了解与抗性淀粉合成相关基因的表达量和效果.本研究结果显示,控制抗性淀粉含量的基因在整个籽粒灌浆时期均有表达,不存在时间上的间断,并且控制抗性淀粉合成的基因在灌浆末期的表达量对成熟籽粒抗性淀粉的含量起重要作用.     

春小麦籽粒淀粉和蛋白质积累与底物供应的关系

利用产量和蛋白质含量不同的三个春小麦品种,在盆栽条件下,研究了籽粒灌浆过程中淀粉和蛋白质积累与可溶性糖、游离氨基酸含量变化的关系。结果表明,开花后5～20d三个品种籽粒可溶性糖含量急剧下降,对应时期的淀粉含量快速上升,后期当可溶性糖含量回升时,其相应淀粉含量下降或增加的幅度很小。籽粒游离氨基酸含量随着灌浆进程渐次降低,品种间蛋白质含量的变化与游离氨基酸的变化一致。所有品种淀粉积累速率变化呈抛物线型变化,高产中蛋白品种的淀粉积累速率最高。进一步认为,可溶性糖作为淀粉合成的底物向淀粉的转化可能更多地依赖于籽粒利用和合成能力的大小,而蛋白质积累更多地直接依赖供应源。     

春小麦籽粒淀粉和蛋白质积累与底物供应的关系

利用产量和蛋白南含量不同的三个春小麦品种,在盆栽条件下,研究了籽粒灌浆过程中淀粉和蛋白质积累与可溶性糖、游离氨基酸含量变化的关系。结果表明,开花后５～２０d三个 品种籽粒可溶性糖含量急剧下降,对应时期的淀粉含量快速上升,后期当可溶性糖量的变化与游离氮基酸的变化一致。所有品种淀粉积累速率变化呈抛物线型变化,高产中蛋白品种的淀粉积累速率最高。进一步认为,可溶性粮作为淀粉合成的底物向淀粉的转化可能更多地依     

Variations in Carbohydrate and Protein Accumulation among Spikelets at Different Positions Within a Panicle During Rice Grain Filling

The accumulation dynamics of kernel components for spikelets at different positions within a rice panicle were investigated during grain filling to understand the physiological reasons for the variation of grain quality.Two rice cultivars,Yangdao 6 (indica) and Yangjing 9538 (japonica),were field-grown,and the grain filling characters and contents of starch,soluble sugar,and protein of the spikelets at different positions were studied.There were significant differences in matter accumulation among spikelets at different positions during grain filling.The early-flowering spikelets presented dominance over the late-flowering spikelets in initial time and initial rate of accumulation.At the initial and mid filling stages,the contents and the rates of starch and amylose accumulation in spikelets decreased with the flowering sequence,but soluble sugar content (SSC) exhibited the opposite trend.The difference in SSC among the spikelets of Yangjing 9538 was greater than that of Yangdao 6,but amylose content in mature spikelets showed no obvious relationship to their flowering sequence.The crude protein content (CPC) of early-flowering spikelets decreased more rapidly than that of late-flowering ones at the initial filling stage,and CPC in the spikelets on the secondary branch was higher than that on the primary branch,but CPC in early-flowering ones was lower than that in late-flowering across the whole grain filling period.Grain water content (GWC) of early-flowering spikelets decreased more rapidly than that of late-flowering spikelets on the same branch at the initial and mid filling stages,especially for the top grain on each primary branch.The results suggested that poor grain filling of late-flowering spikelets may be attributed to their low biological activity rather than carbohydrate supply limitation.     

早红突A不同穗位颖花花粉育性的变异

从6月11日至7月2日连续观察早红突A花粉育性的变化动态，不同时期镜检结果表明，染色花粉频率呈现较大变（27．1％－92．3％），染色花粉数与颖花着生的部位有密切关系。其中，第4枝梗染色花粉频率相对较高，第6枝梗单位颖花内染色花粉数最多；染色花粉频率和所含染色花粉数随着枝梗位置上升有逐步递增的趋势，相关分别达显著（0．852 6^*）和极显著水平（0．911 9^**）；每一枝梗基部1－4朵颖花（第1镜检单位）含染色花粉数和染色花粉频率一般高于同枝梗其它颖花，并从枝梗基部往上逐步递减。染色花粉数的增加与镜检前10d日平均气温和最低气温分别呈显著和极显著正相关，表明它对高温有较强的敏感性。讨论了单株选择对花粉育性的影响。     

密穗型和散穗型粳稻穗部不同部位直链淀粉含量的差异分析

对粳稻密穗型品种浙粳22和散穗型品种浙粳27单株主穗上的单粒稻米,利用碘比色法进行了直链淀粉含量测定。结果表明,浙粳22和浙粳27直链淀粉含量最大值与最小值相差分别达到13.53和10.30个百分点,密穗型比散穗型的变幅大;稻穗内各籽粒在不同直链淀粉含量区间的频数变化趋势呈正态分布;密穗型和散穗型一、二次枝梗籽粒直链淀粉含量与其粒位间的相关系数分别为-0.1167*和-0.3140**,一次枝梗籽粒要高于二次枝梗籽粒,散穗型较密穗型更显著;枝梗顶端籽粒的直链淀粉含量较高,而与此相连的第2粒的直链淀粉含量较低;散穗型与密穗型品种在穗内直链淀粉含量分布上存在相似的规律,如单粒或半粒取样时应以各枝梗上第3、4粒部位的较好。     

不同施氮水平下水稻穗上不同部位籽粒的蒸煮与营养品质变化

以中熟籼稻扬稻6号和中熟粳稻武育粳3号为材料,研究了不同施肥水平下稻米蒸煮及营养品质在穗上不同粒位籽粒间的差异及其分布特点。 总体而言,穗下部一、二次枝梗籽粒的胶稠度较低,直链淀粉含量较高;穗中、上部一、二次枝梗的胶稠度较高,直链淀粉含量较低。在同一个枝梗上,二次枝梗上早开花的第1粒的胶稠度最高,穗子中、上部一次枝梗迟开花的第2粒的直链淀粉含量较高。扬稻6号穗中部一次枝梗籽粒的粗蛋白含量较低,穗上、下部枝梗上籽粒的粗蛋白含量较高;而武育粳3号一次枝梗和二次枝梗籽粒的粗蛋白含量在穗上、中、下三部位间无明显差异。从不施氮到少量施氮（120 kg/hm2）,稻米的胶稠度和粗蛋白含量增加,直链淀粉含量降低。但从少量施氮（120 kg/hm2）到中等施氮（240 kg/hm2）,稻米的胶稠度降低,直链淀粉和粗蛋白含量有不同程度增加。     

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.     

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。     

Changes in Cooking and Nutrition Qualities of Grains at Different Positions in a Rice Panicle under Different Nitrogen Levels

Cooking and nutrition qualities of grain are two of the most important aspects of rice quality. To understand the difference in cooking and nutrition qualities among the grains at different positions within a rice panicle, the distributions of gel consistency (GC), amylose content (AC) and crude protein content (CPC) of grains in a panicle in association with different nitrogen levels (0, 120 and 240 kg/ha) were investigated by using two rice varieties, Yangdao 6 (indica) and Wuyujing 3 (japonica). In general, the grains at the basal part of a panicle had lower GC and higher AC than those at the upper or middle part of a panicle. The 1st grain on the secondary branch with earlier flowering exhibited the highest GC, whereas the 2nd grain on the primary branch with later flowering showed the highest AC. For Yangdao 6, CPC in the grains on the primary branches was lower at the middle part of a panicle than at the upper or basal part of a panicle. For Wuyujing 3, there were no significant differences in CPCs in the grains among the upper, middle and basal parts of a panicle. GC in the grains was increased, whereas AC was reduced from zero nitrogen application (0N) to low amount of nitrogen application (LN), and the result was reversed from LN to medium amount of nitrogen application (MN). CPC was increased with the increase in the amount of nitrogen application.     

稻穗枝梗和颖花形成的基因型及播期效应分析

以71个不同基因型水稻为材料,通过大田条件下的分期播种,于齐穗期考查了稻穗枝梗和颖花形成有关指标,分析了各指标的基因型和播期效应及其相互关系。结果表明： 1）各基因型间现存一次枝梗数、一次枝梗退化数、现存颖花数、一次枝梗分化数、现存二次枝梗数的基因型值和播期效应值差异均显著,且5个指标的差异仅与特定的基因型有关,而与其是否属于杂交组合、常规品种和雄性不育系等类型无关。2）现存一次枝梗数、现存二次枝梗数、现存颖花数、一次枝梗分化数4个指标的基因型值较大,播期效应值较小;一次枝梗退化数播期效应值较大。3）单穗颖花现存数（即每穗总粒数）与现存一次枝梗数、一次枝梗分化数、现存二次枝梗数呈密切正相关,与一次枝梗退化数相关性小,现存一次枝梗数主要通过改变现存二次枝梗数来影响单穗颖花现存数。另外,还综合分析了供试71个材料单穗颖花现存数的基因型值和播期效应值,并对其大穗潜力进行了评价。     

Changes in Enzyme Activities Involved in Starch Synthesis and Hormone Concentrations in Superior and Inferior Spikelets and Their Association with Grain Filling of Super Rice

The changes in activities of key enzymes involved in sucrose-to-starch conversion and concentrations of hormones in superior and inferior spikelets of super rice were investigated and their association with grain filling was analyzed.Four super rice cultivars,Liangyoupeijiu,IIyou 084,Huaidao 9 and Wujing 15,and two high-yielding and elite check cultivars,Shanyou 63 and Yangfujing 8,were used.The activities of sucrose synthase (SuSase),adenosine diphosphoglucose pyrophosphorylase (AGPase),starch synthase (StSase) and starch branching enzyme (SBE),and the concentrations of zeatin + zeatin riboside (Z + ZR),indole-3-acetic acid (IAA) and abscisic acid (ABA) in superior and inferior spikelets were determined during the grain filling period and their relationships with grain filling rate were analyzed.Maximum grain filling rate,the time reaching the maximum grain-filling rate,mean grain filling rate and brown rice weight for superior spikelets showed a slight difference between the super and check rice cultivars,but were significantly lower in the super rice than in the check rice for inferior spikelets.Changes of enzyme activities and hormone concentrations in grains exhibited single peak curves during the grain filling period.The peak values and the mean activities of SuSase,AGPase,StSase and SBE were lower in inferior spikelets than in superior ones,as well as the peak values and the mean concentrations of Z + ZR and IAA.However,the peak value and the mean concentration of ABA were significantly higher in inferior spikelets than in superior ones and greater in the super rice than in the check rice.The grain filling rate was positively and significantly correlated with the activities of SuSase,AGPase and StSase and the concentrations of Z + ZR and IAA.The results suggested that the low activities of SuSase,AGPase and StSase and the low concentrations of Z + ZR and IAA might be important physiological reasons for the slow grain filling rate and light grain weight of inferior spikelets in super rice.