稻鸭共育对水稻生长后期农艺性状及产量的影响

为探讨稻鸭共育模式下水稻生长后期地上部农艺性状和籽粒灌浆动态的变化,设置稻鸭共育(RD)、常规水稻栽培(RH)和不施任何药剂栽培水稻(CK)的对比试验,研究水稻生长后期地上部农艺性状的动态变化及产量形成.结果表明:RD和RH处理的水稻分蘖、地上部干物质积累、剑叶叶片SPAD值、根伤流液、籽粒灌浆和产量均优于CK处理.与RH处理相比,RD处理降低了水稻分蘖的峰值,两者相差0.45,保持分蘖中后期水稻分蘖数的稳定;增加水稻地上部干物质的积累量,增幅为4.20%~16.42%,齐穗期和成熟期达到显著性差异;水稻生长后期维持剑叶叶片SPAD值和根伤流液在较高的水平,利于水稻籽粒充实度和粒重的增加,从而有利于水稻产量的增加.     

耕播方式与减氮对扬辐麦13氮素吸收利用的影响

为明确不同机械耕播方式下减氮对小麦氮素吸收利用的影响,在水稻秸秆全量还田条件下,以扬辐麦13为材料,研究两种机械耕播方式[板茬+2BMF-稻茬免耕条播机(NT)、旋耕+2BFG-10(8)230型播种机(CT)]和三个施氮模式[常规模式(N1):施氮量270 kg·hm^-2,基肥∶分蘖肥∶拔节肥∶孕穗肥=5∶1∶2∶2;减氮模式(N2):施氮量225 kg·hm^-2,基肥∶分蘖肥∶拔节肥∶孕穗肥=5∶1∶2∶2;减氮减次模式(N3):施氮量180 kg·hm^-2,基肥∶拔节肥=5∶5]对小麦氮代谢酶活性、氮素吸收利用特征以及籽粒产量的影响。结果表明,播种前土壤相对含水量为84%,与CT处理相比,NT处理提高了植株硝酸还原酶(NR)和谷氨酰胺合成酶(GS)活性,使花前氮素转运量增加和氮素在籽粒中的分配量分别增加10.78%(P<0.01)和7.56%(P<0.05),获得较高的氮肥偏生产力和氮肥表观利用率,其最终籽粒产量提高5.36%(P<0.05)。N2处理在小麦生育中后期可维持较高的氮代谢酶活性,获得...     

氮肥运筹比例对稻田套播强筋小麦产量及花后旗叶衰老的影响

为给稻田套播小麦优质高产栽培提供理论依据,在江苏淮北地区通过大田试验,研究氮肥运筹比例对稻田套播强筋小麦花后旗叶叶绿素含量、超氧化物歧化酶（SOD）活性、丙二醛（MDA）含量和籽粒产量的影响。结果表明,在总施氮量（240 kg·hm^-2）相同条件下,随拔节肥和孕穗肥施氮比例的上升,小麦产量、氮肥偏生产力（PFP）和氮肥农学效率（NAE）逐渐升高,但后期施肥比例过高,产量有所下降,以基肥∶分蘖肥∶拔节肥∶孕穗肥为3∶3∶2∶2的处理籽粒产量、PFP和NAE最高。随花后生育进程的推移,小麦旗叶叶绿素含量和SOD活性呈单峰曲线变化,MDA含量呈上升趋势。随拔节肥和孕穗肥施用比例的提高,旗叶叶绿素含量和SOD活性下降速率变缓,MDA含量上升速率也减缓。本试验条件下,基肥∶分蘖肥∶拔节肥∶孕穗肥施用比例为3∶3∶2∶2的氮肥运筹方式有利于减缓花后旗叶衰老,提升氮肥利用效率,提高粒重和产量。     

硅氮配施对水稻光合特性、叶绿素荧光及产量的影响

为探明氮肥和硅肥用量对水稻光合作用及叶绿素荧光参数的调控效应,及氮硅配施调控水稻光合作用的内在生理基础。以超级稻品种广两优476为供试材料,采用2个氮肥水平、3个硅肥水平的大田试验,研究氮硅互作对水稻光合及荧光特性的影响。结果表明,增施氮肥和硅肥均能提高水稻叶片叶绿素含量,低氮水平下高硅肥处理光合作用最强,高氮水平下中硅肥处理光合作用最强,适当增施氮肥有利于水稻叶片降低非辐射能量耗散,将更多的吸收光能用于光化学反应,低氮水平下增施硅肥能有效改善叶绿素荧光参数指标,提高水稻叶片光合性能,但在高氮条件下,随着硅肥用量的增加,初始荧光（F0）、非光化学淬灭系数（NPQ）表现为先减后增,而PSⅡ潜在活性（Fv/F0）、实际光化学效率（ΦPSⅡ）表现为先增后减,表明硅肥过量会导致水稻光化学效率下降。硅氮互作对水稻光合生理指标影响显著,低氮水平下增施硅肥能有效改善水稻叶片光合性能,高氮水平下适宜的硅肥用量为37.5 kg/hm2,此时水稻叶片光能利用效率最高,利于光合产物的形成和积累,可为高产打下良好的基础。     

不同施氮量下稻虾共作水稻产量与田面水水质特征

研究了不同氮用量对稻虾共作水稻产量与田面水水质的影响,以为稻虾共作实现精确施肥提供理论依据。试验共设5个氮肥用量处理,分别设置氮0、60、120、180和240 kg/hm²,依次以CK、N₆₀、N₁₂₀、N₁₈₀、N₂₄₀表示,氮肥均按基肥:分蘖肥7∶3施肥。结果表明,施肥能维持土壤较高的无机氮含量并能促进水稻干物质积累,施肥处理提高水稻产量8%～42%,其中N₁₂₀产量最高,比CK增产42%;施氮后3 d内田面水中氨态氮含量迅速增加,随着时间的推迟氨态氮随之降低,在14 d后降到最低且趋于稳定,其中施氮后5 d内各处理的氨态氮浓度差异显著,施氮越多其值越大;田面水中亚硝态氮浓度在前5 d先升高后降低再升高,其中第3 d各施肥处理差异较显著,第7 d后其浓度处理间差异不显著;不同施氮量显著影响了田面水的pH,各处理在施肥后14 d内的pH波动在6.57～8.22之间,但14 d以后各处理差异不显著。适宜的施氮量促进水稻增产的同时也减少了田间表面水氨态氮和...     

氮肥施用量对C两优华占产量及生长性状的影响

通过设置6个氮肥用量并测定相关生长性状及产量,研究了C两优华占的适宜施氮量.结果表明,施氮量增加可以显著提高水稻分蘖数和株高,显著提高水稻SPAD值,在拔节—齐穗期和灌浆—成熟期两个干物质积累盛期显著促进水稻的干物质积累,增加叶面积,从而提高光合能力,增加产量,但过高的氮肥施用量在成熟期会导致水稻贪青严重,抑制水稻干物...     

施氮时期对扬稻6号颖果发育及稻米品质的影响

通过盆栽试验研究了相同施氮量下不同施氮时期（分蘖期和孕穗期）对扬稻6号颖果发育及稻米品质的影响。与对照相比,增施氮肥（尿素）特别是孕穗肥能显著提高稻米精米率、整精米率、蛋白质含量,降低垩白粒率和直链淀粉含量;在分蘖期和孕穗期施氮肥能明显影响颖果发育,提高粒重,而后者的效果更为明显;在颖果发育过程中不同时期增施氮肥能显著降低颖果的总淀粉和直链淀粉含量,但对支链淀粉含量影响较小;不同时期增施氮肥特别是孕穗肥对淀粉体和蛋白质体的发育及结构均有显著影响,能显著改变籽粒中不同部位特别是腹部淀粉体和蛋白质的分布、数目和形状。与对照相比,淀粉体和蛋白质体的排列更紧密、相互间空隙较少、数量增加、密度增大,淀粉体形状多数呈晶状体。     

不同施肥处理对水稻病虫害及天敌发生的影响

2005年在湘阴开展了不同施氮量和施肥方法对晚稻病虫及天敌群落影响的研究。结果表明：含氮高的普肥区病虫及天敌发生量与其他低氮量施肥区比较总是偏高的，但无肥（未施氮）情况下，病虫及天敌发生量并不总是比施氮区低，特别水稻生长后期，施有机肥和控释肥的稻田病虫及天敌反而低于无肥区。只有适量施肥或施控释肥，让水稻均匀吸收，才能达到控制病虫害上升的目的。     

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。     

氮肥运筹模式对冬小麦氮素吸收利用的影响

为给小麦高产、高效、无污染及可持续生产提供合理的氮肥运筹技术和理论依据, 以烟农19为材料,在大田条件下,研究了不同施氮量和基追比例对土壤小麦系统氮素积累及分配的影响。结果表明,施氮可提高0~100 cm土体内的全氮含量。在小麦越冬前, 0~40 cm土层中NO3-N含量随氮肥用量和基肥比例的增加显著增加;起身期到拔节期,施氮量为180和240 kg·hm-2且基肥∶拔节肥∶孕穗肥为3∶5∶2处理的0~40 cm土层内NO3-N含量下降,而施氮量为240 kg·hm-2且基肥∶拔节肥为7∶3和5∶5的处理及施氮量为300 kg·hm-2且基肥∶拔节肥为7∶3的处理则显著增加;拔节期到成熟期,随施氮量的增加,0~60 cm土层速效氮增加幅度有所提高。孕穗肥可明显提高灌浆期的植株全氮含量。因此,在240 kg·hm-2 施氮水平、基肥∶拔节肥∶孕穗肥为3∶5∶2条件下,施氮既能减少土壤硝态氮累积量,又能有效降低土壤硝态氮污染地下水的可能性。     

Effects of Nitrogen Fertilizer Treatments on Filling and Respiratory Rate of Caryopsis in Rice

An experiment was conducted to study the effects of nitrogen （N） rate and application time on grain filling and respiratory trait of caryopsis in two rice varieties, IR36 and Dali. The treatments were consisted of no N application topdressing at both tillering and booting stages （CK）, 6 g/pot of N topdressing at the tillering stage and 2 g/pot of N topdressing at the booting stage, 2 g/pot of N topdressing at the tillering stage and 6 g/pot of N topdressing at the booting stage. The results showed that the proper utilization of N fertilizer can be helpful to maintain the higher water content, higher respiratory rate and higher dehydrogenase activity of rice caryopsis in late filling phase, and prolong the course for filling and maintaining higher respiratory rate and dehydrogenase activity of rice caryopsis. More N application at booting was more effective compared to more N application at tillering.     

Effects of Nitrogen Fertilizer Treatments on Caryopsis Filling and Respiratory Rate of Rice

The application of N fertilizer has been reported to have a great effect on filling of caryopsis. For example, the dry matter of caryopsis derived from photosynthates by tillers and leaves at two stages i.e. before and after panicle emergence [1-4]. Moreover, proper utilization of N fertilizer can improve N content and photosynthetic rate [5-7], delay leaf senescence [7-9], and increase the amount of dry matter for grain filling, thus improve the productivity of rice [5-10]. On the other hand…     

Pre-anthesis non-structural carbohydrate reserve in the stem enhances the sink strength of inferior spikelets during grain filling of rice

Sink strength plays an important role in grain filling of cereals but how it is related to the pre-anthesis non-structural carbohydrate (NSC) reserves is not clear. This study investigated if and how an increase in NSC reserves could enhance sink strength, and consequently improve grain filling of later-flowering inferior spikelets (in contrast to the earlier flowering superior spikelets) for rice varieties with large panicles. Two “super” rice varieties (the recently bred high-yielding rice) and two New Plant Type (NPT, named in IRRI for the extra-large panicle) rice lines were compared with two elite inbred varieties under field-grown conditions. Three nitrogen (N) treatments, applied at the stages of panicle initiation, spikelet differentiation or both, were adopted with no N application during the mid-season as control. Both super rice and NPT rice showed a greater yield capacity as a result of a larger panicle than the elite inbred rice. However, a lower percentage of filled grains limited the realization of higher yield potential in super rice and especially in NPT rice, due to their lower grain filling rate and the smaller grain weight of their inferior spikelets. The low grain filling rate and small grain weight of inferior spikelets are mainly attributed to a poor sink strength as a result of small sink size (small number of endosperm cells) and low sink activity, e.g. low activities of sucrose synthase (SuSase) and adenosine diphosphoglucose pyrophosphorylase (AGPase). The amounts of NSC in the stem and NSC per spikelet at the heading time are significantly and positively correlated with sink strength (number of endosperm cells and activities of SuSase and AGPase), grain filling rate, and grain weight of inferior spikelets. Nitrogen application at the spikelet differentiation stage significantly increased, whereas N application at the panicle initiation or at both panicle initiation and spikelet differentiation stages, significantly reduced, NSC per spikelet at the heading time, sink strength, grain filling rate, and grain weight of inferior spikelets in super rice. The results suggest that pre-anthesis NSC reserves in the stem are closely associated with the sink strength during grain filling of rice, and N application at the spikelet differentiation stage would be a good practice to increase pre-anthesis NSC reserves, and consequently to enhance sink strength for rice varieties with large panicles, such as super rice varieties.     

Effects of Nitrogen Application Time on Caryopsis Development and Grain Quality of Rice Variety Yangdao 6

A pot experiment was conducted to study the effects of different nitrogen application time(during the tillering or the booting stages)with the same nitrogen rates on the caryopsis development and grain quality of rice variety Yangdao 6.The increased nitrogen fertilizer(urea),especially applied during the booting stage,could evidently increase the milled rice rate,head rice rate and protein content in rice grains compared with the control(no nitrogen application),and decrease chalky grain rate and amylose content.Moreover,the increased nitrogen fertilizer significantly affected the caryopsis development and enhanced the grain weight when nitrogen applied during the tillering and the booting stages,especially during the booting stage.During caryopsis development the increased nitrogen fertilizer applied during the tillering and booting stages could obviously decrease the total starch and amylose contents,but not obviously for the amylopectin content in rice grain.Increased topdressing of nitrogen fertilizer,especially applied during the booting stage,had significant effect on the development and structures of amyloplasts and proteinoplasts.That is,it could change the distribution,number and shape of amyloplasts and proteinoplasts in the endosperm cells especially in grain abdomen.Compared with the control the arrangements of amyloplasts and proteinoplasts were closer,with more numbers,higher density and less interspaces each ohter.Furthermore,most amyloplasts showed polyhedron under the increased nitrogen fertilizer level.     

Development and Substance Accumulation of Caryopsis in Transgenic Rice with Antisense Wx Gene

China is one of the leading nations in production as well as consumption of rice. Almost more than half of Chinese people live on rice. But most of the widely grown rice is of low quality, especially with high amylose content [1]. The higher level of amyl…     

转反义Wx基因水稻颖果的发育及物质积累

以转反义Wx基因粳稻和籼稻品系为材料,研究其颖果的发育和物质积累。结果表明,直链淀粉含量降低后的转基因水稻品系籽粒的粒重会有所下降,而且直链淀粉含量下降越多,粒重的下降幅度也越大。单个颖果胚乳细胞的数目也有不同程度的下降,但在籽粒发育早期（花后6 d前）,转基因水稻的胚乳细胞增殖速率明显高于其亲本。直链淀粉降低后的转基因品系籽粒可溶性糖含量在发育初期（花后9 d前）低于其同时期的亲本,而花后9 d后则明显高于其亲本。转基因水稻籽粒中的总淀粉含量有不同程度的下降,而支链淀粉的含量却相对增加,从而改变了籽粒中淀粉的组成,但对籽粒中蛋白质的积累没有显著影响。     

粒重对氮素的响应及其与子粒灌浆参数的相关与通径分析

连续两年采用正交设计,研究了大喇叭口期追施氮肥、开花期浇水、不同氮肥施用量以及施用时期对不同品种粒重的影响效应。结果表明：品种自身的遗传特性是导致粒重差异的主要因素,高淀粉玉米品种对氮素的需求量高于普通玉米,粒重对氮肥施用量的反应较氮肥施用时期敏感。Logistic方程拟合表明,处理间单粒重的差异主要在授粉40 d之后,受处理方式影响幅度较大的3个灌浆特征参数为缓增期灌浆速率、最大灌浆速率和快增期灌浆速率,较小的3个特征参数为灌浆持续期、缓增持续期和最大灌浆速率出现时间。相关及通径分析表明,粒重主要受平均灌浆速率的直接影响,较高的平均灌浆速率是获得高粒重的前提,而平均灌浆速率提高的根本在于提高渐增期灌浆速率;灌浆持续期对粒重的直接影响效应非常小,其对粒重的影响主要是通过其他灌浆参数间接实现。     

施氮量对超级杂交稻产量和稻米品质的影响

为探明超级杂交稻在成都平原的适宜施氮量,达到高产与优质协同,以超级杂交稻德优4727、普通杂交稻川优6203和常规稻五山丝苗为材料,于2016年在四川德阳进行大田试验,设置4个施氮量(0、120、165、210 kg/hm~2,分别记作N0、N120、N165、N210),研究施氮量对水稻产量和稻米品质的影响。结果表明,超级杂交稻产量随施氮量的增加呈先增加后下降的趋势,以N165处理最高;普通杂交稻和常规稻产量随施氮量的增加而增加,以N210处理最高,但与N165处理差异不显著。糙米率、整精米率、蛋白质含量随施氮量的增加而提高;垩白粒率、垩白度对氮肥的响应因品种而异。除普通杂交稻胶稠度外,施氮量对胶稠度和直链淀粉含量的影响不显著。品种间产量和品质均存在显著差异。与普通杂交稻和常规稻相比,超级杂交稻产量显著增加,增产优势主要表现在粒重上。超级杂交稻糙米率、垩白粒率、垩白度、胶稠度显著高于常规稻,直链淀粉含量和蛋白质含量低于常规稻;超级杂交稻整精米率显著高于普通杂交稻,但与常规稻相当。考虑产量和品质两因素,本试验条件下超级杂交稻选择纯N用量165 kg/hm~2,可实现产量和品质的协同提高。     

Function Analysis of Sucrose Transporter OsSUT4 in Sucrose Transport in Rice

【Objective】The transmembrane transport of sucrose is mainly mediated by sucrose transporters, among which five SUT coding genes have been identified in rice. However, the role of OsSUT4 in the sucrose transport is unclear. 【Method】CRISPR/Cas9 techniques were used to construct ossut4-deleted mutants. The ossut4 mutant was featured by lower plant height and grain yield as well as higher tiller number as compared with wild type plants.【Result】Sucrose and starch accumulation in the leaf of the ossut4 mutants lead to slower net photosynthetic rate; insufficient sugar supply results in the postpone of grain filling. Base on the subcellular and histochemical localization, OsSUT4 was located on the cytoplasmic membrane. Tissue localization showed that OsSUT4 was expressed in the embryo of germinating seed, vascular bundles of coleoptile, glume shell, anthers at flowering stage and aleurone layer of caryopsis at filling stage. 【Conclusion】OsSUT4 plays an important role in sucrose transport.