硫氮配施对持绿型小麦氮素运转及叶片衰老的影响

以持绿型小麦品种‘豫麦66号’、‘潍麦8号’及非持绿型品种‘小偃6号’为材料,采用以氮肥为主区硫肥为副区的田间裂区试验,研究了2个施氮水平[纯氮120kg/hm2(N120)、220kg/hm2(N220)]和3个施硫水平[纯硫0kg/hm2(S0)、20kg/hm2(S20)、60kg/hm2(S60)]下植株各部位的含氮量、叶片干鲜重及叶片叶绿素含量的变化,探讨硫氮配施对不同类型小麦氮吸收及衰老的影响。结果表明:在相同处理下,持绿型小麦植株的总含氮量、氮素转运量、叶绿素含量、叶片含水量及穗粒数和千粒重均高于非持绿型小麦。N120处理条件下,不同硫肥处理时持绿型小麦与非持绿型小麦变化趋势相同,开花期茎和叶含氮量及叶绿素含量在S60处理下均低于其他2个硫肥处理,生育后期叶片含水量下降幅度也明显高于其他处理;在N220处理条件下,3个品种开花期叶含氮量、收获期总氮累积量、氮收获指数、叶绿素含量及叶片含水量在S60处理下均高于其他2个处理,其中非持绿型小麦在高硫处理条件下灌浆期的叶绿素含量的增长率明显高于持绿型小麦,而灌浆中后期叶片含水量的下降幅度则明显低于持绿型小麦。研究发现,施用硫肥在氮肥不足时会对小麦植株氮素的吸收利用及叶片衰老等方面产生负面影响,但在氮肥充足时却在氮素的吸收利用、延缓叶片衰老及最终籽粒产量和总生物量等方面表现出正面效应;本实验条件下,220kg/hm2左右施氮量和60kg/hm2左右施硫量有利于各品种小麦生长发育和产量提高;高N和高S水平对于延缓小麦的衰老而言,非持绿性小麦比持绿型小麦更明显。     

不同氮素水平下施硫对高产小麦碳氮运转和产量的影响

在大田栽培条件下,以2个不同穗型的高产冬小麦品种为试验材料,在施240 kg·hm-2(N240)和330 kg·hm-2(N330)纯氮水平下,分别施纯硫60 kg·hm-2(S60)和0 kg·hm-2(S0),研究了施硫对小麦不同器官碳氮运转及其对籽粒产量和蛋白质产量的影响.结果显示:(1)2个供氮水平下,施硫(S60)均比对照(S0)增加了2个小麦品种的叶片、茎、鞘、颖壳和穗轴等营养器官花前贮藏干物质、氮素的运转量和运转率以及总运转量和总运转率,提高了转运干物质、氮素对籽粒重和籽粒氮素的贡献率,极显著提高了籽粒和蛋白质产量.(2)施硫对豫农949品种籽粒和蛋白质产量提高幅度显著高于兰考矮早八;与对照(S0)相比,豫农949的N240S60和N330S60处理使籽粒产量分别增加12.74%和16.41%,蛋白质产量分别增加16.84%和16.14%.结果表明,中氮和高氮水平下施硫均可明显促进高产小麦植株的C-N运转,提高植株对氮的吸收利用和碳物质的积累,从而增加籽粒产量,但不同品种间的施硫效应存在差异.     

有机培肥和减施氮肥对小麦光合特性和氮素吸收及产量的影响

以常规单施氮肥处理为对照(CK,270kg·hm-2),设置秸秆还田(J)、秸秆还田+牛粪(JF)、秸秆还田+沼渣(JZ)3种有机培肥措施,耦合N1(较CK减量10%)、N2(较CK减量20%)和N3(较CK减量30%)3个施氮水平,采用田间试验方法,探究有机培肥和减施氮肥对小麦光合特性、氮素吸收及产量的影响。结果表明:(1)与CK相比,有机肥配施氮肥明显促进了小麦生育期分蘖的发生和有效群体数的形成,提高叶绿素含量并维持旗叶较高光合速率水平,促进小麦地上部干物质积累、植株氮素吸收,增加穗粒数和千粒重,并显著提高小麦产量,产量增幅为4.21%~17.80%,并以JFN2(JF+N2)处理组合产量最高(6 853.43kg·hm-2)。(2)同一有机肥培肥处理中,N2(减施氮肥20%)处理效果最好,能显著促进小麦群体形成,提高小麦叶绿素含量、光合速率和产量;JFN2小麦群体数在成熟期分别比JFN1、JFN3增加5.16%、4.31%,JFN2叶绿素含量在花期分别较JFN1、JFN3增加2.29%、2.31%;JFN2处理产量分别比JFN1和JFN3显著增加11.41%和7.56%。(3)同一施氮水平下,成熟期干物质积累量表现为JZN1处理显著大于JFN1和JN1处理,分别增加8.93%和12.01%;花期JF处理氮素积累量在3种施氮水平下均分别显著高于其它2种有机培肥处理;JFN2处理籽粒产量显著高于JZN2和JN2处理,增幅分别为12.17%和6.09%。研究认为,有机肥耦合施氮量可促进小麦分蘖和有效群体数的形成,提高叶绿素含量和光合速率,增加植株干物质和氮素积累,从而增加小麦产量。     

施氮水平对2种穗型冬小麦品种产量及氮素吸收利用的影响

在大田高产栽培条件下,以大穗型小麦品种‘兰考矮早八’和多穗型品种‘豫麦49-198’为材料,研究了4个施氮水平下2种穗型冬小麦品种的籽粒产量、氮素吸收和氮肥利用效率。结果显示:随着施氮水平的提高,2种穗型小麦植株地上部生物量(返青期、拔节期除外)、籽粒产量和籽粒蛋白质产量均呈先增加后降低的趋势并都显著高于对照(不施氮),且均以180 kg.hm-2施氮处理最高,而2品种小麦各生育期植株氮素积累量和成熟期籽粒蛋白质含量却逐渐增加,且大都显著高于对照;2品种小麦的氮肥利用率、土壤氮贡献率以及氮收获指数均表现出180 kg.hm-2>90 kg.hm-2>360 kg.hm-2的趋势,且不同氮肥处理间均存在极显著差异(P<0.01)。研究表明,2种穗型冬小麦品种在试验条件下施用纯氮180 kg.hm-2可获得较高籽粒产量、蛋白质产量和氮收获指数。     

Identification of Rice Ethylene-Response Mutants and Characterization of MHZ71OsEIN2 in Distinct Ethylene Response and Yield Trait Regulation

Ethylene plays essential roles in adaptive growth of rice plants in water-saturating environment; how- ever, ethylene signaling pathway in rice is largely unclear. In this study, we report identification and characterization of ethylene-response mutants based on the specific ethylene-response phenotypes of etiolated rice seedlings, includ- ing ethylene-inhibited root growth and ethylene-promoted coleoptile elongation, which is different from the ethylene triple-response phenotype in Arabidopsis. We establish an efficient system for screening and a set of rice mutants have been identified. Genetic analysis reveals that these mutants form eight complementation groups. All the mutants show insensitivity or reduced sensitivity to ethylene in root growth but exhibit differential responses in cole0ptile growth. One mutant group mhz7 has insensitivity to ethylene in both root and coleoptile growth. We identified the corresponding gene by a map-based cloning method. MHZ7 encodes a membrane protein homologous to EIN2, a central component of ethylene signaling in Arabidopsis. Upon ethylene treatment, etiolated MHZ7-overexpressing seedlings exhibit enhanced coleoptiie elongation, increased mesocotyl growth and extremely twisted short roots, featuring enhanced ethylene- response phenotypes in rice. Grain length was promoted in MHZ7-transgenic plants and 1000-grain weight was reduced in mhz7 mutants. Leaf senescent process was also affected by MHZ7 expression. Manipulation of ethylene signaling may improve adaptive growth and yield-related traits in rice.     

不同小麦品种氮效率和产量性状的研究

对29个冬小麦品种进行子粒产量和氮效率的研究,结果表明,在氮胁迫条件下,供试小麦品种的子粒产量具有明显差异。缺氮条件下子粒产量的聚类分析结果表明,供试品种可划分为氮高效、中效和低效三类,氮高效品种在其中所占比例较少。在缺氮条件（N-）下,不同氮效率品种成熟期植株全氮含量差异不大,植株氮素积累量、氮效率（NUE）、吸收效率（UPE）和利用效率（UTE）均以氮高效品种最高,中效品种次之,低效品种最低。缺氮条件下较强的氮索吸收和利用能力是氮高效小麦品种氮胁迫条件下高氮效率的主要原因。     

氮肥后移对花后受渍冬小麦灌浆特性及产量构成的影响

2010～2012年连续2个生长季,以小麦品种‘烟农19’为材料,大田试验按基肥∶拔节肥∶孕穗肥比例设为氮肥处理N1(10∶0∶0)、N2(7∶3∶0)、N3(5∶5∶0)、N4(3∶5∶2),采用多项式、Logistic方程拟合不同氮肥运筹对花后受渍冬小麦灌浆期籽粒体积与干重变化过程,研究不同氮肥运筹对花后受渍冬小麦灌浆特性及产量构成的影响.结果表明:(1)两年度间各指标变化趋势基本一致,故各指标结果按其两年度平均值计算.(2)花后渍水使冬小麦籽粒体积减小11.8％,灌浆速率降低15.4％,灌浆历期缩短9.2％,千粒重降低20.9％,穗粒数减少7.0％,籽粒产量降低26.6％,而对穗数无显著影响.相对于氮肥全部作为基肥处理N1,氮肥后移处理N2、N3、N1的小麦籽粒体积分别增加10.2％、15.0％、19.4％,灌浆速率分别提高8.5％、16.0％、18.2％,灌浆历期分别延长5.0％、9.4％、11.5％,千粒重分别增加11.9％、20.2％ 、25.6％,穗粒数分别增加7.9％、12.3％、14.6％,产量分别提高18.1％ 、29.6％、37.6％,而穗数分别降低2.2％、3.8％、4.3％.(3)各灌浆参数与冬小麦籽粒产量的关联度表明,花后渍水逆境对灌浆速率的影响大于对灌浆历期的影响,氮肥后移主要通过提高小麦中后期灌浆速率缓解渍水逆境胁迫伤害.研究认为,在花后土壤受渍冬小麦生产区,生产中可获得最高小麦产量的最佳氮肥运筹模式为N4(3∶5∶2)处理.     

不同施肥灌水处理对不同小麦品种产量和品质的影响

在小麦生育期间降水47.9 mm的条件下,以3个小麦品种为试验材料,采用四因素三水平正交设计,研究了不同灌水和施肥处理对不同小麦品种子粒产量、蛋白质含量和沉降值的影响。结果表明,全生育期施氮量300 kg/hm2和225 kg/hm2的处理子粒产量和蛋白质含量差异不显著,但均显著高于150kg/hm2的处理。在中产条件下氮肥底施和追施比例以7∶3时产量最高。春季灌4水产量显著高于灌2水的处理,但与灌3水差异不显著,子粒蛋白质含量以灌2水时最高。供试品种中以京冬8号的产量、千粒重、容重最高,CA0206和核优1的蛋白质含量差异不显著,但均显著高于京冬8号。CA0206的沉降值显著高于另两个品种。以产量、品质和经济效益综合考虑,在本试验条件下,以春季灌3水、施氮量225 kg/hm2、底施和追施比例为7∶3的处理为宜,与超高产条件下氮素底施和追施比例5∶5的结果有明显的差异。     

施氮量对小麦氮磷钾养分吸收利用和产量的影响

高产条件下研究了不同施氮量对小麦植株氮、磷、钾养分吸收利用及籽粒产量的影响.结果表明,适量施氮可促进小麦植株对氮素的吸收与积累,较高的施氮量不利于起身期之后的氮素积累,致使成熟期小麦氮素积累量未能显著提高;与不施氮肥相比,施氮显著提高植株磷素积累量;随施氮量增加,植株磷素积累量增加不显著;施氮量增加促进小麦生育前期对钾素的吸收积累,在生育后期降低植株钾素的流失.随施氮量增加,籽粒氮素含量呈先增后降的趋势,氮素向籽粒的分配比例趋于降低,植株氮素利用效率无显著变化,氮素收获指数下降;不同施氮处理之间籽粒磷素含量和钾素含量无显著差异,施氮量增加,营养器官钾素含量、钾素积累量和钾素向叶片的分配比例均呈增加趋势;同时,磷素和钾素利用效率降低;不同施氮处理间,植株磷素、钾素收获指数无显著差异.籽粒产量随施氮量增加呈先增加后降低的趋势,以施氮195 kg/hm2的处理籽粒产量最高.     

分期施氮与CO2浓度升高对小麦光合及其物质积累和产量的互作效应

采用开顶式气室和盆栽方法,以冬小麦品种‘小偃22’为材料,探讨了分期施氮与CO2浓度升高对小麦抽穗期和灌浆中期旗叶光合、地上部物质积累和产量的互作效应.结果显示:(1)不施氮条件下CO2浓度升高对小麦旗叶叶绿素含量(SPAD)和可溶性蛋白含量、光合能力、地上部花后干物质和氮素累积量、籽粒产量的影响不明显(P>0.05)或产生显著负效应;在施氮(300mg/kg土)条件下各指标均不同程度增加,且大多数达到显著水平.(2)与氮肥全部基施相比,分期施氮时CO2浓度升高使灌浆期旗叶光合能力、地上部花后干物质和氮素累积以及产量增加的幅度较大,其中以播前、返青期和孕穗期施氮比例为5∶3∶2时最明显.研究表明,适当分期施氮可能更有利于发挥CO2浓度升高对冬小麦的增产作用.     

冬小麦叶片持绿能力及其衰老特征研究

以12个冬小麦(Triticum aestivum L.)品种为供试材料,通过田间实验连续2年于开花后定期测定各品种的绿叶数目、绿叶面积、叶绿素和MDA含量以及SOD和CAT活性等指标,并以生理成熟时的保绿度、衰老启动时间为指标进行Hierarchical聚类分析,对小麦品种持绿能力进行分级.结果表明,参试冬小麦品种可分为持绿和非持绿两种类型,‘潍麦8号'(WM8)和‘豫麦66'(YM66)两年均表现为持绿型小麦.在整个灌浆期,持绿型小麦品种绿叶数目、面积、叶绿素含量明显高于非持绿型品种,叶片保护酶SOD与CAT活性也较非持绿小麦强,而其MDA含量明显低于非持绿型小麦品种.持绿型小麦叶片衰老启动时间延迟,生育后期绿叶面积较大,光合作用时间延长,具有较高的产量.本研究结果为冬小麦的品种选育、布局等相关研究奠定基础.     

Effect of Nitrogen Fertilization and Residual Nitrogen on Biomass Yield of Switchgrass

Switchgrass, Panicum virgatum L., grown for biomass has been extensively researched where the annual precipitation >760 mm and the climate varies from humid to moist-subhumid. Research is needed for areas that receive <700 mm of precipitation, where the climate varies from dry-subhumid to semiarid. The objectives were to determine (1) the effect of nitrogen fertilization on biomass production, (2) the effect of residual nitrogen on biomass production, (3) the nitrogen yield from harvested biomass, and (4) the concentration of soil organic carbon (SOC) from switchgrass plots. Plots were fertilized annually with nitrogen at the rates of 0, 40, 80, and 120 kg ha^?1 from 2008 to 2011 and unfertilized from 2012 to 2015. The biomass yield varied with N rate × production year interactions (P < 0.05), and biomass yield as a function of N rate was either linear or curvilinear depending upon production year. When fertilized, the biomass yield averaged 4.4, 9.4, 11.6, and 13.2 ± 0.4 Mg ha^?1 for the 0, 40, 80, and 120 kg ha^?1 N rates, respectively. Residual nitrogen sustained high biomass yields for 1 year after fertilization ceased. The nitrogen harvested in biomass varied with N rate × production year interactions (P < 0.05), and the harvested nitrogen yield as a function of N rate was linear each year. Fertilization increased the concentration of SOC an average of 1.0 ± 0.2 mg g^?1 of soil. The data suggest that producers could occasionally skip a year of nitrogen fertilization without detrimentally impacting the production of switchgrass biomass.     

氮素营养水平对冬小麦碳氮运转的影响

在大田试验条件下,研究了不同施氮水平对2种穗型冬小麦品种花后干物质和氮素积累与运转的影响及其与产量和品质的关系,以探讨氮素营养水平对冬小麦碳氮运转的影响.结果显示,适宜的施氮量（180 kg·hm^-2）能够极显著增加2种穗型冬小麦品种叶片、茎鞘等营养器官花前贮藏物质及花前贮藏氮素的再运转量和运转率以及总再运转量和运转率,也能够极显著增加成熟期籽粒氮素含量和花前贮藏氮素总运转量对籽粒氮素含量的贡献率.各施氮处理对2种穗型小麦品种花后氮素积累量对籽粒氮素含量贡献率的影响效应不明显.结果表明,适宜的施氮量有利于小麦籽粒和蛋白质产量的提高.     

有机物料和氮肥相互作用对微生物体氮的影响*

培养和田间试验表明,有机物料（作物茎叶和有机肥）和氮肥对土壤微生物体氮的影响有着显著的交互作用。交互作用的大小与有机物料和氮肥的种类有关,因面也与有效碳源和矿质氮的比例有关。有机物料与硝态氮的交互作用大,而与铵态氮的交互作用小,交者是后者的２．７倍,这种８差异与微生物对两种形态氮的固定不同有关,有机物料Ｃ／Ｎ比的影响表现为随着Ｃ／Ｎ比增大,交互作用增加,并且在有机物料分解前期的交互作用大于中、后期     

Impact of CO2 Enrichment and Variable Nitrogen Supplies on Composition and Partitioning of Essential Nutrients of Wheat

This study was conducted to determine effects of nitrogen supply (75 and 150 kg(N) ha⁻¹) and CO₂ enrichment on partitioning of macro and micro nutrients in wheat (Triticum aestivum L. cv. HD-2285). Plants were grown from seedling emergence to maturity inside open top chambers under ambient CO₂ (CA, 350 ± 50 μmol mol⁻¹) and elevated CO₂ (CE, 600 ± 50 μmol mol⁻¹). Leaves, stems and roots of the same physiological age were analyzed for carbon, nitrogen, calcium, copper, iron, zinc and manganese content at 40, 60 and 90 d after germination. C, Cu, Mn and Zn content was higher in the stem, leaves and roots on dry mass basis under CE than CA. However, N and Fe contents decreased in CE grown plants. Ca content was unaffected due to CE and variable N supplies. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effects of Nitrogen Nutrition on Nitrogen Partitioning between Chloroplasts and Mitochondria in Pea and Wheat

Nitrogen partitioning among proteins in chloroplasts and mitochondria was examined in pea (Pisum sativum L.) and wheat (Triticum aestivum L.) grown hydroponically with different nitrogen concentrations. In pea leaves, chloroplast nitrogen accounted for 75 to 80% of total leaf nitrogen. We routinely found that 8% of total ribulose-1,5-bisphosphate carboxylase/oxygenase adhered to thylakoids during preparation and could be removed with Triton X-100. With this precaution, the ratio of stroma nitrogen increased from 53 to 61% of total leaf nitrogen in response to the nitrogen supply, but thylakoid nitrogen remained almost constant around 20% of total. The changes in the activities of the stromal enzymes and electron transport in response to the nitrogen supply reflected the nitrogen partitioning into stroma and thylakoids. On the other hand, nitrogen partitioning into mitochondria was appreciably smaller than that in chloroplasts, and the ratio of nitrogen allocated to mitochondria decreased with increasing leaf-nitrogen content, ranging from 7 to 4% of total leaf nitrogen. The ratio of mitochondrial respiratory enzyme activities to leaf-nitrogen content also decreased with increasing leaf-nitrogen content. These differences in nitrogen partitioning between chloroplasts and mitochondria were reflected in differences in the rates of photosynthesis and dark respiration in wheat leaves measured with an open gas-exchange system. The response of photosynthesis to nitrogen supply was much greater than that of dark respiration, and the CO₂ compensation point decreased with increasing leaf-nitrogen content.     

花期追施氮肥对菜用大豆AC10生理指标及产量影响的研究

选用激光诱变育成的菜用大豆品种AC10,通过在开花初期追施不同的氮素水平,研究其对主要生理指标及产量和产量构成因素的影响。结果表明：花期追施适量氮肥,能明显提高菜用大豆品种AC10植株花后叶面积指数、叶绿素含量、光合速率和荚果可溶性糖含量,从而提高鲜豆荚产量,其中以每公顷追施75．0kg-112．5kg尿素,单株鲜豆荚产量达到92．15g～90．37g,比对照增产8．0％～7．1％;但过量追施氮肥,影响植株生长．造成减产,当每公顷追施尿素达150kg时,单株鲜豆荚产量为81．19g,比对照减产5．1％。     

氮肥基追比对抗虫杂交棉叶片衰老和产量的影响

在盆栽条件下,研究了3种氮肥基追比(2:1、1:1和1 :2)对抗虫杂交棉'豫杂35'的叶片衰老特性和产量的影响.结果表明,氮肥基追比为1;2处理的棉花植株在盛蕾期和开花期的叶片SOD、POD活性和叶绿素、可溶性蛋白质含量相对较低,MDA含量较高;仉在盛铃期之后,其叶片SOD、POD活性和叶绿素、可溶性蛋白质含量却相对较高,MDA含量较低.氮肥基追比为1:2处理的皮棉产量分别比1;1和2:1处理显著增加3.66%和7.33%.研究发现,在本实验条件下,合适的氮肥基追比(1:2)能保持生育后期棉花叶片活性氧代谢相对协调,延缓棉花叶片的衰老进程,从而显著提高棉花产量.