光温条件对短光低温不育水稻育性转换的影响

短光低温不育水稻是一类与长光高温不育水稻育性转换特性相反的新种质,通过对分期播种材料自然条件下的育性及人工短光处理后的育性比较分析表明,宜DIS的光敏期为第一苞分化期至第二次枝梗原基和小穗原基分化期（幼穗分化I－III期）,在常温下光敏期的短日处理可使育性趋于不育,但在高温下光敏期短日不育效应被削弱,宜DIS的花粉育性在高,低温作用下育性的均出现下降,根据高,低温影响育性的资料分析得到的敏感期基本一致,即花粉母细胞形成期至花粉内容物充实期（幼穗分化V－Ⅶ期）。     

短光低温不育水稻不育性的遗传观察

用若干常规品种与短光低温不育水稻宜ＤＩＳ配组,考察双亲及Ｆ１在自然低温影响前后的花粉育性,并于不育系稳定不育期间调查Ｆ２及Ｆ３的育性分离。结果表明：（１）低温是影响双亲及Ｆ１育性稳定性的重要生态因子;（２）Ｆ１的育性稳定性除与父本的育性稳定性有关外,可能尚与其他因素有关,这种育性稳定性表现是由可遗传因子决定的;（３）短光低温不育特性基本上符合２对独立主基因控制的遗传模式,但可能尚受到众多微效基因的     

两个籼型水稻核不育系育性温光反应的研究

在杭州男单通过分期播种,比较了两个籼稻光温敏核不育系的育性及其转换特性。结果表明,光照长度对浙大247S和培矮64S两不育系育性表达的影响小,温度起主导作用,均属温敏型不育系,且日最低温度对不育系育性效应显著高于日平均温度和日最高温度。不育系浙大247S和培矮64S的温度敏感期分析是抽穗前3-18和6-21d,育性转换的临界日期为9月19日和9月25日,转换临界温度为25.28和25.66℃,与培矮64S相比,浙大247S不育期败育较彻底,可育期较长且自交结实率高,在杭州田间可以繁种。     

岷江上游干旱河谷景观变化及驱动力分析

基于遥感和地理信息系统,应用景观格局分析软件,研究了岷江上游干旱河谷1974-2000年的景观变化,并对其驱动因子进行了分析.结果表明,岷江上游干旱河谷的面积在不断扩大,灌木林地面积占景观面积的60%以上,为景观基质.在景观类型面积比例的变化中,耕地的变幅最大.干旱河谷的整体形状较简单,1974-1995年破碎化程度和异质性程度持续增加,1995-2000年表现为降低趋势,而斑块内部的连通性先降低后增加,具体表现为斑块密度、多样性指数先增大后减小,蔓延度指数先减小后增大,而边界密度和分维数持续减小.人口增长和国家政策是导致岷江上游干旱河谷景观变化的主要驱动力.     

低温敏核不育水稻go543S育性对温、光的反应

以新型光温敏核不育（PTGMS,Photo-thermo sensitive genic male sterile)水稻go543S为材料,通过自然生态条件下和人工温、光处理条件下的育性观察,对其育性转换与温度和光周期的关系进行了研究。结果表明：go543S育性主要受温度控制,表现为低温条件下不育,高温条件下可育,育性转换的不育临界温度值为29．5℃,对温度传感的部位是幼穗,敏感时期为花粉母细胞形成致减数分裂,对应的剑叶叶枕距变化范围为－12．2－＋0．7cm;育性敏感期在人工恒温28．0℃条件下,无论长日（14－16h）或短日（10－12h）处理均表现不育,其不育性不受光周期影响,在人工恒温31.5℃条件下,无论长日还是短日处理均表现可育,但短日可明显提高其可育性。     

光敏核不育水稻的温光反应研究

本文选用W_(6154)S、安农S-1和衡农S-13个水稻光敏核不育系做材料,采用分期播种的办法研究,提出了“临界低温”、“临界高温”和“过渡温度”的概念,求得W_(6154)S和安农S-1的临界低温为23℃,临界高温为25℃;衡农S-1的临界低温为23.5℃,临界高温为27℃。认为(1)不同的光敏核不育系的温光反应特性不同;(2)以“生态因子敏感雄性核不育水稻”这一名称代替“光敏核不育水稻”为宜;(3)在生产上可以应用。     

“一元多生态位”原理及其在棉花高产栽培中的应用

“一元多生态位”群体是指由同一个物种(品种)构成,生态元具有不同时间生态位、空间生态位、营养生态位、温度生态位或者水分生态位等．其特征为,群体培育具有目标性,种群组成具有一元性,冠层结构具有多层性,群体形成过程具有人工调控性,群体建立过程具有简单性,所形成的群体各生态元具有特定的生态位宽度、生态位重叠与生态位分离．从产量构成来看。作物“一元多生态位”群体具有群体生产能力的高效性和单株生产能力的差异性特征。     

不同光长诱导HPGMR过氧化物酶活性及同工酶的比较研究(简报)

湖北光敏感核不育水稻(Hubei Photo-period-Sensitive Genic Male-sterile Rice,简称HPGMR)经研究为光周期敏感的隐性雄性核不育遗传。短日照处理后用10 min红光或白光暗中断处理均起到长日不育的作用。这些特性不仅存生产上具有广泛利用的价值,而且在遗传学研究方面也具有重要的理论意义。为了探讨HPGMR的光诱导不育的机理,本文以HPGMR农垦58和正常可育农垦58(O.sativa,Japonica)为材料,对不同发育时期的幼穗和花药过氧化物酶活性及同工酶谱进行研究,试分析不同光长诱导下HPGMR过氧化物酶活性及同工酶谱的特征,结果简报如下:     

光敏核不育水稻育性转换的光温生态

光敏核不育水稻的花粉育性,可依种植地区与种植季节而变化。同一品系既可用作不育系而制杂交稻种子,又可自交繁殖而省去保持系。为水稻杂种优势利用改“三系法”为“二系法”开辟了新途径。光敏核不育材料育性可转换是该材料的宝贵之处。同时,这种可转换特性,特别是温度参预育性转换的调控引起的育性波动,给生产利用带来了一定困难。这种困难同其他科学研究中所遇到的困难一样,有待于进一步研究,加以     

光周期对光敏核不育水稻RNA水平上诱导效应的初步研究

本文以PGMR农垦58为材料,在PGMR育性转换临界期进行不同光周期处理,分析了叶片总RNA的含量和电泳特征。结果表明:叶片总RNA含量在长日照处理下明显减少,光周期对PGMR育性转换和表达在转录水平上可能有一定的调控作用,似乎属于阻遏调控类型。在育性转换期,长日照处理有1个特异的小分子和大分子RNA组份,这些特异RNA组份是否为PGMR的特异阻遏产物还有待进一步研究。     

基于源库生长单位的温室番茄干物质生产-分配模拟

为了量化研究温室番茄果穗间干物质的分配,提高温室番茄栽培的效益,采用源库生长单位的测定方法,将经典的单叶同化物生产模型与GreenLab模型相结合,构建了干物质向源库生长单位内茎节、叶片、果实分配的动态模型,利用越冬茬、早春茬和春夏茬温室番茄各器官的干物质测定数据对模型进行了验证.结果表明:所构建的模型模拟结果与实测结果吻合性较好,不同茬口同化物生产模拟值与实测值的回归方程斜率为0.93,R~2为0.92;源库生长单位内茎节、叶片、果实以及根系的模拟值与实测值间回归方程斜率在0.85～0.89之间,其相对误差(R_e)均值分别为5.3%、5.6%、8.1%和3.6%,说明模型的模拟准确度较高,可为不同茬口温室番茄栽培管理提供理论依据和决策支持.     

油菜地上部干物质分配与产量形成模拟模型

利用油菜器官生长与发育进程及环境因子之间的定量关系,构建了基于分配指数的油菜地上部器官干物质分配动态模拟模型.各器官干物质分配指数随着生理发育时间而变化,基因型、播期、氮素及水分水平影响各器官干物质在地上部分配的大小.其中,氮素营养水平对绿色叶片干物质分配影响最大,氮素营养水平越高,绿色叶片分配指数越大;播期影响角果分配指数,晚播的角果分配指数高于早播.模型引入氮素营养指数、水分及播期影响因子来定量油菜各器官在实际生产条件下的分配强度,同时考虑了品种遗传特性的影响.通过不同品种氮肥处理试验建立模型,利用不同品种播期试验资料对模型进行了初步检验,表明模型具有较好的预测性和适用性.     

光质对温室甜椒干物质生产和分配指数的影响

为了研究不同光质对甜椒植株干物质生产与分配指数的影响,以甜椒茎有限生长品种"苏椒13号"为试验材料,于2010年计不同种彩色塑料薄膜(红、黄、蓝、绿、紫,白色为对照)试验。结果表明:不同光质处理的甜椒单位面积干物质生产量(Wt)与冠层截获的太阳光合有效辐射日积分(daily photosynthetic active radiation integral,PARi,MJ·m-2)之间的模型为Wt=22.07×e0.0054λPARi;单位面积植株总干重、果实的干物质分配指数、果实采收指数和单位面积果实产量均以红膜最高,紫膜最低;蓝膜的茎干物质分配指数最高,红膜最低;蓝膜、绿膜和紫膜的植株叶片干物质分配指数明显高于红膜和黄膜;不同光质处理对甜椒植株地上部分干物质分配指数的影响差异不显著;研究认为红膜和黄膜能够促进甜椒植株的干物质积累和果实发育,紫膜和蓝膜则有明显的抑制作用,该研究结果可为温室甜椒栽培的光质选择和环境调控提供决策依据。     

短期干旱对水稻叶水势、光合作用及干物质分配的影响

采用盆栽水分试验,研究了不同生育期短期干旱处理对水稻叶水势、光合作用和干物质分配的影响．结果表明,干旱胁迫后,水稻叶水势低于对照,午后叶水势回升缓慢。凌晨叶水势随土壤含水量的降低而降低,表现为阈值反应。叶片净光合速率与凌晨叶水势密切相关,低于凌晨叶水势临界值,水稻叶片净光合速率急剧下降在水稻抽穗期和灌浆期叶片净光合速率显著下降的凌晨叶水势临界值为-1.04和-1．13MPa,对应的土壤含水量阈值分别为饱和含水量的61.0％和50．9％,土壤水势分别为-0．133和-0．240MPa干旱胁迫下单叶净光合速率的日变化规律表现为：胁迫较轻时,单叶净光合速率在正午附近出现低谷;胁迫严重时,净光合速率全天低于对照,且不及对照的一半。短期干旱后,水稻叶、根、穗的分配指数均降低,茎鞘的分配指数升高。本研究可为水稻节水灌溉管理和水分限制下水稻的生长模拟提供生理基础和理论依据。     

水分胁迫与光照条件对棉花干物质和产量形成影响的数学模型

从作物冠层净同化速率入手,通过引入对CO2浓度、空气湿度、光照强度和土壤含水量反映较敏感的光能利用系数（β）,建立了考虑水分胁迫和光照条件对作物干物质积累与产量形成影响的数学模型,模型考虑了水分胁迫与低光照下冠层阻力增加的设定,将反映作物冠层水分状况的功能叶水势（Ψl）作为参数纳入本模型,通过对土壤相对含水量（Aw)、气温（Ta）、水汽压差（VPD）的多元回归估算出Ψl,并将空气动力学阻力（Ra）简化为风速（u）的函数,盆载试验应用实例和敏感性分析表明,该模型在诊断环境因子特别是土壤水分与光照因子对作物生长和产量构成的影响具有一定的实用性。     

基于光温的温室多杆切花菊干物质生产与分配的预测模型

根据菊花生长对光温的反应,设计不同品种、不同单株主杆数、不同定植密度和不同定植日期的试验,构建了以生理辐热积(Physiological product of thermal effectiveness and PAR,PTEP)为尺度的温室多杆切花菊的干物质生产与分配预测模型,并用与建模相独立的试验数据对模型进行了检验.结果表明:随单位面积杆数增加,切花菊的单位面积地上干物质产量增加,单枝切花鲜重减少.所建模型对温室多杆切花菊的单株叶干重、茎干重、花干重和地上部分鲜重的预测值与实际观测值基于1:1线的决定系数(R2)分别为:0.96、 0.95、0.82和0.97,回归估计标准误(RMSE)分别为:0.863、1.005、0.201和10.190g ·株-1.模型模拟精度较高,可为温室切花菊栽培密度和保留杆数的优化调控提供理论依据.     

Simulation of leaf area development based on dry matter partitioning and specific leaf area for cut chrysanthemum

This work aims to predict time courses of leaf area index (LAI) based on dry matter partitioning into the leaves and on specific leaf area of newly formed leaf biomass (SLA(n)) for year-round cut chrysanthemum crops. In five glasshouse experiments, each consisting of several plant densities and planted throughout the year, periodic destructive measurements were conducted to develop empirical models for partitioning and for SLA(n). Dry matter partitioning into leaves, calculated as incremental leaf dry mass divided by incremental shoot dry mass between two destructive harvests, could be described accurately (R(2 )= 0.93) by a Gompertz function of relative time, R(t). R(t) is 0 at planting date, 1 at the start of short-days, and 2 at final harvest. SLA(n), calculated as the slope of a linear regression between periodic measurements of leaf dry mass (LDM) and LAI, showed a significant linear increase with the inverse of the daily incident photosynthetically active radiation (incident PAR, MJ m(-2 )d(-1)), averaged over the whole growing period, the average glasshouse temperature and plant density (R(2 )= 0.74). The models were validated by two independent experiments and with data from three commercial growers, each with four planting dates. Measured shoot dry mass increase, initial LAI and LDM, plant density, daily temperature and incident PAR were input into the model. Dynamics of LDM and LAI were predicted accurately by the model, although in the last part of the cultivation LAI was often overestimated. The slope of the linear regression of simulated against measured LDM varied between 0.95 and 1.09. For LAI this slope varied between 1.01 and 1.12. The models presented in this study are important for the development of a photosynthesis-driven crop growth model for cut chrysanthemum crops.     

华北夏玉米干物质分配系数对干旱胁迫的响应

干物质分配系数反映作物各器官干物质的分配与积累,研究干物质分配系数对干旱胁迫的响应,是研究干旱胁迫对作物生长发育影响的基础.本文基于华北夏玉米主产省山东、河北和山西3个试验点2013—2015年田间水分控制试验资料,建立了夏玉米苗期、抽雄期、灌浆期3个主要发育阶段叶、茎、穗的干物质分配系数与土壤相对湿度的定量关系模型,分析了叶、茎、穗干物质分配系数对不同程度干旱胁迫的响应.结果表明: 3个阶段叶、茎、穗的干物质分配系数与土壤相对湿度均呈显著的一元二次关系.干旱胁迫下,叶片向外转运的干物质相对减少,叶干物质分配比例增加,并且在轻、中度干旱胁迫时的灌浆期(叶干物质分配系数增加0.04~0.09)以及重度干旱胁迫时的抽雄期(叶干物质分配系数增加0.17)响应最敏感.穗干物质分配系数对干旱胁迫表现为负响应,干旱胁迫越严重,分配系数越小,轻-重度干旱胁迫使穗干物质分配系数减小0.08~0.34.茎干物质分配系数对干旱胁迫的响应总体表现为灌浆期(正响应)＞抽雄期(负响应)＞苗期(负响应).     

Improving efficiency of breeding for higher crop yield

Summary Exclusive selection for yield raises, the harvest index of self-pollinated crops with little or no gain in total bipmass. In addition to selection for yield, it is suggested that efficient breeding for higher yield requires simultaneous selection for yield's three major, genetically controlled physiological components. The following are needed: (1) a superior rate of biomass accumulation. (2) a superior rate of actual yield accumulation in order to acquire a high harvest index, and (3) a time to harvest maturity that is neither shorter nor longer than the duration of the growing season. That duration is provided by the environment, which is the fourth major determinant of yield. Simultaneous selection is required because genetically established interconnections among the three major physiological components cause: (a) a correlation between the harvest index and days to maturity that is usually negative; (b) a correlation between the harvest index and total biomass that is often negative, and (c) a correlation between biomass and days to maturity that is usually positive. All three physiological components and the correlations among them can be quantified by yield system analysis (YSA) of yield trials. An additive main effects and multiplicative interaction (AMMI) statistical analysis can separate and quantify the genotype × environment interaction (G × E) effect on yield and on each physiological component that is caused by each genotype and by the different environment of each yield trial. The use of yield trials to select parents which have the highest rates of accumulation of both biomass and yield, in addition to selecting for the G × E that is specifically adapted to the site can accelerate advance toward the highest potential yield at each geographical site. Higher yield for many sites will raise average regional yield. Higher yield for multiple regions and continents will raise average yield on a world-wide basis. Genetic and physiological bases for lack of indirect selection for biomass from exclusive selection for yield are explained.     

Environmental effects on dry matter partitioning between shoot and root of crop plants: relations with growth and shoot protein concentration

The literature on environmental effects on dry matter partitioning in higher plants, in particular crop plants, is reviewed focussing on changes in shoot to root dry weight ratio (S:R). Of particular consistency is the finding that S:R increases with increased nitrogen (N) supply. Relations between nitrogen (N) supply, growth, S:R and tissue N and protein concentration are examined. In some cases, the increase in S:R with increased N supply is likely to have been at least in part an effect on growth and development, but there is unequivocal evidence that N affects S:R independently of growth and development. A positive correlation between S:R and leaf protein concentration is highlighted. It is argued that the N effect on S:R outside the effect on growth and development is related to increased shoot protein concentration. Specifically, shoot and root growth are colimited by local carbon (C) and N (primarily protein) substrate concentrations and shoot growth will increase relative to root growth with increased N substrate availability due to the proximity of the shoot to the C source. It is further argued that results in the literature are consistent with the proposal that macronutrient, water, irradiance, CO₂ and temperature effects on S:R are often primarily mediated through their effects on growth and development, and shoot protein concentration and hence shoot growth.