厚轴茶雄性不育株花药败育的生物学特性和细胞学研究

为明确厚轴茶(Camellia crassocolumnaH. T. Chang)雄性不育株花器发育形态、花药和花粉败育时期及兵细胞学特征,利用体视显微镜、石蜡切片技术、染色体制片和DAPI染色法,对厚轴茶雄性不育株和可育株开花迚程、花器形态、花药发育过程、花粉母细胞减数分裂及小孢子发育过程比较观察。结果显示,厚轴茶花属于完全花,花药其四室、呈蝶形,花药壁发育为基本型,绒毡层细胞其双核,于四分体时期形成分泌型细胞,单核花粉期开始降解,花粉母细胞经过减数分裂Ⅰ、减数分裂Ⅱ和胞质分裂后形成四面体型四分体,小孢子呈三角形,成熟花粉为二细胞型花粉。花蕾发育早期,不育株雄蕊发育正常,与可育株无明显差异。花蕾发育后期,不育株花丝弯曲,花药粘连、干瘪、褐化、坏死,不裂药。不育株减数分裂期绒毡层细胞异常增生、排列混乱,单核至双核花粉期绒毡层延迟降解。不育株花粉母细胞减数分裂过程中存在环状单价体、滞后染色体、染色体桥、染色体缺失、不均等分离、微核和多分体等异常现象。不育株小孢子胞质紊乱,单核期花粉粒相互粘附,花粉壁皱缩变形,花粉细胞质和细胞核模糊不清,成熟花粉细胞空瘪凹陷。研究结果表明,厚轴茶雄性不育花器形态属雄蕊萎缩型和花药异常型,花药发育受阻于减数分裂至单核花粉期,存在花粉母细胞败育型和单核败育型。单核花粉期是兵花药败育的主要时期。花药绒毡层异常发育和延迟降解,花粉母细胞减数分裂染色体行为异常,小孢子和花粉粒发育异常可能是兵花药败育的主要原因。     

甘蓝型油菜温敏细胞核雄性不育系160S花药败育的形态学特征和细胞学研究

明确甘蓝型油菜温敏核雄性不育系160S花器形态变化、花药败育的时期和细胞学特征,初步探究败育的原因,为深入研究不育系160S的内在分子调控机制提供理论基础,也对其在油菜两系杂交育种中的实际应用具有指导意义。本研究在15℃和28℃条件下培养试验材料160S,利用体式显微镜分别观察花发育形态特征;采用醋酸洋红染色方法观察各时期小孢子发育形态;通过石蜡切片和苏木精-伊红染色对可育植株(MaleFertile/160S-MF)和不育植株(MaleSterile/160S-MS)花药细胞学特征进行显微观察;TUNEL染色法检测花药发育各时期绒毡层细胞凋亡情况。160S-MF在15℃表现为可育,雄蕊正常发育,成熟的花药呈黄色,形态饱满,正常开裂,表面一层有活性的花粉附着在上面;28℃条件下, 160S-MS花朵的雌蕊、萼片与160S-MF花朵无差异,但花瓣变小,花丝变短,雄蕊明显退化,花药干瘪呈黄褐色,无花粉粒附着在花药上,表现出雄性完全不育。160S-MF的小孢子能正常发育为成熟有活力的花粉。而160S-MS由于雄蕊完全败育,未观察到小孢子和花粉粒。160S-MS花药在造孢时期和花粉母细胞时期与160S-MF无明显差异,但在减数分裂期,160S-MS花药绒毡层形态和结构出现异常,绒毡层细胞排列不整齐,细胞空泡化,伴随提前解体。同时花粉母细胞发育受阻,无四分体结构形成,最终在减数分裂期完成前形成空的花粉囊。TUNEL检测发现, 160S-MS花药绒毡层细胞在减数分裂期开始凋亡。本研究结果表明, 160S属花粉母细胞败育型不育系,败育时期发生在减数分裂期,绒毡层异常降解,绒毡层未向腺质型转化,不能提供花粉母细胞发育所需要的营养物质,致使花粉母细胞发育受阻无法形成四分体结构,从而导致小孢子无法形成,花药形成空的花粉囊,产生雄性不育。     

在水稻极耐寒冷品系Norin-PL8的遗传背景下矮秆基因d18-κ对孕穗期冷害耐性的多效性

水稻对低温最敏感的生育期是孕穗期，特别是从四分体到早期小孢子阶段，主要受害特征是由花药发育不完全和花粉败育引起小穗授粉失败。孕穗期低温还能引起小穗退化。水稻对低温的第二个敏感时期是开花期；低温阻碍了开花，在此期间花药开裂和花粉萌发都受到了影响，导致了不育小穗的增加。在日本北部和其它国家，如加利福尼     

棉花细胞质雄性不育花药败育过程中内源激素的变化

利用酶联免疫检测（ELISA）技术,研究了棉花细胞质雄性不育系、保持系、恢复系和杂种一代花药在造孢细胞增殖期、花粉母细胞减数分裂期、四分体至小孢子释放期、花粉发育期和花粉成熟期内源吲哚乙酸（IAA）、赤霉素（GA₃）、玉米素核苷（ZR）和脱落酸（ABA）含量的动态变化。结果表明,在保持系、恢复系和杂种一代可育花药间内源激素含量差异不明显,但在可育与不育花药间差异显著。在IAA、GA₃和ZR含量上,不育花药低于可育花药,但在ABA含量上,不育花药高于可育花药,这种差异在花粉母细胞减数分裂时期达最大值。根据内源激素的功能推测,不育花药IAA含量过低使花药淀粉积累受阻,GA₃含量不足影响花粉母细胞和绒毡层细胞的膨大,过低的ZR含量使花粉母细胞不能分裂形成四分体,过高的ABA含量促进花粉母细胞退化和死亡。     

西瓜G17AB不育花药的细胞形态学及组织化学研究

观察研究表明,不育花药绒毡层细胞异常,造成花粉母细胞不能进行正常减数分裂,败育发生于四分体形成之前,无花粉粒形成.雄性不育花药组织内的不溶性多糖和蛋白质含量较可育花药低.     

特优671水稻优质高产制种技术

株高90cm左右，茎秆粗壮，根系发达，穗大粒多，穗长18～20cm，每穗总粒数115粒左右，分蘖力中等偏强，柱头外露率高达65％左右，且开颖角度大。尤其双侧外露率明显高于珍汕97A，抽穗当天一般不开花，花时比珍汕97A早0．5h，在福安市基地夏制播始历期71～73d，主茎总叶片数在14叶。其育性易受环境因素影响，在抽穗前12～15d(即花粉母细胞减数分裂期)，温度在29℃以上的条件下，败育彻底；在28．5～25．5℃的温度条件下则可染花粉增多，     

保持系稻株对孕穗期干旱胁迫伤害与补水修复的育性响应

以负压式土壤湿度计和取土烘干法双重监控盆栽试验的土壤水势变化,观测我国14个常用水稻保持系的孕穗期耐旱性,并以干旱胁迫指数人为划分钝感、耐旱、不耐旱与敏感4个等级,其中K22-B、金23-B为孕穗期干旱胁迫钝感材料,珍汕97-B、中9-B为孕穗期干旱胁迫敏感材料,比较研究它们对干旱胁迫伤害的育性响应与补水修复的特征。结果表明,钝感或敏感保持系稻株主穗耐旱性均强于分蘖穗,粒位间强势粒耐旱性均高于弱势粒。这一生物学现象似"植物顶端优势"的逆境生理学表现。比较孕穗期中花粉母细胞减数分裂期、花粉粒形成期与花粉粒充实期的耐旱性,花粉粒充实期耐旱性最弱,花粉母细胞减数分裂期耐旱性较强。孕穗期干旱后补水对结实伤害的恢复效果明显,尤其对耐旱性强的保持系稻株修复更明显,主要途径是降低秕谷率而不降低空壳率,表明干旱胁迫育性损伤是不可逆的。     

甜椒雄性不育两用系小孢子发育的显微观察

以甜椒雄性不育两用系为试材,对不育株与可育株花粉母细胞减数分裂过程中染色体行为、花药和小孢子发育过程进行了研究。结果表明,不育株花粉母细胞减数分裂染色体行为未见异常,败育发生在四分小孢子形成之后。导致小孢子败育的原因与四分体胼胝质壁不适时解体和绒毡层细胞发育异常、延迟解体有关。     

栽培密度不同的春小麦小孢子发育的细胞学观察

本文对栽培密度不同的三个春小麦(Triticum aestivum L.)品种的小孢子和花粉发育进行了细胞学比较研究.结果表明:(1)在花粉母细胞时期.稀植小麦的小孢子发育略快于密植的.即当稀植小麦花粉母细胞开始减数分裂、药壁绒毡层开始解体时.密植小麦花粉母细胞刚形成.药壁完整;(2)到二、四分体时期、稀植小麦花粉母细胞发育加快.当其90%形成二、四分体时,密植小麦花粉母细胞才有50%将分裂成二分体.仅部分形成了二分体;(3)当小孢子发育到单核靠边期.稀植的主穗和分蘖穗发育越来越快.并有分蘖穗赶上主穗的趋势;而密植的分蘖穗发育减慢以至停止.     

我国水稻常用保持系穗期耐旱性测评及育性分析

以负压式土壤湿度计和取土烘干法双重监控盆栽试验的土壤水势变化,观测我国15个常用水稻保持系的穗期耐旱性和育性特征。结果表明,K22-B、金23-B及II-32-B等保持系为穗期干旱胁迫钝感材料,而珍汕97-B、中9-B及协青早-B等为穗期干旱胁迫敏感材料;参试保持系在开花期(花粉粒充实期到小穗灌浆初期)比孕穗期(花粉母细胞分裂期到花粉粒充实期,15 d)对干旱胁迫更敏感;保持系孕穗期干旱胁迫主要伤害颖花育性,其胁迫指数与空壳率正相关(r = 0.6988^**), 开花期干旱胁迫不仅伤害颖花育性并影响小穗充实,其胁迫指数与空壳率正相关(r = 0.7660^**),也与秕谷率正相关(r = 0.5230);穗期耐旱性与其正常生育条件下的穗部结实性状不具直接相关性。     

春季低温对小麦花粉育性及粒数形成的影响

Grain yield and the number of grains per ear of wheat decreased under the low temperature after jointing stage. In order to explore the physiological reasons of the decrease of grains number per ear by low temperature in spring, the spring wheat variety Yangmai 16 and the semi-winter wheat variety Xumai 30 were used as tested varieties to analyze the effects of low temperature in spring on the fertility of pollen and the formation of grain numbers at the appearance of the penultimate leaf stage (5℃/-3℃, day/night), booting stage (8℃/-1℃, day/night), and anthesis stage (12℃/4℃, day/night). The results showed that low temperature at the appearance of the penultimate leaf stage and booting stage resulted in abnormal metabolism of starch and protein in the anther both at the binuclear and tri-nuclear pollen stages and delayed degradation of the tapetum. The low temperature at the booting stage caused abnormal meiosis of pollen mother cells, abnormalities in chromosome pairing, which affected the formation of male gametophyte. The abortion rate of pollen was more significantly increased under low temperature at the appearance of the penultimate leaf stage than that at the booting stage, and it was the minimum at anthesis stage. The abortion rate of pollen in Xumai 30 was higher than that in Yangmai 16. The low temperature at three stages had significant effects on the number of spikelets, the number of fertile spikelets and the number of grains per spikelet. The effect of low temperature at the appearance of the penultimate leaf stage on grains number per spikelet was the most significant. There was a significant positive correlation between the number of grains per spike and pollen fertility, which was affected by abnormal meiosis, delayed degradation of the tapetum, and undersupply of nutriment for anther development. Therefore, the decline of pollen fertility caused by low temperature in spring is the main reason for the decrease of grains number per spike.     

基于顶端发育的小麦产量结构形成模型

小麦产量由单位面积穗数、每穗粒数与粒重构成。本研究以试验资料为基础,通过定量分析小麦茎顶端发育过程及其与环境因子和品种特性的动态关系,构建了小麦穗粒发育与结实的模拟模型,包括对叶原基数、叶片数、小穗原基数、小穗数、籽粒数及籽粒重的预测;进一步结合茎蘖发生与穗数决定模型,最终建立了小麦产量结构形成的模     

Wheat Development as Affected by Radiation at Two Temperatures

A wheat cultivar (Condor) was grown in two experiments (thermal regimes 18/13 and 21/16°C) under low (298 μE m^-2: s^-1) radiation regimes during either an early phase from seedling emergence to terminal spikelet initiation (S₂), a late phase from terminal spikelet initiation to anthesis (S₂), or for the full period from seedling emergence to anthesis (S₁₂), or high (560 μE m^-2s^-1) radiation throughout the growing period (S₁₂) to determine whether developmental events are affected by radiation. The main developmental events considered in this study were the timing of terminal spikelet initiation and anthesis, the final number of leaf and spikelet primordia initiated in the apex and the rate of leaf appearance. Number of grains per spike and culm height were also measured. The duration of each phenophase was not affected by radiation intensity. Temperature affected the rate of wheat development, but the acceleration of development due to temperature during the seedling emergence - terminal spikelet initiation phase only slightly reduced (from 24.8 to 23.2 days). Differences in time from terminal spikelet initiation to anthesis were greater than in the earlier phases, having been the duration reduced from 24.6 to 20.0 days due to high temperature. Associated with the lack of effect of radiation on phasic development and the negligible effect of temperature on the duration of the early phases of development, final Leaf number was practically unchanged in this study by either the radiation level or the growing temperature. Thus, radiation did not affect the rate of leaf initiation. The number of spikelets was affected by neither the treatments nor the thermal environment. The rates of leaf appearance were accelerated by temperature. Radiation, on the other hand, did not significantly alter the rates of leaf appearance in any of the treatments. As expected from many sources in the literature, the number of grains per spike was significantly affected by radiation during the phase from terminal spikelet initiation to anthesis. Due to the lack of significant effects of radiation on the developmental patterns of wheat, the changes in number of grains per spike were due to changes in the number of grains born in each spikelet. The results of the present study were compared with others available in the literature on the effects (or lack of them) of radiation and CO₂ concentration on phasic development, plastochron and phyllochron in wheat to reach the general conclusion that the rate of developmental events in wheat, in contrast to other plants, is almost completely independent of the availability of assimilates, with a possible exception for the Equatorial latitudes.     

Impact of Humidity on Temperature-Induced Grain Sterility in Rice (Oryza sativa L)

High temperature‐induced grain sterility in rice is becoming a serious problem in tropical rice‐growing ecosystems. We studied the mechanism of high temperature‐induced grain sterility of different rice (Oryza sativa L) cultivars at two relative humidity (RH) levels. Four varieties of Indica and Japonica rice were exposed to over 85 % RH and 60 % RH at 36/30 °C, 34/30 °C, 32/24 °C and 30/24 °C day/night air temperatures from late booting to maturity inside sunlit phytotrons. Increasing both air temperature and RH significantly increased spikelet sterility while high temperature‐induced sterility decreased significantly with decreasing RH. Neither Indica nor Japonica rice types were superior to the other in the response of their spikelets to increased air temperature and RH. Increased spikelet sterility was due to increased pollen grain sterility which reduced deposition of viable pollen grains on stigma. Reduction in sterility with decreased RH was more due to decreased spikelet temperature than to air temperature. Thus the impact of RH should be considered when interpreting the effect of high temperature on grain sterility. Spikelet fertility was curvilinearly related to spikelet temperature. Grain sterility increased when spikelet temperature increased over 30 °C while it became completely sterile at 36 °C. The ability of a variety to decrease its spikelet temperature with decreasing RH could be considered as avoidance while the variability in spikelet sterility among varieties at a given spikelet temperature could be considered as true tolerance.     

Availability and Utilization of Assimilates in Relation to Grain Growth Within the Ear of Wheat

The development of grains of different positions in the apical, middle and basal spikelets of wheat var. Kaly-ansona showed that beyond first two basal grains, the more distal a grain in a spikelet the lower its weight. The distal grains received less assimilates than the proximal grains as revealed from sugar concentration in the grains. The eflficiency of distal grains of kalyansona to synthesize reserves was, however, not inferior than the proximal grains in a spikelet. The depression in grain weight lowards extreme spikelet was lower compared to the depression in weight of individual grams towards a distal position in a spikelet. The study seems to suggest that in order to ensure better grain uniformity while maintaining a higher grain number per ear, the spikelet number per ear should be increased instead of increasing the grain number per spikelet.     

不同播期和品种小麦小花结实的粒位差异

确定小麦不同小穗位和小花位发育与结实特性是实现大穗多粒的重要前提，本文通过对冬，春性小麦品种分期播种试验得出，较高的小穗结实力是增加穗粒数的重要因素，不同播期，品种之间，小穗粒重和粒数呈现相同的变化趋势，中部以及基部小穗粒重与穗粒重之间呈高度正相关，体现环境差异的播期效应以对中部小穗发育的影响为主，而冬，春性品种的基因型差异可反映在各个小穗位上，第2小花粒的子粒发育状况反映整个小穗的生产能力，结果表明，促进中部优势小穗（第5－15小穗）结实和第1－3小花位子粒发育是提高小花结实率和穗粒重的关键。     

温光互作对春性小麦小穗建成的效应

利用6个来自不同生态区的春性小麦品种,在温室和生长箱温光控制条件下,研究了温度和光周期对小穗数调节作用的形态学基础。结果表明,温度和光周期从叶原基的分化转化及穗分化持续期两方面调节了小穗数,具体表现为:(1)从温度的影响出发,在长日条件下,低温主要通过延迟二棱以后小穗原基的分化过程而增加小穗数的多少,而     

冀东地区冬小麦春季不同灌水处理的效应研究

在冀东地区对冬小麦春季不同灌水处理效应进行了研究。结果表明：多水处理的叶面积指数一直高于少水处理,且叶面积指数下降平缓。子粒最大灌浆速率出现的时间随灌水次数的增加而推迟。每公顷穗数、穗粒数、千粒重随灌水次数的增加而增加。四水、三水、二水处理的产量极显著高于一水和旱处理的产量,但四水、三水、二水处理产量之间没有显著差异。灌溉水利用效率随灌水次数的增加而下降。从高产、节水出发,冀东地区小麦春季灌水方案为在越冬水的基础上,春季灌拔节期、孕穗期两次水。     

孕穗期高温对水稻生理特性和产量性状影响研究

为探索水稻孕穗期高温对生理生化特性和产量性状的影响,降低水稻生长发育过程中孕穗期高温对水稻的危害提供理论依据。以‘泰优553’和‘隆晶优1212’为材料,在孕穗期幼穗分化Ⅳ-Ⅵ期利用人工气候室以29、32、35、38℃处理7天,以同时期田间自然温度条件作对照（CK,平均温度30.6℃）,研究孕穗期不同温度对水稻生理特性和产量性状的影响。与对照相比,38℃处理显著降低了‘泰优553’和‘隆晶优1212’的可育花粉数和可育率,可育率分别比对照下降了60.2%、54.7%。随温度的升高,2个品种的脯氨酸和丙二醛(MDA)含量呈上升趋势,在38℃处理显著高于对照(CK)和其他处理,过氧化物酶(POD)活性呈先上升后下降的趋势。高温处理显著降低了2个品种的结实率、千粒重和产量,但对有效穗影响较少。水稻孕穗期高温能显著降低可育花粉数和可育率,同时影响幼穗生理指标的变化,致使结实率和产量下降,不同品种对高温危害的表现存在差异。