果梅花粉离体萌发及花粉管生长特性研究

研究了果梅(Prunus mumeSieb.1et Zucc.)花粉在不同培养基组分、花粉不同培养密度和不同温度及培养时间的离体萌发和花粉管生长特性.结果表明:细叶青花粉萌发及花粉管生长最适宜的液体培养基为30mmol/L MES(pH 6.5)缓冲液中含20%蔗糖,0.01%硼酸,20%PEG-4000,0.03?(NO3)2?4H2O,0.02%Mg-SO4?7H2O;萌发率达45.03%,花粉管长度达597.2μm.适宜于果梅花粉萌发和花粉管生长的花粉粒密度为20~80粒/μL.培养温度过高或过低都不利于果梅花粉的萌发和生长,25℃时花粉萌发和花粉管生长最好.细叶青"、月世界"、莺宿"3个品种的平均萌发率为48.6%,平均花粉管长度为762.3μm.果梅花粉在不同培养温度下,萌发及生长不同,在25℃条件下花粉管生长速度最快,集中在0~12 h内,3个品种花粉管平均生长速度为58.5μm/h.     

梅花花粉离体萌发和花粉管生长研究

(南京农业大学园艺学院,南京210095)摘要:研究培养基成分、pH值和培养方式对梅花花粉离体萌发和花粉管生长的影响。结果表明:不同品种梅花花粉离体萌发的最适培养基为ME3+200g.L-1PEG4000(pH5.0),品种‘淡丰后’、‘久观绿萼’、‘喧妍宫粉’和‘月光玉蝶’最高萌发率可分别达到58.6%、60.6%、85.6%和50.7%。PEG4000能显著促进梅花花粉萌发,在培养基各成分中作用最大,不可替代。低浓度(50g.L-1)蔗糖对梅花品种花粉萌发作用不显著,而高浓度(≥100g.L-1)蔗糖明显抑制花粉萌发和花粉管生长。固体和液体培养对梅花花粉离体萌发的影响差异不显著。     

薄壳山核桃花粉离体萌发和花粉管生长特性研究

以6年生薄壳山核桃优良品种‘金华’的新鲜花粉为试材,采用离体培养法,研究了不同复水时间、不同培养基组分、不同培养温度及培养时间对薄壳山核桃花粉萌发和花粉管生长的影响。结果显示:(1)薄壳山核桃花粉萌发试验前进行4h复水处理可显著提高萌发率,萌发率可达51.78%,为对照(2.51%)的20.68倍。(2)蔗糖、H3BO3、Ca(NO3)2·4H2O在一定浓度范围内均具有促进花粉萌发和花粉管生长的作用,但浓度过高则起抑制作用。(3)正交试验结果经实验验证表明,薄壳山核桃花粉萌发和花粉管生长的最适培养基为20%蔗糖+0.02%~0.03%H3BO3+0.05%Ca(NO3)2·4H2O,最佳培养条件为25℃下恒温培养24h,此时的花粉萌发率高达74.46%,花粉管平均长度为258.84μm。     

桃花粉离体萌发和花粉管生长特性研究

采用花粉离体萌发法研究不同培养基组分和培养条件对桃花粉萌发和花粉管生长的影响,同时对不同贮藏温度下的桃花粉寿命进行研究.结果表明:固体培养基与液体培养基对桃的花粉萌发率和花粉管长度影响差异不显著;10%蔗糖是大多数桃品种花粉的最适萌发条件;硼能提高桃花粉的萌发率,但对花粉管的生长没有促进作用;桃花粉在20℃～25℃的培养温度下萌发率最高,花粉管最长;桃花粉萌发率和花粉管长度在培养前3 h内上升最快,3～5 h上升趋势减弱,5 h后基本停止;随着贮藏温度的升高和贮藏时间的延长,花粉生活力呈降低的趋势.     

植物生长调节物质对丰水梨花粉萌发和花粉管生长的影响

采用花粉液体培养法研究了植物生长调节物质对梨花粉萌发和花粉管生长的影响,结果表明：较低浓度的赤霉素、三十烷醇、吲哚乙酸及2,4-D均能促进花粉萌发和花粉管生长,而超过一定浓度时却起抑制作用,最适宜于花粉萌发和花粉管生长的赤霉素浓度为50～300mg／L,三十烷醇为3～100mg／L,吲哚乙酸为5～25mg／L,2,4-D为5～10mg／L。萘乙酸对花粉萌发和花粉管生长有抑制作用,抑制程度随培养基内其浓度的增大而加强。多效唑和脱落酸对花粉萌发有抑制作用,其抑制程度随浓度的上升而增强,但他们对花粉管生长却有促进怍用,其最适宜于花粉管生长的浓度分别为400mg／L和60mg／L,超过此浓度后,促进作用又有所下降,甚至出现抑制作用,如多效唑浓度达到1000mg／L时,能强烈地抑制花粉管生长。     

花粉萌发和花粉管生长发育的信号转导

显花植物授粉是一个复杂的发育过程。从花粉落在柱头上开始,经过粘附、识别、水合、萌发,花粉管在花柱内生长,直至到达子房发生双受精作用,整个过程发生在雌、雄两性细胞和组织之间,受到严格的遗传控制和细胞控制。一方面雌雄配子的基因型决定两者是否亲和,另一方面雌雄两性细胞间发生复杂的相互作用,细胞外信号分子是这些过程的主要调控因子。当花粉或花粉管细胞感知外部信号后,必然通过信号转导级联反应,达到控制萌发、调整花粉管生长方向等目的。这一系列动力学的细胞事件,关系到受精的成败。因此研究此过程中的信号及其转换机…     

类整合素在烟草花粉萌发和花粉管生长中的作用

本文研究了动物整合素VnR抗血清及动物整合素专一性抑制剂含RGD的多肽对体外及半体内培养条件下烟草花粉萌发及花粉管生长的影响。结果表明在体外培养条件下,VnR抗血清及GRGDSP肽对花粉的萌发及花粉管的生长没有明显的抑制作用,但可抑制钙调素促进的花粉萌发和花粉管的生长;两者对柱头上进行的花粉萌发及在花柱里进行的花粉管生长也有一定程度的抑制。对类整合素在花粉萌发及花粉管生长中的作用进行了讨论。     

培养基组分及pH值对梨花粉萌发和花粉管生长的影响

采用花粉液体培养法研究不同培养基组分和pH值对梨花粉萌发和花粉管生长影响.结果表明:培养基内硼酸、氯化钙、PEG-4000、蔗糖、葡萄糖、麦芽糖、山梨醇、果糖在一定浓度范围内,对花粉萌发及花粉管生长起促进作用,但超过一定浓度时起抑制作用;最适的培养基组分为:30mmol/LMES、0.01%硼酸、0.03%CaCl2·2H2O、15%PEG-4000、5%果糖 或5%山梨醇、10%蔗糖 ,最适的pH值为6.5.在该培养基内梨花粉萌发率约为59.2%,花粉管生长长度为966.3μm.     

桔梗花粉萌发与花粉管生长研究

以2年生桔梗植株为材料,采用液体培养法研究了培养基种类、PEG、蔗糖、pH以及培养温度、培养时间对桔梗花粉离体萌发生长的影响,结果表明:(1)浓度为100~150 g.L-1的PEG可显著促进桔梗花粉萌发和花粉管的生长;200~250 g.L-1PEG显著促进花粉萌发,但对花粉管生长的作用不显著。(2)100 g.L-1的蔗糖有利于花粉萌发和花粉管生长,高浓度蔗糖(200 g.L-1)有明显抑制作用;(3)桔梗花粉离体萌发和花粉管生长的适宜培养基为ME3+BK+10%蔗糖+150 g.L-1PEG(pH5.8);(4)25~40℃条件下桔梗花粉均可较好萌发,以30℃培养1.5 h为最佳培养条件。     

Pollen germination and pollen tube growth in Fraxinus pennsylvanica

With regard to adaptation of green ash (Fraxinus pennsylvanica Marshall) to ecological conditions in Croatia, pollen germination and pollen tube length after 2, 4 and 6 hours were examined in vitro at 10, 15, 20 and 25°C during two years 2001 and 2002. Narrow leaved ash (F. angustifolia Vahl) pollen served as a control in 2002. The year, time and temperature, and the interaction between time and temperature were significant for both germination percentage and pollen tube length. Interactions year × temperature and year × time were significant for pollen tube length only. The highest germination percentage (17.86% in 2001 and 19.40% in 2002) of green ash pollen was at 15°C after 6 hours. The pollen tube length was greatest at 20°C (393.46 μm) in 2001 and 25°C (899.50 μm) in 2002 after 6 hours. Narrow leaved ash pollen had the highest germination percentage (19.22%) at 20°C after 6 hours and was significantly reduced at 25°C. The pollen tube length was greatest at 25°C (518.90 μm) after 6 hours. It can be concluded that green ash pollen has satisfactory germination in ecological conditions in Croatia and that the optimum temperature for pollen germination is higher than 20°C.     

马占相思花粉离体萌发研究

马占相思(Acacia mangium)是含羞草科(Mimosaceae)金合欢属(Acacia Mill.)树种,在我国的广东、广西、福建以及海南等省(区)大面积种植推广。马占相思用途广泛,其杂交育种工作近年来逐渐受到重视,马占相思花粉研究对其杂交育种成败具有重要影响。该研究以新鲜的马占相思花粉为供试材料,开展不同蔗糖浓度(50、100、150、200、250和300 g·L~(-1))、不同硼酸浓度(100、200和300 mg·L~(-1))以及不同培养温度(26、28和30℃)对马占相思花粉离体萌发影响的研究,同时使用筛选出的马占相思花粉离体萌发的最佳处理,开展对另外3株与初试的马占相思生长发育状况接近的马占相思的花粉活力检测研究,并观察记录马占相思花粉离体萌发特征。结果表明:将刚开放的马占相思花序采回室内阴干,于次日10:00后,用毛笔刷法成功收集大量马占相思花粉,经显微镜观察检测,花粉纯度较高,可以保证后续研究备用;马占相思花粉离体萌发的最佳处理为200 g·L~(-1)蔗糖、100 mg·L~(-1)硼酸、28℃培养温度;马占相思花粉在培养24 h之后,花粉萌发率最高(为94.28%),花粉管最长(为6.0 D);检测3株马占相思的花粉萌发率分别为90.11%、82.31%、85.67%,具有显著差异。该研究结果为今后进一步开展人工控制授粉、选育优良的相思杂交新品种提供了基础。     

Electrophoretic profiling and immunocytochemical detection of pectins and arabinogalactan proteins in olive pollen during germination and pollen tube growth

Background and Aims

Cell wall pectins and arabinogalactan proteins (AGPs) are important for pollen tube growth. The aim of this work was to study the temporal and spatial dynamics of these compounds in olive pollen during germination.

Methods

Immunoblot profiling analyses combined with confocal and transmission electron microscopy immunocytochemical detection techniques were carried out using four anti-pectin (JIM7, JIM5, LM5 and LM6) and two anti-AGP (JIM13 and JIM14) monoclonal antibodies.

Key Results

Pectin and AGP levels increased during olive pollen in vitro germination. (1 → 4)-β-d-Galactans localized in the cytoplasm of the vegetative cell, the pollen wall and the apertural intine. After the pollen tube emerged, galactans localized in the pollen tube wall, particularly at the tip, and formed a collar-like structure around the germinative aperture. (1 → 5)-α-l-Arabinans were mainly present in the pollen tube cell wall, forming characteristic ring-shaped deposits at regular intervals in the sub-apical zone. As expected, the pollen tube wall was rich in highly esterified pectic compounds at the apex, while the cell wall mainly contained de-esterified pectins in the shank. The wall of the generative cell was specifically labelled with arabinans, highly methyl-esterified homogalacturonans and JIM13 epitopes. In addition, the extracellular material that coated the outer exine layer was rich in arabinans, de-esterified pectins and JIM13 epitopes.

Conclusions

Pectins and AGPs are newly synthesized in the pollen tube during pollen germination. The synthesis and secretion of these compounds are temporally and spatially regulated. Galactans might provide mechanical stability to the pollen tube, reinforcing those regions that are particularly sensitive to tension stress (the pollen tube–pollen grain joint site) and mechanical damage (the tip). Arabinans and AGPs might be important in recognition and adhesion phenomena of the pollen tube and the stylar transmitting cells, as well as the egg and sperm cells.     

响应面法优化麻疯树花粉离体萌发培养基的研究

麻疯树因其种子含油率较高,种子油提炼的生物柴油可部分替代汽油,而成为一种极具潜能的能源作物,但由于产量低,麻疯树在热带、亚热带的发展受到极大限制。杂交育种是提高产量的重要手段,杂交亲本花粉生活力的高低直接影响到育种的成效。因此,寻求麻疯树离体花粉萌发的最适培养基配方,探明花粉萌发培养基中各主要培养基成分间的交互作用对生产上麻疯树杂交结实率和种子产量的提高具有重要意义。该研究以麻疯树开花初期雄花上花药刚散粉时的成熟花粉粒为材料,采用Box-Behnken设计(Box-Behnken design,BBD)的响应面法,对麻疯树花粉离体萌发培养基中各主要培养基成分的浓度配比及各主要培养基成分的交互作用进行了研究。以花粉萌发率为响应指标,建立了4种营养成分(蔗糖、硼酸、硝酸钙、硝酸钾)与花粉萌发率的响应面模型,并对各主要培养基成分的浓度配比进行了优化。通过R软件进行响应面分析的结果表明:4因素对花粉萌发率的影响顺序为蔗糖硼酸硝酸钙硝酸钾;蔗糖与硼酸、蔗糖与硝酸钙、蔗糖与硝酸钾之间的交互作用显著。响应面建模优化后的最佳培养基为13.77%蔗糖+32.14 mg·L~(-1)硼酸+22.21 mg·L~(-1)硝酸钙+19.95 mg·L~(-1)硝酸钾+200 mg·L~(-1)硫酸镁,在此条件下的理论萌发率为99.73%。采用此培养基成分配比得到麻疯树花粉离体试验萌发率为98.97%,与理论响应值相吻合,同时也表明利用BBD设计的响应面模型进行麻疯树花粉离体萌发培养条件优化方法的有效性。     

The effect of temperature on pollen germination, pollen tube growth, and stigmatic receptivity in peach

Temperature is a major climatic factor that limits geographical distribution of plant species, and the reproductive phase has proven to be one of the most temperature-vulnerable stages. Here, we have used peach to evaluate the effect of temperature on some processes of the progamic phase, from pollination to the arrival of pollen tubes in the ovary. Within the range of temperatures studied, 20 degrees C in the laboratory and, on average, 5.7 degrees C in the field, the results show an accelerating effect of increasing temperature on pollen germination and pollen tube growth kinetics, as well as an increase in the number of pollen tubes that reach the style base. For the last two parameters, although the range of temperature registered in the field was much lower, the results obtained in the laboratory paralleled those obtained in the field. Increasing temperatures drastically reduced stigmatic receptivity. Reduction was sequential, with stigmas first losing the capacity to sustain pollen tube penetration to the transmitting tissue, then their capacity to offer support for pollen germination and, finally, their capacity to support pollen grain adhesion. Within a species-specific range of temperature, this apparent opposite effect of temperature on the male and female side could provide plants with the plasticity to withstand changing environmental effects, ensuring a good level of fertilization.     

Arabidopsis ACT11 modifies actin turnover to promote pollen germination and maintain the normal rate of tube growth

Actin is an ancient conserved protein that is encoded by multiple isovariants in multicellular organisms. There are eight functional actin genes in the Arabidopsis genome, and the precise function and mechanism of action of each isovariant remain poorly understood. Here, we report the characterization of ACT11, a reproductive actin isovariant. Our studies reveal that loss of function of ACT11 causes a delay in pollen germination, but enhances pollen tube growth. Cytological analysis revealed that the amount of filamentous actin decreased, and the rate of actin turnover increased in act11 pollen. Convergence of actin filaments upon the germination aperture was impaired in act11 pollen, consistent with the observed delay of germination. Reduction of actin dynamics with jasplakinolide suppressed the germination and tube growth phenotypes in act11 pollen, suggesting that the underlying mechanisms involve an increase in actin dynamics. Thus, we demonstrate that ACT11 is required to maintain the rate of actin turnover in order to promote pollen germination and maintain the normal rate of pollen tube growth.     

Effect of smoke derivatives on in vitro pollen germination and pollen tube elongation of species from different plant families

Plant‐derived smoke stimulates seed germination in numerous plant species. Smoke also has a positive stimulatory effect on pollen germination and pollen tube growth. The range of plant families affected my smoke still needs to be established since the initial study was restricted to only three species from the Amaryllidaceae. The effects of smoke‐water (SW) and the smoke‐derived compounds, karrikinolide (KAR₁) and trimethylbutenolide (TMB) on pollen growth characteristics were evaluated in seven different plant families. Smoke‐water (1:1000 and 1:2000 v:v) combined with either Brewbaker and Kwack's (BWK) medium or sucrose and boric acid (SB) medium significantly improved pollen germination and pollen tube growth in Aloe maculata All., Kniphofia uvaria Oken, Lachenalia aloides (L.f.) Engl. var. aloides and Tulbaghia simmleri P. Beauv. Karrikinolide (10^?6 and 10^?7 m ) treatment significantly improved pollen tube growth in A. maculata, K. uvaria, L. aloides and Nematanthus crassifolius (Schott) Wiehle compared to the controls. BWK or SB medium containing TMB (10^?3 m ) produced significantly longer pollen tubes in A. maculata, K. uvaria and N. crassifolius. These results indicate that plant‐derived smoke and the smoke‐isolated compounds may stimulate pollen growth in a wide range of plant species.     

Response of in vitro pollen germination and pollen tube growth of groundnut (Arachis hypogaea L.) genotypes to temperature

Air temperatures of greater than 35 °C are frequently encountered in groundnut‐growing regions, especially in the semi‐arid tropics. Such extreme temperatures are likely to increase in frequency under future predicted climates. High air temperatures result in failure of peg and pod set due to lower pollen viability. The response of pollen germination and pollen tube growth to temperature was quantified in order to identify differences in pollen tolerance to temperature among 21 groundnut genotypes. Plants were grown from sowing to harvest in a poly‐tunnel under an optimum temperature of 28/22 °C (day/night). Pollen was collected at anther dehiscence and was exposed to temperatures from 10° to 47·5 °C at 2·5 °C intervals. The results showed that a modified bilinear model most accurately described the response to temperature of percentage pollen germination and maximum pollen tube length. Genotypes were found to range from most tolerant to most susceptible based on both pollen characters and membrane thermostability. Mean cardinal temperatures (T_min, T_opt and T_max) averaged over 21 genotypes were 14·1, 30·1 and 43·0 °C for percentage pollen germination and 14·6, 34·4 and 43·4 °C for maximum pollen tube length. The genotypes 55‐437, ICG 1236, TMV 2 and ICGS 11 can be grouped as tolerant to high temperature and genotypes Kadiri 3, ICGV 92116 and ICGV 92118 as susceptible genotypes, based on the cardinal temperatures. The principal component analysis identified maximum percentage pollen germination and pollen tube length of the genotypes, and T_max for the two processes as the most important pollen parameters in describing a genotypic tolerance to high temperature. The T_min and T_opt for pollen germination and tube growth, rate of pollen tube growth were less predictive in discriminating genotypes for high temperature tolerance. Genotypic differences in heat tolerance‐based on pollen response were poorly related (R² = 0·334, P = 0·006) to relative injury as determined by membrane thermostability.