白菜雄性不育相关基因BcMF3功能的反义RNA验证

为了研究白菜等十字花科植物花粉发育及雄性不育发生的机理,根据编码果胶甲酯酶的白菜雄性不育相关基因BcMF3的cDNA序列设计特异引物,从普通白菜(Brassica campestris ssp.chinensis var.communis,syn.B.rapa ssp.chinensis var.communis)花蕾cDNA中扩增出458 bp的片断,构建BcMF3的反义RNA植物表达栽体,然后转化菜心(B. campestris ssp.chinensis var.parachinensis).研究发现,31.3%菜心转基因植株花粉表现出畸形,而且只有部分花粉具有活力,花粉离体萌发率降低为31.6%,其花药果胶甲酯酶活性降低了12.8%.上述结果表明BcMF3基因与普通白菜和菜心等白菜植物的花粉发育密切相关.     

白菜雄性不育相关基因BcMF4的反义RNA验证

根据普通白菜(Brassica campestris ssp.chinensis var.communis)雄性不育相关基因BcMF4的cDNA序列设计特异引物,从普通白菜花蕾cDNA中扩增出607 bp的片断,然后将该片段连接至双元载体pBI12l中,得到反义RNA植物表达载体并导入农杆菌LBA4404菌株中;通过组织培养途径转化菜心(B.campestris ssp.chinensis var.parachinensis),得到了12株转基因植株,其中5株的43.7%的花粉为缩小空瘪畸形,29.6%的花粉缺乏生活力,而且其花粉离体萌发率降低至24.7%.结果表明,反义RNA技术沉默BcMF4基因导致了菜心转基因植株的部分花粉发育不良,BcMF4基因在普通白菜和菜心等花粉发育中起着重要作用.     

马尾松种子园花期观察与分析

通过对忠县马尾松种子园２７个无性系花期的观察,结果表明：雌雄花期历时１３ｄ,雄球花散粉盛期只有３３ｄ,雌球花可授粉盛期有６ｄ;无性系间及无性系内分株间花期虽有差异性,但用反映亲本在开花期间母本接受父本花粉机率的开花物候重叠指数对无性系花期分析表明２７个无性系间及无性系内分株间花期同步性是较好的,能随机交配。     

华山松开花习性的初步研究

1987年和1990年,在云南省楚雄市紫溪山对华山松(Pinus arman-dii Franch)的开花习性进行了初步研究。结果表明,华山松三个人工林群体间、个体间的开花量、花粉发芽率等性状都存在明显的差异。华山松花粉发芽特点与落叶松(Larix sibirica)和花旗松(Pseudotsnga menxiesii)的花粉发芽特点不相似。花粉在一般的蔗糖琼脂培养基上发芽得很好。此外,对华山松的良种选育问题也作了讨论。     

CMLs参与调控植物花粉授粉竞争的作用

目的在显花植物生殖过程中花粉萌发和花粉管生长起着至关重要的作用,这一过程受许多因素的影响,其中钙调素类似蛋白（calmodulin-like proteins,CMLs）通过直接或间接的作用机制调控花粉萌发及花粉管生长。然而,迄今人们对CMLs的功能研究尚少。本文旨在初步了解CMLs蛋白在花粉竞争优势中的作用,为深入探究CMLs蛋白在植物花粉竞争优势中的分子机制奠定理论基础。方法本文主要通过对参与调控花粉萌发以及花粉管生长过程的CMLs蛋白的结构、表达水平、细胞定位及其作用机理的归纳,结合不同植物中出现的花粉竞争现象,综合分析并总结国内外相关研究结果。结果CMLs蛋白约有4个保守的EF手性结构域,当CMLs蛋白结合Ca2+时,其构象发生变化,增强与下游受体蛋白的结合能力,并启动Ca2+依赖的级联信号放大效应,引起花粉管中Ca2+的浓度变化,影响从萌发孔到花粉管顶端Ca2+浓度梯度的形成,从而调控花粉管的正常生长。CMLs蛋白的表达还可以影响Mg2+、NO等离子的浓度变化,影响Ca2+与EF手性结构域的结合及花粉管生长的导向。不同CMLs蛋白具有不同生理功能,其中参与花粉萌发及花粉管生长的CMLs蛋白主要在植物花器官中表达;部分显花植物在受精过程中,不同倍性花粉之间可能由于基因组大小或者营养物质含量的差异,导致萌发率及生长速率的不同。结论CMLs蛋白可能通过在不同倍性花粉中的差异表达,影响花粉在体内萌发的进程,使其在某一时期表现出竞争优势。      

2009年春季兰州大学花粉雨研究

[目的]探讨大气花粉沉降过程中,花粉类型和开花植物的关系以及花粉丰度与气象因子间的关系。[方法]以高10 m平台自然沉降方法获取2009年兰州大学校园春季花粉的沉降记录,并分析花粉沉降数量、持续时间、沉降种类与周围植被及天气的关系。[结果]主要花粉种类为杨属、柳属、泡桐属、悬铃木科等,其花粉沉降数量、持续时间和校园相应植被的花期相一致;花粉沉积种类和丰度主要受风力影响,风力越大种类越丰富,基本没有外来花粉;尘暴天气未观测到孢粉组合的明显变化。[结论]该研究可为自然植被花粉的现代过程研究奠定基础。     

2009年春季兰州大学花粉雨研究

[目的]探讨大气花粉沉降过程中,花粉类型和开花植物的关系以及花粉丰度与气象因子间的关系。[方法]以高10m平台自然沉降方法获取2009年兰州大学校园春季花粉的沉降记录,并分析花粉沉降数量、持续时间、沉降种类与周围植被及天气的关系。[结果]主要花粉种类为杨属、柳属、泡桐属、悬铃木科等,其花粉沉降数量、持续时间和校园相应植被的花期相一致;花粉沉积种类和丰度主要受风力影响,风力越大种类越丰富,基本没有外来花粉;尘暴天气未观测到孢粉组合的明显变化。[结论]该研究可为自然植被花粉的现代过程研究奠定基础。     

Summary of Influencial Factors on Pollen Viability and Its Preservation Methods

植物花粉贮藏技术研究是开花生物学特性研究中的一项重要内容。在此,就植物花粉生活力的影响因素、花粉生活力的测定方法、花粉的贮藏步骤、方法进行了概述,列出了部分植物的花粉在不同条件下所能贮藏的时间和贮藏一定时间后的生活力状况,并指出了今后花粉贮藏的方向。     

滇型杂交水稻榆杂29制种技术研究

 通过对榆杂29制种亲本特征特性的观察,提出榆杂29制种父母本播种差期以叶龄差为主是实现花期相遇的基础,采取综合农艺措施促使双亲平衡生长是实现花期相遇的保证.对父本单独多施肥以增加颖花数和花粉量是制种高产的有效途径之一.     

澳洲坚果花期水分胁迫效应的研究

花期的澳洲坚果植株经不同强度水分胁迫处理后 ,植株的花粉育性、SOD和POD活性、座果率以及叶绿素含量、总糖含量和淀粉含量等光合产物与对照之间存在显著性差异。在水分胁迫条件下 ,处理间的花粉育性、SOD和POD活性、座果率及光合产物随水分胁迫强度的加剧而下降 ,处于过饱和灌溉的处理也表现为下降。这是由于水分胁迫导致酶活性降低、光合产物减少、花粉萌发率低、花粉管生长速度慢 ,造成花期不遇、授粉受精不良、座果率低 ,最后造成产量降低的缘故。正常灌溉的“处理N” ,植株的综合效应达到最佳。该试验的 3个澳洲坚果品种的耐旱性是Kau >Pahala >O .C .。花期干旱季节进行 6 0 %田间持水量灌溉有利于澳洲坚果的授粉受精 ,提高座果率及产量     

The FERONIA receptor-like kinase mediates male-female interactions during pollen tube reception

In flowering plants, signaling between the male pollen tube and the synergid cells of the female gametophyte is required for fertilization. In the Arabidopsis thaliana mutant feronia (fer), fertilization is impaired; the pollen tube fails to arrest and thus continues to grow inside the female gametophyte. FER encodes a synergid-expressed, plasma membrane-localized receptor-like kinase. We found that the FER protein accumulates asymmetrically in the synergid membrane at the filiform apparatus. Interspecific crosses using pollen from Arabidopsis lyrata and Cardamine flexuosa on A. thaliana stigmas resulted in a fer-like phenotype that correlates with sequence divergence in the extracellular domain of FER. Our findings show that the female control of pollen tube reception is based on a FER-dependent signaling pathway, which may play a role in reproductive isolation barriers.     

Lower cretaceous angiosperm flowers: fossil evidence on early radiation of dicotyledons

Three-dimensionally preserved unisexual angiosperm flowers and inflorescences have been recovered from the Lower Cretaceous Patapsco Formation (Potomac Group) of eastern North America, in sediments palynologically dated as late Albian, approximately 100 million years old. In situ tricolpate pollen shows that the flowers were produced by some of the earliest higher (nonmagnoliid) dicotyledons, and the morphology of pollen, flowers, and inflorescences indicates a close relation to extant Platanaceae. Combined with architectural and cuticular features of associated leaves these floral remains suggest that Platanus-like plants with unisexual, probably insect-pollinated flowers were an important element in the mid-Cretaceous diversification of dicotyledonous flowering plants.     

Pollen tube attraction by the synergid cell

In flowering plants, guidance of the pollen tube to the embryo sac (the haploid female gametophyte) is critical for successful fertilization. The target embryo sac may attract the pollen tube as the final step of guidance in the pistil. We show by laser cell ablation that two synergid cells adjacent to the egg cell attract the pollen tube. A single synergid cell was sufficient to generate an attraction signal, and two cells enhanced it. After fertilization, the embryo sac no longer attracts the pollen tube, despite the persistence of one synergid cell. This cessation of attraction might be involved in blocking polyspermy.     

The pollination of zygogynum (winteraceae) by a moth, sabatinca (micropterigidae): an ancient association?

The primitive and vesselless angiosperm Zygogynum (Winteraceae), which is restricted to New Caledonia, is pollinated by a moth, Sabatinca (Micropterigidae). Fossil records of both the moth and the plant families extend to the Early Cretaceous. Adult Sabatinca have grinding mandibles and usually feed on the spores of ferns and on pollen. The insects use the flowers as mating sites and eat the pollen which is immersed in a dense pollenkitt. This mode of pollination in which flowers serve as mating and feeding stations with floral odors acting as cues may have been common in the early evolution of flowering plants.     

Participation of Male Cytoplasm During Gamete Fusion in an Angiosperm, Plumbago zeylanica

The embryo sac of Plumbago, lacking synergids, reveals an alternative course for pollen tube growth in angiosperms and provides ultrastructural evidence for transmission of sperm cytoplasm into the zygote and endosperm. Study of such evolutionarily reduced female gametophytes may aid in elucidating the structural basis for genetic transmission of plastids and mitochondria in flowering plants.     

Collaborative non-self recognition system in S-RNase-based self-incompatibility

Self-incompatibility in flowering plants prevents inbreeding and promotes outcrossing to generate genetic diversity. In Solanaceae, a multiallelic gene, S-locus F-box (SLF), was previously shown to encode the pollen determinant in self-incompatibility. It was postulated that an SLF allelic product specifically detoxifies its non-self S-ribonucleases (S-RNases), allelic products of the pistil determinant, inside pollen tubes via the ubiquitin-26S-proteasome system, thereby allowing compatible pollinations. However, it remained puzzling how SLF, with much lower allelic sequence diversity than S-RNase, might have the capacity to recognize a large repertoire of non-self S-RNases. We used in vivo functional assays and protein interaction assays to show that in Petunia, at least three types of divergent SLF proteins function as the pollen determinant, each recognizing a subset of non-self S-RNases. Our findings reveal a collaborative non-self recognition system in plants.     

FLOWERING PLANTS AND ENTOMOPHAGOUS ARTHROPODS IN THE AGRICULTURAL LANDSCAPE: A PRACTISE-ORIENTED SUMMARY OF A COMPLEX RELATIONSHIP

● Most entomophagous arthropods consume nectar or pollen as alternative diets. ● The attractive of floral resource with different traits varies in a wide degree. ● Floral resource plays positive effects on not only entomophagous insects but also agricultural biodiversity, multiple ecosystem services and crop production. There is a growing demand for high-quality agricultural products and more countries have adopted landscape management by sowing flowering plants in agricultural fields as an important branch of conservation biological control. However, there has been less concern over the interactions and trade-offs between floral plants and entomophagous arthropods. This paper review progress in pollen/nectar feeding habits of entomophagous insects including parasitoids and predators which are important natural enemies of crop pests in agricultural fields. Factors that influence the preference of different guilds of natural enemies are reviewed to guide the selection of flowering plants in conservation biological control practices. Most studies find that floral resources have positive effects on both biological traits of natural enemies and their abundance and diversity, and this is believed to contribute greatly to pest control. Furthermore, the potential impacts of floral resources on crop yields are also discussed with an emphasis on a guild of entomophagous insects that provides both pest control and pollination services.     

采粉期及贮藏条件对猕猴桃花粉生活力的影响

【目的】研究不同采粉期及贮藏条件对猕猴桃花粉生活力的影响,为猕猴桃生产中人工辅助授粉和杂交育种提供依据。【方法】以猕猴桃品种“中华系401”为试材,分别于开花前3,2,1 d及大蕾期和开花后6,12,24 h采集花粉,比较不同采粉期对猕猴桃花粉生活力的影响;以“软枣猕猴桃”、“秦雄201”、“中华系401”和“毛花猕猴桃”雄株为试材,采集大蕾期花粉,分别进行常温贮藏（18～26 ℃）、低温(4和-15 ℃)贮藏,比较不同贮藏条件下猕猴桃的花粉生活力。【结果】开花前3 d,猕猴桃花粉生活力仅为1.92%;开花前2和1 d,猕猴桃花粉生活力分别达到48.07%和69.11%;大蕾期猕猴桃花粉生活力最高,达82.31%;开花后6,12和24 h的花粉生活力分别为66.89%,46.03%和31.40%,均不及大蕾期高。4种猕猴桃新鲜花粉的生活力均较高,达70%以上。常温条件下,猕猴桃花粉仅可贮藏6～9 d;4 ℃冷藏条件下,花粉生活力可维持60～150 d,平均达90 d;而-15 ℃冷冻条件下花粉生活力更长,可达360 d。【结论】以采用大蕾期花粉进行人工授粉为宜;贮藏温度是影响猕猴桃花粉生活力的重要因素之一,温度越低,花粉的贮藏效果越好。     

Micropylar pollen tube guidance by egg apparatus 1 of maize

Pollen tube guidance precedes the double fertilization of flowering plants. Here, we report the identification of a small maize protein of 94 amino acids involved in short-range signaling required for pollen tube attraction by the female gametophyte. ZmEA1 is exclusively expressed in the egg apparatus, consisting of the egg cell and two synergids. Chimeric ZmEA1 fused to green fluorescent protein (ZmEA1:GFP) was first visible within the filiform apparatus and later was localized to nucellar cell walls below the micropylar opening of the ovule. Transgenic down-regulation of the ZmEA1 gene led to ovule sterility caused by loss of close-range pollen tube guidance to the micropyle.     

不同花期花粉授粉对烟草授粉效果和种子质量的影响

[目的]为确定烟草花粉的适宜采集时期。[方法]采集不同花期的花粉,研究不同花期花粉授粉对云烟85、云烟87和K326授粉效果和种子质量的影响。[结果]随着花粉采集花期的延长,花粉活力逐渐提高;对于云烟85、云烟87和K326,始开期和盛开期的花粉授粉效果好,种子产量和质量高。[结论]在保证种子产量、质量和纯度的基础上,宜采集始开期花粉进行授粉。