Ecology and evolution of flowering plant dominance

Birds and mammals are important seed dispersers and their diversification in the Cretaceous may have created niches for many plant specialists on scattered resources. Maintaining sexual recombination through wind pollination in such sparse populations is difficult, and so angiosperms with their sophisticated systems for insect pollination were favored in many critical situations.     

In search of the first flower: A jurassic angiosperm, archaefructus, from northeast china

Angiosperm fruiting axes were discovered from the Upper Jurassic of China. Angiosperms are defined by carpels enclosing ovules, a character demonstrated in this fossil. This feature is lacking in other fossils reported to be earliest angiosperms. The fruits are small follicles formed from conduplicate carpels helically arranged. Adaxial elongate stigmatic crests are conspicuous on each carpel. The basal one-third of the axes bore deciduous organs of uncertain affinities. No scars of subtending floral organs are present to define the individual fertile parts as floral units, but the leaf-like structures subtending each axis define them as flowers. These fruiting axes have primitive characters and characters not considered primitive.     

Ancient bisexual flowers

Fossil flowers discovered in 94-million-year-old clays of the Dakota Formation in Nebraska are among the earliest known demonstrably bisexual flowers. The flowers are of medium size and have pentamerous whorls of clearly differentiated floral parts, petals alternate with the sepals, short stamens are borne opposite the petals, the carpels are fused, and a receptacular disk is present. The pollen is small and tricolporate. These flowers appear to be well adapted to insect pollination. The numerous floral features and pollen characters provide sufficient diagnostic data to assess its systematic position. No extant order accommodates the features of this flower and it shares some features of various extant orders. The classification of flowering plants and our understanding of their evolution must be influenced by the fossilized remains of ancient flowers.     

柿品种性状演变与分化研究

系统观察了柿品种的农艺性状并研究了其演变与分化规律。结果表明：柿花器由短缩枝演化而成；一些异花授粉品种具有单性结实的能力；绝大多数品种在进化过程中果面绒毛脱落；缢痕是子房基部细胞不同程度分裂成果肉细胞的结果，果实的心皮数由多心变为四心皮，心室数由多心室变为八心室；随着单宁数量的减少和酒精脱氢酶含量的增加，果实在成熟时可溶性单宁含量极少，完全涩柿演变为完全甜柿。     

基于InVEST模型的崇明岛野生蜜蜂传粉服务功能分析

传粉是生态系统的一项重要服务功能,而蜜蜂是传粉服务中最重要的传粉者。我国对野生蜜蜂传粉的研究文献较少。对丰度进行模拟可以更好地保护野生蜜蜂及其生境,节约其传粉成本,达到保护和利用野生蜜蜂资源的目的。通过运用InVEST模型传粉者丰度模块对崇明岛的野生蜜蜂丰度进行模拟,并利用Arc GIS技术对结果进行分析。结果表明:(1)农田周围有适当林地分布,且建设用地、水体和滩涂区域较少,野生蜜蜂的丰度会较高,得到较好的野生蜜蜂传粉服务;(2)崇明岛中西部地区农田野生蜜蜂丰度较高,应维持该区域的农田不受破坏,避免在该区域新建建筑和开发旅游区域,农田应种植需要昆虫授粉的作物;岛屿边缘和东部农田区域的野生蜜蜂丰度较低,应增加林地和花圃种植,同时控制人类活动区域以创造更适宜野生蜜蜂的生境;(3)应根据野生蜜蜂丰度格局对作物的播种方案制定长期的计划,将大面积种植的西瓜、柑橘等需要昆虫传粉服务的作物移至中西部野生蜜蜂丰度较高的区域,以充分利用和保护野生蜜蜂资源,而将传粉服务要求较低的短期作物移至野生蜜蜂丰度较低的区域。     

昆虫授粉效能的评价

分析了目前用于衡量昆虫授粉效能的几个指标（昆虫数量、采集活动的时间、访花速率及座果率）的不足之处，提出在授粉研究中，对授粉效能的评价应注意把昆虫的数量同昆虫的外部形态结合起来，采集活动时间同植物开花泌蜜时期综合考虑，访花速率应参照具体的行为进行分析，座果率应考虑到是否有其他昆虫的作用，并强调了行为在授粉中的重要作用．     

被子植物心皮及其相关功能基因研究进展

【目的】汇总国内外心皮起源、作用和发育过程、遗传及激素调节、控制心皮发育的相关基因等研究结果,为作物多心皮品种改良提供参考。【方法】收集国内外文献资料,汇总、整理分析。【结果】心皮的起源目前有心皮学说和生殖叶学说两种学说;心皮具有保护胚珠、接受花粉致使卵细胞受精、保护和传播种子的作用;其发育过程通常在花的器官中经过折叠、卷曲形成内在的空间,胚珠被包裹在其中发育;心皮数目的遗传较为稳定,激素对其生长发育有重要影响;基因在调控心皮数量和发育方面具有重要作用。【结论】心皮作为被子植物雌蕊发育的关键,对于产量性状的建成极为重要。心皮研究应重点围绕心皮发育的全过程,尽早明晰调控心皮数量和发育的相关功能基因,通过基因改良培育出多心皮、高产优质品种。     

Archaefructaceae, a new basal angiosperm family

Archaefructaceae is proposed as a new basal angiosperm family of herbaceous aquatic plants. This family consists of the fossils Archaefructus liaoningensis and A. sinensis sp. nov. Complete plants from roots to fertile shoots are known. Their age is a minimum of 124.6 million years from the Yixian Formation, Liaoning, China. They are a sister clade to all angiosperms when their characters are included in a combined three-gene molecular and morphological analysis. Their reproductive axes lack petals and sepals and bear stamens in pairs below conduplicate carpels.     

木芙蓉的繁育系统及传粉生物学

以木芙蓉为研究材料,运用杂交指数、花粉数/胚珠数、座果率、种子萌发率等指标对木芙蓉的繁育系统及传粉生物学等进行研究。结果表明:木芙蓉单花的花期1 d,整体花期7—11月份;木芙蓉的杂交指数为4,繁育系统为异交、部分自交亲和、需要传粉者;木芙蓉的花粉数/胚珠数为415±11.3,繁育系统属于兼性异交类型;木芙蓉自然座果率为74%;同株同花授粉的座果率为40%;人工异株异花授粉座果率为71%;各种授粉方式下,单个果实的种子个数为128~148,差别不大;各种授粉方式下,平均种子萌发率为47%~60%,没有显著差异;传粉昆虫有蜂类、甲虫,其中中华蜜蜂、黑小蜜蜂为主要传粉昆虫。     

Asynchronous diversification in a specialized plant-pollinator mutualism

Most flowering plants establish mutualistic associations with insect pollinators to facilitate sexual reproduction. However, the evolutionary processes that gave rise to these associations remain poorly understood. We reconstructed the times of divergence, diversification patterns, and interaction networks of a diverse group of specialized orchids and their bee pollinators. In contrast to a scenario of coevolution by race formation, we show that fragrance-producing orchids originated at least three times independently after their fragrance-collecting bee mutualists. Whereas orchid diversification has apparently tracked the diversification of orchids' bee pollinators, bees appear to have depended on the diverse chemical environment of neotropical forests. We corroborated this apparent asymmetrical dependency by simulating co-extinction cascades in real interaction networks that lacked reciprocal specialization. These results suggest that the diversification of insect-pollinated angiosperms may have been facilitated by the exploitation of preexisting sensory biases of insect pollinators.     

昆虫授粉研究与应用概述

简单介绍昆虫授粉的作用和价值，详细阐述近几年授粉研究包括外部形态、内部生理、植物激素及其挥发性化合物、昆虫行为等几个领域取得的成绩，讨论了授粉系统中的竞争关系、协同关系和互惠关系，分析了国内外授粉研究和应用的现状及存在的问题，并对我国的授粉研究与应用提出了自己的看法．     

昆虫访花机制研究概述

介绍了植物性状（包括花形、花色、花味和植物次生挥发性物质）、昆虫结构及生理（包括外部、内部和微观结构）以及特殊的专性传粉关系对昆虫访花的影响,从中探讨了昆虫访花的一般机制,如花的形态影响昆虫访花的难易程度;花色、花味和植物次生挥发性物质是昆虫访花的嗅觉定向因素;昆虫的外部、内部和微观结构决定其访花的选择机制等。     

油茶传粉昆虫研究现状和保护策略

油茶是重要的木本油料树种,制约油茶生产的最主要问题是授粉问题.鉴此,对油茶的传粉生物学、传粉昆虫的种类及主要传粉昆虫的特点进行了综述,并就传粉昆虫的资源保护提出了建议.     

鲁梅克斯K-1杂交酸模传粉生物学研究

利用去雄、套袋、人工授粉方法研究不同授粉方式和授粉时间对鲁梅克斯K-1杂交酸模结实率的影响。结果表明,鲁梅克斯K-1杂交酸模自花授粉、异花授粉都能正常结实,结实率达95%以上。异花授粉最佳时间为花开放后1~6 h。花粉量大。风媒传粉,未见昆虫访问。     

传粉综合征预测传粉者准确性检验——以邱北冬蕙兰为例

目的传粉综合征理论为植物与传粉者相互关系的进化提供了经典的假说, 然而, 随着越来越多泛化传粉系统被报道, 基于传粉综合征预测传粉者的准确性受到质疑。邱北冬蕙兰隶属于兰属建兰亚属, 花具香味, 唇瓣具紫色斑点。这些形态特征与已报道的由中华蜜蜂传粉的多种建兰亚属植物, 如兔耳兰、春兰等相似。我们根据传粉综合征理论预测邱北冬蕙兰传粉者同样为中华蜜蜂。本研究将验证利用传粉综合征预测传粉者这一方法的准确性, 探讨其适用范围。方法以邱北冬蕙兰为实验材料, 于2010—2012年在广西雅长兰科植物国家级自然保护区开展系统的传粉生物学研究, 包括开花物候观测、花形态测量、昆虫传粉行为观察、花颜色测量、花气味分析及人工繁育系统实验。结果中华蜜蜂的工蜂是邱北冬蕙兰唯一的传粉者, 花内不存在任何报酬物质, 推测具食源性欺骗传粉机制。唇瓣紫色斑点作为假蜜导欺骗中华蜜蜂访花, 花气味中含有酚类、酯类、醛类等物质, 其中醛类物质可能在吸引中华蜜蜂传粉过程中起着重要的作用, 利用传粉综合征预测传粉者的准确性得到成功检验。结论本研究为传粉综合征能够准确地预测传粉者的科学假设提供研究案例。但由于传粉综合征是由一组动态的、进化的花部性状组成, 通过传粉综合征预测传粉者时, 在已知亲缘关系相近植物传粉者前提下还需注意到生境变化、次级传粉者、传粉者功能群、历史演化、基因等因素的影响。      

棉花核雄性不育材料天然授粉制种的初步研究

2005年在河南驻马店地区安排了几个棉花核不育材料601446、601561、601452的小面积试验,研究棉花核不育材料利用虫媒天然授粉制种的可行性。试验采用的生产管理和当地棉区一致,花期仅施用BT等生物农药,不施用其他农药,吐絮期进行田间调查和籽棉的实收计产。研究表明,在该地区利用棉花核不育材料虫媒天然授粉制种是完全可行的,不同的陆地棉核不育材料之间在利用虫媒天然授粉制种上没有差异,只是材料本身特性上有差异。     

北疆苜蓿种子田结荚期虫害发生动态研究

在结荚期不同阶段对苜蓿种子田虫害发生动态进行研究,结果显示:(1)苜蓿虫害在结荚初期已经发生,荚果内种子的虫蚀率由结荚初期的(9.85±1.67)%增加到结荚末期的(52.85±1.46)%。随着果熟期的推迟,虫害不断加剧。(2)从幼虫发生情况看,其数量相对稳定,并且在花序中的分布是随机的,没有明显的位置效应。荚果内种子虫蚀率的增加主要是由于幼虫的采食量增加所致。(3)虫蚀率过高与初花期传粉不足成为当地苜蓿种子产量的两个重要制约因素。     

提高黄瓜制种纯度和产量的途径

黄瓜是雌雄同株异花授粉作物,昆虫传粉杂交率很高,人工杂交制种无论是在产量上还是在纯度上都有一定的难度。采取加强人工措施,减少自然杂交和人为混杂机率。根据生物学特性改善栽培环境条件。科学认真的抓好隔离区的设置,去杂,尤其父本去杂。化学杀雄诱雌,集中坐瓜节位,减少雄花,授粉做标记,把清除自交瓜作为保纯的一项关键措施。根据黄瓜产量的构成因素突出抓好选地,科学施肥,确保单位面积有效株数,单株坐瓜数,授粉质量,及时防治病虫害,改变中后期的肥水管理,适时收获等重要环节。只有严格科学有效地抓好各项技术措施的落实,才能提高黄瓜人工杂交制种纯度和产量,获得边际效益最大值。     

不同高效授粉树对红富士苹果品质的影响

研究高效授粉树授粉对红富士果实品质的影响,为选育优良的高效授粉树提供理论依据。结果表明,所有高效授粉树优系均可不同程度的改善果实品质,特别是在增大增重、增加果实硬度、增糖降酸和促进Vc合成上。因此,高效授粉树能够提高果园产量、改善果实品质,并具有极高的观赏价值,可以作为授粉树在果园配置、推广。     

Insect diversity in the fossil record

Insects possess a surprisingly extensive fossil record. Compilation of the geochronologic ranges of insect families demonstrates that their diversity exceeds that of preserved vertebrate tetrapods through 91 percent of their evolutionary history. The great diversity of insects was achieved not by high origination rates but rather by low extinction rates comparable to the low rates of slowly evolving marine invertebrate groups. The great radiation of modern insects began 245 million years ago and was not accelerated by the expansion of angiosperms during the Cretaceous period. The basic trophic machinery of insects was in place nearly 100 million years before angiosperms appeared in the fossil record.