RAD-seq data reveals robust phylogeny and morphological evolutionary history of Rhododendron

Rhododendron is famous for its high ornamental value.However,the genus is taxonomically difficult and the relationships within Rhododendron remain unresolved.In addition,the origin of key morphological characters with high horticulture value need to be explored.Both problems largely hinder utilization of germplasm resources.Most studies attempted to disentangle the phylogeny of Rhododendron,but only used a few genomic markers and lacked large-scale sampling,resulting in low clade support and contradictory phylogenetic signals.Here,we used restriction-site associated DNA sequencing(RAD-seq)data and morphological traits for 144 species of Rhododendron,representing all subgenera and most sections and subsections of this species-rich genus,to decipher its intricate evolutionary history and reconstruct ancestral state.Our results revealed high resolutions at subgenera and section levels of Rhododendron based on RAD-seq data.Both optimal phylogenetic tree and split tree recovered five lineages among Rhododendron.Subg.Therorhodion(cladeⅠ)formed the basal lineage.Subg.Tsutsusi and Azaleastrum formed cladeⅡand had sister relationships.CladeⅢincluded all scaly rhododendron species.Subg.Pentanthera(cladeⅣ)formed a sister group to Subg.Hymenanthes(cladeⅤ).The results of ancestral state reconstruction showed that Rhododendron ancestor was a deciduous woody plant with terminal inflorescence,ten stamens,leaf blade without scales and broadly funnelform corolla with pink or purple color.This study shows significant distinguishability to resolve the evolutionary history of Rhododendron based on high clade support of phylogenetic tree constructed by RAD-seq data.It also provides an example to resolve discordant signals in phylogenetic trees and demonstrates the application feasibility of RAD-seq with large amounts of missing data in deciphering intricate evolutionary relationships.Additionally,the reconstructed ancestral state of six important characters provides insights into the innovation of key characters in Rhododendron.

Age-related changes of leaf traits and stoichiometry in an alpine shrub(Rhododendron agglutinatum) along altitudinal gradient

Leaf morphological and stoichiometric characteristics are considered to represent both the interior inheritable characters in the plant and its adaptations to specific exterior environments. Rhododendron agglutinatum,an evergreen alpine shrub species,occupies a wide range of habitats above timberline in the Miyaluo Natural Reserve,southwestern China. Along an altitudinal gradient ranging from 3700 to 4150 m,we measured leaf morphological characters including leaf dry matter content(LDMC),leaf dry mass per unit area(LMA),and one leaf area(OLA),as well as carbon(C) and nutrient(N,P) contents in leaves of three different age groups(juvenile leaves,mature leaves and senescent leaves). We also calculated the stoichiometric relationships among carbon and nutrients(C/N,C/P and N/P). Results showed thatboth age and altitude affected the leaf morphological and stoichiometric properties of R. agglutinatum. Mature leaves possessed the highest LDMC,LMA and C contents both on a dry mass basis and on a unit area basis. Younger leaves possessed higher contents of nutrients. OLA as well as ratios between carbon and nutrients(C/N,C/P) increased with ages. Juvenile leaves possessed lowest ratio between nitrogen and phosphorus. In juvenile leaves,nutrients increased with altitudinal elevation,whereas other traits decreased. In mature leaves,nutrients and their ratios with carbon showed consistent trends with juvenile leaves along increasing altitude,whereas LMA and carbon on a unit area basis showed opposite trends with juvenile leaves along increasing altitude. In senescent leaves,only content of phosphorus on a unit area basis and N/P were found linearly correlated with altitude. Our results demonstrated a clear pattern of nutrient distribution with aging process inleaves and indicated that a high possibility of N limitation in this region. We also concluded that younger leaves could be more sensitive to climate changes due to a greater altitudinal influence on the leaf traits in younger leaves than those in elder leaves.

Structural characterization of four Rhododendron spp.chloroplast genomes and comparative analyses with other azaleas

Azalea is a general designation of Rhododendron in the Ericaceae family.Rhododendron not only has high ornamental value but also has application value in ecological protection,medicine,and scientific research.In this study,we used Illumina and PacBio sequencing to assemble and annotate the entire chloroplast genomes(cp genomes)of four Rhododendron species.The chloroplast genomes of R.concinnum,R.henanense subsp.lingbaoense,R.micranthum,and R.simsii were assembled into 207,236,208,015,207,233,and 206,912 bp,respectively.All chloroplast genomes contain eight rRNA genes,with either 88 or 89 protein-coding genes.The four cp genomes were compared and analyzed by bioinformatics,and the phylogenetic analysis based on chloroplast genomes of 26 species of Ericaceae,Actinidiaceae,and Primulaceae under Ericales was conducted.A comparison of the linear structure of cp genomes of four Rhododendron showed that there were substantial sequence similarities in coding regions,but high differences in non-coding regions.A phylogenetic analysis,based on chloroplast whole genome sequences,showed that all Rhododendron species are in the clade Ericaceae.This study provides valuable genetic information for the study of population genetics and evolutionary relationships in Rhododendron and other azalea species.

Projecting the potential distribution and analyzing the bioclimatic factors of four Rhododendron subsect.Tsutsusi species under climate warming

Tsutsusi is one of the eight subgenera of the Rhododendron genus.Four Tsutsusi species,R.indicum,R.simisii,R.oldhamii,and R.schlippenbachii,have high ornamental and medicinal values,resulting in an increasing market demand.These species thrive in cool and humid environments and are widely distributed in Europe and Asia.Whether global climate warming will affect the distribution of these valuable resources remains unclear.Thus,this study analyzed the climatic suitability of these species for the first time on the basis of 1552 geographical distribution points and 19 bioclimatic factors using the maximum entropy model.The results show that a suitable distribution area for all four species would decrease under climate warming.The main bioclimatic factors affecting their distribution are the mean temperature of the coldest quarter for R.indicum,the mean diurnal range for R.simisii,and precipitation of the warmest quarter for R.oldhamii and R.schlippenbachii.In addition,the contribution of the temperature-related bioclimatic factors to the distribution of R.indicum and R.simisii is higher than that of the associated precipitation-related climatic factors;in contrast,the contribution of precipitation-related bioclimatic factors to the distribution of R.oldhamii and R.schlippenbachii is higher than that of the temperature-related climatic factors.These results provide references for the introduction,conservation,sustainable development,and utilization of these four species in the future,and may also provide information with regards to other Rhododendron species.

Shrub Landscape Design of the Summer Palace in Beijing

As one of the outstanding representatives of classical Chinese gardens,the Summer Palace has a variety of shrub plant species,and the configuration of shrub plants is also unique.The shrub landscape configuration of the Summer Palace is varied,with solitary planting,pair planting,cluster planting and group planting as the landscaping forms,providing people with the functional role of watching,interacting and using in leisure and entertainment,so that domestic and foreign tourists will linger in the Summer Palace.Through detailed introduction of distribution,landscaping form and aesthetic value of shrub configuration in the Summer Palace,analysis and discussion of its role,people can appreciate the fun of plant configuration in the royal garden in more detail.

Soil Seed Bank Characteristics of the Mbe and Nguela Shrub Savannas, and Implications for the Reforestation, Republic of Congo

The soil seed bank is an important source of restoration and resilience of disturbed ecosystems. This study evaluates the regeneration potential through the soil seed bank of the shrub savannas of Nguela and Mbe in order to predict the eventual dynamics. Three plots of 0.25 ha subdivided into four sub-plots of 0.015 ha have been installed in each savannah. In total, 48 samples of each savannah, i.e. 96 samples of both savannas, have been taken from the soil layers, 0 - 5 cm, 5 - 10 cm, 10 - 15 cm and 15 - 20 cm. Species diversity and abundance of the soil seed bank have been assessed after germination. The results reveal 167 seedlings belonging to 23 species in the Mbe savannah and 144 seedlings belonging to 14 species in the Nguela savannah. The total densities of the germinated seeds were respectively 463.63 seeds/m2 and 400 seeds/m2. Nevertheless, the 20 cm deep layers have illustrated themselves compared to the superficial layers with densities of 16.29 seeds/m2 and 21.66 seeds/m2, respectively, in the savannas of Mbe and Nguela. Herbaceous species largely dominated, with percentages of 91% and 100%, respectively, in the savannas of Mbe and Nguela. Alone, the Trema orientalis (L.) Blume species has been identified as woody species in the Mbe savannah. The greatest specific richness has been obtained in the first five centimeters of soil, with 21.73% and 28.57% of exclusive species, respectively, in the savannas of Mbe and Nguela. The results reveal that restoration through the soil seed bank would be limited to a single woody species found (T. orientalis). Consequently, the study suggests silvicultural interventions based on planting or enrichment techniques for sustainably managed savannas exposed to anthropogenic disturbances.

Application of Shrub Landscape on Campus from the Perspective of Ornamental Characteristics of Plants

In the campus greening design,the shrub height is generally consistent with people’s horizontal line of sight,which plays a significant role in people’s visual focus.From the perspective of ornamental characteristics of plants,the application of shrub landscape is explored in a campus environment.Based on the analysis of the selection,arrangement and maintenance of shrub plants in campus gardens,the application of shrub landscape on campus was evaluated comprehensively from the theoretical analysis of plant ornamental characteristics and campus shrub landscape.Based on the research background of the problems existing in the application of shrub landscape on campus,this paper first collected and sorted out the relevant theories extensively,and then conducted in-depth research on the relevant theories by using analysis methods such as literature data,field investigation and questionnaire survey.The results will provide a theoretical guidance and practical advocacy for campus garden planning and design,and help to create a livable and comfortable campus environment.It is hoped that the results will have some references for future campus shrub landscape and play a certain promoting role.

Ecosystem Service Value Assessment of Wutong Mountain Rhododendron moulmainense Ecological Landscape Forest in Shenzhen City in 2021

Taking Wutong Mountain Rhododendron moulmainense ecological landscape forest in Shenzhen City as an example,the value of the forest was assessed by constructing an ecological service value assessment system and accounting method.The assessment results showed that the total ecosystem service value of R.moulmainense ecological landscape forest was 13.195 billion yuan,and the top three services included the value of forestry products,the value of biodiversity maintenance and the value of leisure and recreation,indicating that the ecosystem service of Wutong Mountain R.moulmainense ecological landscape forest in Shenzhen has great ecological and economic value,especially in forestry products,biodiversity maintenance,and leisure and recreation.

灌丛资源及其管理利用研究进展

灌丛是中国山地和干旱地区的常见植被类型,分布范围广泛、生态功能多样、经济价值可观。然而,自然资源、生态环境、国民经济等相关部门多将灌丛拆分归属于森林或草原,其重要性未能充分体现。学术界有关灌丛资源的概念、内涵未有明确统一共识,基于资源属性特点的灌丛资源分区分类体系尚未建立。草原灌丛化的发生范围、速度及其生态影响不够明确,严重影响灌丛资源的高效保护、科学管理与可持续利用。这已然成为亟需凝聚共识和深入探究的理论技术难点与实践问题。建议在科学界定灌丛资源的概念内涵、建立健全灌丛资源分类体系基础上,深入发展和应用灌丛植被多基遥感和人工智能识别技术,科学掌握不同区域灌丛变化特别是草原灌丛化的过程及原因,全面系统地评估灌丛化的生态经济影响,优化分区分类灌丛管理利用策略,促进灌丛资源可持续管理和利用。

郑州市常绿灌木滞留颗粒物能力及季节差异

选取郑州市12种常见常绿阔叶灌木为研究材料,运用3级滤膜法测定叶片对各粒径颗粒物(TSP、PM_(>10)、PM_(10)、PM_(2.5))的滞留量,并通过超景深显微镜和扫描电镜观察比较12种灌木的叶表面微形态结构,分析灌木叶片的滞尘能力、滞尘粒度特征及季节差异。结果表明:1)不同植物的滞尘能力差异显著(P<0.05),火棘和夹竹桃滞留各粒径颗粒物的能力最强,洒金桃叶珊瑚和南天竹最弱。叶片滞留的颗粒物以PM_(>10)为主,其次为PM_(2.5),PM_(2.5~10)的占比最小,在2.52%~15.36%。2)各植物在滞尘粒度特征和滞尘量方面存在季节差异。植物对不同粒径颗粒物的滞留量总体呈现冬季大于春、夏、秋三季的规律,但对PM_(>10)、PM_(2.5)和PM_(2.5~10)的质量占比分别在冬春季、夏季和春季最高。3)叶表面微结构观察表明,叶尖和叶尾是滞留颗粒物的重要部位,而微结构如沟槽、凸起、绒毛、簇状结构等微形态结构则增强了植物的滞尘能力。电镜观察发现,有些植物叶表面具有菌丝,相关分析发现蜡质含量越多则菌丝越多,滞尘能力越强。滞尘树种的筛选应该综合考虑滞尘量、滞尘粒度及季节更替等因素,火棘和夹竹桃对各粒径颗粒物的滞留能力均较强,可以作为郑州市园林绿化中的首选树种。

锦绣杜鹃和映山红花冠营养成分及元素含量比较分析

为探究杜鹃花属植物食用价值,本研究以该属锦绣杜鹃和映山红两种植物为研究对象,对两种植物花冠营养成分及元素含量进行了分析研究。研究结果表明,锦绣杜鹃的花直径和花瓣宽特性显著大于映山红(P<0.05),但两者的花瓣长、花斑长和花斑宽3个特性方面没有显著差异(P>0.05);锦绣杜鹃花冠N含量显著高于映山红,但P含量显著低于映山红(P<0.05),两者的C含量没有显著差异(P>0.05);锦绣杜鹃花冠K、Na、Ca、Mg的含量显著高于映山红(P<0.05),而Fe和Mn的含量前者显著低于后者(P<0.05),两者花冠Zn的含量没有显著差异(P>0.05);锦绣杜鹃花冠的粗纤维含量和热值显著高于映山红花冠(P<0.05)。可见,锦绣杜鹃和映山红两种植物花冠中含有丰富的营养元素和金属元素,显示了较高的食用花卉开发潜力,但两者间存在一定的差异。

灌木平茬机切割系统参数优化设计与验证

为分析圆盘锯式切割系统的切割机理,在Solidworks中建立单组圆盘锯及灌木枝条的简化模型,并在动力学分析软件ABAQUS中进行仿真分析,研究灌木切割过程中工作参数与圆锯片参数的关系。同时,以锯片转速、行进速度、枝径为影响因素,以锯切力为评价指标,对其影响的因素进行虚拟正交试验,并用Design Expert动态响应软件进行分析,得到响应面回归方程,得知当圆锯转速为2500r/min、前进速度为0.9m/s时平茬效果较好。用小型灌木平茬机上进行实地试验,结果表明破茬率和留茬高度均能满足农艺要求。

保鲜剂对杜鹃切花采后品质的影响

为探究不同保鲜剂对杜鹃切花采后观赏品质的影响,并筛选出杜鹃切花的适合保鲜剂配方,以东洋杜鹃品种‘红元宝’为研究对象,采用不同保鲜剂对其进行瓶插处理,测定不同处理对切花瓶插寿命、鲜质量变化、水分平衡、质膜稳定性等生理指标和观赏品质的影响。结果表明:100~300 mg/L 8-羟基喹啉对‘红元宝’切花的保鲜具有积极作用,可有效延缓花瓣边缘卷曲和萎蔫,促进花径的增大并保持更长的开花时间(18 d),维持切花体内水分平衡,减缓其鲜质量变化及质膜透性的增加。而0.2~0.6 mmol/L硫代硫酸银处理不利于‘红元宝’杜鹃切花采后品质的保持,反而加剧了切花的衰老。经筛选,确定30 g/L蔗糖+200 mg/L 8-羟基喹啉为‘红元宝’杜鹃切花的最适保鲜剂。

荒漠草原灌丛转变过程土壤水分亏缺空间特征及影响因素

草地灌丛化对生态系统结构、功能与服务产生重要影响,目前已经认识到其对土壤水分的负面影响,但还缺乏其在区域尺度的定量评价及其驱动机制研究。在宁夏荒漠草原选取43块成对样地(即荒漠草地和灌丛地),引入样地土壤水分相对亏缺指数(PCSWDI)评价荒漠草原向灌丛转变后土壤水分亏缺空间格局现状及其驱动因子。结果表明:荒漠草原转变为灌丛后0~100 cm和100~200 cm土壤含水量分别显著下降了27.80%和57.92%,0~100 cm灌丛地的PCSWDI显著低于荒漠草地,表明0~100 cm灌丛地目前不存在土壤水分亏缺现象。地统计学分析表明,荒漠草地和灌丛地的0~100 cm土壤水分相对亏缺指数的结构方差比分别为94.73%和95.29%,均属于强空间自相关,主要受结构性因子控制。此外,地理探测器的因子探测发现0~100 cm土壤储水量、坡向和田间持水量是影响灌丛地土壤水分相对亏缺指数的主导因子;交互探测表明,灌丛地0~100 cm土壤水分相对亏缺指数空间分异是多因子共同作用的结果。尽管分析得到0~100 cm灌丛地不存在土壤水分亏缺,但100~200 cm土壤含水量显著下降已经预示了深层土壤水分的消耗。因此,干旱半干旱地区的植被恢复必须考虑其植被承载力和水分阈值,基于自然的解决方案可能是未来植被恢复的主流思路。

杜鹃花总黄酮通过抑制TNF-α/caspase-8/caspase-3信号通路减轻大鼠脑缺血再灌注损伤的作用

目的探索杜鹃花总黄酮(TFR)通过抑制TNF-α/caspase-8/caspase-3信号通路保护脑缺血再灌注(I/R)损伤的机制。方法采用大脑中动脉闭塞术(MCAO)建立大鼠I/R模型,将造模成功大鼠随机分为假手术(Sham)、脑缺血再灌注(MCAO)和脑缺血再灌注术后TFR 200 mg/kg干预(TFR 200 mg/kg)组,制备MCAO大鼠模型,在脑缺血再灌注损伤手术后,TFR 200 mg/kg组连续14 d给予TFR(200 mg/kg)药物溶液。术后14 d,依据大鼠神经功能评分,脑血流图观察脑血流情况,处死大鼠,苏木精-伊红(HE)染色观察脑组织细胞形态学变化,试剂盒检测大鼠血清中乳酸脱氢酶(LDH或LD)和神经特异性烯醇化酶(NSE)两种酶活性;ELISA试剂盒检测白细胞介素-1(IL-1)和IL-6水平,Western blot和免疫组化同时检测大鼠脑组织中裂解型胱天蛋白酶3(cleaved caspase-3)、caspase-8、肿瘤坏死因子(TNF)-α蛋白的表达水平。结果脑缺血再灌注处理后,MCAO导致了大鼠神经功能异常,神经功能评分指数显著升高,脑组织病理形态学和脑血流量变化明显,脑组织中cleaved caspase-3、caspase-8、TNF-α蛋白的表达水平显著增加,血清中LDH、NSE、IL-1、IL-6水平明显升高;TFR 200 mg/kg组大鼠神经功能评分明显降低,脑组织病理损伤显著改善,脑组织中cleaved caspase-3、caspase-8、TNF-α蛋白的表达以及血清中LDH、NSE、IL-1、IL-6水平降低。结论TFR可能通过抑制TNF-α/caspase-8/caspase-3信号通路减轻脑缺血缺氧性损伤。

桂南不同造林模式对植物物种组成和多样性特征的影响

[目的]摸清不同造林模式林下植物多样性特征及变化规律,为探寻科学、合理的人工林种植模式提供理论依据。[方法]以广西藤县3种常见造林模式林(纯林、混交林、人工-天然混交林)为研究对象,采用典型取样法,对林下灌木层、草本层从植物种类、物种多样性指数和相似性关系等方面进行分析。[结果]纯林、混交林和人工-天然混交林灌木层和草本层的物种数分别为33、36、29种和32、29、9种。3种造林模式灌木层优势植物种为玉叶金花和地稔,混交林和人工-天然混交林草本层优势种为铁芒萁,求米草为纯林优势种。灌木层物种多样性指数均以人工-天然混交林最高,纯林最低,除均匀度指数外,Shannon-Wiener指数、Simpson指数和丰富度指数在人工-天然混交林和纯林间存在显著差异(P<0.05),草本层物种多样性在不同造林模式间差异均不显著(P>0.05)。灌木层、草本层物种相似性系数均普遍较低。[结论]混交林和人工-天然混交林物种多样性高,是未来林地经营培育的方向。

平潭岛木麻黄群落灌木层优势物种生态位及种间联结分析

为探究平潭岛木麻黄群落灌木层优势物种的种间关系及群落发展状态,基于群落调查数据,通过生态位特征计算和种间联结分析,结果表明:(1)灌木层植物共计56种,重要值和生态位宽度最大的为木麻黄;生态位宽度并不完全与物种重要值大小变化一致,还可能与频度有关。(2)有43.8%的种对不产生生态位重叠,优势物种间的生态位重叠程度普遍较低;生态位宽度较小的物种也存在与其他物种产生较大的生态重叠现象。(3)灌木层优势物种的总体联结性呈不显著负联结。(4)χ2检验、Pearson相关检验和Spearman秩相关检验结果均表明种间关联程度较弱,种间联结较松散;AC值比χ2检验增加了联结显著率,但是也夸大了联结性的强度,导致出现极显著负联结种对数过高的现象。平潭岛木麻黄灌木层群落处于不稳定的演替阶段,亟需加强其群落稳定性的构建和植被修复保护的相关工作。

元谋干热河谷不同植被类型对生物多样性的影响

以元谋干热河谷草地、稀树灌草丛、人工混交林、人工纯林4种代表植被类型为对象,应用植物重要值、Simpson优势度指数、Shannon多样性指数、Margalef丰富度指数、Pielou均匀度指数、Jaccard相似系数,分析研究区不同植被的生物多样性水平及不同植被对生物多样性的影响。结果表明:研究区共有植物27科43属52种,其中,乔木层6科8属9种,灌木层13科16属17种,地被层17科26属26种。乔木层以滇榄仁(Terminalia franchetii)、余甘子(Phyllanthus emblica)、锥连栎(Quercus franchetii)为优势种,灌木层以华西小石积(Osteomeles schwerinae)、沙针(Osyris lanceolata)、西南杭子梢(Campylotropis delavayi)、车桑子(Dodonaea viscosa)为优势种,地被层则以扭黄茅(Heteropogon contortus)和拟金茅(Eulaliopsis binata)为优势种。元谋干热河谷主要植物群落的多样性水平较低。其中,人工混交林的Shannon多样性指数、Margalef丰富度指数最高,分别为1.90、2.28,植物种类相对较多、物种多样性较好;以禾本科为主要优势种的草地Simpson优势度指数、Pielou均匀度指数最高,分别为0.82、0.98。不同植被类型间Margalef丰富度指数差异显著,Simpson优势度指数、Shannon多样性指数、Pielou均匀度指数差异不显著。元谋干热河谷植被生物多样性指数普遍较低,4种植被类型的Jaccard相似系数为0.16~0.31,相似性程度较低,物种组成有较大差异。

水分条件变化对典型园林灌木叶片水势及光合特征的影响

北京市拥有丰富的灌木资源,很多种类具有较高的观赏价值和低耗水、抗旱性强等特点,有效地开发利用灌木资源应用于城市园林绿化,不仅可以节约园林灌溉用水量,还可降低园林养护成本。以北京市典型园林灌木大叶黄杨(冬青卫矛,Euonymus japonicus)、金叶女贞(Ligustrum×vicaryi)、紫叶小檗(Berberis thunbergii var.atropurpurea)和棣棠(Kerria japonica)为研究对象,对4种灌木进行模拟干旱试验,分析干旱条件下,不同灌木的叶片水势、净光合速率和气孔导度等指标的变化规律以及相互关系。结果表明:(1)各灌木水分胁迫对水势的影响呈上升趋势,紫叶小檗变化最为明显,干旱组水势升高幅度为55.56%。(2)4种灌木中,大叶黄杨净光合速率对水分的适应能力较强,在干旱后期较干旱前净光合速率从1.3μmol·m^(-2)·s^(-1)增大到11.0μmol·m^(-2)·s^(-1)。(3)金叶女贞气孔导度开放值变化较其余3种灌木最大,2022年8月21日达到531.26 mmol·m^(-2)·s^(-1),而干旱组大叶黄杨变化最大,较干旱初期气孔导度上升30.75%。因此,适度干旱对于4种灌木的生长影响不显著。

锦绣杜鹃花药发育及散粉孔形成的形态与解剖学研究

被子植物中部分类群的花药开裂方式为孔裂,人们对此类花药的发育与散粉孔的形成及散粉机制了解甚少。杜鹃属(Rhododendron)植物的花药普遍为顶孔开裂,为探究其花药的发育和散粉孔的形成及散粉机制,该研究对锦绣杜鹃(Rhododendron×pulchrum)进行了解剖观察和石蜡切片。结果表明:(1)锦绣杜鹃花药顶端成孔区与花药主体具有不同的组织构成,成孔区由薄壁组织构成,起源于雄蕊原基顶端的分生组织,花粉成熟时薄壁细胞分解成为散粉孔;花药的主体由孢原细胞发育而来,孢原细胞经多次分裂分化成为具多层花药壁的花粉囊。(2)锦绣杜鹃的花药壁在小孢子母细胞至小孢子四分体时期发育完全,有6~7层细胞,包括1层表皮、2~3层药室内壁、1~2层中层和1层绒毡层,中层在小孢子四分体形成后即分解,绒毡层在花粉完全成熟前分解消失,花药壁在花粉成熟时有表皮和2~3层药室内壁。(3)与纵裂型花药不同,锦绣杜鹃的药室内壁在花粉成熟时不发生纤维化,但因积累多糖而增厚,具有韧性和弹性。(4)锦绣杜鹃花粉发育过程中小孢子母细胞产生的4个小孢子不分离,成熟花粉为四合花粉,花粉间具有粘丝。推测锦绣杜鹃具多层药室内壁且加厚可使花粉囊空间缩小,从而将上部花粉“挤出”散粉孔,而花粉间的粘丝使昆虫传粉时可将花粉成团带出,其药室内壁多层且积累多糖是与顶孔开裂相适应的特征。