Phenotypic plasticity of floral traits and pollination adaption in an alpine plant Pedicularis siphonantha D. Don when transplanted from higher to lower elevation in Eastern Himalaya

Phenotypic plasticity and/or pollinatormediated selection may be responsible for the changes in floral traits of plants when they are forced to live in new conditions. Although the two events could be independent, we hypothesized that phenotypic plasticity in floral traits might help to coordinate plant-pollinator interactions and enhance plant reproductive success in changing habitats. To test this hypothesis, we investigated floral traits and pollination on three natural populations of a lousewort(Pedicularis siphonantha) ranging at different elevations, as well as two downward transplanted populations in Shangeri-La County and Deqin County, northwest Yunnan, China. The results indicated that floral traits, i.e. phenology, longevity,display size, corolla tube length and pollen production differed significantly among populations. Moreover,or the two transplanted populations, floral traits diverged from their original populations, but converged to their host populations. Although the phenotypic plasticity in floral traits might be a rapid response to abiotic factor such as warmer environment, the changes in floral traits were found to be well adapted to pollination environment of the host population. Compared with plants of their original habitats in higher elevation, the transplanted individuals advanced flowering time, shortened flower longevity, reduced floral display size and pollen production, received higher visiting frequency and yielded more seeds. These findings suggested that phenotypic plasticity of floral traits might help plants adjust their resource allocation strategy between preand post-pollination stages in response to harsh or temperate conditions, which might correspondingly meet a pollinator-poor or hyphen rich environment.This would be beneficial for the widely-distributed species to adapt to various environmental changes.

Fitness-related selection on floral traits in the distylous plant Primula poissonii (Primulaceae)

Aims Reproductive fitness of different floral phenotypes varies within and/or among populations.These variations are important to understand the process of natural selection and the evolution of floral traits.In this study,we focused on a distylous,self-incompat-ible species,Primula poissonii,to investigate fitness-related selec-tion on floral traits.Our aim was to determine how traits vary as targets of natural selection and whether morph-specific selection occurs.Methods This study was conducted at two sites(Yushuizhai at 2700 m and Haligu at 3200 m)in the Lijiang Alpine Botanical Garden,northwest-ern Yunnan,southwestern China.Insects visiting flowers of P.pois-sonii were observed,captured and identified.Randomly selected plants of long-and short-styled morphs were labeled.Five floral/inflorescence traits were measured including floral display,corolla width(CW),floral tube length(FTL),tube opening width(TOW)and floral scape height.Fruit and seed set were recorded.The total num-ber of seeds per individual plant(plant fitness)and seed production per capsule(flower fitness)were calculated.Multiple regression analyses were used to quantify selection gradients.Important Findings The frequencies of the two morphs did not deviate from the expected 1:1 ratio at both sites.Except for FTL,the four other traits did not dif-fer significantly between the long-and short-styled morphs.Floral scape height,floral display and FTL differed between two sites.The selection regimes differed between two morphs and between two sites.At the Yushuizhai site,linear selection for shorter floral tubes was stronger in the short-styled morph.However,nonlinear selec-tion on the floral display was stronger in the long-styled morph than selection on the short-styled morph.At the Haligu site,linear selec-tion for a smaller corolla was stronger in the long-styled morph.A morph-specific nonlinear selection on CW and floral display was also detected.Morph-specific selections were detected through the estimation of flower fitness only in Haligu population.In this site,morph-specific linear selection was also detected for CW and floral display.Morph-specific nonlinear selection on traits was detected only in CW.We found that butterflies and sphingid moths dominated at Yushuizhai,while long-tongued bees dominated at Haligu.The difference in pollinator fauna suggested that selection on floral tubes may be due to differences in pollinator assemblages.Overall,variation of floral and/or inflorescence traits in P.poissonii was probably driven by pollinator selection.Selection regime dif-ferences between two morphs,in part,due the inter-morph diver-gences of sexual functions in distylous plant.

Differences in floral traits and flower visitation rates in mating systems in Prunella vulgaris(Lamiaceae)

Floral traits and the number of visitors are expected to change with different mating systems.We tested this hypothesis by comparing flowers of Prunella vulgaris(Lamiaceae)with inserted and exserted styles across a strongly exserted style biased,an exserted style biased,and a strongly inserted style biased subalpine population.We examined flowering phenology,floral morphology,flower visitation rate,capacity for autonomous selfpollination and visitor contribution to seed production for each style type and in each population.We also examined inbreeding depression(ID)by comparing the relative performance of progeny from self-and crosspollination.Exserted style plants had larger and more open flowers,increased pollen production,higher amounts of nectar rewards and higher visitation and outcrossing rates than inserted style plants.Similarly on the population level,the visitation rates were higher in the exserted style-biased populations than in the inserted style-biased population.Inserted style plants provided a stronger reproductive assurance(RA)through autonomous selfing than exserted style plants.RA and outcrossing rates did not differ among populations,showing low visitation rates may be sufficient for adequate seed production in P.vulgaris.Although inserted style plants had a lower ID level than exserted style plants,the ID of both was less than 0.5,suggesting that an ID should not counteract the evolution of selfing in this species.Inserted style plants provide RA through autonomous selfing,and exserted style plants ensure outcrossing through pollinator services,supporting a stable mixed mating system in this subalpine plant.

Patterns and drivers of plant sexual systems in the dry-hot valley region of southwestern China

Sexual systems play important roles in angiosperm evolution and exhibit substantial variations among different floras. Thus, studying their evolution in a whole flora is crucial for understanding the formation and maintenance of plant biodiversity and predicting its responses to environmental change. In this study, we determined the patterns of plant sexual systems and their associations with geographic elements and various life-history traits in dry-hot valley region of southwestern China, an extremely vulnerable ecosystem. Of the 3166 angiosperm species recorded in this area, 74.5% were hermaphroditic,13.5% were monoecious and 12% were dioecious, showing a high incidence of diclinous species. Diclinous species were strongly associated with tropical elements, whereas hermaphroditic species were strongly associated with temperate and cosmopolitan elements. We also found that hermaphroditism was strongly associated with showy floral displays, specialist entomophily, dry fruits and herbaceous plants.Dioecy was strongly associated with inconspicuous, pale-colored flowers, generalist entomophily, fleshy fruits, and woody plants, whereas monoecy was strongly associated with inconspicuous, pale-colored flowers, anemophily, dry fruits, and herbaceous plants. In addition, hermaphroditic species with generalist entomophily tended to flower in the dry season, whereas diclinous species with specialist entomophily tended to flower in the rainy season. However, independent of sexual systems, plants that produce dry fruits tended to flower in the rainy season and set fruits in the dry season, but the opposite pattern was found for fleshy fruit-producing plants. Our results suggest that in the dry-hot valleys, plant sexual systems are associated with geographic elements as well as various life-history traits that are sensitive to environmental change.

霸王表型可塑性对土壤水分的响应

植物的表型可塑性是受不同环境影响而产生的表型特征,是植物对环境的适应与表达。为探讨霸王(Zygophyllum xanthoxylum)在不同生境下的表型可塑性及其资源分配格局,本文选取固定沙地和砾质沙地两种生境,研究不同生境下霸王的生长参数、叶片性状和花性状的变化特征。结果表明,由于生境间土壤含水量的差异,霸王的表型性状也表现出不同的适应特征:在土壤含水量较低的生境下:(1)霸王的株高、体积和地上生物量较大,表现出较好的生长状况;(2)叶面积、叶片含水量和比叶面积也较大,叶片肉质化程度高;(3)花总数较少、花直径和花瓣面积较小,表现为对繁殖投资的减少。综合来看,在生境土壤可利用水分少的情况下,霸王会采取较为保守生存策略,将更多的物质能量投入到营养生长方面,从而降低繁殖投资以保证其生存。该研究有助于阐释霸王表型可塑性及资源分配对环境变化的适应,为荒漠植物的恢复与保护提供一定的理论基础。

干旱胁迫对栀子花叶性状及抗氧化酶活性的影响

为探究干旱胁迫对栀子Gardenia jasminoides植株生长、花叶性状及抗氧化酶活性的影响,采用‘灵地珍栀’扦插苗为试材,测定不同干旱胁迫程度下其株高增长量、地径增长量、相对叶绿素含量、花与叶性状的变化。结果表明,干旱胁迫显著降低栀子株高和地径增长量,降低花直径、新增叶数、叶长、叶宽等指标,且随着干旱程度的加深,抑制效果愈加明显,但SPAD总体呈上升趋势,且随着干旱胁迫时间延长,栀子SOD活性总体上升,POD、CAT活性总体下降。干旱胁迫缩短了栀子单叶的生长周期,加速叶片成熟,抑制新叶的形成和生殖生长,打破了栀子叶片原有抗氧化酶之间的协同作用,以此降低能量和水分消耗,导致抗氧化还原失衡,自由基积累,膜脂过氧化加剧,栀子花、叶片变小变少。

Dynamic Changes in Endogenous Hormones in Rhododen- dron simsii Floral Organs

This study was conducted to investigate the dynamic changes of several hormones in Rhododendron simsii floral organs to provide theoretical basis for controlling its flowering period. A R. simsii variety ＂Purple Crane＂ was selected as the experimental material, and its flower organs were sampled at nine floral developmental stages to measure the contents of gibberellic acid-3 （GA3 ）, abscisic acid （ABA）, indole-3-acetic acid （IAA）, and zeatin riboside （ZR） through enzyme-linked immunosorbent assay （ELISA）. The results showed that the content of ZR was highest at full flowering stage; IAA and GA3 contents were higher than other stages in the process of flower bud differentiation and flowering. ABA played an important role in the regulation of flower bud formation. The results will provide theoretical references for exploring the regulation of plant hormones towards Rhododendron flower traits and breeding new varieties.

蝴蝶兰杂交F_(1)代的花部性状遗传分析

以蝴蝶兰“Phal.B”为父本,分别与玫红色系“兰九”“双龙”“光芒四射”和白色系“V 3”等栽培品种进行杂交,对4个杂交组合F_(1)代的花被片颜色、花斑、肉突颜色、中裂片颜色等花部性状进行观察和分析,探究其遗传规律。结果表明,杂交F_(1)代花色、肉突颜色和中裂片颜色均表现出中亲和超亲优势;在花色遗传方面,以“V 3”为母本时,杂交F_(1)代花色分离出白花紫红斑和纯白花2种类型,以玫红色系为母本的3个组合杂交F_(1)代花色分离规律一致,呈梯度分布,分离出了4种类型:深紫红色、紫红花斑、玫红-粉色、白色;杂交F_(1)代中有紫红色和无紫红色分离比都趋近1∶1,推测紫红色可能是由单基因控制的性状,深紫红色花可能是紫红花斑色在花被片上均匀分布及玫红色叠加效应而导致的;在肉突的遗传方面,紫红色肉突、黄底带紫红斑块肉突与花色存在一定的正向相关性,当花被片上呈现紫红色时,肉突颜色会表现出紫红色或者黄底带紫红斑块,且随着花被片上紫红色越深、分布面积越大,紫红色肉突所占比例会增大;在中裂片颜色遗传方面,近紫红色所占比例较少,仅在深紫红色群体中出现,近紫红色中裂片与花色、紫红色肉突都有一定的正向相关性。

大花紫薇花部综合特征和繁育特性

为深入了解大花紫薇(Lagerstroemia speciosa)的开花生殖特性,推动其杂交育种工作,提高观赏性,对其花部特征进行观察记录和测量,并通过杂交指数估算、测定花粉活力和柱头可授性、观察访花昆虫以及人工授粉试验等对其进行了研究。结果表明:大花紫薇集中在5—8月开放,单花花期2~8 d;花朵一般于凌晨开放,开花过程可分为4个阶段(花萼开裂期、花瓣外展期、花药散粉期、枯萎凋落期)。大花紫薇花粉数-胚珠数比为5 445.45,杂交指数为4。雌蕊与雄蕊同步成熟。大花紫薇自然状态下结实率为72%,人工异株异花授粉、同株异花授粉和自花授粉的结实率分别为90%、74%和68%。根据以上结果判定,大花紫薇繁育系统是以异交为主、部分自交亲和的混合交配系统,且需要传粉者完成授粉过程。大花紫薇传粉者包括蜂类、蝇类和蝶类昆虫等,主要传粉昆虫为熊蜂和中华蜜蜂.

同域分布的两种荒漠春季十字花科草本植物的花部特征与花气味差异性比较

卡拉麦里山自然保护区是我国著名的荒漠有蹄类野生动物自然保护区,春季开花植物是该保护区荒漠植被的重要组成部分,也是食草野生动物赖以生存的优良牧草。西伯利亚离子芥(Chorispora sibirica)和扭果花旗杆(Dontostemon elegans)是广泛同域分布在该区域砾质荒漠上的两种十字花科春季开花草本植物。为了比较这两种草本植物的花部特征与花气味的差异性,对两物种的花部性状进行野外观测和测量,同时收集并分析其花气味挥发物的组成。结果表明:(1)两种草本植物的花均具有典型的虫媒花特征,如较大的花冠直径、鲜艳的颜色和芳香的气味,并且两物种的主要花部性状存在着显著的差异,尤其表现在花冠的颜色、直径、花瓣宽以及雌雄蕊长上。(2)两种草本植物的花气味中共分离出41种挥发物,主要以萜类化合物为主,其中西伯利亚离子芥花气味的主要成分为顺-β-罗勒烯,而扭果花旗杆的花气味中α-蒎烯和苯乙醛的含量最高。主成分分析表明两物种花气味的化学组成表现出明显的种间差异性。同域分布中的两种荒漠草本植物具有相似的花部特征和花气味,可吸引共享传粉者,促进两物种进行异交,从而增加开花植物的后代适合度;推测共享传粉者可以利用两草本植物之间的这种差异性来区分出各物种,进而分别为其传粉,从而可以保障两草本植物的种间生殖隔离,维持了该区域内的物种多样性,也对该区域野生动物的保育具有重要意义。

狼毒种群蓟马的访花特征及其对狼毒繁殖的影响

【目的】明确狼毒(Stellera chamaejasme)花性状变异对蓟马访花和狼毒个体雌性适合度的影响。【方法】在高寒草地狼毒种群中,观测蓟马访花特征并测量狼毒花性状。【结果】蓟马成虫多在狼毒花序开花初期和全开期进行访花。在夜间,狼毒花序上蓟马成虫的数量显著高于白天。蓟马(若虫)数量与狼毒的冠口宽度存在显著的正相关关系,与其他性状之间不存在显著的相关性。通径分析发现,狼毒的小花数量和蓟马数量对狼毒雌性适合度的直接作用最大,而冠筒长和冠口宽的直接作用较小。【结论】蓟马访花与狼毒花性状(如花期、冠口大小)密切相关,其活动频次对狼毒雌性适合度有显著影响。

蝴蝶兰Phal.‘B’和Phalaenopsis.SogoYukidian‘V3’正反交后代花部性状分离表现

以蝴蝶兰Phal.‘B’和Phalaenopsis SogoYukidian‘V3’为亲本进行正反交,对杂交F_(1)代花部性状的分离表现进行统计分析。结果表明,正反交F_(1)代的花色花斑、唇部肉突颜色、唇部中裂片颜色分离类别基本一致;蝴蝶兰Phal.B的紫红色花斑可以遗传给后代,且作为父本更容易遗传;同时紫红色肉突与紫红色花斑的分布有一定的正向相关性,当花瓣上有紫红色花斑的,肉突颜色会显现紫红色,而花瓣上没有紫红色花斑的,肉突颜色则不会呈现紫红色,且会随着紫红色花斑面积的增加,紫红色肉突所占比例随之增加;而且紫红色花斑分布对中裂片的颜色有一定的影响,当花瓣上有紫红色花斑时,中裂片更易呈现红色,且Phal.B为父本时杂交后代中这种遗传影响尤甚。

中华猕猴桃雄株花器的性状特征

【目的】探明中华猕猴桃雄株花器性状特征,为中华猕猴桃优势雄株资源筛选、保存及在生产上应用提供理论依据。【方法】以国家果树种质云南特有果树及砧木圃保存的XZ-1、XZ-25及XZ-44等27份中华猕猴桃雄株为材料,采用流式细胞仪检测倍性,通过观察雄株花器表型性状(花序类型、花瓣形状及花冠类型等9个)和测量数量性状(花朵花冠直径、花梗长度及花瓣数量等8个),结合变异分析和聚类分析研究其雄株花器性状特征。【结果】27份中华猕猴桃雄株均为四倍体。花器描述型性状较一致,雄株花序均为聚伞花序,花瓣椭圆形,6~7瓣,基部大部分重叠;花萼绿色,5~6个;花瓣内侧主色有黄、黄白、白及橙色;花丝白色(XZ-37淡绿色除外);花药长椭圆形,黄色。花朵花梗长度、花粉量、花粉生活力和离体萌发率存在明显差异,各指标的变异系数为32.65%、26.32%、34.14%和70.00%。对其花粉量、花粉生活力和离体萌发率进行聚类分析,可将27份中华猕猴桃雄株分为4类:第Ⅰ类花粉量和花粉生活力高,但花粉离体萌发率低,包括XZ-25、XZ-1、XZ-20和XZ-16等共13个雄株;第Ⅱ类花粉量、花粉生活力和花粉离体萌发率均较低,包括XZ-4、XZ-3和XZ-10等共4个雄株;第Ⅲ类花粉量、花粉生活力和离体萌发率均较高,包括XZ-44、XZ-35和XZ-19等共8个雄株;第Ⅳ类花粉生活力和花粉离体萌发率高,但是花粉量低,包括XZ-37和XZ-42共2个雄株。【结论】27份中华猕猴桃雄株花器性状变异丰富,其中8个雄株(XZ-44、XZ-35、XZ-19、XZ-34、XZ-29、XZ-13、XZ-9和XZ-8)花粉量、花粉生活力及离体萌发率均较高,可作为与其花期相遇的中华猕猴桃品种授粉候选资源。

基于同质园栽培的21种淫羊藿属植物花部特征的分类学意义

以采自中国多地并同质园栽培于吉首大学种质资源圃的21种淫羊藿为研究材料,通过观测这些物种的花梗长、花直径、内萼片长宽、蜜距长、雌雄蕊长、花药长、花柱长、胚珠数、花粉大小及花粉量等16个花部特征数量性状和花序类型、有无蜜距、花瓣颜色、内萼片颜色、内萼片与花瓣相对长度及花粉颜色6个质量性状,并对其分类学意义进行探讨。结果表明,(1)21种淫羊藿内轮萼片花瓣状,4枚花瓣除无距淫羊藿外均特化成蜜距,但花部形态种间存在显著差异,尤其体现于花直径、内萼片长宽、蜜距长、雌蕊长、胚珠数、花粉量、花粉直径等特征。(2)主成分分析显示花直径、内萼片长、花药长、胚珠数和花粉直径等性状信息负荷量较大,在该属分类中起主要作用。(3)根据花部特征聚类分析,物种间区分良好,21物种可分为4支:第1支花小,花瓣短于内轮萼片,囊状距或兜状距;第2支花较大,花瓣远长于内轮萼片,长距状;第3支花小,花瓣没有特化形成蜜距;第4支花较小,花丝伸长明显,可达10 mm,花蜜距呈钻状。(4)依据所观察到的花部形态特征编写了淫羊藿属21种植物花部特征分种检索表。研究认为,基于同质园栽培下的淫羊藿属物种的花部特征具有分类学意义,可以为该属分类提供一定依据。

小峰熊蜂访花偏爱性

传粉昆虫在访花时,通常会表现出对某一类型花的偏爱性。本研究利用人工制作的大小、颜色、形态和气味不同的9种类型的花来研究小峰熊蜂Bombus hypocrita的访花偏爱性。结果表明:当增加花的大小、形态、气味等附加特征数时,小峰熊蜂的偏爱性程度与花朵附加特征数有显著相关性(P<0.01)。当花朵颜色由2种增加到4种,熊蜂对紫色花的偏爱性程度降低,但花朵颜色的种类与小峰熊蜂的访花偏爱性没有相关性(P>0.05),花颜色的种类对熊蜂访紫色花的偏爱性影响不大。大小为5cm的紫花被访次数(108±9次)明显高于大小为3cm的紫花被访次数(40±4次)(P<0.01),说明熊蜂明显喜欢访大花瓣的紫花。完全盛开的紫花被访次数(129±13次)显著高于刚绽放的花被访次数(26±3次)(P<0.01),说明熊蜂喜欢访盛开的紫花。柠檬味的紫花被访次数(63±8次)明显低于草莓味的紫色花被访次数(88±2次)(P<0.05),说明熊蜂喜欢访草莓味的花朵。

辣椒花器性状与果实性状的遗传相关及因子分析

为掌握1a生辣椒花器性状和果实性状的变化特点及其相互关系，对1a生辣椒4个变种29份材料的8个花器性状和4个果实性状进行了遗传相关分析。结果表明：花器性状和果实性状具有较高的遗传多态性，其变异系数（CV）范围为13．10％（花纵径）-86．81％（单果重）；遗传力在30．81％（果纵径）～88．73％（子房横径）；8个花器性状与4个果实性状之间存在较为紧密的相关关系。因子分析表明：12个花器及果实性状集约于3个主因子上，F1为横茎／重量因子，F2为纵径因子，F3为形态指数因子，这3个主因子对变异的累计贡献率达84．83％，保持了12个性状的绝大部分信息。

濒危植物大果木莲与中缅木莲的花部特征及繁育系统比较

以非濒危种中缅木莲为对照,对其及濒危种大果木莲的花部结构进行了观察和测定,并采用花粉TTC染色、花粉萌发、杂交指数、人工套袋试验、花粉—胚珠比等方法,对二者的花部特征、繁育系统及花粉活力等进行了比较研究。结果表明:大果木莲花朵较大,花色艳丽,香味浓郁,适合虫媒传粉,其雌蕊群、雄蕊、花药都较对照大,而心皮数量、单花胚珠数量及雄蕊数量都较对照少15～31个、3～45粒、93～128个。其花粉—胚珠比为14285.98±4192.2,是对照种的2倍以上,远交程度较高,杂交指数为4。结合套袋试验结果可以确定该物种为异花授粉类型,不存在无融合生殖,部分自交亲和,需要传粉者;对照种亦为异花授粉类型,但自交亲和率较高。根据套袋试验及观察,该物种为虫媒传粉,对照种则有虫媒和风媒传粉2种方式。从生殖生物学方面来看,其繁育系统上的差异导致大果木莲生殖力较对照种低,可能只是大果木莲比中缅木莲濒危的原因之一。

沙丘稀有种准噶尔无叶豆花部综合特征与传粉适应性

植物花部特征进化与传粉适应性一直是进化生态学领域关注的核心问题之一。以古尔班通古特沙漠自然生长的准噶尔无叶豆为对象,对其花部特征和传粉特性进行了野外观察和室内的分析研究。结果表明:种群花期历时21 d,花序花期历时7—12 d,单花花期一般3 d,若遇阴雨天气,花期可延长1—2 d,整个花期龙骨瓣一直保持闭合状态。单花10枚花药在旗瓣微张时已全部完成散粉。准噶尔无叶豆主要靠分泌花蜜、鲜艳的花色以及旗瓣基部的黄色辐射状纹理结构吸引传粉者。准噶尔无叶豆花期的有效传粉者为4种蜂类昆虫,它们的平均访花频率为(7.75±0.57)次·花-1·d-1,访花高峰期表现为三峰型:13:00—14:00,16:00-17:00和19:00—20:00。准噶尔无叶豆人工套袋实验表明该种为自交亲和型,主动自交少见,生殖成功依赖传粉者。胚珠成功受精至果实完全成熟阶段存在自交衰退,柱头角质层结构和花粉刷结构是准噶尔无叶豆在进化过程中形成的减少自交,倾向异交的机制。

菊花花部特征及花冠精油组分与访花昆虫的相关性

菊花(Dendranthema morifolium)是异花授粉植物,具有自交不亲和特性。其自然授粉的主要媒介为蜂类和蝶类。我们对19个菊花品种的花色、花朵繁密度、花冠直径、管状花花盘直径、株高以及花冠精油组分与访花蜂数和访花蝶数的相关性进行了研究。结果表明,黄花色系较吸引西方蜜蜂(Apis mellifera)访花;菊花的花朵繁密度、花冠直径、管状花花盘直径均与访花蜂数有显著相关性,而株高与访花蜂数无相关性。大红蛱蝶(Vanessa indica)青睐红色花,其访花蝶数与花朵繁密度、管状花花盘直径均有显著相关性,而花冠直径和株高与访花蝶数无相关性。经气相色谱-质谱(GC-MS)分析得知,不同菊花品种花冠精油的组分不同,其主要成分均为单萜和倍半萜类及其含氧衍生物;并且不同品种含有某些特定的花冠精油组分,其中樟脑萜(r=–0.909,p<0.05)和6,10,14-三甲基-2-十五酮(r=0.882,p<0.05)与访花蜂数呈一定的相关性,α-萜品醇(r=0.979,p<0.01)、顺柠檬烯氧化物(r=0.979,p<0.01)、金合欢烯氧化物(r=0.979,p<0.01)、p-mentha-6,8-dien-2-ol,cis-(r=0.973,p<0.01)、p-menth-1-en-8-ol(r=0.962,p<0.01)和4-萜品烯醇(r=0.957,p<0.05)与访花蝶数呈一定相关性。

海拔对全缘叶绿绒蒿植株性状和花特征的表型选择分析

为了研究海拔差异对植株性状、花特征表型选择的影响,以青藏高原高寒草甸的全缘叶绿绒蒿(Meconopsis integrifolia)为研究材料,于盛花期内,测定不同海拔(4 452、4 081和3 681m)种群中个体植株性状、花特征、单果结实数并进行统计分析,采用线性回归模型估计不同海拔种群间植株性状、花特征所受的表型选择(选择差与选择梯度)。结果表明:(1)随着海拔升高,全缘叶绿绒蒿植株性状、花特征及单果结实数显著降低,海拔越高的种群中株高越矮、叶面积越小、花数越少、花越小、单果结实数越低。(2)不同海拔种群中各性状的表型选择存在差异,较低海拔(3 681m)种群中花数、花大小具有显著的选择差和选择梯度,表现为花越多、花越大的个体雌性适合度越高;海拔较高(4 081m)的种群中株高、叶面积及花数更容易受到选择,表现为植株越高、叶面积越大、花越多的个体雌性适合度越高;海拔最高(4 452m)的种群中叶面积与花数的选择梯度接近显著。(3)植物性状分化伴随着海拔的变化而呈现出差异,较低海拔种群中花特征容易受到选择,而较高海拔种群中可能由于传粉者稀少、资源限制等因素使得株高、叶面积更容易受到选择。