焕镛木花部数量变异和腋生花现象  

NUMERICAL VARIATION OF FLOWER PARTS AND THE AXILLARY FLOWERS IN WOONYOUNGIA SEPTENTRIONALIS(DANDY)LAW

作　　者：曾庆文[1] 高泽正[1] 张奠湘[1] 

机构地区：[1]中国科学院华南植物研究所,广东广州510650

出　　处：《热带亚热带植物学报》2001年第4期306-310,T001,共6页Journal of Tropical and Subtropical Botany

基　　金：国家自然科学基金资助项目(30070084);中国科学院知识创新工程(创新青年科学家小组)项目

摘　　要：对广西环江木论的焕镛木[Woonyoungiaseptentrionalis(Dandy)Law]自然居群花朵着生方式和性别比例作了随机抽样调查,首次发现其花的着生方式除多数为顶生花外,还有少量的腋生花,自然居群中雄株与雌株的性别比例为1.21:1,对中国科学院华南植物园栽培居群和广西环江木论自然居群20株600朵花进行的解剖统计揭示,雌、雄花各部分的数量是变化的,雄花的花被片一轮或两轮,2-6片,雄蕊81-152枚,雌花的花被片两轮,外轮2-4片,内轮4-13片,心皮3-8枚,只有雄花花药2室及雌花每心皮具2个胚珠是稳定的。花部表型性状的大幅度变异表明焕镛木具有较丰富的遗传多样性。讨论了腋生花与顶生花在木兰科系统发育中的意义、表型性状的异步进化现象以及建立焕镛木属WoonyoungiaLaw的依据。Flowerlocation,sex ratioand numericalvariationof the flowerpartsof Woonyoungia septen trionalis(Dandy)Law,an endemicspeciesin China,wereinvestigatedby randomsamplingtrees fromnaturalpopulationof Woonyoungia septentrionalis inMulunVillage,HuanjiangCounty(Guangxi Province).Althoughmostof theflowers(90%)wereterminalas previouslydescribed,a smallfraction(10%)werefoundto be axillary,whichwas not recordedpreviously.The ratioof maleto female individualswas1.21:1.Statisticresultsfrom600flowersin20individualsfrom introducedtreesin SouthChinaBotanicalGardenandfromnaturalpopulationin Mulunshowthatthenumberof flower parts,exceptthenumberof thecaeperstamenandthenumberof ovulespercarpel,is variable.The variationsare:2-6tepalsin oneor two whorls,81-152stamensin maleflowers,two whorlsof tepals,2-4intheouterwhorl,5-13intheinner,and3-8carpelsinfemalflowers.Two thecaeineachstamen,andtwoovulesineachcarpelaretheonlystablecharacters.Greatvariationinfloralcharactersindicates thatthisspeciespossesseshighgeneticdiversity.The phylogeneticsignificanceof co-occurrenceof axillaryand terminalflowers,the heterobathmyof floralcharacters,and the tenabilityof the genus Woonyoungia arediscussed.

关 键 词：焕镛木 腋生花 花部数量变异 异步进化 木兰科 

分 类 号：Q949.747.1[生物学—植物学]