灰木莲生殖生物学特征及败育机制研究

发布时间：2018-05-23 12:42

本文选题：灰木莲 + 生殖生物学特性　；参考：《中国林业科学研究院》2017年博士论文

【摘要】：为了解灰木莲(Manglietia glauca)的有性生殖特征,探明引种条件下其种实败育的原因,本文以中国林科院热林中心树木园、白云实验场、伏波实验场引种的灰木莲人工林作为研究材料,从灰木莲的开花特征、花芽分化发育、雌雄配子体发育、繁育系统、传粉生物学等方面进行系统研究,主要的研究结论如下:(1)灰木莲在树木园花期从3月上旬持续至5月上旬,始花期为3月上下中旬,3月下旬到4月中旬为盛花期,4月下旬到5月上旬为终花期。白云实验场白云山(BY)和伏波实验场(FB)的始花期分别比中心树木园相应推迟15~20 d和18~25 d,盛花期推迟8~10 d和12~15 d,终花期推迟6~7 d和8~10 d;单花于17:00~18:00开花,开花时间稳定,不受天气和环境的影响;在群体水平时,开花强度为中等,但开花相对集中且同步指数较高;生殖构件分布主要受林分密度的影响,随着林分密度的升高,灰木莲林分的花枝/枝和花/花枝呈下降趋势,林缘单株生殖构件数量显着高于林内植株。(2)灰木莲单花二次开合开花经历以下几个阶段:露白阶段、初次展花、闭合阶段、完全展花、衰败阶段,受不同花期不同气温影响,单花开花周期和闭合阶段时间差异较大;在植株水平上,各轮花表现为异步雌雄异熟,同一轮花为同步集中式开花,在前一轮花的完全展花即雄性表达时,正好为下一轮花初次展花也即雌性表达时,此时两轮开花雌雄性征均较强,雌雄表达重叠可达1-6 h,为同株异花和异株异花传粉提供可能。(3)灰木莲花芽分化发育过程可划分为叶芽期、花发端原基分化期、花器官形成期、雌雄蕊成熟期和花蕾形成期,花器官形成顺序为:花萼-花瓣-雄蕊群-雌蕊群;雄蕊群由140-185枚雄蕊组成,成熟花药具2-6个花粉囊,多数为4个花粉囊,偶见2个或6个花粉囊,药壁发育为双子叶型,腺质绒毡层,小孢子母细胞减数分裂胞质方式为同时型,四分体排列方式为交叉型、左右对称型,偶见有T型和直列式;成熟花粉二细胞型,花粉舟形,具单沟萌发孔。雌蕊群由45-85枚心皮组成,每心皮含两列胚珠8-14个,胚珠倒生,双珠被,厚珠心,胚囊发育为单胞蓼型。(4)灰木莲在大小孢子发生及雌雄配子体形成发育过程中,存在一定比例的异常现象。小孢子母细胞进入减数分裂后,绒毡层和中层细胞大部分解体,仅剩少量残余;从四分体分离出的小孢子发生不同程度变形,变形后的小孢子大部分能发育为正常的小孢子,部分因收缩后不能发育为正常小孢子,雄蕊异常发育比例为16%;雌配子体发育异常主要发生在二核胚囊到八核胚囊的形成期,在二核胚囊和四核胚囊时,出现核仁、核膜解体,细胞萎缩变小,细胞内容物消失,染色变黑模糊;八核成熟胚囊时,中央细胞、助细胞和反足细胞不同时间出现萎缩和消失,胚囊边缘细胞同时解体;少数胚珠会出现内珠被和珠心缓慢或停滞发育,珠心细胞凝聚或消融,珠心与珠被分离,内外珠被分离,雌性败育比例为22%。(5)灰木莲的繁育系统为繁育系统为异交,部分自交亲和的混合交配类型,具有自交不和性的倾向,自交不亲和性表现于自花授粉的自交,部分自交亲和主要表现于同株异花的自交。(6)访花昆虫约13种,其中缨翅目1种,鞘翅目7种,膜翅目3种,双翅目2种。不同林分环境的访花昆虫种类差异较大,较为稳定和有效的传粉者主要有膜翅目的蜂类、鞘翅目的甲虫类和双翅目的蝇类;昆虫访花频率受开花量和天气影响较大,在始花期,昆虫访花频率最低,平均仅为0.5次/花·h,在盛花期10.3次/花·h;在低温的阴天、下雨或强风的天气条件下,即便于盛花期,除了蓟马和偶有甲虫访花外,很少有蜂类和蝇类昆虫进行访花活动。
[Abstract]:In order to understand the sexual reproduction characteristics of Manglitia glauca , the causes of seed abortion under the condition of introduction were studied . The main research conclusions were as follows : ( 1 ) The flowering period was from late March to mid - May , and the flowering period was delayed by 6 - 7 days and 8 - 10 days . ( 3 ) The flower bud differentiation and development process of the two - wheeled flowers is characterized by two - cotyledon type , two or six pollen - boat - shaped flowers and a single - furrow germination hole . The female core group consists of 45 - 85 carpels , each of the two - wheeled flowers has two - row ovules , the ovules are inverted , the double - pearl is formed , the thick nucellar and the embryo sac are developed into a single - cell type . ( 4 ) There is a certain proportion of abnormal phenomena in the development of the sporogenesis and the formation of the male and female gametospore . After the microsporocytes enter the meiosis , the tapetal and middle cells break down , leaving only a small amount of residue . ( 6 ) There are about 13 species of insect - visiting insects , including 1 species , 7 species , 7 species , 2 diptera , 2 species of diptera , and 2 species of diptera . The frequency of insect visit is the lowest , the average is only 0.5 times / flowers 路 h , and in the blooming period , the insect visit frequency is only 0.5 times / flowers 路 h , and there are few bees and fly insects in the blooming period except thrips and even beetles .
【学位授予单位】：中国林业科学研究院
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S792.99

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