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连翘授粉受精特性研究

标题: 连翘授粉受精特性研究
英文标题: Studies on Characteristics of Pollination and Fertilization in Forsythia Suspensa (Thunb.) Vahl
作者: 刘红霞
出版时间: 2009-01-01
所在大学: 河北农业大学
关键词: 连翘,授粉,受精,花粉
英文关键词: Forsythia suspensa (Thunb.)Vahl,Pollination,Fecundation,Pollen
论文级别: 硕士
学位: 学位论文
导师: 任士福
专业: 森林培育学
提交时间: 2009
摘要: 为了找出连翘产量低、药材质量差的问题,本研究以长花柱连翘和短花柱连翘为基本材料,采用电镜扫描、TTC染色、离体培养、杂交授粉、荧光显微和石蜡切片等技术,对连翘开花物候期、花粉的大小、形态、外壁纹饰、花粉数量、花粉的生活力、萌发率、坐果率、花粉管生长和受精过程进行了观察和测定. 通过研究发现,连翘的花期较长且花期集中,长花柱连翘花期为27d,短花柱连翘花期为32d.两种花柱类型连翘的初花期、盛花期不遇,但末花期和谢花期完全相遇,末花期共有15d相遇.通过人工授粉试验可知,连翘自花授粉结实率极低,以异花授粉结实为主,并且柱头的有效授粉期较长,从开花前2d至花后15d均可接受花粉并受精结实,且授粉结实率均达到60%以上,属兼性异交植物. 两种花柱类型的连翘花粉均为长椭圆形,花粉外壁纹饰为典型的网状雕纹,但短花柱连翘花粉的网眼内有颗粒,而长花柱连翘花粉的网眼内无颗粒,对连翘花粉生活力进行测定,短花柱连翘花粉的生活力明显高于长花柱连翘. 短花柱连翘和长花柱连翘花粉萌发的最适温度均为25℃,但连翘开花时的最高气温在15~20℃之间. 两种连翘花粉均在15%蔗糖+400 mg.L-1硼酸培养基上萌发率最高且花粉管最长.其中,长花柱连翘花粉萌发率为28.8%,短花柱连翘花粉萌发率为61.1%,花粉管长度前者为133.50μm,后者为172.50μm. 植物生长调节物质对连翘花粉的影响较大.10~25 mg.L-1萘乙酸、300~500 mg.L-1赤霉素、10~25 mg.L-1吲哚乙酸、10 mg.L-12,4-D对长花柱连翘花粉的萌发率和花粉管伸长均有促进作用,而以上药剂只有25 mg.L-1的吲哚乙酸对短花柱连翘花粉的萌发和花粉管的伸长具有促进作用,其余药剂均对短花柱连翘花粉的萌发和花粉管的生长起抑制作用. 长花柱连翘自花授粉后,有少量花粉管进入花柱内,但向下生长速度缓慢,最后在花柱中停止生长;短花柱连翘自花授粉后,花粉管生长缓慢,最后只有极少数胚珠受精,但授粉后21d胎座干枯死亡,胚珠受精失败.而连翘异花授粉后168h,花粉管进入胚珠,进入胚囊释放精细胞和内容物的时间却是在授粉后18d. 连翘花粉寿命较短,开花后7d两种连翘花粉均失去活力. 所以,在连翘种植过程中应将两种花柱类型的连翘植株混栽,并且在盛花期和末花初期进行异花授粉,提高连翘产量.
英文摘要: To identify the reasons for low yield and medicinal materials poor quality in Forsythia suspensa, both long style type and short style type Forsythia suspensa used as basic material in this paper, the pollen size, shape, surface sculpture, viability, germination rate, setting percentage , pollination and fertilization process were observed and determination by the Scanning Electron Microscope, TTC stainning, culture in vitro, cross pollination, fluorescence microscopy and paraffin section technology. The main results are showed that:Florescence is longer and concentration, which florescence is 27days for long style type Forsythia suspensa and florescence is 32 days for short style type Forsythia suspensa. Initial bloom stage and full bloom stage not encounter, but initial bloom stage and drop bloom stage encounter, initial bloom stage have 15 days encounter between two types of Forsythia suspensa. It main taking crossing pollination, but seed setting rate is very with self-pollination.Stagma have longer effective pollination period, from pre-flowering 2 days to blooming 15days all maybe seed setting and pollination seed setting rate is over 60%,belong to facultative outcrossing plant.Both pollen shape were long ellipse, the exine ornamentation were typical network sculpture; but in short style type Forsythia suspense mesh have particle and long style type Forsythia suspense.mesh have not particle. Pollen viability of short style type Forsythia suspense was obvious higher than long style type Forsythia suspense.Pollen germination optimum temperature is 25℃between two types of Forsythia suspensa.But flowering temperature is 15~20℃.There have longest germination rate and longest pollen tube between two style type pollen in Forsythia suspense with 15%sucrose + 400 mg.L-1boric acid medium, which germination rate of long style type pollen is 28.8%and germination rate of short style type pollen is 61.1%.Pollen were effect between two style type pollen in Forsythia suspense with plant growth regulator. Pollen germination and pollen tube growth was promoted with 0~25 mg.L-1 naphthylacetic acid, 300~500 mg.L-1gibberellin, 10~25 mg.L-1 indoleacetic acid, 10 mg.L-12,4-D in long style type Forsythia suspense, but only 25 mg.L-1 indoleacetic acid promote pollen germination and pollen tube growth for short style type Forsythia suspense, the other plant growth regulator inhibit pollen germination and pollen tube growth for short style type Forsythia suspen.Alitte pollen tube enter stylar canal, but growth seep slowly, stopping growing in stylar canal. Self-pollination in short style type Forsythia suspense, pollen tube growth slowly, only a little ovule fertilizationed, but placenta withered died after pollination 21 day, ovule fertilization failed. But out crossing pollination, pollen tube enter ovule in 168 hours, release sperm cell and nutrient in ovule was after pollination 18 days.Pollen life is shorter in Forsythia suspen, pollen lost viability in blooming 7 days between two style type pollen in Forsythia suspense.So we shoud mixing planting between two style type pollen in Forsythia suspense, outcrossing pollination in full bloom stage and initial bloom stage, increase yield.