1、珊瑚樹生殖生物學、種子發芽與衰化之研究The Reproductive Biology, Seed Germination and Aging in Viburnum odoratissimum Ker研究生：張夢蘭 Chang, Meng-Lan指導教授：張焜標 Chang, Kun-Paio 【摘要】珊瑚樹為台灣之原生樹種，主要分佈在台灣南部如恆春半島一帶。花期主要於 11 月下旬至 4 月上旬；果期於 1 月下旬至 8 月上旬。花序為圓錐狀聚繖花序，花瓣單軸對稱，於苞片與花軸表面佈滿絨毛。花器始原發生順序為向頂性且呈輪狀排列。花藥壁之發育屬於雙子葉型，於花粉成熟時呈纖維化。營養層則為分泌
2、型。小孢子母細胞減數分裂後行同時型之胞質分裂，產生之四分體呈四面體形，外圍為胼胝質圍繞。花粉粒具三溝孔且表面為不規則之網紋。花柱為具傳導組織之閉合型。子房具 3 室，僅 1 室可發育為胚囊。胚珠為倒生型。珠心為薄珠心型，大孢子母細胞可產生直線型排列之大孢子四分體，為單孢子型。成熟胚囊具 1 個卵細胞、2 個助細胞與極核、3 至數個反足細胞，助細胞具有絲狀器，且於受精後便完全消失。成熟胚屬於棒狀之雛形胚，需進行後熟作用以促進發芽。胚乳為細胞型胚乳，並具有胚乳腔。果實為核果，於發育過程中，各部位之生長類型為單 S 型，澱粉與還原糖之儲藏物質隨發育時間而逐漸增加，蛋白質則隨發育時間逐漸減少，油脂之含
3、量於整個發育過程之初期逐漸減少，至發育中後期則又逐漸增加。種子呈勺狀中間具凹溝，內部含有豐富的胚乳。珊瑚樹種子於 4、10、15、20 與 20/25 進行層積，其種子之發芽率隨儲藏時間的增加而逐漸提高且發芽時間亦隨之下降，在 25 與 25/30之層積儲藏效果較差。其中種子以 10、15 與20層積 6 週後，種子於層積期間已有發芽情況產生。種子經無光照之定溫與變溫處理進行發芽試驗，於 10、15 與 20 下種子之發芽率較高且與所需發芽時間較短。種子浸水於 4 種不同時間，其發芽率與平均發芽時間在各處理之間並無顯著差異存在。此外，種子經由衰化試驗，於 4 不同相對溼度儲藏 75 天後，種子
4、仍可維持 51.30-52.54之發芽率。以 42 與室溫（RT）於相對濕度 55分別儲藏 20 與 60 天後，發芽率降至 0。尤其以 42 不同相對濕度儲藏 45 天後，發芽能力全部喪失。種子含水率均隨不同儲藏之溫度與時間而減少，平均發芽時間與電導度值之變化於不同處理間均隨儲藏時間的增加而有增加。關鍵字：珊瑚樹、生殖生物學、發芽試驗、層積處理、種子衰化。【Abstract 】Viburnum odoratissimun (Caprifoliaceae) is an indigenous tree species to Taiwan. The species mainly distribut
5、es in the southern part of Taiwan. Flowers bloom between the late November to the early April. Fruit sets between the late January to the early August. Inflorescence is paniculate-cymose. Petal in corolla is arranged monosymmetry. The surface of bract and flower axis is cover with numerous trichomes
6、. Initiation order of floral primordia is centripetal or acropetal. The development of anther wall layers belongs to dicotyledonous type and anther wall showed fibrous when the pollen matured. Meanwhile the tapetum is secretory type. Microspore mother cell undertakes meiosis with cytokinesis simulta
7、neously to produce tetrahedral tetrads enclosed with callose wall. The mature pollen grains are tricoporate with irregular reticulate sculptures on the surface. The style with transmitting tissue is solid type. Ovary has three cells, only one cell is able to develop to embryo sac. The ovule is anatr
8、opous. Nucellus is tenuinucellate type. Megaspore mother cell produce tetra arranged linearly. It belongs to the monosporic type. Mature embryo sac has one egg cell, two synergids, two polar nuclei and three to several antipode cells. Synergids have filiform apparatus and would disappear after polli
9、nation. The mature embryo is belonged to rudimentary type and need after ripening to germinate. Endosperm appears as celluar type with endosperm cavity. The fruit is a drupe fruit. In the process of fruit development the growth pattern of different parts is all single S type. The storage material of
10、 starch and reducing sugar is increased with the developmental time. The protein content is reduced gradually with the developmental time. The oil content is reduced gradually at the early stage of development, however, increased at the middle and last stage. Spoon-shaped seed has a fillister in the
11、 middle part and contains abundant endosperm inside.The seeds of Viburnum odoratissimun are stratified and stored in the temperature of 4, 10, 15, 20, 25 and 20/25 condition separately. Germination rate increased with the increase of stratified storage time and the germination time decreased. The ef
12、fects of stratified storage in 25 and 20/25 are worse than the others. Among these treatments seeds stratified in 10, 15 and 20 for 6 weeks have been germinated during stratification. Germination test of seeds undergo a constant and alternative temperature in dark condition showed that in 10, 15 and
13、 20 all have higher germination rate and need shorter germination time. When seeds treated with 4 different immersing time the germination rate and germination time are not significantly different in the treatments. Additionally, the results of seeds tested by aging experiment showed that seeds stor
14、ed in different humidity at 4 for 75 days, the germination rate is maintained in the range of 51.30-52.54. When seeds stored in 55 humidity at 42 and room temperature for 20 and 60 days the germination rate decreased to 0. Especially when stored in different humidity at 42 for 45 days the germinatio
15、n capacity all lost. Water content in seeds decreased with the increase of different storage temperature and duration. The variation of mean germination time and the value of electronic conductive in different treatments increased with the increase of storage duration. Keywords：Viburnum odoratissimun, reproductive biology, germination test, stratified treatment, seed aging.
