| 摘要註: |
現今蝴蝶蘭栽培種在經過數十年不斷的相互雜交後,染色體情況相當的複雜。一般的栽培業者在進行交配時,在親本的染色體資訊不明的情況下,因此時常會有具有優良性狀的親本在授粉後,無法正常產生果莢,或者是果莢中種子數目較少等情況。因此本實驗首先對目前市場上常用來做為親本的栽培種蝴蝶蘭進行其基因組組成與核DNA含量的分析,推估出市場上栽培種蝴蝶蘭的染色體狀況。接著分析上述一些栽培種間互相雜交後之第一子代(F1)的園藝性狀與核DNA含量,希望可以得到其遺傳關連性。在得到上述的資訊後,可以得知某些品種因染色體異常,而不容易產生配子。為了能使染色體異常之異源倍體雜交種得以產生正常配子,因此利用了蝴蝶蘭的核內細胞分裂(Endomitosis)現象,希望能使異源三倍體雜交種經過染色體倍加後成為同質異源六倍體(Autoallohexaploid)。在進行倍加實驗時,本研究使用了染色體狀況為三倍體(Triploidy)且核內同時具有大型與小型染色體的朵麗蝶蘭滿天紅(Dtps. Queen beer)作為實驗材料,並且設計了兩個實驗的方法:1.將擬原球體(Protocorm Like Body, PLB)進行橫切,誘導產生多倍化PLB; 2.以葉片與根部誘導產生多倍化之PLB,希望可以得到能正常產生配子之同質異源六倍體。欲了解經過了染色體的倍加後,同質異源六倍體的植株生長狀況與性狀是否會與異源三倍體時有所差異,因此對本實驗室先前所誘導出的同質異源六倍體蝴蝶蘭栽培種-婚宴(P. Wedding Promenade)做生長狀況調查,希望可以了解染色體倍加對植株的影響。依照花色與大小的不同,將蝴蝶蘭栽培種分為九個不同的群組,並分析完栽培種基因組中所包含的原生種百分比後,發現在不同分類中所包含的原生種種類皆有所不同。在同一分類中所包含的原生種種類則大多相似,而且同一分類中不同栽培種的基因組中不同原生種所占的百分比例都極為相似。在基因組組成分析方面,大型花分類大多為四倍體,中型花、黃色花與小丑花則倍數體較不穩定,較常出現三倍體或非整數倍體(aneuploidy)。在十個不同的雜交組合中,利用了染色體推估後發現,親本為二倍或四倍體之植株在進行交配時,大多能產生健康之果莢。若親本為三倍體或非整數體者,果莢的產生則較不健康,而種子之數目較少且生長不易。同質異源六倍體誘導的結果顯示,朵麗蝶蘭滿天紅的葉片與根部相較於其他品種較不易產生擬原球體。擬原球體之橫切則能順利產生出六倍體,且隨著橫切次數的增加,多倍性植株的比例也會上升。同質異源六倍體婚宴的調查結果顯示,與三倍體植株相比,六倍體植株生長狀況較為不穩定,植株大小差異相當大,同樣株齡之三倍體植株大小全數栽種於3.5吋盆中,而六倍體則以生長狀況優劣分別栽種於3.5吋、2.5吋與1.5吋中。此調查結果與前人在其它植物的研究是相符的,即多倍化後的植株大多生長會較為緩慢之結果。 In nowadays, Phalaenopsis cultivars undergo cross over continuously for dozens of years, the genomic constitution is fairly complex. General breeders always make cross using parents with good characteristics in the parental genome information unknown circumstances. It usually can't produce healthy capsules, or seeds in a large number after pollination. Therefore, this study uses the popular cultivars to analyze their genomic constitution of wild species and nuclear DNA content. In addition, some cultivars with their first offspring (F1) were analyzed on their horticultural traits and nuclear DNA content, hoping to get their genetic relation. After obtaining the above information, we can know some of the cultivars due to chromosomal abnormalities, resulted in the difficulty of normal gametes development. An autopolyploidy was made for using tissue culture technology with endomitosis phenomenon for doubling chromosome in Phalaenopsis. In chromosome doubling experiments, a triploid cultivar which have large and small chromosomes called Doritaenopsis Queen Beer was used as experimental material. Two experimented methods were tested as follow: 1. autoallohexaploid induced by horizontal sectioning of protocorm like bodies (PLBs); 2. autoallohexaploid induced by sectioning leaf and roots. In addition, An autoallohexaploid cultivar “P. Wedding Promenade” which induced by our laboratory was also investigated to observe the growth traits. Based on the different color and size of Phalaenopsis cultivars, nine different groups were assigned for analyzing the genomic constitution of the wild species and their nuclear DNA content. Different groups always contain different species constitutions. In the same group, cultivars usually contain similar species constitution and the similar percentage of species contribution. In the analysis of genomic constitution, large flower groups mostly tetraploid, medium-sized flower, yellow flower and harlequin flower groups have more unstable ploidy, more frequently triploid or aneuploid. In 10 different cross combinations, undergoing analysis of the genomic constitution it was found that parents with tetraploid or diploid were usually able to produce healthy capsules. If the one of parents is triploid or aneuploid, capsules usually had less healthy, only a small number of seeds. In autoallohexaploid induced experiment, it showed leaf and roots from Dtps. Queen Beer compared to other cultivars are more difficult to induce PLBs. Polyploidy induced by horizontal section of PLBs create autoallohexaploidy successfully, and the increase of the number of horizontal sectioning, the proportion of autoallohexaploidy will also increase. In observing the growth traits experiment, hexoploid plants are more instability in growth rate, significant differences in plant size. The same growth stage of the clones, the triploid plants grow in 3.5 inch pot, while hexoploid plants grow in 3.5 inch, 2.5 inch and 1.5 inch, respectively. The results of this survey is similar to previous studies in other plants, polyploid plants always have slower growth rate. |