彩葉芋微體繁殖再生個體之變異以及葉片形質之安定性

The Variation and the Hereditary Stability on Leaf Character of Plantlets Regenerated from Micropropagation in Caladiums

9個彩葉芋廣葉品種及4個狹葉品種的葉片培養再生個體中，出現了葉色及葉形的變異。葉色之變異可分為葉脈色的變異及斑紋色的變異，其中葉脈色的變異為葉脈由白色、紅色或粉紅色轉變為綠色，該種變異在培養的13個品種中有8個以很高的變異率出現，'Ms.Muffer'的變異率高達79.8%、最低的'GingerLand'變異率亦達14.9%。斑紋色的變異為斑紋由粉紅色或紅色轉變為白色，其變異在培養的13個品種中只有'Pink Cloud'及'C.R.5'2個品種出現，變異率分別只有1.3%及2.5%。在葉形的變異方面，出現了圓厚葉及狹長葉2種變異。圓厚葉的變異在廣葉品種中有8個、狹葉品種只觀察到1個，其變異率不高、最高的'CandidumJr.'只有5.5%;而狹長葉的變異只在狹葉品種的'Rosary'及WhiteWing'中觀察到、變異率分別為1.2%及0.7%。在變異性狀的安定性方面，綠色葉脈變異個體、白色斑紋色變異個體、圓厚葉或狹長葉變異個體作為培植體，再度進行葉片培養時，再生個體的以上變異性狀完全與培植體相同、並未改變。但是，在'PinkCloud'的白色斑紋色變異個體以及'Rosary'的狹長葉變異個體由來的再生個體中，卻再度出現了綠色葉脈的變異。在綠色葉脈變異率之變動方面，以'Pink Cloud為例，變異率因培植體的不同而改變，較後展開的葉片其再生個體的變異率較高，且同一枚葉片的粉紅色部位較綠色部位之再生個體的變異率高，而以莖頂為培植體時再生個體中未觀察到任何綠色葉脈的變異。

Expanding leaves of caladium were cultured on MS containing BA and NAA medium from which multiple shoot primordia were obtained. The leaf color. variations in the plant lets regenerated from the multiple shoot primordia were very different among the thirteen cultivars. Leaf color variants were not observed in the plants regenerated from the multiple shoot primordia of 'Candid um Jr.','Aron','Freida Hemple', 'C.R.5', 'Kethleen', but they were observed with high frequency in those of'Tropicana','Pink Cloud', 'White Wing', 'Rosary' ,'Ginger Land', 'Fire Chir亡 'White Queen',ru1d'Ms. Muffer'. All leaf color variants in the regenerated plants changed from the white or red veins to the green. The variants of blotch color were obtained from in vilro leaf blade culture of 'Pink Cloud' and'C.R.5', and the variation of color in central interveinal areas changed from pink into red or white. At the same time, the variants of leaf shape were also obtained , and the variations of leaf shape were the leaf changed into round or slender shapes respectively in different varieties. The variation rates of these leaf colors and shapes were 0.7-5.5% lower. Furthermore, the variants of these leaf colors or shapes were recultured with in vilro leaf blade, there were no variations observed again in plantlets. As a results, the variations of these colors and shapes were stable. On the other hand, the variations of color in green vein occured with high frequency in'Pink Cloud'and'Rosary', and then the blotch color variants of'Pink Cloud' or the leaf shape variants of 'Pink Cloud' and 'Rosary' were recultured with in vilro leaf blade, the variations of color in green vein were observed again. So that, the variation of color in green vein in caladium were very unstable. The green leaf vein color variation frequency was correlated with the age of the explants. There were no green leaf vein variation in plantlets derived from the shoot tips of'Pink Cloud'.