香蕉組織培養植株之變異

Variation in Banana Plants Propagated Through Tissue Culture

木文報告香蕉組織培養苗在幼苗期及抽穗期變異發生情形及發生頻率。從調查30，000株經假植雨個月後的組織培養蕉苗發現有0.25%蕉苗葉片發生葉綠素變異，有0.12%蕉苗之葉片形狀異於正常株。在抽穗期調查46，260株所發現的變異性狀包括株高、葉形、假莖顏色、和果房性狀等四種變異型，其出現頻率分別是1.44%, 0.46%，0.11%和0.42%，其中以矮花變異之頻率1.39%為最高。速績經過三代種植觀察，除葉綠素變異株呈現不穩定之外，其餘變異特性都很穩定。在以傳統吸芽種植之蕉園調查40，000餘蕉株則未發現到任何變異株。本文並討論香蕉組織培養變異特性利用於黃葉病選種和改良香蕉品種之可行性。

This paper reports the nature and rate of variation occuring in banana plants derived from tissue culture of the variety Musa AAA ”Giant Cavendish”. Two types of variations. variegation and abnormal leaf shape, were recognized at young nursery plants stage. Among 30, 0 of two-month-old plants examined, about 0.25% of them were found with variegated leaves, and 0.12% with abnormal leaf shapes distinctively different from those of ordinary plants. In mature plants, four variant types were recognized differing from the ordinary plants in stature, leaf shape, pseudostem color, and bunch characters, and occurring in rate of 1.44, 0.46, 0.11, and 0.4%, respectively, in 46, 260 plants surveyed. Dwarf variant appeared to be the moat common with a variation rate of 1.39%. With the exception of variegated variant which is unstable, all other types ware preserved consistantly in three successive clonal generations. No variations ware detected among approximately 40,000 mature banana plants propagated from suckers, the conventional planting material. The potential use in screening for fusarial wilt resistance and for improvement in crop, character among tissue culture propagated plants is discussed.