攀附性仙人掌果品系分類、開花著果習性與修剪

Abstract

本研究調查攀附性仙人掌果品系特性、開花結實習性以及探討修剪反應。台灣栽培的攀附性仙人掌果(Selenicereus和Hylocereus)種類與品系繁多，目前並無固定的分類方式。試驗針對42栽培種及品系的形態特徵進行研究。結果顯示可用肉質莖形態、刺座特徵、花器構造與果肉顏色等做為品系鑑定與分類的依據。依照上述標準，初步制訂42品系的檢索表，包括Selenicereus 和Hylocereus分別為3及39栽培種或品系。 為了發展新興仙人掌果樹，調查黃龍果(Selenicereus megalanthus) 物候期及果實品質。於冬季及春季抽梢，於春末至秋季開花。開花枝佔每植栽柱總肉質莖的60%。於七月前，所有開花枝皆源自非當季肉質莖，當季肉質莖需遲至七月才轉變成開花枝。黑色種子數與果重呈正相關(r2=0.87)。冬季果實的大小、重量、果肉率及總 可溶性固型物皆顯著高於夏季果。 為探討紅龍果白肉品系疏刪及短截修剪的反應。11月及12月疏刪肉質莖，可提早萌發營養梢且提高當季與非當季肉質莖轉變成開花枝的比率，但不影響花芽初萌日期。於6月份肉質經短截至30、60、90及120公分。肉質莖長度保留120公分者，可提早且提高肉質莖轉變成開花枝的比率。於2月份依肉質莖原始長度短截掉10%、25%、50%及75%。於萌花初期，隨著短截程度增加，當季與非當季肉質莖萌梢枝的比例也增加，然而肉質莖轉變成開花枝的比例則下降。當季肉質莖10%短截可提早形成花芽。當季肉質莖於1月、2月、3月及4月，依其原始長度短截10%。於1月、2月及3月短截者可提早且提高肉質莖轉成開花枝的比率。本研究結果建議，不同的修剪類型，可用來調節紅龍果白肉品系的營養及生殖生長。

Taxonomy base on morphology of different lines, flowering and fruiting Characteristics of yellow pitaya (Selenicereus megalanthus), and pruning responses of climbing cactus were studied. Many cultivars (cv.) or lines of climbing cactus, Selenicereus and Hylocereus, not yet identified and classified, are cultivated in Taiwan for fruit production. The characteristics of plant of 42 cultivars (cv). or lines were studied. The morphology of cladodes, characters of areoles and spines, structure of floral organs and color of fruit fleshes can be used for identification and taxonomy. Based on the above criteria, keys are built and a preliminary synopsis for 42cv. or lines, including 3 of Selenicereus and 39 of Hylocereus is provided. As a new cactus fruit in Taiwan, the phenology and fruit quality of yellow pitaya were studied. Vegetative growth occurred in the winter and spring seasons, whereas flowering occurred between the end of spring and autumn. On average each single-pillar trellis had 60% of flowering cladodes. All flowering cladodes were derived from non-current cladode before July. Current cladode did not have flower until July. The number of black seeds has a positive correlation with the fruit weight (r2=0.87). The size, weight, the percentage of pulp and total soluble solid content of winter crop were significantly higher than those of summer crop. Responses of heading-back and thinning-out pruning on white pitaya (Hylocereus undatus) were studied in the commercial orchard. Cladodes thinned-out in November or December had earlier vegetative-bud sprouting and higher percentage of their transformation into flowering cladodes, either current or non-current ones, although their initial flowering dates were not differ from the unthinned ones. Cladodes were headed-back in June to 30, 60, 90, or 120 cm of length. Those retained 120 cm of length had the earliest initial flowering and the highest percentage of transforming into flowering cladodes. Cladodes were headed-back 10%, 25%, 50%, and 75% of their original length in February. During the initial flowering period, the current or non-current cladodes retained as vegetative increased whereas their transformation into flowering cladodes decreased with increasing severity of pruning. Cladodes with 10% of heading-back length had earlier formation of flower buds. Current cladodes were headed-back 10% of their original length during January, February, March, and April. Those pruned in January, February, and March showed earlier initial flowering and higher percentage of transforming into flowering cladodes. The results suggested that different types of pruning can be used for manipulating vegetative and reproductive growth of white pitaya.