Studies on pollen morphology and activity, fruit growth of pitaya(Hylocereus undatus Britt. & rose)

• Main Authors: Chin-Mei Cheng, 鄭金梅
• Other Authors: Shen-wei Weng
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/00993080328365042399

碩士 === 國立中興大學 === 園藝學系 === 88 === Pollen of dragon fruit (Pitaya, Hylocereus undatus Britt. & Rose)was oval shaped with three colporate. Tropic face and polar face of pollen was flatted round and round shape, respectively. Small needle like obstacle within small holes were found on pollen surface. No significant difference was found on pollen morphology of red and white flesh dragon fruit. The best medium condition for dragon fruit pollen germination in vitro on sugar concentration, pH value, boric concentration, Ca concentration, and germination temperature were 25%, pH 5-6, 100 ppm, 100 ppm, and 25-30℃, respectively. Pollen germination percentage decreased as storage period increased under room temperature. Pollen germination of dragon fruit cv. ''DR3'' and ''Vietnam White Flesh'' loss 24 hours and 36 hours after anthesis. Pollen germination of ''DR3'' was far higher than that of ''Vietnam White Flesh'' in this study. This study was trying to understand the fruit development and fruit content change of white and red flesh dragon fruits(Pitaya, Hylocereus undatus Britt. & Rose) . Growth curve of two cultivars tend to be single sigmoid curve and very similar. As fruit growth more mature, the shape is rounder. During the mid stage of fruit development, change of soluble solid, acidity, and TSS/Acidity ratio in two cultivars was similar. However, change of fruit gravity and water of two cultivars were different. As white fruit grew larger, the fruit gravity increased and water content decreased three weeks after anthesis, increased thereafter. Fruit gravity of red flesh cultivar decreased during the early stage of fruit development, increased two weeks after anthesis. Water content of red flesh cultivar increased as fruit grew further. Fruit width, fruit weight, fruit volume, soluble solid, and starch content of mature red and white flesh dragon fruit were not different significantly. Fruit length, fruit shape index, fruit firmness, fruit peel weight, and seed number of white flesh cultivar were larger than that of red flesh cultivar. Fruit gravity, fruit water content, total soluble solid of red flesh cultivar were higher than that of white flesh cultivar. Main soluble solid of white and red flesh dragon fruit were reduction sugar and non-reduction sugar, respectively. As seed number increased, fruit weight increased within the cultivar.