Flowering biology and pollination requirement in red pitaya (Hylocereus spp.)

Abstract

This study explored the flowering biology and effects of pollination methods ((hand cross-, hand self-, automatic self-, and open-pollination) on fruit set, and fruit characteristics in 4 red pitaya (Hylocereus spp.) genotypes: [‘Vietnam White’ (‘VN-White’), ‘Chaozhou 5’, ‘Orejona’, and ‘F11’] in Pingtung, Taiwan. The fruit production season started from the beginning of May and ended at the beginning of September with 6-7 flowering cycles and 22-32 flowers/plant/year. The flowering duration took from 15-19 days and fruit duration spent around 30 -32 days. The relative location of anthers were lower than the stigma, except in ‘VN-White’. ‘VN-White’, fully self-compatible, obtained high fruit set rates (80.0 - 90.5%) in all pollination treatments and the maximum fruit weight (402.6 g) in hand self- and (403.4 g) in open-pollination. ‘Chaozhou 5’ was partially self-compatible while ‘Orejona’ and ‘F11’ were completely self-incompatible. Hand cross-pollination significantly increased fruit set and fruit weight in ‘Chaozhou 5’, ‘Orejona’ and ‘F11’. Total soluble solid (TSS) content was not influenced by pollination methods. 本研究探討四個紅龍果基因型在屏東的開花生物學及授粉方法(人工雜交、自交、自然自交及開放授粉)對著果及果實性狀之影響。其開花期約在5月初至9月初之間，每年每株有6-7批花以及22-32朵花。花苞孕育期約15-19天，而果實生長期約30-32天。除了｀越南白肉´之外，其它品種花藥的相 對位置均低於柱頭。完全自交親和之‘越南白肉’在所有授粉處理中均有高的著果率(80.0 – 90.5%)，且在人工自交及開放授粉下有最大果重。｀潮州5號´為部分自交親和，而｀Orejona´及｀F11´為完全自交不親和。人工雜交授粉顯著增加｀潮州5號´、｀Orejona´及｀F11´之著果率。授粉處理對果肉 可溶性固形物並無顯著影響。