소핵을 가진 노란 화색의 이수성 호접란의 꽃가루 생식력 분석

Analyzing Pollen Fertility Based on Micronuclei Presence in Yellow Aneuploid Phalaenopsis

Interspecific hybridization has long been used to produce Phalaenopsis hybrids with superior traits such as flower size, color, lipmorphology, heavy pigmentation spots, spike number, plant height, floret number and size, inflorescence angle, and branching. For a successfulbreeding program, superior parents with desirable horticultural traits must be selected for hybridization based on market preferences. However,many existing hybrids produce triploids or aneuploids and are almost completely sterile. A database of the cytogenetic backgrounds of species andcultivars is essential for formulating systematic breeding programs. However, this information is limited to the Phalaenopsis cultivars. Therefore,chromosome composition, pollen viability, and meiotic abnormality of two Phalaenopsis yellow cultivars, namely Phalaenopsis ‘Fuller’s Sunset’and Phalaenopsis ‘Geumgongju,’ were analyzed in this study. Cytogenetic analyses revealed that both cultivars had hypotetraploid andasymmetrical chromosomes. Assessment of pollen viability using the 2,3,5-triphenyl tetrazolium chloride (TTC) staining test and in vitro pollengermination in five flower developmental stages demonstrated that P. ‘Fuller’s Sunset’ pollinia were viable because it were stained in all stageswith pollen tube growth. In contrast, unstained pollinia and the absence of pollen tubes were observed in P. ‘Geumgongju.’ Sporad stageanalysis showed that P. ‘Geumgongju’ contained predominantly abnormal sporads with micronuclei compared to those of P. ‘Fuller’s Sunset.’The results of this study provide vital information for breeding programs for Phalaenopsis cultivars and emphasize the importance of selectingappropriate parents for hybridization.