Dịch bài viết sau ra tiếng Việt (tiếng Anh chuyên ngành sinh học)

(Wang et al., 1997), but reports on fruiting and seed set were lacking. The present study offered another regenerative system for In vitro flowering, which allowed the formation of multiple shoots, flowering plantlets, and fertile seed production. This reproductive system might play an important role in orchid breeding because shoot-tip explants can be easily obtained. The cytokinin requirement for the growth and development of flower buds has been reported in several plants (Heylen & Vendrig, 1988; Huang et al., 1999; Zhang, 2007), and BA was found to be effective for early floral induction in orchids (Chang & Chang, 2003; Wang et al., 1997; Sim et al., 2007). However, TDZ has been considered to be more potent than most of the commonly used cytokinins (Sajid & Aftab, 2009; Naz et al., 2009). The importance of TDZ for In vitro flower induction has been reported in D. nobile and Cymbidium ensifolium, where TDZ had a stronger flower-inducing effect than BA (Chang & Chang, 2003; Wang et al., 2009). The results in this study agreed with those findings. However, abnormal flowers occurred in the culture with higher TDZ concentrations (Table 2), so the cytokinins may influence a delicate regulative system in floral development. Some genes controlling shoot apical meristem activity may be related to floral regulation (Lindsay et al., 2006). The cultures with optimal BA and TDZ concentrations produced normal flowers; these flowers resembled the flowers of field-grown plants and had complete structures. However, the In vitro plantlets produced fewer and smaller inflorescences than thefield-grown plants (Table 2). This could be due to the smaller size of the In vitro plantlets, since reproductive output may be affected by plant size (Sletvold, 2002). The morphology of pollen and female organs in the In vitro flowers was normal. The morphological and anatomical examination showed that a normal column