Propagation of Ornamental Plants
23(4): 107-117, 2023
PHOTOSYNTHETIC PHOTON FLUX DENSITY AND PLANT GROWTH REGULATORS AFFECT SOMATIC EMBRYOGENESIS IN AGAPANTHUS PRAECOX WILLD. SUBSP. ORIENTALIS (F. M. LEIGHT.) F. M. LEIGHT.
Miao Wang1,2, Ruotong Liu1,3, Yan Dong4, Xinyi Wang1, Mengfan Liu1, Changmei Du1, and Jianhua Yue1*
1 School of Horticulture, Xinyang Agriculture and Forestry University, 1 Beihuan Road, Pingqiao District, 464100 Xinyang, China, *E-mail: jhyues@163.com 2 College of Horticulture, South China Agricultural University, 483 Wushan Road, Tianhe District, 510642 Guangzhou, China 3 College of Life Sciences, South China Agricultural University, 483 Wushan Road, Tianhe District, 510642 Guangzhou, China 4 School of Forestry, Xinyang Agriculture and Forestry University, 1 Beihuan Road, Pingqiao District, 464100 Xinyang, China
Callus was induced by using pedicel of Agapanthus praecox Willd. subsp. orientalis (F. M. Leight.) F. M. Leight. as explant, and then the effects of photosynthetic photon flux density (PPFD), auxin, paclobutrazol (PAC), and cytokinin (CTK) on the regeneration process of somatic embryogenesis were studied. The results showed that the requirement of proper PPFD in somatic embryogenesis was continuously enhanced. The reasonable PPFD for embryonic callus (EC) induction, somatic embryo (SE) induction, SE development, plantlet induction, and plantlet development were 0, 20, 20, 40, and 80 μmol m-2 s-1, respectively. The gibberellin (GA) biosynthesis inhibitor PAC showed no significant effect on EC induction, and the browning rate was higher under a PPFD of 20 μmol m-2 s-1 than in dark. The combination of 0.05 mg l-1 N-(1-naphthyl) phthalamic acid (NPA) and 0.05 mg l-1 PAC promoted SE induction. However, PAC showed an inhibitory effect on the development and maturation of SEs. The addition of 1.0 mg l-1 6-benzylaminopurine (BAP) and 0.1 mg l-1 α-naphthaleneacetic acid (NAA) to the medium promoted plantlet induction and development, respectively. This study optimized the application of PPFD and PGRs in the somatic embryogenesis of A. praecox, which can promote the regeneration efficiency of this species in vitro via somatic embryogenesis.
Key words: auxin, cytokinin, embryonic callus, plant regeneration, somatic embryo.
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