Osmotic potential intensity in the control of direct somatic embryogenesis in coffee tree

Abstract The objective of this work was to characterize the effect of the osmotic potential of the culture medium on the control of direct somatic embryogenesis in coffee (Coffea arabica) tree. Leaf explants of the Mundo Novo cultivar and four hybrids were subjected to the direct route in the presence of polyethylene glycol 6000, at the following concentrations: 0, 2.5, 5.0, 7.5, 10.0, 12.5, and 15.0%. Embryogenic structures and somatic embryos were formed at a threshold osmotic potential of up to -0.691 and -0.374 MPa, respectively, with a reduction or inhibition in these responses under a more negative osmotic potential.摘要 本研究旨在明确培养基渗透势对咖啡（Coffea arabica）直接体细胞胚胎发生的调控效应。以Mundo Novo品种的叶片外植体及4个咖啡杂交品种为试材，采用直接体细胞胚胎发生途径，添加浓度分别为0、2.5、5.0、7.5、10.0、12.5%与15.0%的聚乙二醇6000（polyethylene glycol 6000）进行处理。结果显示，胚性结构与体细胞胚胎分别在渗透势阈值达-0.691 MPa与-0.374 MPa时形成；当渗透势更负时，上述响应会出现降低或被完全抑制。