Lo K H, Giles K L, Sawhney V K
Department of Horticulture Science, University of Saskatchewan, 51 Campus Drive, S7N 5A8, Saskatoon SK, Canada.
Department of Biology, University of Saskatchewan, 112 Science Place, S7N 5E2, Saskatoon SK, Canada.
Plant Cell Rep. 1997 Mar;16(6):416-420. doi: 10.1007/BF01146785.
Leaf discs fromSaintpaulia ionantha xconfusa hybrids (African violet) were transferred between basal medium (BM) containing no hormones and shoot-inducing medium (SIM) containing 2.0 mg 1 indole acetic acid and 0.08 mg l 6-benzylaminopurine to determine whether there is a "window" of competence for shoot regeneration. Leaf discs precultured on BM prior to transfer to SIM formed buds 3 days earlier than the controls (leaf discs not precultured) regardless of whether the discs were placed upside down or right side up on the medium. This suggests that cultured leaf cells were not competent for shoot induction during the first 3 days of culture. Leaf discs cultured right side up (abaxial surface to the medium) did not form buds on BM alone, unlike discs cultured upside down. Leaf disc survival was affected by a delay in hormonal exposure, but surviving leaf discs produced as many shoots as control leaf discs. This suggests that in the absence of exogenous plant hormones, cellular competence to regenerate shoots is not lost in excised leaf discs of African violet.
将非洲紫罗兰（Saintpaulia ionantha x confusa杂种）的叶片圆盘在不含激素的基础培养基（BM）和含有2.0毫克/升吲哚乙酸和0.08毫克/升6-苄基腺嘌呤的芽诱导培养基（SIM）之间转移，以确定芽再生是否存在“感受态窗口”。转移到SIM之前在BM上预培养的叶片圆盘比对照（未预培养的叶片圆盘）提前3天形成芽，无论圆盘是倒置还是正放在培养基上。这表明培养的叶细胞在培养的前3天没有芽诱导能力。与倒置培养的圆盘不同，正放（背面接触培养基）培养的叶片圆盘在单独的BM上不形成芽。激素暴露延迟会影响叶片圆盘的存活，但存活的叶片圆盘产生的芽与对照叶片圆盘一样多。这表明在没有外源植物激素的情况下，非洲紫罗兰离体叶片圆盘中再生芽的细胞能力不会丧失。
