%A C. L. Lee and Chang Hsin-ying %T Studies on the Embryos of Pinus koraiensis Grown In Vitro I %0 Journal Article %D 1962 %J J Integr Plant Biol %R %P -${article.jieShuYe} %V 10 %N 2 %U {https://www.jipb.net/CN/abstract/article_25039.shtml} %8 %X Non-stratified mature seeds of Pinus koraiensis Sieb. et Zucc. were selected for culture in vitro. The megagametophytes were exposed and surface-sterilized with saturated bleaching powder. The embryos were excised aseptically and were grown on agar media in three ways: (1) with the radicle in agar, (2) with the cotyledons in agar, leaving the radicle free in the air, and (3) with both cotyledons and radicle in agar, i. e. the "doubletube culture". The embryos cultured by the last mentioned method displayed the greatest beneficial effect both on rate and duration of root growth. Investigation on the ability of the cotyledons in sucrose absorption was also attempted using four kinds of double-tube cultures: (1) with the upper tube containing 5% of sucrose, but none in the lower, (2) with the lower tube containing 5% of sucrose and none in the upper tube, (3) with both tubes containing 5% of sucrose, and (4) both without the sugar. No significant difference in embryonic growth in various culture tubes was detected in the first week. Subsequently, salient growth of the embryos with the cotyledons embedded in the 5% sucrose medium but the radicle inserted in the sucrosefree medium (ⅢA) was achieved by the second week.