title: In vitro induction of tetraploid plants from diploid Zizyphus jujuba Mill. cv. Zhanhua.
abstract: Tetraploid plants of Zizyphus jujuba Mill. cv. Zhanhua were obtained with in vitro colchicine treatment. Shoot tips from in vitro-grown plants were treated with five different concentrations of colchicine (0.01, 0.03, 0.05, 0.1, 0.3%) in liquid MS medium (Murashige and Skoog 1962), and shaken (100 rpm) at 25 degrees C in darkness for 24, 48, 72 or 96 h, respectively. Tetraploids were obtained at a frequency of over 3% by using 0.05% colchicine (48 h, 72 h) and 0.1% colchicine (24 h, 48 h) treatment as determined by flow cytometry. Cytological and morphological evidence confirmed the results of flow cytometric analysis. The chromosome number of diploid plants was 24 and that of tetraploid plants was 48. The stomata sizes of tetraploid plants were significantly larger than those of diploid plants, while the frequency of stomata were reduced significantly. Similarly, the chloroplast number of guard cells of tetraploid plants increased significantly. The selected tetraploid plants were grafted onto mature trees of Z. jujuba Mill. cv. Zhanhua in the field, resulted in thicker stems, rounder and succulent leaves, larger flowers and a delay in florescence time (3-4 days later) than diploid plants.
authors.affiliation: School of Life Science, Shandong University, 27 Shanda Nanlu, Jinan 250100, People's Republic of China.
authors.forename: X F
authors.initials: XF
authors.lastname: Gu
authors.forename: A F
authors.initials: AF
authors.lastname: Yang
authors.forename: H
authors.initials: H
authors.lastname: Meng
authors.forename: J R
authors.initials: JR
authors.lastname: Zhang
mesh_terms: D002467:Cell Nucleus; D002736:Chloroplasts; D003078:Colchicine / Q000494:pharmacology*; D004171:Diploidy; D005434:Flow Cytometry; D035264:Flowers / Q000033:anatomy & histology; D018515:Plant Leaves / Q000033:anatomy & histology / Q000187:drug effects; D018517:Plant Roots / Q000166:cytology; D011123:Polyploidy; D012038:Regeneration; D013534:Survival; D046509:Tissue Culture Techniques; D031957:Ziziphus / Q000033:anatomy & histology / Q000187:drug effects* / Q000235:genetics* / Q000502:physiology
chemical_list: D003078:Colchicine