Gu X F, Yang A F, Meng H, Zhang J R
School of Life Science, Shandong University, 27 Shanda Nanlu, Jinan 250100, People's Republic of China.
Plant Cell Rep. 2005 Dec;24(11):671-6. doi: 10.1007/s00299-005-0017-1. Epub 2005 Aug 11.
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.
通过秋水仙素离体处理获得了沾化冬枣四倍体植株。将离体培养植株的茎尖在含有五种不同浓度秋水仙素（0.01%、0.03%、0.05%、0.1%、0.3%）的液体MS培养基（Murashige和Skoog，1962）中处理，并分别在25℃黑暗条件下以100转/分钟的速度振荡24、48、72或96小时。通过流式细胞术测定，使用0.05%秋水仙素（处理48小时、72小时）和0.1%秋水仙素（处理24小时、48小时）处理可获得频率超过3%的四倍体。细胞学和形态学证据证实了流式细胞术分析的结果。二倍体植株的染色体数为24，四倍体植株的染色体数为48。四倍体植株的气孔尺寸显著大于二倍体植株，而气孔频率显著降低。同样，四倍体植株保卫细胞中的叶绿体数量显著增加。将筛选出的四倍体植株嫁接到沾化冬枣成年树上，结果显示其茎更粗，叶片更圆且多汁，花朵更大，花期比二倍体植株延迟（3 - 4天）。
