秋水仙素处理桑树杂种实生苗诱导四倍体植株的研究

应用秋水仙素处理桑杂种实生苗诱导获得四倍体植株56份,诱导率为4.28％。试验结果表明,浓度0.2％的药液,处理2天即可;处理时期以5月和10月效果较优,经处理后的幼苗,一个半月后,苗株生长出现四个形态类型:(1)生长点分裂,出现顶端两枝同步生长。(2)叶片仍绉缩变型。(3)茎粗、节密或侧枝早发。(4)枝叶正形生长。从四个形态类型中选择叶肉厚、手感粗糙、生长势强的单株。经培育后抽样镜检,于处理当代选株中获得四倍体株达68—85％。其中出现于第一类型占33.73％,第二类型占41.07％,第三类型占1.79％,第四类型占23.21％,我们重视从四个类型中选择,对提高诱导率是有实用意义的。

STUDIES ON INDUCTION OF HYBRID MULBERRY SEEDLINGS TO TETRAPLOID PLANTS BY USING COLCHICINE

56 steins of mulberry tetraploid were obtained by treating the hybrids of mulberry plants with colchicine, and the induction rate was 4.28%. This is the first time for obtaining tetraploid of the Guangdong mulberry. The results of the experiment were as follows: 1. The plants were treated with the colchicine solution with 0.2% concentration, two days were sufficient for the time for treatment. 2. The most suitable time for treatment using the chemical was in May and October. 3. After one and a half month treatment of colchicine, according to the growth appearance of the plants 4 different types of the plants were obtained: (1) The cone of the growth of the plant was divided into two parts, which grew out to be two terminal branches synchronously. (2) The leaf blades of plants shrunk and deformed. (3)The stems of the plants were large in size, with short internodes and the lateral branches grew out early. (4) Stems and leaves of the plant grew normally. From all of the above mentioned plants, some indivdual plants with thick leaf blade, leaf surface felling rough by hand, and with vigorous growth, were selected and cultured; samples were then selected from them at random for examination under microscope, 68-85% of them belonging to tetreploids were found among the most recently Selected, treated plants, among which the first type accounted for 33.73%, the second type 41.07%, the third 1.79%,and the fourth 23.21%. We stress the selection undertaken from all four types, becuse it has the pranctical significance in enhancing the induction rate.