不同倍性白魔芋植株的细胞学形态观察与核型分析

Cytomorphological Observation and Karyotype Analysis of Amorphophallus albus Plants with Different Polyploidy

采用种子浸泡法、根状茎生长点滴液法和离体不定芽混培法3种途径诱导白魔芋四倍体植株,并对二倍体和四倍体植株外部形态、叶片气孔特征和核型进行分析比较.结果表明,与二倍体植株相比,四倍体植株叶片明显变宽、叶形指数变小,叶柄粗短,叶片下表皮气孔及其保卫细胞体积变大、密度减小.植株外部形态特征变异和叶片下表皮气孔密度变小等特征可作为鉴定变异材料的间接方法,四倍体和二倍体均为"2B"核型,可认为四倍体是由二倍体经秋水仙素诱导直接加倍产生的同源四倍体.

Three methods, i.e. seed soaking, liquid turing in vitro, were adopted to induce tetraploidy stoma characteristics and karyotypes of the diploid dropping on apical buds of rhizomes and shoot co-culin Amorphophallus albus, and the morphology, leaf and tetraploid plants of A. albus were analyzed and compared. The results showed that compared with their diploid counter broader and thicker leaves, smaller leaf index, shorter but thicker petio parts les bi the tetraploid plants had leaf gger and less dense and bigger stomata and guard-cells on the epidermis. Both morphological characteristics and stoma density can be used as important ondicators in the identification of polyploids in variant population. Both diploids and tetraploids were found to he of Type 2B, thus suggesting that the tetraploid plants induced by colchieine were the autotetraploids derived directly from the diploids of A. albus.