变叶海棠(Malus toringoides)x陇东海棠(M.kansuensis)研究

A STUDY ON THE HYBRID SEEDLINGS OF MALUS TORINGOIDES X M.KANSUENSIS

对兼性无融合生殖种变叶海棠(3x)和陇东海棠(2x)的杂种实生苗进行了鉴别和矮化效应预测。结果表明,4x 杂种苗占65.2%,3x 母体苗占34.8%。杂种苗的酶谱可分为偏母型、互补型和突变型。互补型酶谱杂种苗的平均根皮率和叶片过氧化物酶活性显著高于偏母型酶谱杂种苗。选出的7株杂种单株,酶谱均属于互补型或突变型,表明陇东海棠的特征酶带20和21与其矮化效应有关。利用过氧化物酶同工酶谱可对该组合杂种苗的矮化效应作初步预测。

The somatic chromosome number and karyotype of the hybrid seedlings of the apomicticspecies Malus toringoides(3x)with M.kansuensis(2x)were investigated.Of the seedlings tested 34.8% proved to be 3x apomicts and 65.2% were 4x hybrids,their leaf characters being differentfrom each other.Leaf isoperoxidase banding patterns of the hybrids appeared to be of three ge(?)-types:maternal(Ⅰ),complementary(Ⅱ)and mutational(Ⅲ).The root bark/wood ratiosand leaf peroxidase activity of the hybrids of banding pattern Ⅱ were higher than those of the hy-brids of banding pattern Ⅰ.Seven hybrid seedlings of banding patterns Ⅱ and Ⅲ were predictedto be of great dwarfing potential according to their bark/wood ratios,leaf peroxidase activity andshoot internode length.Isoperoxidase bands 20 and 21 were presumed to be related to the dwarfingpotential.Hence,the dwarfing potential of hybrid seedlings might be predicted by their isoperoxi-dase banding patterns.