根尖压片法制备树莓染色体标本的研究

以红泡刺藤(R.niveus)、栽秧泡(R.ellipticusvar.obcordatus)和插田泡(R.coreanus)绿枝或硬枝扦插生根的根尖为材料,通过取材时季与扦插环境气温,8-羟基喹啉、秋水仙素和对二氯苯3种药剂在不同的温度下预处理不同时间,混合酶液和盐酸在不同温度下解离,醋酸洋红、卡宝品红、席夫试剂和铁矾-苏木精各染色剂染色压片等的对比研究,并以细胞中有丝分裂中期分裂相的数目、染色体的清晰性、分散程度和聚缩程度以及染色体的形态为衡量指标,探索出适于树莓属植物核型分析的根尖压片方法是:当根尖长至1~2 cm、扦插环境气温17~23℃时取材,卡诺氏固定液I低温固定24 h,用0.002 mol/L 8-羟基喹啉在0~4℃下预处理24 h,再用1 mol/L HCl(60±1)℃恒温解离4~7 min,最后用卡宝品红染色压片能获得效果好树莓染色体标本,该染色体标本完全适用于核型分析。

Studies on Root-tip Squashing Method for Chromosome Preparation of Rubus L.

Using the root-tips of Rubus niveus,R.ellipticus var.obcordatus and R.coreanus as materials,the key factors,such as the sampling times and environmental temperatures when sampling materials,pretreatment agents(8-hydroxyquinoline,8-hydroxyquinoline plus colchicine and saturated p-dichlorobenzene),temperatures and times,dissociating agents(25 g/L cellulase plus 25 g/L pectic enzyme and hydrochloric acid),processes and times and staining agents(acetocarmine,carbol fuchsin,schiff' solution and ferriammonium sulfate-haematoxylin),and methods,which influences the preparation of chromosome,had been studied.Based on the contrasts of numbers of mitosis metaphase cells,the difficulty of techniques,the degree of treatment complications and the fact that chromosomes are distinct and countable from their background under microscope,the suitable root-tip squashing method for chromosome preparation of Rubus is as follows: sampling materials when the roots are 1～2 cm in length and the environrmental temperature is 17～23 ℃ and fixating with Carnoy's I,pretreating with 0.002 mol/L 8-hydroxyquinoline at 0～4 ℃ for 24 h,dissociating with 1 mol/L HCl at(60±1) ℃ for 4～7 m,and staining with carbol fuchsin solution.The chromosomes obtained by above preparation method could be used for karyotype analysis.