风信子根尖预处理及核型分析

Pretreatment Reagents for Hyacinthus Root Tip and Karyotype Analysis

采用秋水仙素、8-羟基喹啉、放线菌酮3种试剂及秋水仙素与8-羟基喹啉的混合液、冰水混合物等,按不同时间梯度对风信子‘Pink Pearl’根尖进行预处理,以获得进行染色体分析的清晰制片,为风信子品种染色体分析及其微结构研究奠定基础。结果表明:‘Pink Pearl’根尖经5种预处理后,再经固定、解离、染色、压片均可获得分散良好、形态正常、易于计数并进行核型分析的高质量染色体制片。秋水仙素和8-羟基喹啉的最适预处理时间分别是12h、20h;放线菌酮、秋水仙素与8-羟基喹啉混合液、冰水混合物的最适预处理时间均是24h。染色体核型分析表明:风信子的核型公式为2n=2x=16=6m+4sm+2smsat+4st;核不对称系数为60.2%,为2C核型。

Hyacinth cultivar ‘Pink Pearl’ root tips were pretreated with five reagents including colchicine,8-hydroxyquinoline,cycloheximide,mixture of colchicine and 8-hydroxyquinoline and ice-water mixture by different time grads to obtain well dispersed chromosome.These results laid a foundation for the hyacinth chromosome analysis and fine structure researches.The results showed that after fixed with Carnoy fixative I,dissociated,dyed,squashed,the root tips pretreated with these 5 reagents all could be used in chromosomes preparation,which the chromosomes spreader well,given a normal form,and were easy for counting and karyotype analysis.The most favorable treated time for colchicine and 8-hydroxyquinoline was 12 h and 20 h,respectively;and for the other three reagents cycloheximide,mixture of colchicine and 8-hydroxyquinoline and ice-water mixture,the most favorable treated time was all 24 h.Hyacinth karyotype analysis was carried out with chromosome from root tip cells.The result showed that the karyotype formula was 2n=2x=16=6m＋4sm＋2smsat＋4st.The asymmetry index was 60.2% and belonged to category 2C of Stebbins.