橙花破布木染色体制片及核型分析

Chromosome Preparation and Karyotype Analysis of Cordia subcordata

为了解橙花破布木的遗传背景,以其根尖为试验材料,采用体细胞染色体常规制片法着重探索取材和预处理两个实验环节,选取染色体分散较好的细胞进行数目确定及核型分析。结果表明:(1)橙花破布木最佳取材时间为9:30~10:00和14:00~14:30,最佳预处理试剂及时间为饱和对二氯苯预处理2h;(2)橙花破布木染色体数目为32条,共16对染色体,为二倍体植物;核型公式为2n=2X=32=32m,核型属于"1A"型;染色体组绝对长度变化范围为0.38~0.69μm,相对长度(%)变化范围为4.48~8.24,相对长度组成为2n=2L+14M1+14M2+2S;核型不对称系数(As.K%)为58.40%。研究结果为破布木属植物染色体制片技术及核型分析提供参考,也可为橙花破布木基因进行染色体定位等细胞遗传学及表观遗传学研究奠定基础。

In order to understand the genetic background of Cordia subcordata,we used the root tips asmaterials to investigate optimal sampling and pretreatment conditions,and the cells with better chromosomedispersion were selected for karyotype analysis.The results showed that:(1)The best sampling time of C.subcordata was from 9:30-10:00 am and from 14:00-14:30 pm and the optimal pretreatment was immersingthe root tips in saturated p-dichlorobenzene for 2 hours;(2)C.subcordata was diploid,with 32 chromosomes,totally 16 pairs.The karyotype formula was 2 n=2 X=32=32 m,and the karyotype was"1 A".The absolute lengthvariation range of chromosome was 0.38-0.69μm,and the relative length(%)varied from 4.48-8.24.Therelative length composition was 2 n=2 L+14 M1+14 M2+2 S.The karyotype asymmetry coefficient(As.K%)was58.40%.These results would provide references for chromosome preparation and karyotype analysis,and laid afoundation for cytogenetic and epigenetic studies on C.subcordata.