利用组织培养和辐射诱变创造高频率小麦与簇毛麦染色体易位

High Efficient Intergeneric Chromosomal Translocations Between Wheat (Triticum aestivum L.) and Dasypyrum villosum arising from Tissue Culture and Irradiation

利用荧光原位杂交证明普通小麦与硬粒小麦-簇毛麦双二倍体杂种培养细胞和再生植株中能够发生属间染色体易位，易位染色体不仅有臂间易位，还有小片段易位，表明通过杂种组织培养是创造属间易位的一个可行的方法。辐射处理能够大幅度促进杂种愈伤组织细胞中的染色体数目和结构变异，特别是易位频率达到7.4％。观察还表明，培养时间对杂种愈伤组织细胞中染色体数目和结构变异都有较大影响，培养细胞的染色体变异在培养的初期阶段就已出现。在一定时间里，随培养时间的延长，未发生变异的细胞频率逐渐下降，染色体数目减少的细胞逐渐增多。培养时间对染色体数目增加的细胞频率影响不大。对于染色体结构变异，培养时间延长主要是提高了端着丝点染色体的频率。在杂种培养细胞中还观察到一定频率的染色体加倍细胞（2n=84），但是培养一段时间后这类细胞就逐渐消失了。

Intergeneric chromosomal translocations were discemable both in callus cellsand in regenerants arising from crosses between Triticum aestivum and Tdurum-Dasypyrum villosum amphiploid c.v. TH1 and TH1 W by means of fluorescencein situ hybridization. There were not only reciprocal translocations, but small fragmenttranslocations. The results proved again the feasibility of creating intergenerictranslocations via tissue culture. Irradation facilitated numerical and structuralchromosom changes in callus cells. The frequency of translocations was as high as7.4 Percent in irradiated callus cells. colus age had an important impact on numericaland structural chromosome abnomalites. During a given time of culture, the frequencyof unchanged cells was declined, while those cells with chromosome losses wereinclined. The duration of culture had not significant effects on cells with chromosomegains. As structural chromosome changes is concerned, the duration of culturepredominantly increased the frequency of cells with telocentric chromosomes. Thechromosomal changes occurred at the initiation period of tissue culture. A number ofcells which were doubled their chromosome numbers (2n=84) were observed at acertain frequency in the period of tissue culture . These cells, however, disappeared inthe successive culture.