【摘要】 在小黑麦单倍体愈伤组织中,自然发生的细胞变异体,其变异频率对耐1%NaCl来说大约是0.86×10^-6,对耐pH10是0.81×10^-6。经过诱变剂（EMS）处理后,其突变频率可提高1-2倍。筛选出来的变异体约有23-33%是不稳定的。有2/3或更多的变异体是比较稳定的,其抗性不因培养条件的改变而丧失。特别是从耐pH 10的TR₄细胞系中分化出来的再生植株,以及由这些植株的外植体重新诱导出的愈伤组织都依旧保持了这种抗性。更多还原

【Abstract】 Haploid Triticale callus did not grow on N₆ medium with pH adjusted to 10 by 1% NaOH or with 1% NaCl, and was killed totally after culture for 40-50 days. However, living spots could be found in few dead inoculated calluses. When these living spots were transferred to the same medium, some of them will continue to grow and others dying off. These media are called screening media and the calluses growing more or less normally on them, variants. It is supposed that each variant came from a single callus cell. One gram of fresh callus contains about 1.65×10⁶ cells, and the variation rate for resistance to 1% NaCl, as calculated from total quantity of inoculum, is 0.86 per million cells, and for resistance to pH 10, 0.81. R₄ is a variant resistant to pH 10. The variation rate of R₄ for resistance to pH 11 is 1.01 per million cells. If selection is made directly from the normal callus, the variation rate for resistance to pH 11 could be estimated as (0.81×10^-6)× (1.01×10^-6), or 0.82 per 10¹² cells. For such a low rate of variation, it would be impossible to isolate them under the usual condition of laboratory. However, it could be achieved easily if a stepwise selection schedule is adopted. The variation rate can be increased one to two times by pretreatmentt of eallues cells with 0.4% EMS aqueous solution for two hours. When the variants were cultured in normal medium for 3 to 5 passages （28 days between two subcultures）, 23-33% of variants could not maintain their resistance. However, the two-third or more variants are stable and maintain their resistance through passages in normal media. Besides, plantlets induced from the callus of pH 10 resistant line TR₄, could grow on the pH 10 medium. And callus induced from these plantlets explant maintains the resistance. These facts indicate that the stable resistant variants selected from the callus cells would be valuable for breeding purpose.更多还原