~(60)Coγ射线和EMS处理冬小麦雄配子及合子的诱变效果研究

利用~(60)Coγ射线0.5—4.0kR 不同照射量辐照小麦"原冬一号"、"原冬94"、"农大139"雄配子发育不同时期的植株和用0.5—1.0kR 三个照射量、0.3-0.4%EMS 两个浓度处理"农大139"授粉后7-13小时的休眠合子。处理当代的结实率随照射量增加而下降;M_1代损伤效应明显,出苗率减少,植株生长受抑,抽穗延迟,育性降低;M_2代有较高的突变率,处理雄配子、合子总突变频率达17.1%,有益突变频率分别为4.8%、12.5%,并且变异谱较宽。γ射线处理合子的诱变效果优于 EMS。γ射线辐照雄配子的适宜时期为二核期、三核期,适宜剂量二核期为0.5-1.5kR;三核期为1.0-2.0kR:合子处理的适宜剂量γ射线为0.5-0.75kR,EMS 为0.3-0.4%。

INDUCING MUTATION BY TREATING MALE GAMETES AND ZYGOTES OF WINTER WHEAT WITH ~(60)Co GAMMA RAYS AND EMS

The male gametes of three varieties of winter wheat at different deve- lopmental stages were irradiated by γ-rays with different doses 0.5—4.0 kRThe dormant zygotes of winter wheat variety"NongDa 139"in the ran- ge from the 7th to 13th hr after pollination were treated with 0.5,0.75, 1.0kR of γ-rays and 0.3—0.4% concentration of EMS.The results showed that the rate of seed-setting decreased with increasing the mutagen dosage in M_0 generation.The damage was significant in M_1 generation:the sur- viral rate of seedling decreased,plant growth was inhibited,and heading stage was delayed.The frequency and spectrum of mutation were higher and wider in M_2 generation.The total frequency of mutation amounted to 17.1%,the frequency of advantagous mutation was 4.8% and 12.5% in treating male gametes and zygotes respectively.Especially,the frequency of variation in zygotes treatment was higher(22%).The efficiency of indu- cing mutation with γ-rays was higher than that with EMS in zygotes treatment.The radiosensitivity of zygotes to γ-radiation was higher than that of male gametes.The male gametes at dikaryotic and trikaryotie sta- ge were appropriate for irradiation;The suitable dosage was 0.5—1.5kR at dikaryotic stage and 1.0—2.0kR at trikaryotic stage.For zygote treat- ment the suitable dosage was 0.5—0.75kR with y-rays,and 0.3—0.4% with EMS.