Comparison between Two Genera, Species and Cultivars in Lactuceae
II. Effects of seed-irradiation on chiasma frequency
1985 年 50 巻 4 号 p. 841-853
詳細
1985 年 50 巻 4 号 p. 841-853
Seeds of Lactuca sativa (cultivars Lobjoits Green Cos, Tom Thumb) and Lactuca serriola collected from the field, were irradiated with 10 and 30 Kr of gamma radiation. These and control seeds were grown on, and the chiasma frequencies determined in the M1 plants. Chromosome types had been identified (Haque and Godward, Paper I) so that it was possible to determine chiasma frequency for each chromosome type. The relationship between chromosome length and chaisma frequency, dose and chiasma frequency, per bivalent and per nucleus, for each cultivar or species, was examined. There was reduction with dose of chiasma frequency in L. serriola, but increase with dose in the two clutivars of L. sativa. The results are discussed in relation to genic control of chiasma frequency, and genic control of sensitivity to radiation. Chiasma frequency was not determined in C. intybus.
