Cucurbit Genetics Cooperative Report 1:13 (article 12) 1978
Mutagenic Experiments with the Cucumber
R. W. Robinson
New York Agricultural Experiment Station, Geneva, NY 14456
Chemical and irradiation treatments were applied to cucumber seed to induce gene mutations. Mutagenic agents and doses that were successful include 5,000 to 30,000¥ x- rays, 9 to 18 hours of thermal neutrons, 0.5 to 2% ethyl methane sulfonate, 0.5 to 2.0% methyl ethane sulfonate, 0.05 to 0.20% ethylene imine, and .025 to .200% diepoxy butane. The highest dose listed for each agent resulted in the most mutations. The greatest frequency of mutations for all treatments resulted from 18 hours of thermal neutrons.
All mutations observed were recessive. It is necessary, therefore, to self pollinate M1 plants. Treated monoecious plants were self pollinated by hand, but it was possible to use open pollinated seed for hermaphroditic or andromonoecious plants. The higher degree of natural self pollination in these plants permits the recovery of recessive mutants in the M2 generation produced by open-pollination. Both pedigree and mass selection techniques were used.
Recurrent treatments were used to increase the frequency of mutants. Seed of the M2 generation of thermal neutron treatments was treated again, and the next generation was given the same treatment as before. The next generation segregated for mutants induced by all three treatments, in a frequency much higher than that for any single treatment.
Numerous chlorophyll deficient mutants of many types occurred. Some were nonviable albinos, others were virescent or lutescent, and still others maintained different degrees of chlorophyll deficiency in all stages of development. Male sterile mutants were frequently observed. Other induced mutations affected internode length, leaf shape, trichome development, and flower structure.