Mutagenesis in Lotus corniculatus L.

Some 7,500 seeds of Lotus corniculatus cv. Mirabel were treated with X-rays (3,000-12,000 Rads), ethyl methanesulfonate, 8-ethoxycaffeine, n-hydroxyurea, and 2-aminopurine (0.001 to 1.0% solutions). A total of 93 selfed, partially inbred, and open-pollinated lines, comprising some 22,000 plants, were generated over four generations. Mutagenic effects were assessed on germination, seedling survival, meiotic aberrations, pollen abortion, seed and forage yields, pod dehiscence, winter hardiness, brown floral keel tip color, and cyanoglycoside (HCA) content in the leaves. Dose effects were largely confined to the M(,1) generation. Germination and seedling survival could not be used to predict mutation rates. Higher levels of forage and seed yields and lower levels of HCA content were induced. Pod dehiscence, winter hardiness and brown keel tip frequency were not affected. Three qualitative mutants, chlorotica, vestigial floret, and dwarf, were tetrasomic recessives. Only tetrasomically inherited characters were found. X-rays and EMS were the most effective mutagens