Comparison of plants derived from cuttings, node cultures, and ethyl methanesulfonate treated node cultures of bird's-foot trefoil (Lotus corniculatus)

Plants derived from node cultures of six genotypes of bird's-foot trefoil (Lotus corniculatus L.) were compared under field conditions with plants propagated by stem cuttings. Culture- and cutting-derived plants flowered at the same time, but for most other traits there was a strong interaction of genotype and propagation method. Plants from node culture were either similar to those from cuttings or else flowered at a lower node, were shorter, had reduced leaflet length:width ratio, lower pollen stainability, and (or) reduced seed yield. Number of stems per plant was increased for all genotypes and three genotypes had higher forage yield in the 1st year after node culture propagation. On average, this increase in yield and stem number persisted in the 2nd year. Treatment of node cultures with the mutagen ethyl methanesulfonate prior to plant regeneration delayed shoot development and induced a number of chlorophyll-deficient variants, but seldom affected any of the quantifiable plant traits. Most of the observed differences between cutting-derived and node culture derived plants were likely due to hormonal or epigenetic effects of the culture system.