Promotive effect of lysine monohydrochloride on morphogenesis in cultured seedling and mature plant tissues of castor (Ricinus communis L.)

In vitro response of various seedling and mature plant tissues of six castor genotypes has been assessed. The culture variables tested include explant type, basal media composition, growth regulators singly and in various combinations, growth adjuvants such as casein hydrolysate, castor endosperm extract, coconut water and lysine monohydrochloride. Most of the media variables caused the production of flaky callus while a few combinations resulted in organogenic callus. Shoot bud regeneration was low, occasional and erratic with limited reproducibility. Incorporation of the antiauxin TIBA failed to improve the morphogenic response of different cultured tissues. A broad range experiment having 81 combinations at three levels of minerals, sucrose+growth factors+amino acids besides growth regulators, revealed low caulogenic response of castor explants for direct as well as callus-mediated shoot regeneration. Incorporation of 0.1% lysine monohydrochloride in B5 medium supplemented with BA and IBA improved morphogenic competence of castor tissues.