I noticed that seeds of soybean [glycine max (L.) Merrill cv. Dunn] remained dry and brittle after a prolonged period of rain, even though the senescent pods were thoroughly wetted. This observation led me to hypothesize that pods might contain substances which block imbibition of water by seeds.
Callus tissue of ‘Seyval’ (Seyve-Villard 5-276) (Vitis sp.), a French hybrid grape, formed adventitious embryos when transferred from a medium with 2,4-dichlorophenoxyacetic acid (2,4-D) to a medium containing 1-napthaleneacetic acid (NAA). Embryos began to turn green and develop into apparently normal vines when placed on a medium free of hormones and vitamins in the light. Histological evidence indicated that plants derived from callus originated from embryo-like structures and not from plantlets or excised buds. Secondary embryoids formed on primary embryoids, and tertiary embryoids occasionally formed on secondary embryoids. More than 50 vines and several hundred adventitious embryoids were obtained from approximately one cubic centimeter of callus.
