Histology of Malformations Produced on Bean Plants by Culture Filtrate of Aspergillus Niger

Postlethwait, S. N., and Roy W. Curtis. (Purdue U., Lafayette, Ind.) Histology of malformations produced on bean plants by culture filtrate of Aspergillus niger. Amer. Jour. Bot. 46(1) : 31‐35. Illus. 1959.—The stem and leaf petioles of bean seedlings treated with culture filtrates of A. niger exhibit severe curvatures, increased diameter, reduced length, and irregular protrusions. These malformations result from an apparent partial loss of polarity of the cells in the actively growing region of young internodes and petioles. Enlargement and multiplication of cells in the affected regions occur mostly at an angle to the longitudinal axis of the plant. The effect is localized and the portion of the plant produced from the apical meristem subsequent to treatment matures in a normal way.