INHERITANCE OF JUVENILE LEAF AND STEM MORPHOLOGICAL TRAITS IN CROSSES OF CHINESE AND AMERICAN CHESTNUT

Progeny from crosses of American and Chinese chestnut were examined for the following traits: occurrence of simple hairs on interveinal areas of abaxial leaf surfaces (interveinal hairs); density of simple hairs on twigs (twig hairs) and on abaxial leaf midribs and secondary veins (vein hairs); stipule size; stipule dehiscence; green or red stem color; and bud shape. The inheritance of bud shape could not be ascribed to a simple Mendelian model. All other traits appear to be controlled by two genes, with two exceptions: high density of vein hairs on Chinese chestnut is probably controlled by three dominant genes, and occurrence of interveinal hairs in Chinese chestnut may be controlled by a single gene with additional modifiers. High density of twig hairs on Chinese chestnut is probably controlled by two incompletely dominant genes. Red stem color on American chestnut may be controlled by two complementary genes. Small stipule size on American chestnut may be controlled by two incompletely dominant genes. Large stipules on Chinese chestnut take much longer to senesce and dehisce than small stipules on American chestnut. This appears to be strictly related to stipule size and controlled by the same gene(s). The three hair traits and stem color were linked to each other. Stem color also was linked to stipule size. The stem color determinations were the most interesting from a pathological perspective. Data on bud break at one date prior to the first frost-free date in spring are also presented.