CHARACTERIZATION OF LEAF MORPHOGENESIS IN MULBERRY MUTANTS (MORUS SPP.)

Characterization of leaf, petiole and chloroplast development in mulberry was performed by using the mulberry mutants ‘Ryoumenguwa’, ‘Enashi’ and ‘Kibajumonji’ in comparison with normal types. ‘Ryoumenguwa’ exhibited leaf blade morphological changes expressed as more than one blade in a petiole and complex morphological features were seen in the polarized adaxial-abaxial leaves. The development of a leaf comes from an early developmental stage that is controlled by several genes dependently or interactively. In this study, the possible role of the PHANTASTICA (PHAN) and the ASYMMETRIC LEAVES2 (AS2) genes on ‘Ryoumenguwa’ leaf development was investigated. ‘Enashi’ developed shorter petioles on its leaves. Morphological characterization of ‘Enashi’ was defined by measuring the length of the petiole in various leaf sizes and comparing them to normal types. ‘Kibajumonji’ showed abnormal chloroplast development – in general, leaves appeared yellowish in color and in several parts of leaf blades had a green mottling. Histological analysis of the yellow leaf tissue showed that it lacked chlorophyll content compared to the greenish mottles. The possible roles of genes related to petiole development of ‘Enashi’ and chlorophyll biosynthesis of ‘Kibajumonji’ are discussed.