| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2000: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1999: ¥2,900,000 (Direct Cost: ¥2,900,000)
|
|---|
| Research Abstract |
Flowers and fruits were anatomically and ontogenetically investigated in the tribe Desmodieae of Leguminosae including its outgroups, subtribes Kennediinae and Erythrininae in the tribe Phaseoleae, and then the evolutionary trends of these characters were assumed.
1. Flower structure
Flowers of Desmodieae were compared with genera Kennedia and Hardenbergia of the subtribe Kennediinae. These two genera have floral nectaries at the inside base of the androecium. In comparison with the two flower types recognized in the tribe Desmodieae, "simple type" and "explosive type", the features observed in the outgroups correspond to those of the "simple type". This result, therefore, suggests that the "simple type" is more primitive, or plesiomorphic, in the tribe Desmodieae.
Moreover, the usefulness of flower morphology was examined in the tribe Desmodieae. The calyx and petal were shown to be more useful in this tribe. By this examination one new species of the genus Lespedeza, L.hisauchii T.Nemoto ＆ H.Ohashi, was recognized and published (Nemoto ＆ Ohashi, 1999).
2. Fruit structure
The anatomical structures of pericarps of the tribe Desmodieae were compared with those of subtribes Kennediinae and Erythrininae. The latter two subtribes represent oblique arrangement of fibers in the sclerenchyma, which is obviously different from the transverse arrangement commonly found in the tribe Desmodieae. This suggests that the common arrangement of fibers in the tribe Desmodieae is evolved at the root of the clade of the tribe from the oblique arrangement in the allied subtribes of the tribe Phaseoleae.
Mapping of anatomical characteristics onto the molecular phylogenetic tree obtained from sequence data of chloroplast rbcL gene shows differences in evolutionary trends of pericarp and joint structures in each clade of the tree. Moreover, the evolution of fruit structure is shown to be closely correlated with that of flower structure in the tribe Desmodieae.
|
