A collection of wild rices from different countries were grown and compared. The cultures were originally considered to be varieties of O. perennis Moench emend. Sampath. The study showed that at least three collections from Assam, Thailand and Africa are of hybrid origin, probably between O. perennis andO. sativa, and are to be classified as O. rufipogon Griffith. There is variation in the authentic O. perennis collections, and this could be due to evolution or due to introgressive hybridisation.
Calli were obtained from very young flower buds, roots and stems of Tradescantiapaludosa. These calli have been subcultured every six weeks on modified White's agar medium for over two years. The callus contains scattered meristematic colonies where cell division is observed. The chromosome number is normal diploid (2n=12) and the karyotype is normal except lacking a trabant. The giant cell has an abnormal polyploid nucleus. These cells seem to have been produced in connection with a polyploid nucleus which may result from endomitosis. The giant cell with an abnormal nucleus may lose the ability of normal division and finally die. The cell with a diploid nucleus may continue to increase in number and retain normal karyotypes. It follows that the normality of cells is not changed by culture in this species.
1. The productive structures of Miscanthus sinensis- and Arundinella hirta-type communities in Kirigamine grassland, Nagano Prefecture, were investigated in August of 1959, using the stratified-clip method. In the former, the upper layer was mostly occupied by M. sinensis and the lower layer by other forbs, showing marked vertical stratification (Fig. 1-B). In the latter, no clear stratification was found and greater part of the foliage was distributed in the lowermost layer, 0-20cm above ground-level (Fig. 1-A). 2. Above-ground standing crop of the whole vegetation began to increase from early May and reached their maxima by late August (Arundinella type, ca. 270g/m2) or early September (Miscanthus type, ca. 380g/m2), then decreased rapidly towards the end of growing season in November (Fig. 2). Underground standing crop ranged from 487 to 717g/m2 for Miscanthus type, and from 402 to 502g/m2 for Arundinella type, showing no clear seasonal trends during the growing period (Table 1). Mean value in winter of 600g/m2 was observed in Miscanthus-type community. Amount of litter was maximal at the end of growing season, in October or November, ca. 430g dry weight/m2 for Miscanthus type and ca. 200g/m2 for Arundinella type. 3. Characteristic seasonal change in above-ground standing crop was shown for each constituent species of the communities (Fig. 3). Miscanthus sinensis assumed the largest proportion (about 40-60%) in total aboveground standing crop of Miscanthus-type community throughout the growing season, and it had a seasonal peak of ca. 240g dry weight/m2 in early September. Compositae species, such as Aster, Solidago, and Anaphalis, followed M. sinensis in rank of standing crop. In Arundinella-type community, grasses made the largest contribution to aboveground standing crop especially in late August, when the seasonal maximum, ca. 180g dry weight/m2, of grasses was attained. Liliaceae species, and Scabiosa japonica showed their seasonal maxima in June and in August, respectively. Seasonal peaks of the top weight/total plant weight ratio (%) were observed in late June for Liliaceae species, in late July for Compositae species, in August for Scabiosa japonica, and in late August or later for Miscanthus sinensis and other grasses (Fig. 4). 4. Above-ground standing crops of these communities were compared with those of other Japanese herbaceous communities (Table 3).
A pink carotenoid pigment was separated by column chromatography from the red, autumnal leaves of plants belonging to the family, Taxodiaceae. The results of analytical studies on this pigment may be summarized as follows: 1. One and the same pink carotenoid pigment was found in red, autumnal leaves of 9 genera of Taxodiaceae in common. 2. The pink pigment was identified as rhodoxanthin, which belongs to the group of xanthophyll. 3. The color change from green to red occurring in autumnal leaves of taxodiaceous plants is due to the formation of rhodoxanthin. 4. As the synthesis of rhodoxanthin proceeds in leaves, other carotenoids, especially carotenes, seem to decrease in amount.