抄録
Radioactive CO2 gas feedings in an assimilation chamber were conducted on Ladino clover plants in different stages of regrowth after cutting to reveal the translocation of 14C-assimilates in the plant body. To prepare for the simultaneous treatment, the plants grown in pots were cut on different dates so that they were on their 18th, 15th, 12th, 9th, 6th, and 3rd day of regrowth and immediately after cutting. All plants were fed 14CO2 for 2 hours in an assimilation chamber at the same time. 14CO2 feeding experiments werd repeated three times, and 1st experiment plant were harvested immediately after 14CO2 feeding, while in the 2nd and the 3rd experiment the plants were harvested 2 days and 5 days after 14CO2 feeding, respectively. Sample were prepared with Van-Slyke-Folch's wet-oxydation apparatus and radioactivity of various parts of the plants were counted by gas-flow type counter. With the same assimilation chamber and design of experiment, another feeding experiment of 14CO2 was conducted. The plants were harvested 2 days after feeding and the radio-autographs were taken. The results of these experiments led us to the following findings. 1) Of the plant immediately after cutting, the young leaves which had not yet opend assimilated 14CO2 though in small amounts, but no translocation to other parts of plant was seen (Fig. 3 Fig. 6-A). 2) Of the plant 3 days of regrowth, the leaves assimilated actively, and the assimilates were seen being exported to the opening leaves at the growing points. Export to the reserve organs such as stolons and roots was observed but very slightly (Fig. 3 Fig. 6-B). 3) Of the plant 6 days after cutting, the laeves assimilated very actively the actvity reaching the highest level. The transport to the reserve organs started at this time, the radioactivity in the stolons and roots were increasing (Fig. 3). 4) The most rapid increase in radioactivity in the stolons and roots was seen in 6 (lays to 9 days after cutting (Fig. 3 Fig. 6-D). With the increase of leaf area the ratio exporting 14C-assimilates to the reserve organs increased (Fig. 5).
