抄録
This paper diels with the fasciation and the, other abnormalities experimentally produced in soy bean and Azuki bean by the treatment of seeds with the aqueous solution of heteroauxin.
1. In 0.15% (Exp.I) and 0.1% (Exp. II) aqueous solutions of heteroauxin, air dry seeds were soaked for 10, 20, , 30, 40, and 50 hours (A-E) the former, and for 20, 30, 40, 50, and 60 hours (B-F) in the latter. In both experiments, the seeds thus treated were washed with water and sown in the field to observe the effects of the treatment. The seed-soaking in the chemical was carried out in a thermostat kept at 25°C.
2. In soy bean the following abnormalities were met with as shown in Table 1. (a) Two or three branches, instead of one, are produced on the third node. (b) Two compound leaves are produced oppositely on the third node (Fig. 16) and 1-5 branches arise from it. (c) The petioles of the two opposite leaves on the third node are united on one side (Fig. 1c) and 0-5 branches are produced at their base. (d) The petioles of the two opposite leaves on the third node are united cylindrically on both sides, including and suppressing, the apical growth point. of the plant (Fig. 1d); accordingly branches arise from the first and the second nodes. (6) The growth of the main stem stops at the early stage of growth, accordingly branches are produced only on the first node (Fig. 1e).
3. Fasciation was observed in some of the branches grown on tne tnird node of the plants belonging to (a), (b), and (c) type abnormalities (Fig. 2), and in some of those branches on the first node of (e) type abnormal plant (Fig. 3).
4. As shown in Table 2, the proportions of the fasciated plants to the total seedlings tend to increase with the length of treatment and with the concentration of the solution, but in the case where the length of treatment is too long, the proportion tend to decrease on the contrary; this seems to be due to the increase in the number of the individuals belonging to (c) and (d) type abnormalities, which accompany with little fasciation, in Exps. I-E, II-E and II-F.
5. Fasciation is accompanied with (b) type abnormality more frequently than with the other types.
6. In Azuki bean, the following abnormalities were observed, but fasciation was not met with at all. (a) The production of opposite leaves on the third node; (b) the production of simple leaves on the third node and (c) the production of compound leaves having supernumeral leaflets on the third or the forth node.
