抄録
The present paper describes the experimental results on the amount of free auxin in normally growing plants compared with that of abnorml ones such as the virus-infected body and the various fungous galls caused by blister blight, rust, white rust or smut.
The avena test was done by regular Went's method and its modified one: The tip of the coleoptile of oats was cut off at the place 2cm below from, the tip after 3 hours from the 1st cutting, and then the small agar piece was put on the cut head. The observation was done after 14 hours.
The agar pieces containing free auxin was prepared as follows: The agar pieces are immersed into the pressed-out juice from the tissue, or else a tissue piece of definite volume is put on the agar plate. The results are briefly stated as follows:
1. The amount of free auxin (examined, by the modified method and the pressed-out juice) tested with eleven fungous galls are given in Table 1. Usually in these galls the free auxin is contained in greater quantity than in the healthy tissues, and the upper part of leaf-blade contained free auxin in greater quantity than the lower part.
2. According to the results obtained by the modified method, the free auxin in the tissues of nine galls formed on the stem and the leaf-blade are contained in greater quantity than that of the healthy ones (see Table 2), and the amount of free auxin in these experiments showed smaller figures than in the case with the pressed-out juices.
3. The lateral migration of free auxin through the tissue in the fungous gall is possible, though the migrating quantity is smaller than in the case of vertical migration. Any growth-inhibiting substance is not found in the galls (see Table 3).
4. In the experiments with the modified method, the amount of free auxin in the stem of virus-infected potato and radish shows smaller quantity than that of the healthy ones (see Table 4).
5. The amount of free auxin (examined by the Went's method and the diffusion from the tissue) in the young stems of sweet potato infected with mosaic-virus shows smaller in quantity than that of healthy ones, and the culture test of the healthy stems also shows better growth (see Table 5-7).
6. From the experimental results above mentioned, the writer considers that the relation between the abnormal growth (hypertrophy or dwarfing) caused by the fungi or the virus correlates proportionally with the amount of contained free auxin n the tissues.
