The purpose of this paper is to indicate the causes of the paulownia tree's early death affected by witches'-broom. The experiment was designed to compare the diurnal changes of translocation of starch of the diseased leaves with that of healthy. The materials were collected twelve times a day at every two hours under fine weather in August. The leaf starch was determined by the iodine reaction. The results were as follows: 1. The starch of the young healthy leaves began to decrease at about 11 p.m. and disappeared from 5 a.m. till 9 a.m. and began to reappear at about 11 a.m. However, the starch of the young diseased leaves began to decrease at about 5 a.m.and much decreased from 9a.m. till 11 a.m., though entire disappearance of starch was not observed. 2. The starch of the young diseased leaves began to decrease at about 1 a.m. and much decreased from 7 a.m. till 9a.m., then without entire disappearance it began to increase at about 11 a.m. again. While the old diseased leaves showed any remarkable changes of starch content. This apparently indicated that a large part of the starch assimilated in the diseased leaves remained without transportation. It seems likely that the death of the diseased paulownia tree is promoted in partby this low translocation of starch.
Mendeley出力
