Abstract
In a previous paper, no profitable combination was found for the improvement of quality of the fLax fibers, when the plants grown under natural photoperiod were transferred to various durations of short photoperiod, though some effects of photoperiod on the growth and formation of the fiberous tissue were recognized. In the present paper, the reverse combinations of those applied in the previous work were designed; i.e. the plants were transferred to natural long day (14hrs 20min to 14hrs 40min) after having received 2 (SC1), 3 (SC2) and 4weeks (SC3) of the short day (8hrs). The short day (S) and natural long day (C) plots were provided as controls. The results obtained are summarized as follows: 1) When short day was followed by long day, the fLax plants grew rapidly and their stems elongated more than those of the C plot on the later growth stage. The, dicotyledonal axilla of the plants transferred from S to C in the earlier growth stage grew longer than those of the S plot. The longer period of the short day treatment, the longer branches were produced. These results may be attributable to the effects of short day. 2) The dry weight of the above-ground parts of the flax plant, when transferred from S to C, reduced in comparison with that of the C plot. This seems to ascribe to the effect of short day, because of the rapid elongation of the plants. 3) When the flax plants were transferred from S to C, the effect of short day was recognized in the date of anthesis. Date of anthesis in the SC3 plot delayed only a little compared with that of the S Plot. 4) When Short day was followed by long day, the effects of short day were recognized in the contents of crude fibers of dried stems, the number of fiber-cells and the diameter of the fiber-cells, but they were smaller than those obtained in the C plot. Short day did not affect on the thickness of the cell-wall of the fiber-cells, this value was almost the same as that of the C plot. 5) The crude-cellulose contents decreased with increasing in the duration of the short day treatment, and the α-cellulose contents were not affected by short day. The lignin contents of the plants subjected to short day increased more than those of the C plot. And the effects of short day were remarkably rcognized
