ナス苗の素質に関する生理的研究 Ｉ 日長時間と日照の強さの影響

Abstract

The effects of daylength and light intensity on the chemical constituents in stems and hormones levels in shoot apices of eggplant seedlings were studied to establish the physiological characteristics of good seedlings which may produce higher yield.1. The growth was inhibited by shorter daylengths or lower light intensities by shade treatments. Smaller stem dry weight to root dry weight (S/R) value was obtained on the seedlings grown under the natural daylength or natural light intensity.2. Seedlings grown under shorter daylengths or lower light intensities contained less carbohydrates and nitrogen compounds in stems than those grown under the natural conditions. There was a close correlation between S/R value and total sugars or insoluble nitrogen in stems.3. It was shown that cytokinin, abscisic acid and indoleacetic acid contents in shoot apices were increased by longer daylength or higher light intensity, however gibberellin-like substances level was lower under those conditions.4. There was a negative correlation between S/R value and cytokinin, abscisic acid or indoleacetic acid level, and a positive correlation between S/R value and gibberellin-like substances level in shoot apices. Seedlings with more total sugar and insoluble nitrogen in stems contained more cytokinin, abscisic acid and indoleacetic acid, and less gibberellin-like substances in shoot apices.5. From above-mentioned results, it may be suggested that seedlings with smaller S/R value morphogenetically contains more sugar and insoluble nitrogen in stem, and more cytokinin, abscisic acid and indoleacetic acid, and less gibberellin-like substances level in shoot apices.