Studies on Final Leaf Shape of Tobacco in Relation to Temperature in Young Stage of Leaf : 1. Effects of high temperature in young stage of tobacco leaf on its final leaf shape

[摘要] In order to investigate the effects of high temperature in young stage of tobacco leaf on the final leaf shape, tobacco (flue-cured variety, BY-4), planted in the pot of 1/2000 a, was grown in four plots in the controlled conditions, i.e., (Plot 1) 20°C (9:00-17:00) /15°C (17:00-9:00) for 4 weeks from April 10 (the 5th day after planting) in 1969 (control), (Plot 2) 35°C/15°C for 2 weeks from April 10 and 20°C/15°C for the successive 2 weeks, (Plot 3) 20°C/15°C for 2 weeks from April 10 and 35°C/15°C for next 2 weeks, (Plot 4) 35°C/15°C for 4 weeks from April 10, in the phytotron of Okayama Tobacco Experiment Station (Table 1). And in the field, tobacco (BY-4) was grown in three plots, i.e., Non-covered plot (control), Plot covered with polyethylene film for 21 days after planting, on April 2 in 1971, Plot late covered with polyethylene film for 13 days (from the 34th day to the 47th day after planting) (Table 2). The following results were obtained; 1. In Plot 2, width/length ratio of the mature leaves under the 16th leaf (numbered from cotyledons) got greater than that of the comparable leaves in Plot 1 (Fig. 3). 2. In Plot 3, the mature leaves above the 15th leaf got broader than the comparable leaves in Plot 1, but there was little difference in width/length ratio of the mature leaves under the 15th leaf between Plot 3 and Plot 1, in spite of smaller size of them in Plot 3 than the comparable leaves in Plot 1 (Figs. 1, 3). 3. In Plot covered after planting, width/length ratio of the mature leaves under the 15th leaf got greater than that of the comprable leaves in Non-covered plot, and in Plot late covered, the upper leaves from the 21st leaf got broader than the comparable leaves in Non-covered plot (Fig. 8). These results indicates that the final leaf shape of tobacco was distinctly affected by high temperature in the young stage of the leaf and that high temperature little affected the final shape of the leat except its size, which has been comparatively large.

[学科分类] 农业科学（综合）