報告書番号

V04001

タイトル（和文）

低日照条件におけるアブラナ科葉菜類の徒長抑制に対する光質変換の効果

タイトル（英文）

The effect of qualitative control of light for preventing spindly growth of leaf vegetables in Brassica under low sunshine conditions.

概要 （図表や脚注は「報告書全文」に掲載しております）

人工光チャンバーを用いて、曇雨天時に近い低日照条件でチンゲンサイとベカナを水耕栽培し、葉柄の伸長、葉の厚さ、地上部乾物重に及ぼす光質変換の効果を調べた。昼間に遠赤色光を減らす処理（遠赤色光カット）を行うと葉柄の伸長が抑制され、葉の厚さが増加した。遠赤色光カットと青色光を増やす処理（青色光プラス）を同時に施すと葉柄の伸長抑制が強く現われたが、可食部である地上部の乾物重は減少した。夜間（2:00～6:00）に青色補光（青色光だけをPPFD80μmol㎡/sで補光）を行うと地上部の乾物重と葉の厚さが増加したが、葉柄が伸びる徒長傾向も認められた。そこで昼間の遠赤色光カットを併用したところ、葉柄の伸長抑制、葉の厚さの増加、および地上部乾物重の増加が起こり、徒長の抑制と可食部乾物重の増加がともに達成可能であることが明らかになった。

概要 （英文）

In order to improve the spindly growth of the brassica plant due to lack of solar radiation, the effects of light quality on growth was investigated using the artificial light in growth chambers set as the lighting environment of cloudy rainy weather. When the level of far-red light was reduced in the daytime, the length of a petiole became short, and the thickness of a leaf increased. Although the effect which shortens a petiole became strong when level of blue light was increased simultaneously in addition to reduction of the level of far-red light, dry weight of shoot decreased. On the other hand, although the influence by conversion of light quality in supplemetal light (2:00 - 6:00) at night was investigated, the improvement effect of spindly growth was not acquired. Although dry weight of shoot and the thickness of a leaf increased when supplemetal blue light was irradiated on the level of photosynthetic photon flux density (PPFD) 80μmol/㎡/s at night (2:00 - 6:00), the length of petiole was extended and spindly growth occurred. Then, when the level of far-red light of daytime was decreased in addition to irradiation of supplemetal blue light at night, the length of petiole became short, the thickness of a leaf increased, and dry weight of shoot increased. Therefore, it was shown that it is effective in the improvement of spindly growth of brassica plant and promotion of growth to reduce far-red light from sunlight and to irradiate supplemetal blue light at night.

報告者

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