Effects of LED Light Quality on the Physiology and Morphological Structure of Camellia oleifera Leaves

Light quality is an important factor in plant growth and development. Camellia oleifera is a tree with a high economic value, and the effects of light quality on C. oleifera have not been adequately researched. Therefore, this study explored the effects of light quality on physiological parameters and the morphological structure of C. oleifera leaves. Light treatments with four light-emitting diodes (LEDs) were set: blue (B), red (R), white (W, the control group), and a combination of red and blue light (RB). Results showed that the net photosynthetic rate (P_n), maximum net photosynthetic rate (P_(n-max)), and stomatal conductance (G_s) of mature leaves under treatment B were significantly higher than those under W, those of treatment R were considerably lower than those of W, while those of treatment RB were higher than those of W but lower than those of treatment B. Bud numbers were markedly higher in treatment B than in W, and strikingly lower in treatment R than in W. The number of stomata increased under treatment RB, whereas stomatal size increased under treatment B. Palisade and spongy tissues developed normally under B and RB treatments, while leaves were thinner under R and W and palisade tissue was not obvious. In conclusion, red light is not conducive to the growth and development of C. oleifera, but blue light can effectively promote its growth. Thus, blue LED lights can be used as an auxiliary light source for growing and strengthening C. oleifera seedlings.

關鍵字

Camellia oleifera ； leaf anatomical structure ； light quality ； photosynthesis ； stomata

並列摘要

光質是影響植物生長發育的重要因素。油茶是一種具高經濟價值的樹木，至今仍未有充分研究其光質的影響。因此，本研究探討了光質對油茶幼苗形態結構和生理參數的影響。設置了四種發光二極體（LED）的光處理：藍光（B）、紅光（R）、白光（W）和紅藍混合光（RB）。結果表明B處理的淨光合速率（P_n）、最大淨光合效率（P_(n-max)）、氣孔導度（G_s）和芽數量均顯著高於W，R處理均顯著低於W，RB處理高於W但低於B處理。B處理芽數量顯著高於W，R處理顯著低於W。紅藍光下氣孔數量增加，藍光下氣孔變大。在B和RB處理下，柵欄組織和海綿組織正常發育，紅光和白光下葉片較薄且柵欄組織不明顯。綜上所述，紅光不利於油茶生長發育，藍光能有效促進油茶生長。因此，藍色LED光是促進油茶生長壯苗的最佳輔助光源。

並列關鍵字

油茶；光質；葉片解剖結構；光合作用；氣孔

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