LED光质对三种叶色生菜光谱吸收特性、生长及品质的影响

Spectral Absorbance,Growth and Nutritional Quality Responses of Three Leaf-color Lettuce Cultivars to LED Light Qualities.

在温室条件下,水培盆栽三种叶色生菜,探究光质对不同叶色生菜生长和品质的影响。结果表明,不同LED光质照射下三种叶色生菜光合色素在330~500nm和640~690nm存在光吸收高峰,在500~640nm和690~800nm吸光度很小且变化幅度小。三种生菜叶绿素a、类胡萝卜素及总光合色素均在红蓝组合光照射下有最大含量,在红光照射下有最小含量,但三种叶色生菜叶绿素b对LED光质的响应不同。在不同LED光质照射下的三种生菜生长有显著不同。绿叶生菜和紫叶生菜在白光照射下地上部鲜重最大,红叶生菜在红蓝组合光照射下最大。红蓝组合光显著提高了三种生菜地上部干重。品质方面,绿叶生菜总酚含量随着氮水平提高显著降低,紫叶生菜和红叶生菜无显著变化。三种生菜类黄酮含量在不同氮水平下均无显著差异,花青素含量存在品种间显著差异,红叶生菜】紫叶生菜】绿叶生菜,受氮水平影响不明显。绿叶生菜和紫叶生菜可溶性糖含量随着氮水平提高稍有减少,而红叶生菜相反。绿叶生菜总酚含量在红蓝组合光下显著高于同品种的其他处理,紫叶生菜和红叶生菜在白光下最高。三种生菜类黄酮含量在白光、红蓝组合光、蓝光下高于红光照射。三种生菜花青素含量在红蓝组合光照射下最大,而在红光照射下最小。紫叶生菜和红叶生菜可溶性糖含量均在红蓝组合光照射下最大,白光照射下最小,绿叶生菜相反。

Lettuces of red,purple and green leaves were planted with hydroponics,and the influence of LED light quality to the spectral absorbance,growth and nutritional quality of the lettuces were studied.There were photosynthetic pigments spectral absorbance high values for three leaf- color lettuce cultivars in the spectrum 330 ~ 500nm and 640 ~ 690nm,and absorbance low values in the spectrum 500 ~ 640nm and690 ~ 800nm. The chlorophylla,carotenoid of three kinds of lettuce got the highest absorbance under red and blue light,and got the lowest absorbance under red light. But the spectral absorbance of chlorophyllb of three kinds of lettuce responded differently to the light qualities. The growth of the lettuces differed greatly under different LED light. The green lettuce and purple lettuce has the heaviest shoot fresh weights when they were under white light,but red lettuce was under red and blue light. And the shoot dry weight of all the lettuces increased remarkably under the red and blue light. The concentrations of phenol of green lettuce reduced with the increase of nitrate level,but that of purple lettuce and red lettuce did not changed greatly.There is no significant difference in the concentrations of flavonoid of all the lettuces under two levels of nitrate. The concentrations of anthocyanin differed distinctly between the cultivars but not the nitrate levels,as the sequence of red lettuce > purple lettuce > green lettuce. The concentrations of soluble sugar of green lettuce and purple lettuce lessened,while that of red lettuce got higher,with the increase of nitrate level.Green lettuce under red and blue light,purple lettuce and red lettuce under white light got the hightest concentration of phenol. The concentrations of flavonoid of all the lettuce under red light were the lowest.The concentrations of anthocyanin of all the lettuce were the highest under red and blue light,and the lowest under red light. Purple lettuce and red lettuce got the highest concentrations of soluble sugar under red and blue light,but the lowest under white light. Green lettuce was the contrary.