光质对海带幼孢子体生长和假根发育的影响

Effect of light quality on young sporophyte growth and rhizoid development of Laminaria japonica Aresch

中文关键词: 海带  孢子体  假根  光质  蓝光

英文关键词: Laminaria japonicaAresch  Sporophyte  Rhizoid  Llight quality  Blue light

中文摘要:

      以海带Laminaria japonica幼孢子体为材料，比较了不同光质（白光、红光和蓝光）对其生长的影响，并对假根的发育进行了研究。在为期56 d的培养期内，蓝光始终促进幼孢子体的生长，平均叶片大小为9530±125μm长/1350±49 μm宽，是对照白光组的4倍之多（2200±56 μm长/356±20μm宽）；而红光下，藻体生长极为缓慢，叶片大小仅为580±63μm长/135±11μm宽。但是三光质下，藻体假根生长差异较小；假根长/叶片长为红光下最大，蓝光下最小，三光质下该比值均随着培养时间的延长而下降。由于海带的主要捕光色素之一岩藻黄素的吸收峰位于蓝光区，因此加大环境中蓝光的辐射可有效提高光能利用率，从而提高实际光合效率，加快藻体的生长；而假根部由于结构和功能特性，光合能力有所退化，对光质差异不敏感，因而在三光质下的生长相似。

英文摘要:

      Effects of light qualities (white light, red light and blue light) on the growth and rhizoid development of Laminaria japonica Aresch young sporophyte were investigated. During the culture period of 56 days, the young sporophyte cultured in blue light had a frond size of 9530±125 μm length/1 350±49 μm width, about four folds greater than that in white light; and the young sporophytes’ growth was much delayed in red light, at a size of 580±63 μm length/135±11 μm width. However, the development of rhizoid showed little difference between different light qualities. The ratios of rhizoid length to frond length were the highest in red light and lowest in blue light, which all decreased as the cultures prolonged. Fucoxanthin, one of the major light harvesting pigments in Laminaria with absorption spectrum peaking in blue light region is highly effective in capturing blue light. Consequently, the more the blue light irradiance was provided, the more the light energy was captured, resulting in the higher photosynthetic rate. Because the rhizoid is differentiated from the Laminaria frond and possesses degraded photosynthetic capacity, it was less reactive to light qualities than the frond and showed similar development under the three lights.