宝山堇菜(Viola baoshanensis)和紫花地丁(V. yedoensis)叶绿素荧光参数的日变化

DIURNAL DYNAMICS OF PHOTOSYNTHETIC PARAMETERS OF VIOLA BAOSHANENSIS AND V. YEDOENSIS

研究了宝山堇菜(Viola baoshanensis)和紫花地丁(V. yedoensis)叶片叶绿素荧光参数的日变化.紫花地丁NPQ呈单峰型增长,宝山堇菜NPQ有先增加,后下降的趋势.2种堇菜rETR首先迅速上升,维持在一个较高水平,然后迅速下降,Ik变化趋势相对一致.紫花地丁Pm和α呈双峰型变化,宝山堇菜有先增加,后下降的变化趋势.相关性显示,宝山堇菜叶片rETR与光合有效辐射呈显著正相关(P<0.05).紫花地丁叶片温度分别与Y、NPQ呈显著负相关和正相关(P<0.05),叶表光合有效辐射与Y、NPQ分别达极显著负相关和正相关(P<0.01),与rETR显著正相关(P<0.05).结果表明,正午时刻2种堇菜光系统Ⅱ遭受了光抑制,热耗散和光呼吸是紫花地丁的重要光保护机制,宝山堇菜通过光呼吸来保护光合机构.

Diurnal dynamics of photosynthetic parameters of Viola baoshanensis and V. rETR （ electron transport rate） of the two species increased very quickly in morning, and kept at a high level, then decreased. There were difference variation patterns between the two viola species for NPQ, rETR, Pro, Ik and α, and a significant relationship between PAR and rETR. For V. yedoensi, a significant negative relationship was found between leaf temperature and Y, a significant positive relationship between leaf temperature and NPQ, and a significant positive relationship between PAR and NPQ. The above results showed that excess light energy dissipated via the xanthophyll cycle and large proportion of electrons allocated to photorespiration for V. yedoensi played roles in protecting the photosynthetic proportion of electrons alloca apparatuses. For V. baoshanensis, preventing photodamage was mainly through large ted to photorespiration.