西葫芦幼苗叶片对低温弱光胁迫的响应

Response of Cucubita pepo Seedling Leaves to Low Light and Low Temperature

为探索逆境条件下西葫芦幼苗叶片结构与功能的关系,为生产中培育壮苗促高产提供理论依据,笔者采用低温弱光(光照度4 000 lx,昼/夜温度15℃/8℃)胁迫研究西葫芦幼苗叶片光合特性及其结构变化。结果表明:低温弱光处理使西葫芦叶片上下表皮细胞密度、细胞直径、气孔密度以及气孔长均变小,叶片厚度变薄,栅栏组织厚度及叶片厚度减小,海绵组织也变得更为疏松,栅栏组织/海绵组织的比值减小,细胞间隙变大;且低温弱光处理后西葫芦幼苗叶片光合速率及叶绿素含量下降较明显。

The leaf photosynthetic characteristics and structure of Cucubita pepo seedlings were studied under the conditions of 4 000 lx and 15℃/8℃（day/night） to probe the relationship between leaf structure and function in C.pepo seedlings under the adversity condition and to provide the theoretical basis for cultivating strong C.pepo seedlings.The results showed that low temperature and low light could decrease cell density,cell diameter,stomatal density and length of upper and lower epidermis of C.pepo seedlings,thickness of leaf and palisade tissue,density of spongy tissue,palisade tissue-spongy tissue ratio and reduce leaf photosynthetic rate and chlorophyll content significantly.