花生不同叶位叶片衰老差异的研究

Studies on senescence difference in leaves on different nodes of peanut plant

在大田条件下,研究了高产花生品种鲁花11号和辐8707主茎不同叶位叶片衰老的差异。结果表明:花生主茎展开18片叶(饱果期)时,主茎叶片叶绿素含量、净光合速率(Pn)、可溶性蛋白质含量(Pr)、超氧化物歧化酶(POD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性逐渐升高,顶3～6叶达最大值,向下逐渐降低。叶片丙二醛(MDA)含量、活性氧(O_2)释放速率随叶位的降低逐渐升高,顶6叶后开始迅速升高。花生主茎顶1～3叶属快速生长叶,顶4～6(7)叶属缓慢衰老叶,顶7(8)～10叶属迅速衰老叶。两品种间差异不大,辐8707叶片的衰老稍早于鲁花11号。

The senescence difference of peanut leaves at different nodes on main stem was studied with two high -- yielding peanut cultivars (Arachis hypogaea L. cv. Luhua No. 11 and Fu 8707) grown in field. When pea- nut plant was at pod maturing phase with 18 unfolded leaves on main stem, the chlorophyll content, net photosyn- thesis (Pn), soluble protein content (Pr), and the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) of leaves on main stem from top to bottom increased gradually, and reached maximum val- ues from top 3rd to 6th leaf, then it decreased gradually. The content of malondialdehyde (MDA) and the produc- tion rate of active oxygen (O_2^-) in leaves increased gradually from the top one to the 6th leaf, but it increased rap- idly in other leaves on lower positions. Based on these results, the leaves was divided into three function groups: fast growing stage (top 1 st to 3rd leaves); slowly senescing stage (4th to 6th or 7th leaves); and rapid senescing stage (7th or 8th to 10th leaves). The leaf senescence in cv. Fu 8707 was a little earlier than that of cv. Luhua No. 11.