遮荫处理对早熟花椰菜花球的生长和抗氧化系统的影响

以早熟花椰菜品种丰喜45天'为材料,在花球开始形成期进行遮荫处理,以研究遮荫对花球生长和抗氧化系统的影响.结果表明:(1)遮荫处理使花椰菜花球纵径、横径和鲜重分别比对照减少17.97%、18.9%和38.59%.(2)除了叶片中愈创木酚过氧化物酶(G-POD)活性显著提高外,遮荫处理降低了花椰菜叶片、花蕾和花茎中超氧化物歧化酶(SOD)、过氧化物酶(CAT)、抗坏血酸过氧化物酶(APX)和G-POD的活性,但与叶片相比,花蕾和花茎中这些酶活性的下降幅度较小.(3)遮荫处理显著降低了花椰菜叶片、花蕾、花茎中脱氢抗坏血酸还原酶(DHAR)和谷胱甘肽还原酶(GR)的活性.(4)遮荫处理降低了花椰菜叶片、花蕾和花茎中抗坏血酸含量(花蕾中还原型抗坏血酸除外)和叶片中谷胱甘肽含量,但花蕾和花茎中谷胱甘肽反而有所提高(花茎中还原型谷胱甘肽除外).

Effect of shading on curd growth and antioxidant system in early cauliflower

In the present experiment,early cauliflower cultivar 'Feng-xi 45-day' was employed to study the effect of shading to curd growth and antioxidant system of the plant.Cauliflower plants were covered with screening net for 14 days when the curd was initiated.During the shading treatment,light intensity was reduced to 30 percent.The main results were as follows.(i) Under shading condition,curd height,curd diameter,and curd weight were reduced by 17.97,18.90 and 38.59 percent,respectively,as compared with the control.(ii) The activities of SOD,CAT,APX,and G-POD in cauliflower leaves,curds and fleshy rachises decreased under shading condition,except for G-POD activity in leaves,which increased significantly,as compared with the control.(iii) The activities of DHAR and GR decreased significantly in the shaded plants.(iv) AsA and DAsA content of cauliflower leaves, curds and fleshy rachises decreased under shading condition,except for AsA content of curds.GSH and GSSG content of leaves decreased under shading condition, but GSH and GSSG content of curds and fleshy rachises increased significantly,except for GSH of fleshy rachises.