不同成熟期对花椰菜种子活力及相关生理生化指标的影响OA北大核心CSTPCD

The harvest period of cauliflower seed is usually estimated based on experience,which may lead to inappropriate harvesting and adverse seed quality.Studying the relationship between maturity period and seed vigor of cauliflower hybrid seeds can help to determine the optimum harvest period.Hybrid cauliflower Ousong 60 seeds harvested at 40,45,50,55,60 and 65 days after pollination were used to investigate the seed physical properties,seed vigor,and antioxidant enzyme activity,etc.The results showed that,with the increase of maturity,the seed water content and fresh 1 000-seeds weight were decreased,electric conductivity of seed soaking solution and MDA content were first decreased and then stabilized,while the specified water 1 000-seeds weight,SOD activity,POD activity,germination percentage,germination rate,vigor index,seedling height and root length were increased first and then stabilized.The seed vigor index,seedling height and root length of seeds harvested at 55,60 and 65 days after pollination presented no significant differences,but were all significantly higher than those at 50 days.Specified water 1 000-seeds weight,SOD activity,POD activity,MDA content,and electric conductivity,also stabilized after 55 days after pollination.Regression analysis revealed that the vigor index was significantly negatively correlated with fresh 1 000-seed weight,seed water content,MDA content and electric conductivity(P<0.05 or P<0.01),while was significantly positively correlated with SOD activity and POD activity(P<0.01).Seed vigor index,SOD activity,POD activity,MDA content and electric conductivity showed binomial relationship with seed development days with significant or extremely significant correlation,y(vigor index)=-0.131x2+16.957x-344.480,y(SOD activity)=-0.020x2+2.668x-10.420,y(POD activity)=-0.112x2+14.417x-368.610,y(MDA content)=0.113x2-13.771x+433.780,y(electric conductivity)=0.088x2-10.319x+338.680,which could be used to predict the seed vigor,ability of the enzymes for scavenging reactive oxygen species and the integrity of cell membrane at different maturity stages.In summary,Ousong 60 seeds at 55 days after pollination were ready to harvest with germination percentage of 98%and the specified water 1 000-seeds weight of 4.364 g,and the seed vigor and physiology were stabilized,exhibiting no impact on seedling growth and reduced risk of seed loss due to falling.The current study provided theoretical basis for determination of appropriate seed harvesting period of cauliflower hybrid seeds.