| Corn is the world's highest yield of cereal crops,can be used as food,feed,industrial raw materials,and so on.With the development of our hybrid corn planting area continues to expand,and the continuous improvement of the degree of agricultural machinery,production of excellent maize hybrids demand increased year by year and the seed quality proposed higher requirements.Seed vigor is a comprehensive index to measure the quality of seed,and high quality seeds are paid more and more attention by people in modern agricultural production.However,at present,there is not a standard method for determination of seed vigor in Maize at home and abroad.This research selects the Tieyan39,Yuyu 32,Lianchuang 7,Zhengdan 958,Suyu 2,Ludan 9002,Wanyu 6,Pudan 6,Ludan 981,Nongda 108,Antun 8,Tianhe 5,12 hybrid corn varieties as materials,through the field dynamic comparison test,differences of different varieties of normal aging and seedling emergence and seedling growth performance of seed treatment;the seedling growth test,radicle elongation was counted,simulated field germination test,accelerated ageing test,NaCl low temperature compound stress determination,and ADH(dehydrogenase),POD(peroxidase),CAT(catalase),SOD(superoxide dismutase),LOX(lipoxygenase)5 enzyme activity determination of 6 methods,the determination of seed vigor,and various vigor indexes and field emergence rate,seedling fresh weight,seedling dry weight And the grain weight of seed and other indexes were analyzed,and the suitable method for the determination of seed vigor of hybrid maize was discussed.The main results are as follows:1.The results showed that there were significant differences in seed vigor of 12 hybrid maize varieties.Aging treatment of field emergence rate,seedling fresh weight,shoot dry weight,most varieties have different degrees of reduction,plant height,ear height,extract,tassel length,stem diameter,grain number per spike,1000 grain weight,different varieties showed inconsistent,some lower some increased.Integrated field seedling rate,bud seedling fresh weight,bud seedling dry weight of 3 indicators,the Lianchuang 7 have high vitality,anti-aging ability.Nongda 108 activity is low,anti-aging ability is weak.2.The results of seedling growth test and correlation analysis showed that there were significant differences in seed vigor of different cultivars.Germination potential and seedling field emergence rate,seedling fresh weight,shoot dry weight showed a significant or extremely significant positive correlation;germination rate and field emergence rate,seedling fresh weight,shoot dry weight showed a highly significant positive correlation;root length and seedling field emergence rate,seedling fresh weight,shoot dry weight showed a significant or extremely significant positive correlation.3.The elongation of radicel count determination and correlation analysis results showed that two kinds of different varieties of radicle elongation number were significantly different.20 ? 66 h of elongation of radicle and seedling emergence rate,seedling fresh weight,seedling dry weight showed a highly significant positive correlation.4.The results of field experiment and correlation analysis showed that there were significant differences in the vigor of different cultivars.There was a significant or very significant positive correlation between simulated field emergence rate and field emergence rate,fresh weight and dry weight of shoots.The seedling fresh weight and dry weight of shoots were significantly positively correlated with grain weight in the field.5.The results of accelerated ageing test and correlation analysis showed that there were significant differences in seed vigor of different cultivars in different aging treatments.45??100% RH?3d high temperature and high humidity aging germination potential,germination rate,seedling dry weight and vigor index were with field emergence rate was significantly positively correlated,the germination potential,germination rate,germination index,vigor index were and seedling fresh weight showed significant positive correlation,germination potential,germination index,vigor index were and seedling dry weight showed significant positive correlation,seedling fresh weight and vigor index were and harvest seed weight was significant or extremely significant positive correlation.Imbibition 12h?45??2d high temperature aging germination potential,germination rate,germination index,was significantly or very significantly positive correlation with field emergence rate,and seedling fresh weight was extremely significant positive correlation,and shoot dry weight were extremely significantly positive correlation;seedling fresh weight,vigor index,and seedling fresh weight was significantly positive correlation,and seedling dry weight showed significant positive correlation.6.NaCl low temperature composite stress analysis and correlation analysis showed that there were significant differences in seed vigor of different varieties,and the composite stress germination rate was significantly positively correlated with the field emergence rate.7.The results of enzyme activity determination and correlation analysis showed that there were significant differences in the activities of the 5 kinds of enzymes in different cultivars.SOD activity was significantly positively correlated with the field emergence rateand the dry weight of the shoots,and there was a very significant positive correlation between the fresh weight and the fresh weight of the buds.8.Comprehensive analysis of 6 kinds of Seed Vigor Determination method that seedling growth test,radicle elongation count determination(20?66h),accelerated aging test(45??100% RH?3d aging;imbibition 12h?45 ??2d aging),simulated field seedling test,determination of NaCl composite low temperature stress,SOD activity determination,and can be used for determination of seed vigor of maize hybrid.Among them,radicle elongation count determination(20 ? 66h),seedling growth test,accelerated aging test(45??100% RH?3d aging)3 kinds of methods,simple and practical,hybrid maize seed vigor determination as a suitable method. |
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