Study On The Effect Of Maturity And Grain Positions On Barley Seed Vigor And Storability

To explore the effect of seed maturity and seed position on seed vigor and storage tolerance.Two barley varieties,P13-3 and Ganpi 4,were used in the experiment.The seeds with different maturity,grain position and aging time were used as the research objects to explore the effects of seed maturity and grain position on seed vigor and the effects of seed maturity on seed storage tolerance.The indexes of grain length,width,thickness,moisture content,dry weight of thousand grain and total starch content were measured respectively,and the relationships between seed germination rate,germination potential,germination index and vigor index and other characters were analyzed.In order to find out the relationship between seed vigor and seed maturity,seed position and storage tolerance,and provide theoretical basis for the best harvest period of seed vigor.The results were follows:(1)The difference of barley seed vigor was significant in different maturity.With the increase of seed maturity,seed vigor increased continuously.When it reached the maximum,seed vigor decreased with the increase of maturity.The correlation indexes of seed vigor of P13-3 at 36 d and that of Ganpi 4 at 30 d were higher,and the activities of antioxidant enzymes were stronger.(2)There were significant differences in physical index,storage substance,antioxidant enzyme activity and electrical conductivity in different days after anthesis.Both varieties showed the grain filling sequence of first increasing length,then width,and finally thickness.With the increase of maturity,the water content and electrical conductivity of grains gradually decreased and stabilized;the dry weight,total starch content,amylose content and amylopectin content of 1000 grains first increased and then stabilized;the antioxidant enzyme activity and fresh weight of 1000 grains first increased and then decreased.(3)The effect of different seed positions on seed vigor was significant.There were differences in the vigor of grains at different grain positions,which showed that the middle part of spike was the best,the lower part of spike was the second,and the upper part of spike was the lowest.On the 36 d of P13-3 and 30 d of Ganpi 4,the highest activity of antioxidant enzymes and related indexes were found in the middle part of spike,which was the best position to obtain high activity seeds.(4)The physical index,storage material,antioxidant enzyme activity and conductivity of different grain positions were different.With the increase of grain maturity,the dry weight of thousand grains,total starch content and antioxidant enzyme activity of P13-3 and Ganpi 4 showed that the middle part of ear was higher than the lower part of spike,and the lower part of spike was higher than the upper part of spike;the conductivity was the highest in the upper part of spike,followed by the lower part of spike,and the lowest in the middle part of spike.(5)Seed width,thickness,dry weight of thousand grains,root length,conductivity,total starch content,amylose content,amylopectin content,superoxide dismutase activity,peroxidase activity and catalase activity can be used as indicators to evaluate seed vigor.The results showed that there were significant or extremely significant correlations between the width,thickness,dry weight,root length,electrical conductivity,total starch content,amylose content,amylopectin content,superoxide dismutase activity,peroxidase activity and catalase activity of seeds and the related indexes.(6)Seed maturity has a significant effect on the storage capacity of seeds.Under the same aging time,with the increase of maturity,the germination index and vigor index of the two varieties increased first and then decreased;the germination index and vigor index of P13-3 reached the maximum at 36 d,and that of Ganpi 4 reached the maximum at 30 d.Superoxide dismutase activity,peroxidase activity and catalase activity of the two varieties increased with the increase of seed maturity,and decreased after reaching the maximum value,which was consistent with the performance of germination index and activity index.The maximum value of P13-3 appeared at 36 d,and the maximum value of Ganpi 4 appeared at 30 d.With the increase of seed maturity,the electric conductivity and malondialdehyde content decreased first and then increased.The minimum value of P13-3 appeared 36 d,and the minimum value of Ganpi 4 appeared at 30 d.To sum up,the seed vigor of P13-3 and Ganpi 4 has a certain regularity with the change of maturity and grain position,and the seeds with high vigor can be obtained by timely harvest.The seed vigor did not always increase with the increase of seed maturity;the seeds 36 d of P13-3 and 30 d of Ganpi 4 had strong vigor and storage resistance,which was the best time for harvest and storage.At the same time,the seed vigor of P13-3 was high in the middle of spike at 36 d and 30 d,and the seedling was strong after germination,which was the best position to obtain high vigor seed.