Effect Of Hypergravity On Physiology,Biochemistry And Drought Resistance Of Millet

In order to study the effects of different hypergravity treatments on the growth and drought resistance of millet,and to select suitable treatment conditions,this paper used Changgu No.1 and Nongda No.8 as experimental materials,and centrifuged for 0.5h,1h and 2h with 3000 r/min,5000 r/min,7000 r/min and10000 r/min,respectively,to study the effects of hypergravity treatment on the germination index and germination vigor of millet seeds.Principal component analysis was used to classify the germination index Y,and the factors affecting the germination index were highly summarized.The condition range of the treatment of millet with hypergravity was reduced,and the changes of physiological and biochemical indexes during the germination period of millet seeds were determined and analyzed.Drought stress was applied to millet under suitable centrifugal speed and treatment time,and the effects of hypergravity on drought resistance physiology during millet germination and seedling stage were discussed.The conclusions are as follows:1.Millet seeds were treated in the range of 3000 r/min-10000 r/min and treatment time 0.5h-2h,and the seed germination test was carried out to determine the 7 germination indexes of the millet seed germination period.The results showed that the seed bud length decreased under different hypergravity treatments.Under suitable treatment conditions,the root length,fresh weight,germination index and vigor index of the seeds increased,and the germination potential and germination rate increased little.Principal component analysis was carried out on these 7 germination indicators,and 7 germination indicators were simplified into a single germination vitality index Y.The germination comprehensive index Y of Changgu No.1 was T5>T2>T4>T3>T8>T1> T7>T10>T9>CK>T11>T6>T12,the germination comprehensive index Y of Nongda No.8 was T5>T1>T2>T4>CK>T7>T6>T3>T8>T11>T10>T9>T12.The germination index of the two varieties was different under different gravity and different time treatments,but the seed germination vigor could be effectively improved under the treatment of medium and low speed and short time,among them,the seed germination effect was best under the treatment of T5(5000 r/min 1h).2.According to the above germination order,the centrifugal speed and treatment time were simplifiedto medium and low centrifugal speed(3000r/min-7000r/min)and suitable treatment time(0.5h,1h)to investigate the effect of gravity on the physiological and biochemical aspects of millet seeds.The MDA content of the two treatment groups was lower than that of the control group.The SOD activity and POD activity of the two varieties increased with the prolongation of germination.The SOD activity and POD activity of each treatment group were significantly higher than that of the control.The SP content of each treatment were higher than that of the control.It is indicated that the appropriate hypergravity treatment can accelerate the metabolism during seed germination and the conversion of nutrients in the seed,effectively reduce the degree of membrane lipid peroxidation and enhance the membrane repairing ability.3.Using PEG-6000 to simulate drought stress,the germination potential,germination rate,bud length and fresh quality of Changgu No.1 seed were improved,which could improve the cultivation and strong seedling during the germination period.In addition to the centrifugal treatment of 7000r/min,the germination index of Nongda 8 has been improved accordingly.It shows that different varieties have different changes in germination effect under centrifugal treatment.On the whole,the centrifugal strength of suitable strength can improve the drought resistance of millet during germination,and the effect of centrifugation speed and treatment time on millet seeds has a threshold effect.4.After using natural drought and hypergravity treatment of millet seeds,the chlorophyll content of millet leaves in seedling stage was increased to different degrees compared with the control,and the chlorophyll content increased most under treatment(3000 r/min 1h).The MDA content of each treatment was lower than that of the control;in addition to the POD content of the two varieties in the treatment(7000r/min 1h),the POD content of the other treatments was higher than that of the control;the SOD activity of Changgu No.1 treatment group was higher than that of the control,and the SOD activity of each treatment of Nongda No.8 was not significantly different from that of the control;the soluble protein content of each treatment of Changgu No.1 and Nongda No.8 was improved compared with the control,the difference between the treatment and the control reached a significant level in Changgu No.1 at 0.5 h(P<0.05),and the treatment of Nongda No.8 was significantly different from the control(P<0.05)..