| Rice is one of the three important food crops in the world.Heilongjiang Province has made great contribution to safeguarding China’s food security.The live broadcast operation is simple and cost-effective.Nitrogen metabolism is one of the important life processes of plants,which has an important influence on crop growth and yield formation.Rice needs a lot of water for its growth and development,and per capita water resources of China account for only a quarter of the world’s total.Therefore,in order to clarify the effects of nitrogen metabolism and yield in cold-spotted rice under different irrigation methods,this experiment used conventional irrigation(W1),light dry-wet alternating irrigation(W2)and heavy weight with Suijing18 and Longqingdao21 as test materials.Heavy dry-wet alternate irrigation(W3)and drought management(W4)were used to study the effects of irrigation methods on key enzyme activities,nitrogen accumulation and transport,grain protein components and yield of nitrogen metabolism in cold-spotted rice,revealing different irrigation.The changes of nitrogen metabolism and yield of rice in cold-spotted rice were studied,and the optimal irrigation method of direct-seeding rice in cold land was clarified,which provided a basis for the development of water-saving irrigation technology for cold-field rice.The main conclusions of this test are as follows:(1)With the development process to promote root system and the function leaf nitrate reductase(NR),glutamine synthetase(GS),glutamate synthetase(incor porated)glutamate dehydrogenase(GDH),aspertate aminotransferase(GOT),cereal third transaminase(GPT)activity were lower after the first rise trend,except root GDH,other key enzyme activity of root and leaf nitrogen metabolism function peak at the heading stage.The NR activity of roots under W2 treatment was significantly lower than that of W1,and the NR activity of functional leaves was not significantly different from that of W1.The activity of GS,GOGAT,GOT and GPT of roots and functional leaves were all higher than that of W1 under W2 treatment.The activity of GS,GOGAT,GOT and GPT in roots and functional leaves treated with W3 and W4 was significantly lower than that of W1,and decreased with the decrease of water potential.There was no significant difference in the activity of GS,GOGAT,GOT and GPT between the two varieties.Compared with W1,GDH activity of roots and functional leaves treated with W2 decreased,while tha t of Sujing18 roots at heading stage was significantly lower than that of Longqingdao21.(2)The activities of GS,GOGAT,GOT and GPT in grains gradually decreased with the increase of days after the heading,and reached the maximum at the 10 th day after th e heading.On the contrary,the activity of GDH increased with the increase of time.The activity of GS,GOGAT,GOT and GPT under W2 treatment was significantly increased compared with that under W1 treatment,while the activity of GDH was significantly de creased.There was no significant difference in the activity of GS,GOGAT,GOT,GPT and GDH between the two varieties.Under W3 and W4 treatment,GS,GOGAT,GOT and GPT were lower than W1,and GDH activity was higher than W1.(3)With the advancement of growth period,the nitrogen accumulation of rice plants increased gradually.There was no significant difference in root nitrogen accumulation between W2 treatment and W1 treatment.Nitrogen accumulation in leaf and stem sheath i ncreased significantly,while nitrogen accumulation in grain was significantly lower than W1 treatment.Nitrogen accumulation in W3 and W4 organs was significantly lower than that in W1,and decreased with the decrease of water potential.The distribution ratio of nitrogen in root system,leaf and stem sheath first increased and then decreased with the growing period,and the heading period was the largest,and then nitrogen was transferred to grain,and the nitrogen accumulation in grain gradually increased with the growing period,and the distribution ratio also gradually increased.With the decrease of water potential,nitrogen output rate and transport contribution rate of nutrient organs increased,but nitrogen production efficiency of rice decreased.C ompared with W1,there were no significant differences in nitrogen output rate,transport contribution rate and nitrogen rice production efficiency between W2 and W1.(4)The protein content of grains under W2 treatment was significantly higher than that under W1 treatment,while the difference between Sujing18 W3 and W4 treatments was not significant,but both treatments were lower than that under W1 treatment.The prot ein content of grains under Longqingdao21 under W3 treatment was higher than that under W1 treatment,while that under W4 treatment was lower than that under W1 treatment.The grain protein components(albumin,globulin,gliadin,and gluten)under W2 treatment were all higher than those under W1 treatment,but there was no significant difference between the two treatments.In the treatment of W3 and W4,the components in eggs were lower than W1 and the water potential in ears was reduced.The differences between Suijing18 W3 and W4 treatments were not significant.The protein components of Longqingdao21 under W3 treatment were significantly higher than those under W4 treatment.The content of gluten in each treatment was the highest compared with the other three protein components.Under the same treatment,the grain protein components of Suijing18 were significantly higher than those of longqingdao21.Correlation analysis showed that the content of grain protein components was positively correlated with the activities of NR,GS,GOGAT,GOT and GPT in roots and functional leaves,and negatively correlated with the activities of GDH.(5)The production decreases with the decrease of water potential.Compared with W1,the yield of Suijing18 under each treatment decreased by 2.80%,28.46% and 41.38% respectively.Compared with W1,the yield under W2 treatment did not decrease significantly.There were significant differences among the treatments of Longqingdao21,with the decreases of 9.87%,32.15% and 43.34%,respectively.From the perspective of sustainable development,light dry and wet alternate irrigation has the greatest comprehensive advantages. |
