Effects of different nitrogen treatments on nitrogen uptake and distribution dynamics in different millet genotypes
[Objective]The study aimed to explore the physiological mechanism of nitrogen utilization of millet by determining dynamic effects of different nitrogen treatments on nitrogen uptake and distribution in different millet genotypes,laying a theoretical basis for the selection and cultivation of nitrogen-efficient millet varieties.[Method]Three varieties,i.e.,the nitrogen-sensitive variety Changnong 35(V1),the nitrogen-efficient variety Jigu 17(V2)and the conventional variety Yugu 18(V3),were employed as the ma-terials,and two treatments,i.e.,normal nitrogen level(NN)and no nitrogen level(N0),were set up.The ni-trogen content,chlorophyll content and photosynthetic rate and nitrogen transport and distribution capacity of each organ of the plants were analyzed in five periods of growth:seedling stage(SS),jointing stage(JS),gestation stage(BS),ear extraction stage(HS)and mature stage(MS)in the year 2021～2022.[Result]Un-der the two nitrogen treatments,the dynamic changes of nitrogen content in roots,stem sheaths and leaves during the whole growth period showed as follows:BS>SS>HS>MS>JS,BS>SS>HS>JS>MS,JS>SS>BS>HS>MS,respectively.The dynamic changes of chlorophyll content and photosynthetic rate in the leaves of different millet varieties showed as following:JS>SS>BS>HS>MS.Without nitrogen treat-ment,the chlorophyll content was 27.0%～34.4%,11.5%～14.7%higher in the leaves of nitrogen-tolerant variety Jigu 17 than in Changnong 35 and Yugu 18,respectively.The average nitrogen content was 13.6%and 1.3%higher in the roots,12.4%and 1.6%higher in stem sheath,and 9.7%and 8.6%higher in leaves of Jigu 17 than the other two cultivars,respectively.In 2022,the average nitrogen content of Jigu 17 was 4.7%and 0.7%higher in roots than Changnong 35 and Yugu 18,16.2%and 3.9%higher in stem sheaths,and 4.8%and 4.7%higher in the leaves.The nitrogen content and distribution ratio of each organ at the ripening stage of different millet cultivars ranged in the order as following:grains>leaves>stem sheaths>roots.Compared with Changnong 35 and Yugu 18,the nitrogen distribution ratio increased by 2.0%and 7.0%in the grain of Jigu 17,respectively.[Conclusion]The higher nitrogen uptake,transport and redistribution capacity of Jigu 17 contribute to its efficient utilization of nitrogen,and even in the envi-ronment of no nitrogen application,it can still grow well.Although the nitrogen-sensitive variety Chang-nong35 also has a strong capacity of nitrogen uptake,the nitrogen transport and redistribution capacity is too low,the nitrogen absorption and transport in the environment without nitrogen application is inadequate,and the nitrogen distribution in grains is too low,which limits the improvement of nitrogen efficiency.
milletgenotypenitrogen absorptionnitrogen distribution
万方数据
维普
