Phenological Change Of Nutritional Components In Fine Root And Leaf Of Chinese Jujube

We used Jinzao,Goutouzao and Qiyuexian Chinese jujube trees to study the varying patterns of soluble sugar,protein,and C,N,P in the fine roots and leaves from different phenological periods(germination stage,leaf extension early stage,leaf extension middle stage,whole leaf stage,fruit maturation stage,defoliation stage).It can provide the basis for aboveground and underground further researching and precise fertilization managemnets.We find that:1.The contents of soluble sugar,protein,organic carbon,total potassium,C/N and C/P increased with increasing root order,whereas the content of total nitrogen(except for the leaf extension middle stage of Qiyuexian)and total phosphorus decreased,N/P content had no obvious variety regulation;2.Along with the passage of the phenological period,soluble sugar and protein contents in fine roots changed as a “W” curve,the minimum value appeared in the fruit maturation stage,first increasing and then decreasing in the leaves,The soluble sugar and protein content of leaves had the minimum value in the defoliation stage and germination stage.The organic carbon content of fine root in Jinzao and Goutouzao was increased first then decreased and increased again,first increased and then decreased with the phenological period in Qiyuexian,the minimum organic carbon content of fine roots appeared in the fruit maturation stage,the organic carbon content changed in the opposite trend simultaneously in leaf and fine roots of Jinzao and Goutouzao,but with a small range,the highest and lowest value were in germination stage and whole leaf stage,organic carbon content in leaf is shown as: Qiyuexian > Goutouzao > Jinzao.3.Total nitrogen content in fine roots of Jinzao and Goutouzao changed as a “W” curve,in fine roots of Qiyuexian initially decreased and then increased,decreasing again in the leaves.Total phosphorus content first decreased and then increased,followed by another decrease in fine roots,the second and third class root in Goutouzao increased in fruit maturation stage,while continued in the leaves until the defoliation period and then increased.Total potassium content initially decreased and then increased,followed by another decrease in fine roots and leaves.Total nitrogen,phosphorus and potassium in leaves had the highest value in germination stage,but total nitrogen and potassium in fine roots had the lowest in germination stage.In fruit maturation stage,Qiyuexian had higher nitrogen and phosphorus content than Jinzao and Goutouzao,maybe illustrate fine roots of Qiyuexian has a better absorbing ability.4.C/N in fine roots and leaves of Jinzao and Goutouzao changed in small increments,but high content in fruit maturation stage,in leaves of Qiyuexian changed in a fluctuating tendency.C/P showed“N”type in Jinzao,Goutouzao and Qiyuexian fine root,in the leaves,decreasing initially and then increasing,and decreasing again,the minium value was observed in the germination stage,the maxium value was observed in the fruit maturation stage.N/P changed as a “N” curve in Jinzao fine roots and Goutouzao fine root,initially decreased and then increased in Qiyuexian fine roots,first increased and then decreased in leaves of Jinzao and Goutouzao,the highest appeared in whole leaf stage,flutuation decreasing in Qiyuexian leaves,the lower value in whole leaf stage.5.The nitrigen content has a positive correlation with phosphorus content in leaves of Jinzao,Goutouzao and Qiyuexian.For the same targets(soluble sugar,soluble protein,organic carbon,total nitrogen,phosphorus and potassium),first-class and second-class root were positively correlated.For the organic carbon,total nitrogen,total phosphorus and potassium,second-class and third-class root had positive correlation.Beyond that,total potassium in fine roots and organic carbon in leaves showed positive correlation.