Effects Of Different Kinds Of Nitrogen Fertilizer On The Growth And Development In Bambusa Emeiensis

Traditional paper industry uses wood as production material,which destroys the ecological environment greatly.It is imperative to find alternative materials for production.Because of its thin-wall of stem and longer fiber,Bambusa emeiensis is considered as a good raw material for papermaking.The Bambusa emeiensis treated by the different kinds of nitrogen fertilizer were used for the study.The shooting amounts,daily growth,base diameter,morphological analysis,soluble protein content,soluble sugar content and related enzyme activity were investigated.Additionally,a nitrate transporter gene NRT were cloned based on the Bambusa emeiensis transcriptome database,and named as BeNRT1.The relative expressions of BeNRT1 in different nitrogen fertilizer treatments of shoots were investigated.Moreover,the annual and biennial bamboos treated by the different kinds of nitrogen fertilizer were used for the study.The stem fiber morphology,fiber content and lignin content,and the soluble protein content,soluble sugar content and related enzyme activity and other biochemical characteristics of the expanded leaf were investigated,It is very important to understand the effects of the different kinds of nitrogen fertilizer on growth and wood property of Bambusa emeiensis.The main results are as follows:There were no obvious changes on the shooting amounts,the daily growth and the base diameter of shoots in Bambusa emeiensis after the different kinds of nitrogen fertilizer treatment.However,the shooting amounts treated by the nitrogen fertilizer are higher than that of non-nitrogen treatment.The effects of fertilization on annual stem fresh weight was not significant.But there were the obvious effects on the biennial stem fresh weight.Among them,the fresh weight of the stem treated by the NO₃^--N treatment was significantly higher than that of the control,which increased about 49.69 % compared with the control.Morphological analysis showed that when the NH₄⁺-N was applied,the thickness of the inner fiber strand and the height of central vascular bundle are significantly higher than those of other groups,and the thickness of the parenchyma cells between the two adjacent vascular bundles was significantly thicker than that of the control group,compared with the control,they were increased by 14.53%,19.49% and 10.58%,respectively.Moreover,the cell wall treated by NH₄⁺-N treatment had the stronger birefringence than other treatments.The analysis of middle biennial stem showed that the fiber length and the cellulose content decreased when treated by the NO₃^--N treatment,and the lignin content increased compared with the other treatments.However,the fiber length,length to width ratio and the cellulose content of the middle biennial stem treated by NH₄⁺-N treatment increased slightly compared with those of control which increased by 5.19% and 2.12% respectively,while the lignin content decreased by 3.01%.Among them,the fiber length,length to width ratio and cellulose content in the middle part of the stem with non-nitrogen were higher than those of other treatments.The soluble protein content in the base of shoots were significantly increased when NO₃^--N and?-CONH2?were applied,which reached 2.02 mg/g and 1.88 mg/g,respectively..However when the NH₄⁺-N was applied,the soluble sugar content at the base of the shoots were increased significantly compared with the other treatments,and increased by 0.96 % compared with the control.In addition,the NO₃^--N treatment could significantly increase the activity of nitrate reductase,and the NH₄⁺-N treatment could significantly increase the activity of glutamyl synthetase.The different kinds of nitrogen fertilizer could increase the chlorophyll content,and the chlorophyll content in the expanded leaves treated with NH₄⁺-N increased by 27.29% compared with the control.The application of NH₄⁺-N decreased the soluble protein content in the expanded leaves,but the soluble sugar content increased.Although,the soluble protein content in the expanded leaves treated by non-nitrogen treatment was significantly higher than that of the other treatments.The NO₃^--N treatment could significantly increase nitrate reductase activity in the expanded leaves,which increased by 334.65 % compared with the control,but the glutamyl synthetase and glutamate synthase activity in the expanded leaves treated by NO₃^--N and NH₄⁺-N treatment were significantly lower than other treatments.The application of NH₄⁺-N significantly increased the synthesis activity of sucrose synthase,and increased by 352.17 % compared with the control.The activity of sucrose phosphate synthase with non-nitrogen treatment was significantly higher than that of other treatments.Although the application of NO₃^--N could increase the fresh weight of the stem from the biennial,but it was unfavorable to the formation of fiber and accumulation of cellulose.The application of NH₄⁺-N could increase the cellulose content in a certain extent,and also reduced the content of lignin,and it was conducive to the formation of fiber.Therefore,it is recommended to apply NH₄⁺-N fertilizer,and to pay attention to the reasonable ratio of nitrogen,phosphorus and potassium,in the future cultivation in Bambusa emeiensis.A NRT gene sequence was cloned,named as BeNRT1?GenBank registration number was KY421770?,and the length of the open reading frame was 1611 bp,encoding a total of 536 amino acid residues.Multiple sequence alignments and phylogenetic analysis showed that the amino acid residues of BeNRT1 were similar to that of NRT genes in Arabidopsis,and the sequence identities among these genes were highly conserved.The BeNRT1 gene may be associated with nitrate transport.Besides,the qRT-PCR of the BeNRT1 gene showed that the application of NO₃^--N could significantly affect the expression in the base of the shoots,and the relative expression was significantly increased compared with the other treatments.