Effects Of Transplanting Period On Growth And Development Of Tobacco Plants And Carbon And Nitrogen Metabolism

Qianxinan Prefecture is one of the main producing areas for tobacco leaf production in Guizhou Province.In order to find a suitable transplanting period in Qianxinan Prefecture,this study carried out field trials on Yunyan 87,the main planted variety in Qianxinan Prefecture,and set 5 transplanting period treatments(T1:April 6,T2: April 13,T3).: April 20,T4: April 27 and T5: May 4)to analyze the effects of transplanting period and ecological environment variables(meteorological data and soil nutrients)on the growth and development of flue-cured tobacco and the expression of key enzymes and genes in carbon and nitrogen metabolism Influence,clarify the suitable transplanting period and its environmental and phenological conditions in the southwestern Guizhou tobacco area.The main findings are as follows:(1)The comparative analysis of agronomic traits,dry matter accumulation and distribution ratio and economic traits of tobacco plants under different transplanting treatments showed that: during the growth period of flue-cured tobacco,T2,T3 and T4 treatments had better agronomic traits,while T1 and T5 treatments are poor;in the early growth period,T3 treatment can effectively promote the dry matter accumulation of flue-cured tobacco roots,stalks and tobacco leaves.The dry matter distribution ratio is leaf>stem>root.The dry matter accumulation effect of tobacco leaves is the best,and the dry matter distribution ratio is stem>leaf>root;the transplanting period has a significant impact on the economic properties of flue-cured tobacco.The yield and output value of flue-cured tobacco are the highest in T4treatment;average price is highest in T3 treatment;The proportion of high-class smoke is the highest;the proportion of medium smoke is the best in T2 treatment.It shows that the growth and development of flue-cured tobacco transplanted in the middle and late April in Qianxinan tobacco area is better.(2)Enzyme-linked immunosorbent assay and SYBR Green?Real Time PCR were used to determine the key enzymes of carbon and nitrogen metabolism and their related genes,and the data obtained were imported into SPSS22.0 for significance analysis and correlation analysis.The results showed that: tobacco sucrose invertase(The activity of SS is highest in T2 treatment.In the same growth period,the SS activity of T2 and T3 treatments is higher than other treatments.The ?-amylase(?-Amylase)activity of T2 and the sucrose synthase(INV)activity of T1 are significantly higher.In other treatments,the nitrate reductase(NR)activity of tobacco plants treated with T1,T2,and T3 showed a trend of first increasing and then decreasing.The glutamate synthase(GS)activity of tobacco plants transplanted later was 40 d The GS activity of tobacco plants transplanted earlier reached the peak at 60 d.Early-transplanted tobacco plants have higher total sugar content in the early growth period,and later-transplanted tobacco plants have a stronger ability to accumulate total sugar content in the later growth period.The reducing sugar content shows a trend of first decline-then increase-then decline-then increase The content of nicotine gradually increased with the postponement of the transplanting period,while total nitrogen showed a pattern of first decreasing and then increasing,protein showed a trend of first decreasing and then increasing.The carbon metabolites of flue-cured tobacco leaves treated with T2 and T3 were closer to that of high-quality tobacco.At the same level,the content of nitrogenous compounds in T3 treated tobacco plants was within the range of high-quality tobacco leaves.It shows that the tobacco plants transplanted in the mid-to-late April in Qianxinan tobacco area have strong carbon and nitrogen metabolism.(3)Compare the change trends of climatic factors and soil nutrients under the treatments of the five transplanting periods,and analyze the correlation between the two and the economic properties of flue-cured tobacco and the main products of carbon and nitrogen metabolism,and find the main climatic factors and soil that affect the growth and development of flue-cured tobacco The results showed that during the growth period of flue-cured tobacco,sunshine hours had a significant correlation with the output value of flue-cured tobacco in the later growth period.The average temperature had a significant correlation with the protein content of the lower leaves.Rainfall,average temperature and 5 cm and 5 cm The average soil temperature of 15 cm was significantly correlated with the nicotine content of the upper leaves,sunshine hours and the reducing sugar and total sugar content of the middle leaves,and the average soil moisture of 5 cm were significantly correlated with the total sugars of the upper leaves and the reducing sugar content of the lower leaves.Soil alkaline hydrolyzable nitrogen and organic matter have a significant correlation with the average price of flue-cured tobacco,available potassium and medium tobacco rate,organic matter and lower leaf nicotine content,available potassium and lower leaf protein content,alkaline hydrolyzed nitrogen and upper leaf total sugar and reducing sugar There is a significant correlation,and other climatic factors and soil nutrient indicators have little effect on the economic characteristics of flue-cured tobacco and carbon and nitrogen metabolites.In summary,through the study of the effects of different transplanting periods on the growth and development of flue-cured tobacco and carbon and nitrogen metabolism,it is concluded that the appropriate transplanting period for flue-cured tobacco in southwestern Guizhou is mid-to-late April.