Fuzhang Ding

The growth and development of plants are sensitive to their surroundings. Although numerous studies have analyzed plant transcriptomic variation, few have quantified the effect of combinations of factors or identified factor-specific effects. In this study, we performed RNA sequencing (RNA-seq) analysis on tobacco leaves derived from 10 treatment combinations of three groups of ecological factors, i.e., climate factors (CFs), soil factors (SFs), and tillage factors (TFs). We detected 4980, 2916, and 1605 differentially expressed genes (DEGs) that were affected by CFs, SFs, and TFs, which included 2703, 768, and 507 specific and 703 common DEGs (simultaneously regulated by CFs, SFs, and TFs), respectively. GO and KEGG enrichment analyses showed that genes involved in abiotic stress responses and secondary metabolic pathways were overrepresented in the common and CF-specific DEGs. In addition, we noted enrichment in CF-specific DEGs related to the circadian rhythm, SF-specific DEGs involved in mineral nutrient absorption and transport, and SF- and TF-specific DEGs associated with photosynthesis. Based on these results, we propose a model that explains how plants adapt to various ecological factors at the transcriptomic level. Additionally, the identified DEGs lay the foundation for future investigations of stress resistance, circadian rhythm and photosynthesis in tobacco.

Effective microorganism biochar-based fertilizer (EMBF) can improve the physiological properties of tobacco (Nicotiana tabacum L.) In this study, the irrigation and EMBF rates were applied as factors that influence the photosynthetic characteristics and chlorophyll content of tobacco. The experiment involved 12 treatments: CK1-CK3, T1-T3, T4-T6, and T7-T9; these four groups represented 0, 100, 300, and 600 g EMBF pot -1 , respectively. Each group was irrigated at rates of 40, 80, and 120 L pot -1 . When comparing with the control treatment CK, results showed that net photosynthetic rate (Pn), stomatal conductance (gs), intercellular CO2 concentration (Ci), transpiration rate (Tr), and soil plant analysis development (SPAD) increased by 8.21%-107.03%, 18.78%-118.27%, 18.78%-118.27%, 7.24%-104.15%, and 3.47%-69.09%, respectively, after EMBF application. The Pn, gs, Ci, and Tr at the growth and maturity stages were highly significant (P < 0.01) and positively correlated with EMBF application. The Pn, gs, and Tr were significant (P < 0.05) and positively correlated with irrigation, and Ci was less affected by irrigation (P > 0.05). The SPAD value of flue-cured tobacco at three growing stages was highly significant (P < 0.01) and positively correlated with the irrigation and fertilization rates. The SPAD values at the growth and maturity stages were higher than those at the rooting stage by 46.73%-79.2% and 2.21%-46.17%, respectively. Furthermore, the 80 L pot -1 irrigation rate combined with 300 g EMBF pot -1 is the best water and fertilizer combination. The results of this study might provide theoretical and practical guidance for growing flue-cured tobacco in production areas.

This study aimed to determine the effect of irrigation amount and irrigation frequency on drip-irrigated flue-cured tobacco evapotranspiration (ETa), yield, and water use efficiency. Four irrigation treatment levels were imposed: 100% IRT (fully irrigated treatment, no stress), 85% IRT, 70% IRT, RFT (rainfed treatment), and high, medium, and low irrigation frequencies were set. The relationship between irrigation volume and yield is a quadratic curve. The evapotranspiration had a positive relationship with the irrigation amount. The yield of flue-cured tobacco was the highest in 2016 (wet year), and the corresponding ETa was the smallest. The irrigation water use efficiency (IWUE) in the driest year, 2017, was lower than IWUE in the wet years 2015 and 2016, and the crop water use efficiency (CWUE) had similar results for the three years. IWUE increased with irrigation amount. The effect of irrigation frequency on CWUE was not significant. The CWUE had a positive relationship with yield. No significant differences due to irrigation frequency were found for yield.

Abstract An appropriate coupling of water fertilizer can improve the quality and yield of tobacco ( Nicotiana tabacum L.). However, the optimal scheme of that is still unknown under the condition of effective microorganisms (EM) biochar‐based fertilizer application. In this study, 12 treatments were set up, which were divided into four fertilization gradients (0, 100, 300, and 600 g pot –1 , represented CK1–CK3, T1–T3, T4–T6, and T7–T9, respectively), and each fertilization gradient had three irrigation gradients (40, 80, and 120 L pot –1 ). Each treatment was set in triplicate. Compared to CK, the nicotine content, reducing sugar, total nitrogen, potassium, chlorine, and yield of flue‐cured tobacco increased by 13.22–48.87%, 1.53–13.46%, 7.68–29.23%, 7.73–21.76%, 6.48–34.55%, and 7.93–65.51% after the application of EM biochar‐based fertilizer. The quality of flue‐cured tobacco was less affected by the amount of irrigation ( P &gt; .05), and the yield was positively correlated with the amount of irrigation and EM biochar‐based fertilizer ( P &lt; .05). The principal component analysis (PCA) was performed on all indexes of flue‐cured tobacco quality and established the comprehensive evaluation system. Analytic hierarchy process–entropy weight method (AHP–EWM) and projection pursuit classification (PPC) algorithms were utilized to build the model, and the optimal water–fertilizer coupling scheme was selected according to AHP–EWM score and projection values. In conclusion, 120 L pot –1 irrigation combined with 100 g pot –1 of EM biochar‐based fertilizer application treatment was the best water‐fertilizer coupling scheme, and the AHP–EWM score and projection value were .632 and 1.169. The results of this study might provide theoretical and practical guidance for the plantation of flue‐cured tobacco in production areas.