Fragrant rice has a high market value,and it is a popular rice type among consumers owing to its pleasant flavor.Plantation methods,nitrogen(N)fertilizers,and silicon(Si)fertilizers can affect the grain yield and frag...Fragrant rice has a high market value,and it is a popular rice type among consumers owing to its pleasant flavor.Plantation methods,nitrogen(N)fertilizers,and silicon(Si)fertilizers can affect the grain yield and fragrance of fragrant rice.However,the core commercial rice production attributes,namely the head rice yield(HRY)and 2-acetyl-1-pyrroline(2-AP)content of fragrant rice,under various nitrogen and silicon(N-Si)fertilization levels and different plantation methods remain unknown.The field experiment in this study was performed in the early seasons of 2018 and 2019 with two popular indica fragrant rice cultivars(Yuxiangyouzhan and Xiangyaxiangzhan).They were grown under six N-Si fertilization treatments(combinations of two levels of Si fertilizer,0 kg Si ha^(−1)(Si0)and 150 kg Si ha^(−1)(Si1),and three levels of N fertilizer,0 kg N ha^(−1)(N0),150 kg N ha^(−1)(N1),and 220 kg N ha^(−1)(N2))and three plantation methods(artificial transplanting(AT),mechanical transplanting(MT),and mechanical direct-seeding(MD)).The results showed that the N-Si fertilization treatments and all the plantation methods significantly affected the HRY and 2-AP content and related parameters of the two different fragrant rice cultivars.Compared with the Si0N0 treatment,the N-Si fertilization treatments resulted in higher HRY and 2-AP contents.The rates of brown rice,milled rice,head rice,and chalky rice of the fragrant rice also improved with the N-Si fertilization treatments.The N-Si fertilization treatments increased the activities of N metabolism enzymes and the accumulation of N and Si in various parts of the fragrant rice,and affected their antioxidant response parameters.The key parameters for the HRY and 2-AP content were assessed by redundancy analysis.Furthermore,the structural equation model revealed that the Si and N accumulation levels indirectly affected the HRY by affecting the N metabolism enzyme activity,N use efficiency,and grain quality of fragrant rice.Moreover,high N and Si accumulation directly promoted the 2-AP content or affected the antioxidant response parameters and indirectly regulated 2-AP synthesis.The interactions of the MT method with the N-Si fertilization treatments varied in the fragrant rice cultivars in terms of the HRY and 2-AP content,whereas the MD method was beneficial to the 2-AP content in both fragrant rice cultivars under the N-Si fertilization treatments.展开更多
Vermicompost is an organic fertilizer contains multiple nutrient elements.However,the application of vermicompost in fragrant rice production is rarely reported.In order to study the effects of vermicompost applicatio...Vermicompost is an organic fertilizer contains multiple nutrient elements.However,the application of vermicompost in fragrant rice production is rarely reported.In order to study the effects of vermicompost application on fragrant rice(Oryza sativa L.)seedling performances,present study was conducted with two fragrant rice cultivars and four vermicompost rate treatments(0(CK),2.5(Wo1),5.0(Wo2)and 10.0(Wo3)g kg−1).The results showed that vermicompost treatments significantly increased dry weight of fragrant rice seedling by 8.31–32.56%compared with CK.21.10–59.13%higher net photosynthetic rates and 10.66–59.16%higher chlorophyll contents(chlorophyll a,chlorophyll b and total chlorophyll)were recorded in vermicompost treatments than CK.Application of vermicompost also significantly increased 2-acetyl-1-pyrroline(2-AP,the key compound of fragrant rice aroma)content and reduced the transcript level of gene BADH2 which related to 2-AP biosynthesis in fragrant rice seedling.Moreover,compared with CK,vermicompost treatments enhanced activities of superoxide dismutase,peroxidase,catalase by 24.42–28.66%,24.98–25.73%and 22.45–23.57%,respectively.11.54–40.53%lower malonaldehyde contents were recorded in vermicompost treatments in related to CK.In conclusion,vermicompost improved growth,increased 2-AP content and might enhance stress resistant of fragrant rice seedling.展开更多
Deep placement of nitrogen fertilizer is a key strategy for improving nitrogen use efficiency. A two-year field experiment was conducted during the early rice growing seasons(March–July) of 2016 and 2017.The experime...Deep placement of nitrogen fertilizer is a key strategy for improving nitrogen use efficiency. A two-year field experiment was conducted during the early rice growing seasons(March–July) of 2016 and 2017.The experimental treatments comprised two rice cultivars: Wufengyou 615(WFY 615) and Yuxiangyouzhan(YXYZ), and three N treatments: mechanical deep placement of all fertilizers as basal dose at 10 cm soil depth(one-time deep-placement fertilization, namely OTDP fertilization);manual surface broadcast(the common farmer practice) of 40% N fertilizer at one day before sowing(basal fertilizer)followed by broadcast application of 30% each at tillering and panicle initiation stages;and no fertilizer application at any growth stage as a control. One-time deep-placement fertilization increased grain yield of both rice cultivars by 11.8%–19.6%, total nitrogen accumulation by 10.3%–13.1%, nitrogen grain production efficiency by 29.7%–31.5%, nitrogen harvest index by 27.8%–30.0%, nitrogen agronomic efficiency by 71.3%–77.2%, and nitrogen recovery efficiency by 42.4%–56.7% for both rice cultivars, compared with the multiple-broadcast treatment. One-time deep-placement fertilization reduced CH4-induced global warming potential(GWP) by 20.7%–25.3%, N2O-induced GWP by 7.2%–12.3%, and total GWP by 14.7%–22.9% for both rice cultivars relative to the multiple-broadcast treatment. The activities of glutamine synthetase and nitrate reductase were increased at both panicle-initiation and heading stages in both rice cultivars following one-time deep-placement fertilization treatment. Larger leaf area index at heading stage and more favorable root morphological traits expressed as larger total root length, mean root diameter, and total root volume per hill were also observed. One-time deep-placement fertilization could be an effective strategy for increasing grain yield and nitrogen use efficiency and lowering greenhouse-gas emissions under mechanical direct-seeded cropping systems.展开更多
基金This project was financially supported by the National Natural Science Foundation of China(31601244 and 31971843)the Guangdong Provincial Key Field Research and Development Plan Project,China(2019B020221003)the Modern Agricultural Industrial Technology System of Guangdong Province,China(2020KJ105).
文摘Fragrant rice has a high market value,and it is a popular rice type among consumers owing to its pleasant flavor.Plantation methods,nitrogen(N)fertilizers,and silicon(Si)fertilizers can affect the grain yield and fragrance of fragrant rice.However,the core commercial rice production attributes,namely the head rice yield(HRY)and 2-acetyl-1-pyrroline(2-AP)content of fragrant rice,under various nitrogen and silicon(N-Si)fertilization levels and different plantation methods remain unknown.The field experiment in this study was performed in the early seasons of 2018 and 2019 with two popular indica fragrant rice cultivars(Yuxiangyouzhan and Xiangyaxiangzhan).They were grown under six N-Si fertilization treatments(combinations of two levels of Si fertilizer,0 kg Si ha^(−1)(Si0)and 150 kg Si ha^(−1)(Si1),and three levels of N fertilizer,0 kg N ha^(−1)(N0),150 kg N ha^(−1)(N1),and 220 kg N ha^(−1)(N2))and three plantation methods(artificial transplanting(AT),mechanical transplanting(MT),and mechanical direct-seeding(MD)).The results showed that the N-Si fertilization treatments and all the plantation methods significantly affected the HRY and 2-AP content and related parameters of the two different fragrant rice cultivars.Compared with the Si0N0 treatment,the N-Si fertilization treatments resulted in higher HRY and 2-AP contents.The rates of brown rice,milled rice,head rice,and chalky rice of the fragrant rice also improved with the N-Si fertilization treatments.The N-Si fertilization treatments increased the activities of N metabolism enzymes and the accumulation of N and Si in various parts of the fragrant rice,and affected their antioxidant response parameters.The key parameters for the HRY and 2-AP content were assessed by redundancy analysis.Furthermore,the structural equation model revealed that the Si and N accumulation levels indirectly affected the HRY by affecting the N metabolism enzyme activity,N use efficiency,and grain quality of fragrant rice.Moreover,high N and Si accumulation directly promoted the 2-AP content or affected the antioxidant response parameters and indirectly regulated 2-AP synthesis.The interactions of the MT method with the N-Si fertilization treatments varied in the fragrant rice cultivars in terms of the HRY and 2-AP content,whereas the MD method was beneficial to the 2-AP content in both fragrant rice cultivars under the N-Si fertilization treatments.
基金supported by National Natural Science Foundation of China(31971843)Technology System of Modern Agricultural Industry in Guangdong(2019KJ105)XT received the grant.
文摘Vermicompost is an organic fertilizer contains multiple nutrient elements.However,the application of vermicompost in fragrant rice production is rarely reported.In order to study the effects of vermicompost application on fragrant rice(Oryza sativa L.)seedling performances,present study was conducted with two fragrant rice cultivars and four vermicompost rate treatments(0(CK),2.5(Wo1),5.0(Wo2)and 10.0(Wo3)g kg−1).The results showed that vermicompost treatments significantly increased dry weight of fragrant rice seedling by 8.31–32.56%compared with CK.21.10–59.13%higher net photosynthetic rates and 10.66–59.16%higher chlorophyll contents(chlorophyll a,chlorophyll b and total chlorophyll)were recorded in vermicompost treatments than CK.Application of vermicompost also significantly increased 2-acetyl-1-pyrroline(2-AP,the key compound of fragrant rice aroma)content and reduced the transcript level of gene BADH2 which related to 2-AP biosynthesis in fragrant rice seedling.Moreover,compared with CK,vermicompost treatments enhanced activities of superoxide dismutase,peroxidase,catalase by 24.42–28.66%,24.98–25.73%and 22.45–23.57%,respectively.11.54–40.53%lower malonaldehyde contents were recorded in vermicompost treatments in related to CK.In conclusion,vermicompost improved growth,increased 2-AP content and might enhance stress resistant of fragrant rice seedling.
基金supported by the Key-Area Research and Development Program of Guangdong Province(2019B020221003)National Natural Science Foundation of Guangdong Province(008175187004)National Natural Science Foundation of China(31471442)。
文摘Deep placement of nitrogen fertilizer is a key strategy for improving nitrogen use efficiency. A two-year field experiment was conducted during the early rice growing seasons(March–July) of 2016 and 2017.The experimental treatments comprised two rice cultivars: Wufengyou 615(WFY 615) and Yuxiangyouzhan(YXYZ), and three N treatments: mechanical deep placement of all fertilizers as basal dose at 10 cm soil depth(one-time deep-placement fertilization, namely OTDP fertilization);manual surface broadcast(the common farmer practice) of 40% N fertilizer at one day before sowing(basal fertilizer)followed by broadcast application of 30% each at tillering and panicle initiation stages;and no fertilizer application at any growth stage as a control. One-time deep-placement fertilization increased grain yield of both rice cultivars by 11.8%–19.6%, total nitrogen accumulation by 10.3%–13.1%, nitrogen grain production efficiency by 29.7%–31.5%, nitrogen harvest index by 27.8%–30.0%, nitrogen agronomic efficiency by 71.3%–77.2%, and nitrogen recovery efficiency by 42.4%–56.7% for both rice cultivars, compared with the multiple-broadcast treatment. One-time deep-placement fertilization reduced CH4-induced global warming potential(GWP) by 20.7%–25.3%, N2O-induced GWP by 7.2%–12.3%, and total GWP by 14.7%–22.9% for both rice cultivars relative to the multiple-broadcast treatment. The activities of glutamine synthetase and nitrate reductase were increased at both panicle-initiation and heading stages in both rice cultivars following one-time deep-placement fertilization treatment. Larger leaf area index at heading stage and more favorable root morphological traits expressed as larger total root length, mean root diameter, and total root volume per hill were also observed. One-time deep-placement fertilization could be an effective strategy for increasing grain yield and nitrogen use efficiency and lowering greenhouse-gas emissions under mechanical direct-seeded cropping systems.
