Soil temperature influences crop growth and quality under field and greenhouse conditions;however, precise investigation using controlled cultivation systems is largely lacking. We investigated effects of root-zone te...Soil temperature influences crop growth and quality under field and greenhouse conditions;however, precise investigation using controlled cultivation systems is largely lacking. We investigated effects of root-zone temperatures on growth and components of hydroponically grown red leaf lettuce (Lactuca sativa L. cv. Red Wave) under a controlled cultivation system at 20°C. Compared with ambient root-zone temperature exposure, a 7-day low temperature exposure reduced leaf area, stem size, fresh weight, and water content of lettuce. However, root-zone heating treatments produced no significant changes in growth parameters compared with ambient conditions. Leaves under low root-zone temperature contained higher anthocyanin, phenols, sugar, and nitrate concentrations than leaves under other temperatures. Root oxygen consumption declined with low temperature root exposure, but not with root heating. Leaves of plants under low rootzone temperature showed hydrogen peroxide production, accompanied by lipid peroxidation. Therefore, low temperature root treatment is suggested to induce oxidative stress responses in leaves, activating antioxidative secondary metabolic pathways.展开更多
The production of a secondary metabolite such as anthocyanin is coordinately regulated by plant intrinsic factors and influenced by multiple environmental factors. In red leaf lettuce, the red pigment component anthoc...The production of a secondary metabolite such as anthocyanin is coordinately regulated by plant intrinsic factors and influenced by multiple environmental factors. In red leaf lettuce, the red pigment component anthocyanin is important for the commercial value of the crop, but its synchronous regulation by multiple factors is not well understood. Here, we examined the synergistic effects of a night temperature shift and methyl jasmonate (MJ) on the production of anthocyanin in red leaf lettuce. Low or high night temperature treatment for 3 days just before harvesting induced the production of anthocyanin without affecting plant biomass. Temperature-dependent activation of anthocyanin accumulation was accelerated by treating with MJ. Night temperature shifts and MJ triggered oxidative stresses in leaves, as indicated by hydrogen peroxide accumulation and lipid peroxidation. Interestingly, these oxidative stresses were more evident in leaves simultaneously treated with both a high night temperature and MJ. The activity of the superoxide dismutase (SOD) was increased alongside the elevation of oxidative stress. Taken together, these results indicate that the combined treatment of a night temperature shift with MJ may accelerate anthocyanin production by increasing the levels of oxidative stress to the leaves of red leaf lettuce.展开更多
Understanding plant responses under low-pressure conditions is important for developing closed cultivation systems that simulate space environments.This study aimed to assess the effects of different pressure levels o...Understanding plant responses under low-pressure conditions is important for developing closed cultivation systems that simulate space environments.This study aimed to assess the effects of different pressure levels on growth,photosynthesis,and secondary metabolite accumulation in red leaf lettuce(Lactuca sativa L.var.‘Super Caesar’s Red’).Plants were cultivated for three weeks in sealed chambers under 101 kPa(atmospheric pressure),66 kPa(moderate low pressure),and 33 kPa(severe low pressure).Growth analysis showed that leaf length and leaf area decreased significantly with reduced pressure,while chlorophyll content and SPAD values increased gradually.Photosynthetic measurements indicated lower transpiration and stomatal conductance under low pressure relative to atmospheric conditions,consistent with reduced stomatal size and density observed by SEM.Secondary metabolite analysis showed strong induction of anthocyanins(41.3%at 66 kPa and 190.8%at 33 kPa),with significant increases in phenolic and flavonoid contents.Thus,low-pressure conditions may suppress morphological growth but promote secondary metabolite contents,offering potential advantages for quality-oriented cultivation strategies.This study provides fundamental insights into physiological adaptation under low pressure and practical implications for crop selection and management in space agriculture and other controlled environments.展开更多
[ Objective] Correlation of microstructure of leaf sheath epidermis and nutrient composition of palm plants with the damage degree of red palm fiber elephant in four kinds of plants in Nanning were analyzed in order t...[ Objective] Correlation of microstructure of leaf sheath epidermis and nutrient composition of palm plants with the damage degree of red palm fiber elephant in four kinds of plants in Nanning were analyzed in order to control the occurrence and damage of this insect in Nanning. [Method] Taken 4 kinds of Palmae plants in Nanning including Ravenea fivulafis, Washingtonia filifera, Phoenix canafiensis, Roystonea regia （HBK.）O. F. Cook as materials, damage situation of the red palm fiber elephant was investigated, microstructure of leaf sheath epidermis and nutrient composition of palm plants were analyzed and determined. [ Result] The results showed that there was direct correlation between the microstructure of leaf sheath epidermis and nutrient composition with the physical resistance of palm plant against red palm fiber elephant. The extend of damage from red palm fiber elephant had negatively relation with the thickness of corneum and leaf epidermis. The damage degree caused by red palm fiber elephant increased with the content of crude protein, crude ash and nitrogen free extract increasing, also increased with the content of rude fiber decreasing. [Condusion] The damage degree of red palm fiber elephant had a relationship with microstructure of leaf sheath epidermis and nutrient composition of palm plants.展开更多
In the introduction and propagation of red sandalwood （Pterocarpus santalinus）, a serious leaf disease of its seedlings in winter and spring seasons was found, but the name of the disease and its pathogen species ha...In the introduction and propagation of red sandalwood （Pterocarpus santalinus）, a serious leaf disease of its seedlings in winter and spring seasons was found, but the name of the disease and its pathogen species have not been reported. The pathogen isolated from infected leaves of 18-month-old seedlings was identi- fied as Colletotrichum gloeosporioides by morphological characteristics of colony and conidium, and analysis results of rDNA-intemal transcribed spacer sequence （ITS） of the strain. Pathogenicity test results further confirmed that C. gloeosporioides was the pathogen responsible for the infected leaves symptoms of red sandal- wood. However, the disease belongs to an atypical anthraenose. Control of the leaf diseases of red sandalwood seedlings was discussed.展开更多
文摘Soil temperature influences crop growth and quality under field and greenhouse conditions;however, precise investigation using controlled cultivation systems is largely lacking. We investigated effects of root-zone temperatures on growth and components of hydroponically grown red leaf lettuce (Lactuca sativa L. cv. Red Wave) under a controlled cultivation system at 20°C. Compared with ambient root-zone temperature exposure, a 7-day low temperature exposure reduced leaf area, stem size, fresh weight, and water content of lettuce. However, root-zone heating treatments produced no significant changes in growth parameters compared with ambient conditions. Leaves under low root-zone temperature contained higher anthocyanin, phenols, sugar, and nitrate concentrations than leaves under other temperatures. Root oxygen consumption declined with low temperature root exposure, but not with root heating. Leaves of plants under low rootzone temperature showed hydrogen peroxide production, accompanied by lipid peroxidation. Therefore, low temperature root treatment is suggested to induce oxidative stress responses in leaves, activating antioxidative secondary metabolic pathways.
文摘The production of a secondary metabolite such as anthocyanin is coordinately regulated by plant intrinsic factors and influenced by multiple environmental factors. In red leaf lettuce, the red pigment component anthocyanin is important for the commercial value of the crop, but its synchronous regulation by multiple factors is not well understood. Here, we examined the synergistic effects of a night temperature shift and methyl jasmonate (MJ) on the production of anthocyanin in red leaf lettuce. Low or high night temperature treatment for 3 days just before harvesting induced the production of anthocyanin without affecting plant biomass. Temperature-dependent activation of anthocyanin accumulation was accelerated by treating with MJ. Night temperature shifts and MJ triggered oxidative stresses in leaves, as indicated by hydrogen peroxide accumulation and lipid peroxidation. Interestingly, these oxidative stresses were more evident in leaves simultaneously treated with both a high night temperature and MJ. The activity of the superoxide dismutase (SOD) was increased alongside the elevation of oxidative stress. Taken together, these results indicate that the combined treatment of a night temperature shift with MJ may accelerate anthocyanin production by increasing the levels of oxidative stress to the leaves of red leaf lettuce.
基金supported by the National Research Foundation(NRF)funded by the Korean government(MSIT)(No.RS-2024-00459463).
文摘Understanding plant responses under low-pressure conditions is important for developing closed cultivation systems that simulate space environments.This study aimed to assess the effects of different pressure levels on growth,photosynthesis,and secondary metabolite accumulation in red leaf lettuce(Lactuca sativa L.var.‘Super Caesar’s Red’).Plants were cultivated for three weeks in sealed chambers under 101 kPa(atmospheric pressure),66 kPa(moderate low pressure),and 33 kPa(severe low pressure).Growth analysis showed that leaf length and leaf area decreased significantly with reduced pressure,while chlorophyll content and SPAD values increased gradually.Photosynthetic measurements indicated lower transpiration and stomatal conductance under low pressure relative to atmospheric conditions,consistent with reduced stomatal size and density observed by SEM.Secondary metabolite analysis showed strong induction of anthocyanins(41.3%at 66 kPa and 190.8%at 33 kPa),with significant increases in phenolic and flavonoid contents.Thus,low-pressure conditions may suppress morphological growth but promote secondary metabolite contents,offering potential advantages for quality-oriented cultivation strategies.This study provides fundamental insights into physiological adaptation under low pressure and practical implications for crop selection and management in space agriculture and other controlled environments.
基金Jiangsu Province Basic Research Program （Natural Science Foundation） （BK2011443） Major Project of Ningbo, Zhejiang Province for Science and Technology Development （2009C10004）
基金Supported by Guangxi Agricultural College Science Topics(B070206)~~
文摘[ Objective] Correlation of microstructure of leaf sheath epidermis and nutrient composition of palm plants with the damage degree of red palm fiber elephant in four kinds of plants in Nanning were analyzed in order to control the occurrence and damage of this insect in Nanning. [Method] Taken 4 kinds of Palmae plants in Nanning including Ravenea fivulafis, Washingtonia filifera, Phoenix canafiensis, Roystonea regia （HBK.）O. F. Cook as materials, damage situation of the red palm fiber elephant was investigated, microstructure of leaf sheath epidermis and nutrient composition of palm plants were analyzed and determined. [ Result] The results showed that there was direct correlation between the microstructure of leaf sheath epidermis and nutrient composition with the physical resistance of palm plant against red palm fiber elephant. The extend of damage from red palm fiber elephant had negatively relation with the thickness of corneum and leaf epidermis. The damage degree caused by red palm fiber elephant increased with the content of crude protein, crude ash and nitrogen free extract increasing, also increased with the content of rude fiber decreasing. [Condusion] The damage degree of red palm fiber elephant had a relationship with microstructure of leaf sheath epidermis and nutrient composition of palm plants.
基金Supported by Natural Science Foundation of China(31270674)Innovative High School Key Research Platform of Zhaoqing University(CQ201607)
文摘In the introduction and propagation of red sandalwood （Pterocarpus santalinus）, a serious leaf disease of its seedlings in winter and spring seasons was found, but the name of the disease and its pathogen species have not been reported. The pathogen isolated from infected leaves of 18-month-old seedlings was identi- fied as Colletotrichum gloeosporioides by morphological characteristics of colony and conidium, and analysis results of rDNA-intemal transcribed spacer sequence （ITS） of the strain. Pathogenicity test results further confirmed that C. gloeosporioides was the pathogen responsible for the infected leaves symptoms of red sandal- wood. However, the disease belongs to an atypical anthraenose. Control of the leaf diseases of red sandalwood seedlings was discussed.
