The application of nitrogen （N） fertilizers in agriculture has been increasing dramatically since 1970s. However, the over-fertilization causes could cause environmental problems, as well as low N use efficiency （...The application of nitrogen （N） fertilizers in agriculture has been increasing dramatically since 1970s. However, the over-fertilization causes could cause environmental problems, as well as low N use efficiency （NUE）. Promoting NUE in plants and minimizing the environmental impacts of N fertilizers had been the focus of the current research. We reviewed the importance of N, N metabolism and plant growth, plant N physiology and the molecular aspect of N metabolism in this paper. The future development of N use and NUE of plants was also discussed.展开更多
In order to develop the resources of native turfgrass,the morphological traits and drought resistance of native Siberian bluegrass(Poa sibirica,abbreviated as PS)was evaluated using the introduced Kentucky bluegrass&#...In order to develop the resources of native turfgrass,the morphological traits and drought resistance of native Siberian bluegrass(Poa sibirica,abbreviated as PS)was evaluated using the introduced Kentucky bluegrass'Midnight'(Poa pratensis,abbreviated as PP)as a control.Two water schemes were imposed to plants in this pot culture study in greenhouse.One was with drought stress persistent limiting water supply for 20 days,the other was re-hydrated until 14 days after drought.The leaf shape,turf color,water status and cell plasma membrane permeability were evaluated.Similar changing trends with these parameters were shown for both species,and there were not significant differences with most evaluations during drought and re-water periods.The values leaf width and length of PS were higher while leaf color intensity was slightly lower than that of PP,but the greenness of PS leaf was still visually acceptable.There were not significant differences with cell membrane stability between the two species.In comparison,the native wild species PS possessed the potential for to be domesticated into a new cultivar for turf industry.展开更多
In order to reveal the photosynthetic characteristics of C. trichotomum responses to drought, salt and water-logging stresses, one-year-old potted seedlings were taken as materials, and the several stresses including ...In order to reveal the photosynthetic characteristics of C. trichotomum responses to drought, salt and water-logging stresses, one-year-old potted seedlings were taken as materials, and the several stresses including natural drought, submergence stress, water-logging and different salt treatments （0.2%, 0.4%, 0.6% and 0.8% NaCl） were carried out on August 15, 2012. The morphological and photosynthetic characteristics were observed and determined. The results showed that adverse enviromental stress had a significant effect on the morphological changes and photosynthetic characteristics of C. trichotomum. On the 14th day after natural drought, the leaves wilted and could not recovery at night, and 60% of the seedlings could recover after re-watering. From the 7th day to the 10th day after submergence stress treatment, the 2nd and the 3rd leaves at the base of 60% seedling turned yellow and the lenticels were observed. At the early stage of water-logging stress, white lenticels appeared at the base of seedlings, and the leaves wilted, chlorina and fallen off on the 8th day. A large number of leaves fallen off under 0.6% NaCl or more salt stress, and even the whole plant died. The chlorophyll content, net photosynthetic rate （Pn） and transpiration rate （Tr） decreased gradually with the stress process, such as 8 days after natural drought, less than 0.4% salt stress and water-logging stress, but the changes were not significant compared with those of the control. With the increase of the stress intensity and the prolonged time, the changes of photosynthetic index were significant. All the results indicated that C. trichotomum had a certain degree of tolerance to drought, water and salt, but it was not suitable for living, in water-logging condition for a long time.展开更多
In order to explore the effects of low temperature on the two different genotypes of white clover, electrical conductivity （EC）, soluble sugar, malondialdehyde （MDA） and some other physiological indexes of plants ...In order to explore the effects of low temperature on the two different genotypes of white clover, electrical conductivity （EC）, soluble sugar, malondialdehyde （MDA） and some other physiological indexes of plants were compared under laboratory conditions. Seedlings of Longping No.1 and Koala were undergone a series of degrading temperatures set in turn 25℃, 10℃, 5℃, 0℃, –5℃ and –10℃. The results showed that the activities of superoxide dismutase （SOD）, electrical conductivity, soluble sugar, free proline and MDA increased obviously with the decrease of stress temperature, while the content of starch decreased, and the content of soluble protein increased first and then decreased during the process. Comprehensive assessments on physiological responses to low temperature stress indicated that the cultivar Longping No.1 had stronger cold resistance than that of cultivar Koala.展开更多
The mowing height and mowing frequency are the key factors that affect the turf quality and turfgrass growing ability. The purpose of this study was to reveal the alternative effcient interaction between mowing height...The mowing height and mowing frequency are the key factors that affect the turf quality and turfgrass growing ability. The purpose of this study was to reveal the alternative effcient interaction between mowing height and mowing frequency in Kentucky bluegrass turf management. The Kentucky bluegrass cultivar ＇Kenblue＇ （Poa pratensis L.） was used to evaluate the interactions of mowing heights （H1, H4 and H7） and mowing frequencies （F2, F5 and F8） on the performance of turfgrass and turf physiological responses under the feld condition. The results showed that the treatment of H7×F8 had perfect infuence on the turf texture, root elongation, and also enhanced soluble sugar and free proline content in plants. While, the turf quality, color, uniformity and the increasing tiller numbers were performed more superior in the treatment of H4×F5 than other treatments. In all the interacting treatments, the relation between leaf green index and number of shoots （dm2） was positively correlated, thus, it could be speculated that the proper mowing height with frequency had a strong impact on the increasing of turfgrass tillers. On the whole, the interaction of H4×F5 on turf quality was the most excellent treatment in this experiment.展开更多
基金Supported by the National Natural Science Foundation of China(3127219131372091)the Natural Science Foundation of Heilongjiang Province(C200619)
文摘The application of nitrogen （N） fertilizers in agriculture has been increasing dramatically since 1970s. However, the over-fertilization causes could cause environmental problems, as well as low N use efficiency （NUE）. Promoting NUE in plants and minimizing the environmental impacts of N fertilizers had been the focus of the current research. We reviewed the importance of N, N metabolism and plant growth, plant N physiology and the molecular aspect of N metabolism in this paper. The future development of N use and NUE of plants was also discussed.
基金Supported by the National Natural Science Fundation of China(31971772,31772354,31372091)College Student Innovation and Entrepreneurship Training Program of China(201910224035)。
文摘In order to develop the resources of native turfgrass,the morphological traits and drought resistance of native Siberian bluegrass(Poa sibirica,abbreviated as PS)was evaluated using the introduced Kentucky bluegrass'Midnight'(Poa pratensis,abbreviated as PP)as a control.Two water schemes were imposed to plants in this pot culture study in greenhouse.One was with drought stress persistent limiting water supply for 20 days,the other was re-hydrated until 14 days after drought.The leaf shape,turf color,water status and cell plasma membrane permeability were evaluated.Similar changing trends with these parameters were shown for both species,and there were not significant differences with most evaluations during drought and re-water periods.The values leaf width and length of PS were higher while leaf color intensity was slightly lower than that of PP,but the greenness of PS leaf was still visually acceptable.There were not significant differences with cell membrane stability between the two species.In comparison,the native wild species PS possessed the potential for to be domesticated into a new cultivar for turf industry.
基金Supported by the Major Scientific Research Projects of the 12th Five-year National Public welfare Industry(201104002-6)
文摘In order to reveal the photosynthetic characteristics of C. trichotomum responses to drought, salt and water-logging stresses, one-year-old potted seedlings were taken as materials, and the several stresses including natural drought, submergence stress, water-logging and different salt treatments （0.2%, 0.4%, 0.6% and 0.8% NaCl） were carried out on August 15, 2012. The morphological and photosynthetic characteristics were observed and determined. The results showed that adverse enviromental stress had a significant effect on the morphological changes and photosynthetic characteristics of C. trichotomum. On the 14th day after natural drought, the leaves wilted and could not recovery at night, and 60% of the seedlings could recover after re-watering. From the 7th day to the 10th day after submergence stress treatment, the 2nd and the 3rd leaves at the base of 60% seedling turned yellow and the lenticels were observed. At the early stage of water-logging stress, white lenticels appeared at the base of seedlings, and the leaves wilted, chlorina and fallen off on the 8th day. A large number of leaves fallen off under 0.6% NaCl or more salt stress, and even the whole plant died. The chlorophyll content, net photosynthetic rate （Pn） and transpiration rate （Tr） decreased gradually with the stress process, such as 8 days after natural drought, less than 0.4% salt stress and water-logging stress, but the changes were not significant compared with those of the control. With the increase of the stress intensity and the prolonged time, the changes of photosynthetic index were significant. All the results indicated that C. trichotomum had a certain degree of tolerance to drought, water and salt, but it was not suitable for living, in water-logging condition for a long time.
基金Supported by the State Key Lab of Plant Cell and Chromosome Engineering(PCCE-KF-2017-02)
文摘In order to explore the effects of low temperature on the two different genotypes of white clover, electrical conductivity （EC）, soluble sugar, malondialdehyde （MDA） and some other physiological indexes of plants were compared under laboratory conditions. Seedlings of Longping No.1 and Koala were undergone a series of degrading temperatures set in turn 25℃, 10℃, 5℃, 0℃, –5℃ and –10℃. The results showed that the activities of superoxide dismutase （SOD）, electrical conductivity, soluble sugar, free proline and MDA increased obviously with the decrease of stress temperature, while the content of starch decreased, and the content of soluble protein increased first and then decreased during the process. Comprehensive assessments on physiological responses to low temperature stress indicated that the cultivar Longping No.1 had stronger cold resistance than that of cultivar Koala.
基金Supported by the National Natural Science Foundation of China(31772354)the National Science Foundation of Heilongjiang Province of China(C200619)the State Key Lab of Plant Cell and Chromosome Engineering(PCCE-KF-2017-02)
文摘The mowing height and mowing frequency are the key factors that affect the turf quality and turfgrass growing ability. The purpose of this study was to reveal the alternative effcient interaction between mowing height and mowing frequency in Kentucky bluegrass turf management. The Kentucky bluegrass cultivar ＇Kenblue＇ （Poa pratensis L.） was used to evaluate the interactions of mowing heights （H1, H4 and H7） and mowing frequencies （F2, F5 and F8） on the performance of turfgrass and turf physiological responses under the feld condition. The results showed that the treatment of H7×F8 had perfect infuence on the turf texture, root elongation, and also enhanced soluble sugar and free proline content in plants. While, the turf quality, color, uniformity and the increasing tiller numbers were performed more superior in the treatment of H4×F5 than other treatments. In all the interacting treatments, the relation between leaf green index and number of shoots （dm2） was positively correlated, thus, it could be speculated that the proper mowing height with frequency had a strong impact on the increasing of turfgrass tillers. On the whole, the interaction of H4×F5 on turf quality was the most excellent treatment in this experiment.
