Can soil nitrate： ammonium ratios influence plant carbon： nitrogen ratios of the early succession plant？ Can plant carbon： nitrogen ratios limit the plant growth in early succession？ To address these two question...Can soil nitrate： ammonium ratios influence plant carbon： nitrogen ratios of the early succession plant？ Can plant carbon： nitrogen ratios limit the plant growth in early succession？ To address these two questions, we performed a two-factor （soil nitrate： ammonium ratio and plant density） randomized block design and a uniform-precision rotatable central composite design pot experiments to examine the relationships between soil nitrate： ammonium ratios, the carbon： nitrogen ratios and growth rate of Artemisia sphaerocephala seedlings. Under adequate nutrient status, both soil nitrate： ammonium ratios and plant density influenced the carbon： nitrogen ratios and growth rate of A. sphaerocephala seedlings. Under the lower soil nitrate： ammonium ratios, with the increase of soil nitrate： ammonium ratios, the growth rates of plant height and shoot biomass of A. sphaerocephala seedlings decreased significantly; with the increase of plant carbon： nitrogen ratios, the growth rates of shoot biomass of A. sphaerocephala seedlings decreased significantly. Soil nitrate： ammonium ratios affected the carbon： nitrogen ratios of A. sphaerocephala seedlings by plant nitrogen but not by plant carbon. Thus, soil nitrate： ammonium ratios influenced the carbon： nitrogen ratios of A. sphaerocephala seedlings, and hence influenced its growth rates. Our results suggest that under adequate nutrient environment, soil nitrate： ammonium ratios can be a limiting factor for the growth of the early succession plant.展开更多
Rice with polyembryony characterized bytwin seedlings is a good genetic tool for apomixisresearch.A study on the effect of five plantgrowth regulators(IAA,KT,GA,2,4-D and6-BAP)on rate of twin seedlings in 3 rice varie...Rice with polyembryony characterized bytwin seedlings is a good genetic tool for apomixisresearch.A study on the effect of five plantgrowth regulators(IAA,KT,GA,2,4-D and6-BAP)on rate of twin seedlings in 3 rice varie.ties with polyembryony(Shuang 3,Shuang 13and Lu 52)was conducted.The results showed展开更多
To address how the ratios of nitrogen and phosphorus (N:P ratios) in soil affect plant growth, we performed a two-factor (soil available N:P ratios and plant density) randomized block pot experiment to examine the rel...To address how the ratios of nitrogen and phosphorus (N:P ratios) in soil affect plant growth, we performed a two-factor (soil available N:P ratios and plant density) randomized block pot experiment to examine the relationships between soil N:P ratios, and the N:P ratios and growth rate of Artemisia ordosica seedlings. Under moderate water stress and adequate nutrient status, both soil N:P and plant density influenced the N:P ratios and growth rates of A. ordosica. With the increase of soil N:P ratios, the growth rates of A. ordosica seedlings decreased significantly. With the increase of soil N:P ratios, N:P ratios in A. ordosica seedlings increased significantly. While the nitrogen concentrations in the plant increased slightly, the phosphorus concentrations significantly decreased. With the increase of plant density, the shoot N:P ratios and growth rates significantly decreased, which resulted from soil N:P ratios. Thus, soil N:P ratios influenced the N:P ratios in A. ordosica seedlings, and hence, influenced its growth. Our results suggest that, under adequate nutrient environment, soil N:P ratios can be a limiting factor for plant growth.展开更多
The cluster planting pattern （3 plants per hole） for cotton （Gossypium hirsutum L.） may increase economic yield over those of the traditional planting pattern （1 plant per hole） in arid regions of China. This in...The cluster planting pattern （3 plants per hole） for cotton （Gossypium hirsutum L.） may increase economic yield over those of the traditional planting pattern （1 plant per hole） in arid regions of China. This increase in yield depends on either increased biomass production or greater partitioning to fruit. This study was conducted to determine whether differences in biomass accumulation or partitioning to reproductive growth contributed to higher yield in the cluster planting pattern compared with the traditional one. Growth parameters, biomass accumulation, crop growth rate and partitioning between cluster planting pattern and traditional planting pattern was compared in northwest of China. The biomass production and partitioning in cluster planting plot was higher than in traditional planting one. Biomass accumulation was faster early in the clustered treatment, and it was also higher at harvest time. Total dry matter production per unit area was significantly higher than in the traditional planting. On a per plant basis, dry matter accumulation was faster and total biomass production was significantly higher in the cluster planting pattern. Numbers of sympodia and boll sizes were also larger, indicating that facilitation among plants was promoting crop yield. The increase in yield in the cluster planting treatment occurred through increased partitioning of dry matter to fruits than in the traditional planting pattern, resulting in more bolls and increased lint yield in arid regions.展开更多
Cushion species occur in nearly all alpine environments worldwide. In past decades, the adaptive and ecosystem-engineering roles of such highly specialized life forms have been well studied. However, the adaptive stra...Cushion species occur in nearly all alpine environments worldwide. In past decades, the adaptive and ecosystem-engineering roles of such highly specialized life forms have been well studied. However, the adaptive strategies responsible for cushion species reproductive success and maintenance in severe alpine habitats remain largely unclear. In this study, we reviewed the current understanding of reproductive strategies and population persistence in alpine cushion species. We then present a preliminary case study on the sexual reproduction of Arenaria polytrichoides(Caryophyllaceae), a typical cushion species inhabiting high elevations of the Himalaya Hengduan Mountains, which is a hotspot for diversification of cushion species. Finally, we highlight the limitations of our current understanding of alpine cushion species reproduction and propose future directions for study.展开更多
Objective:To investigate the effects of radiation on growth-arrested(GA) and micronucleus-production(MP) rates,and the radioprotective properties of Thai medicinal plants in mouse macrophage cell line RAW264.7 in vitr...Objective:To investigate the effects of radiation on growth-arrested(GA) and micronucleus-production(MP) rates,and the radioprotective properties of Thai medicinal plants in mouse macrophage cell line RAW264.7 in vitro.Methods:Mouse macrophage cell line(RAW264.7) was cultured in vitro.Various radiation exposures, growth-arrested rate assay,micronucleus production assay,and radioprotection by Thai medicinal plants were performed.Results:The results showed that GA and MP rates forγ-rays and UV were dose-dependent. The 50%-affected dose ofγand UV radiation for the GA rate was 10 Gy and 159 microwatt/cm for 0.5 seconds, respectively.After X-ray exposure,there was no apparent effect on RAW264.7 cells,even with a fortyfold human diagnostic dose.Two exposures toγradiation at 20 Gy resulted in a significantly higher MP rate than 20 Gy single exposure or control(P【0.05).The Thai medicinal plants(Kamin-chun capsules,Curcuma longa Linn;Hed lingeu,Ganoderma lucidum;Ya Pakking capsule,Murdannia loriformis) could not prevent cell damage,but epigallocatechin gallate and L-cysteine could provide protection from 2 Gyγ-ray exposure. Conclusion:γradiation caused chromosomal damage during cell division and UV caused cell death, while X-ray radiation was safe.The radioprotective effects of Thai medicinal plants,Kamin-chun,Hed lingeu, and Ya Pakking,could not prevent cell damage in this study.展开更多
基金supported in part by the National Basic Research Program of China (2009CB421303)supported by National Natural Science Foundation of China (30970546)
文摘Can soil nitrate： ammonium ratios influence plant carbon： nitrogen ratios of the early succession plant？ Can plant carbon： nitrogen ratios limit the plant growth in early succession？ To address these two questions, we performed a two-factor （soil nitrate： ammonium ratio and plant density） randomized block design and a uniform-precision rotatable central composite design pot experiments to examine the relationships between soil nitrate： ammonium ratios, the carbon： nitrogen ratios and growth rate of Artemisia sphaerocephala seedlings. Under adequate nutrient status, both soil nitrate： ammonium ratios and plant density influenced the carbon： nitrogen ratios and growth rate of A. sphaerocephala seedlings. Under the lower soil nitrate： ammonium ratios, with the increase of soil nitrate： ammonium ratios, the growth rates of plant height and shoot biomass of A. sphaerocephala seedlings decreased significantly; with the increase of plant carbon： nitrogen ratios, the growth rates of shoot biomass of A. sphaerocephala seedlings decreased significantly. Soil nitrate： ammonium ratios affected the carbon： nitrogen ratios of A. sphaerocephala seedlings by plant nitrogen but not by plant carbon. Thus, soil nitrate： ammonium ratios influenced the carbon： nitrogen ratios of A. sphaerocephala seedlings, and hence influenced its growth rates. Our results suggest that under adequate nutrient environment, soil nitrate： ammonium ratios can be a limiting factor for the growth of the early succession plant.
文摘Rice with polyembryony characterized bytwin seedlings is a good genetic tool for apomixisresearch.A study on the effect of five plantgrowth regulators(IAA,KT,GA,2,4-D and6-BAP)on rate of twin seedlings in 3 rice varie.ties with polyembryony(Shuang 3,Shuang 13and Lu 52)was conducted.The results showed
基金supported in part by the National Basic Re-search Program of China (2009CB421303)supported by National Natural Science Foundation of China (30970546)
文摘To address how the ratios of nitrogen and phosphorus (N:P ratios) in soil affect plant growth, we performed a two-factor (soil available N:P ratios and plant density) randomized block pot experiment to examine the relationships between soil N:P ratios, and the N:P ratios and growth rate of Artemisia ordosica seedlings. Under moderate water stress and adequate nutrient status, both soil N:P and plant density influenced the N:P ratios and growth rates of A. ordosica. With the increase of soil N:P ratios, the growth rates of A. ordosica seedlings decreased significantly. With the increase of soil N:P ratios, N:P ratios in A. ordosica seedlings increased significantly. While the nitrogen concentrations in the plant increased slightly, the phosphorus concentrations significantly decreased. With the increase of plant density, the shoot N:P ratios and growth rates significantly decreased, which resulted from soil N:P ratios. Thus, soil N:P ratios influenced the N:P ratios in A. ordosica seedlings, and hence, influenced its growth. Our results suggest that, under adequate nutrient environment, soil N:P ratios can be a limiting factor for plant growth.
基金supported by the National Natural Sciences Foundation of China(31300323)China Postdoctoral Science Foundation Funded Project(2014M552515)
文摘The cluster planting pattern （3 plants per hole） for cotton （Gossypium hirsutum L.） may increase economic yield over those of the traditional planting pattern （1 plant per hole） in arid regions of China. This increase in yield depends on either increased biomass production or greater partitioning to fruit. This study was conducted to determine whether differences in biomass accumulation or partitioning to reproductive growth contributed to higher yield in the cluster planting pattern compared with the traditional one. Growth parameters, biomass accumulation, crop growth rate and partitioning between cluster planting pattern and traditional planting pattern was compared in northwest of China. The biomass production and partitioning in cluster planting plot was higher than in traditional planting one. Biomass accumulation was faster early in the clustered treatment, and it was also higher at harvest time. Total dry matter production per unit area was significantly higher than in the traditional planting. On a per plant basis, dry matter accumulation was faster and total biomass production was significantly higher in the cluster planting pattern. Numbers of sympodia and boll sizes were also larger, indicating that facilitation among plants was promoting crop yield. The increase in yield in the cluster planting treatment occurred through increased partitioning of dry matter to fruits than in the traditional planting pattern, resulting in more bolls and increased lint yield in arid regions.
基金supported by grants from the National Key Research and Development Program of China (grant no. 2017YFC0505200)the Major Program of National Natural Science Foundation of China (grant no. 31590823) to H Sunthe Natural Science Foundation of China (Grant no. 31500185 to JG Chen, 31470321 to Y Yang)
文摘Cushion species occur in nearly all alpine environments worldwide. In past decades, the adaptive and ecosystem-engineering roles of such highly specialized life forms have been well studied. However, the adaptive strategies responsible for cushion species reproductive success and maintenance in severe alpine habitats remain largely unclear. In this study, we reviewed the current understanding of reproductive strategies and population persistence in alpine cushion species. We then present a preliminary case study on the sexual reproduction of Arenaria polytrichoides(Caryophyllaceae), a typical cushion species inhabiting high elevations of the Himalaya Hengduan Mountains, which is a hotspot for diversification of cushion species. Finally, we highlight the limitations of our current understanding of alpine cushion species reproduction and propose future directions for study.
基金supported by the Faculty of Tropical Medicine,Mahidol University.
文摘Objective:To investigate the effects of radiation on growth-arrested(GA) and micronucleus-production(MP) rates,and the radioprotective properties of Thai medicinal plants in mouse macrophage cell line RAW264.7 in vitro.Methods:Mouse macrophage cell line(RAW264.7) was cultured in vitro.Various radiation exposures, growth-arrested rate assay,micronucleus production assay,and radioprotection by Thai medicinal plants were performed.Results:The results showed that GA and MP rates forγ-rays and UV were dose-dependent. The 50%-affected dose ofγand UV radiation for the GA rate was 10 Gy and 159 microwatt/cm for 0.5 seconds, respectively.After X-ray exposure,there was no apparent effect on RAW264.7 cells,even with a fortyfold human diagnostic dose.Two exposures toγradiation at 20 Gy resulted in a significantly higher MP rate than 20 Gy single exposure or control(P【0.05).The Thai medicinal plants(Kamin-chun capsules,Curcuma longa Linn;Hed lingeu,Ganoderma lucidum;Ya Pakking capsule,Murdannia loriformis) could not prevent cell damage,but epigallocatechin gallate and L-cysteine could provide protection from 2 Gyγ-ray exposure. Conclusion:γradiation caused chromosomal damage during cell division and UV caused cell death, while X-ray radiation was safe.The radioprotective effects of Thai medicinal plants,Kamin-chun,Hed lingeu, and Ya Pakking,could not prevent cell damage in this study.
