Using Tongxian No.2 as material, the effects of different film-covering time, different sowing time and different planting density on the occurrence of freeze injury and yield of fresh broad beans were investigated. T...Using Tongxian No.2 as material, the effects of different film-covering time, different sowing time and different planting density on the occurrence of freeze injury and yield of fresh broad beans were investigated. The randomized block design was adopted. The results showed that with the delayed film covering, the incidence of mild freeze injury and number of headless seedlings were increased correspondingly, but the yield was increased; with the delayed sowing, the branch number per plant, effective branch number per plant, incidence of mild freeze injury and number of headless seedlings were all reduced, and the broad beans, sowed on September 30 th, obtained the highest yield; planting density showed on effect on the occurrence of freeze injury, and the yield was increased with the increase of planting density. Under the same film-covering time, the incidence of freeze injury was reduced with the delayed sowing time and it showed no changes when planting density was changed, but the yield was increased with the increase of planting density and it was highest when broad bean seeds were sowed on September 30th;under the same sowing time, the incidence of freeze injury was increased with the delayed film-covering time and it showed no changes when planting density was changed, and the yield was increased with the delayed film-covering time and increased planting density; under the same planting density, the incidence of freeze injury was increased with the delayed film-covering time but was reduced with the delayed sowing time, and the yield was increased with the delayed film-covering time and it was highest when the broad bean seeds were sowed on September30 th. Under same film-covering time and sowing time, the total branch number per plant and effective branch number per plant were reduced, but the yield was increased with the increase of planting density; under same film-covering time and planting density, the incidence of freeze injury was reduced with the delayed sowing time, and the yield was highest when broad bean seeds were sowed on September30th; under same sowing time and planting density, the incidence of freeze injury and the yield were all increased with the delayed film-covering time.展开更多
Freezing injury is one of the major disasters for the production of winter wheat in the North China Plain, which leads to a significant decrease of wheat yield. This study was conducted to investigate the impact of su...Freezing injury is one of the major disasters for the production of winter wheat in the North China Plain, which leads to a significant decrease of wheat yield. This study was conducted to investigate the impact of subfreezing temperature on freezing injury of various winter wheat cultivars at different sowing time. Three wheat cultivars, including Zhengmai 9023, Wanmai 48 and Wanmai 50, were sowed on 25 September and 5 October, respectively. Plant anatomy was applied to investi- gate the impact of subfreezing temperature on cells of three wheat cultivars, results showed that severe plasmolysis occurred in wheat sowed earlier suddenly encoun- tered subfreezing temperature without cold acclimation, compared with wheat sowed at proper sowing time. The degree of plasmolysis of different cultivars and tissues of wheat had significant differences and showed positive correlation with subfreezing temperature. Wanmai 50 had the highest cold resistance compared with Zhengmai 9023 and Wanmai 48, and there was no significant difference between Zhengmai 9023 and Wanmai 48. This study concluded that wheat cold resistance may be im- proved by adopting proper cultivars and sowing dates.展开更多
[ Objective] This study was to understend the optimized combination of planting density, duration of disclosing plastic film and nitrogen fertilization under no-tillage cultivation. [ Method] Quadratic polynomial regr...[ Objective] This study was to understend the optimized combination of planting density, duration of disclosing plastic film and nitrogen fertilization under no-tillage cultivation. [ Method] Quadratic polynomial regression and saturated D-optimal design were employed to investigate the effects of planting density, duration of disclosing plastic film and nitrogen fertilization on the dynamics growth of rapeseed under no-tillage cultivation.[ Result] Within the experimental range, the growth dynamics of no-tillage cultivated rapeseed assumed a rise-fall tend. For the effects to the growth dynamics of no-tillage cultivated rapeseed, nitrogen application amount was higher than planting density and duration of disclosing plastic film. The interaction effect between planting density and duration of disclosing plastic film was higher than that between nitrogen application amount and planting density, and between nitrogen application amount and duration of disclosing plastic film. [ Conclusion] The optimized combination of these factors for dynamic growth of rapeseed under no-tillage cultivation was determined to be: planting density of per hectare 154 925 individuals, duration of disclosing plastic film of 110 d, nitrogen application amount of 315 kg/hm^2.展开更多
We examined the competitive ability of larval toads (Bufo gargarizans ) and frogs (Rana kukunoris ) which co-occur in natural pools in the Jiuzhaigou Nature Reserve. We measured the activity level, growth rate, ma...We examined the competitive ability of larval toads (Bufo gargarizans ) and frogs (Rana kukunoris ) which co-occur in natural pools in the Jiuzhaigou Nature Reserve. We measured the activity level, growth rate, mass at metamorphosis and larval period in a laboratory experiment. Tadpoles of B. gargarizans were significantly more active when food was abundant than scarce, while there was no significant difference in the activity of R. kukunoris tadpoles at different food levels. At low food availability, mass at metamorphosis and growth rate of R. kukunoris were significantly increased in the presence of B. gargarizans, whereas the presence of R. kukunoris had no significant effect on the mass and growth rate of B. gargarizans. In all treatments, the larval period of B. gargarizans at low food availability was the shortest. These results suggest that B. gargarizans can adapt to different food levels by changing their activity rate. At high food level, B. gargarizans increased activity to gain more food. At low food level, B. gargarizans decreased activity and achieved early metamorphosis. However, when food resources were limited, R. kukunoris could gain more food than B.gargarizans .展开更多
[Objective] The aim was to improve part of auto-control system of aquatic seedling breeding and to lay foundation for highly-efficient and stable use of the sys- tem. [Method] The executive and drive modules of the au...[Objective] The aim was to improve part of auto-control system of aquatic seedling breeding and to lay foundation for highly-efficient and stable use of the sys- tem. [Method] The executive and drive modules of the auto-control system were im- proved, after which real-time monitor, data display and alarm modules were tested on time. [Result] In the test, for the improved system, stability and sensitivity were enhanced; different components matched better; transmitting electric resistanc6 was reduced. [Conclusion] The research provides references for auto-control of water temperature and dissolved oxygen, and faults clearing in aquatic seedling breeding.展开更多
This paper considers the travelling wave fronts to a delayed lattice differential equation. The existence of the travelling wave solutions is proved by making use of the technique of the upper and lower solutions deve...This paper considers the travelling wave fronts to a delayed lattice differential equation. The existence of the travelling wave solutions is proved by making use of the technique of the upper and lower solutions developed by J Wu and X Zou in [6]. This work extends that of [4] in a general class of nonlinear terms.展开更多
[Objective] This study was conducted to investigate the effects of different gibberellic acid and hydrogen peroxide concentrations and different soaking time on the germination potential and germination rate of Scutel...[Objective] This study was conducted to investigate the effects of different gibberellic acid and hydrogen peroxide concentrations and different soaking time on the germination potential and germination rate of Scutellaria baicalensis, so as to improve the breeding efficiency of S. baicalensis. [Method] Dry seeds were divided into 3 groups, each containing 50 grains, which were weighed and put in a culture dish and soaked with distilled water covering the surface of seeds at room temperature. The seed weight was measured by gravimetric method once every 30 min from 30 rain after soaking, until the weight of the seeds no longer changed. [Result] With the increase of the concentration of hydrogen peroxide, the germination rate of S. baicalensis was improved gradually, and reached 32.0% under the concentration of 1.0% at the soaking time of 24 h; and with the increase of the concentration of gibberellic acid, the germination rate of S. baicalensis was improved gradually, and reached 64.0% under the concentration of 600 mg/L at the soaking time of 24 h. [Conclusion] The constant temperature at 25 ℃ in the incubator could also improve the seed germination rate; and the germination rate achieved by treating the seeds with gibbereUic acid was remarkably higher than that achieved by treating the seeds with hydrogen peroxide.展开更多
Chunyou 59 is a japonica-indica hybrid rice combination developed from Chunjiang 16A(a late japonica CMS line with dwarfness and early anthesis time)and CH59(an indicaclinous wide compatibility restorer line).It has t...Chunyou 59 is a japonica-indica hybrid rice combination developed from Chunjiang 16A(a late japonica CMS line with dwarfness and early anthesis time)and CH59(an indicaclinous wide compatibility restorer line).It has the characteristics of strong heterosis,strong stem,good lodging resistance,large panicles,good cold tolerance,high yield and wide adaptability.It was registered and released by Jiangxi Provincial Crop Variety Appraisal Committee in March 2009.The breeding procedure,characteristics,major techniques of cultivation and seed production of Chunyou 59 were introduced in the paper.展开更多
AIM To evaluate the accuracy of the elastography score combined to the strain ratio in the diagnosis of solid pancreatic lesions(SPL). METHODS A total of 172 patients with SPL identified by endoscopic ultrasound were ...AIM To evaluate the accuracy of the elastography score combined to the strain ratio in the diagnosis of solid pancreatic lesions(SPL). METHODS A total of 172 patients with SPL identified by endoscopic ultrasound were enrolled in the study to evaluate the efficacy of elastography and strain ratio in differentiating malignant from benign lesions. The semi quantitative score of elastography was represented by the strain ratio method. Two areas were selected, area(A) representing the region of interest and area(B) representing the normal area. Area(B) was then divided by area(A). Sensitivity, specificity, positive predictive value(PPV), negative predictive value(NPV), and accuracy were calculated by comparing diagnoses made by elastography, strain ratio and final diagnoses.RESULTS SPL were shown to be benign in 49 patients and malignant in 123 patients. Elastography alone had a sensitivity of 99%, a specificity of 63%, and an accuracy of 88%, a PPV of 87% and an NPV of 96%. The best cut-off level of strain ratio to obtain the maximal area under the curve was 7.8 with a sensitivity of 92%, specificity of 77%, PPV of 91%, NPV of 80% and an accuracy of 88%. Another estimated cut off strain ratio level of 3.8 had a higher sensitivity of 99% and NPV of 96%, but with less specificity, PPV and accuracy 53%, 84% and 86%, respectively. Adding both elastography to strain ratio resulted in a sensitivity of 98%, specificity of 77%, PPV of 91%, NPV of 95% and accuracy of 92% for the diagnosis of SPL. CONCLUSION Combining elastography to strain ratio increases the accuracy of the differentiation of benign from malignant SPL.展开更多
In this research, one-dimensional stratiform a novel dual-model system, cold cloud model (1DSC) coupled to Weather Research and Forecast (WRF) model (WRF-1DSC for short), was employed to investigate the effects ...In this research, one-dimensional stratiform a novel dual-model system, cold cloud model (1DSC) coupled to Weather Research and Forecast (WRF) model (WRF-1DSC for short), was employed to investigate the effects of cloud seeding by silver iodide (AgI) on rain enhancement. Driven by changing environmental conditions extracted from the WRF model, WRF-1DSC could be used to assess the cloud seeding effects quantitatively. The employment of WRF- 1DSC, in place of a one-dimen- sional two-moment cloud seeding model applied to a three-dimensional mesoscale cloud-resolving model, was found to result in massive reduction of computational resources. Numerical experiments with WRF-1DSC were conducted for a real stratiform precipitation event ob- served on 4-5 July 2004, in Northeast China. A good agreement between the observed and modeled cloud system ensured the ability of WRF-1DSC to simulate the observed precipitation process efficiently. Sensitivity tests were performed with different seeding times, locations, and amounts. Experimental results showed that the optimum seeding effect (defined as the percentage of rain enhancement or rain enhancement rate) could be achieved through proper seeding at locations of maximum cloud water content when the updraft was strong. The optimum seeding effect was found to increase by 5.61% when the cloud was seeded at 5.5 km above ground level around 2300 UTC 4 July 2004, with the maximum AgI mixing ratio (As) equaling 15 ng kg-1. On the other hand, for an overseeded cloud, a significant reduction occurred in the accumulated precipitation (-12.42%) as Xs reached 100 ng kg^-1. This study demonstrates the potential of WRF- 1DSC in determining the optimal AgI seeding strategy in practical operations of precipitation enhancement.展开更多
With super hybrid rice cultivar Y Liangyou 1 as the experimental material, seed-setting rate, abortive grain rate, empty grain rate and 1 000-seed weight were investigated for continuous 10 days since the first day po...With super hybrid rice cultivar Y Liangyou 1 as the experimental material, seed-setting rate, abortive grain rate, empty grain rate and 1 000-seed weight were investigated for continuous 10 days since the first day post-harvest to reveal the correlation between differences in seed-setting characters of rice and seed investiga- tion time. The results indicated that seed-setting rate, abortive grain rate, empty grain rate and 1 000-seed weight varied at different seed investigation time. With the postponement of seed investigation, seed-setting rate and 1 000-seed weight showed downward trends, abortive grain rate showed an upward trend, while empty grain rate exhibited a significant correlation with seed investigation time. Seed-setting rate, abortive grain rate and 1 000-seed weight exhibited no significant differences within the first three days after the harvest; since day 4, seed-setting rate and 1000-seed weight declined remarkably, while abortive grain rate increased signifi- cantly. Based on the correlation between seed-setting characters of rice and seed investigation time, the analysis of seed-setting characters of rice and other cereal crops should be completed within the first three days after the harvest, thereby im- proving the accuracy of relative conclusion.展开更多
A laboratory reactor was designed to test the effect of the interference instant of HY on the pyrolysis of pubescens.The time instant for intermediate species from pyrolysis to contact HY was controlled by varying the...A laboratory reactor was designed to test the effect of the interference instant of HY on the pyrolysis of pubescens.The time instant for intermediate species from pyrolysis to contact HY was controlled by varying the position of the catalyst bed relative to the pyrolytic cell.It was found that the effect of the interference instant was significant on the variation of different intermediate species,and the yield and quality of the products.The results also showed that,with the increase in the distance between the pyrolytic cell and the catalyst bed,the yield of liquid and relative content of the organics such as aldehyde,phenols,etc.,decreased,while the yield of residue and relative content of acetic acid increased.The deoxygenation of the intermediate species was favored when the catalyst exerted its performance on them immediately after their formation.展开更多
The aim of the study is to examine the influence of the outplanting time on the cultivation of the kelp Laminaria saccharina in the northwestern Spain, close to its southern limit of distribution in the North Atlantic...The aim of the study is to examine the influence of the outplanting time on the cultivation of the kelp Laminaria saccharina in the northwestern Spain, close to its southern limit of distribution in the North Atlantic coast. We compared two L. saccharina cultures outplanted in February and December. We found that the starting time of outplanting affects to the yield and the substantiality value, as well as the growth rate. The yield, the substantiality value and the growth rates of L. saccharina sporophytes obtained for the trial outplanted in December were significantly higher than those in February. These results can be mainly explained by the effect of temperature on the growth of L. saccharina sporophytes during cultivation. On the other hand, our results show that even in the southern limit of distribution of L. saccharina, the cultivation of this species was very profitable in high yield and quality.展开更多
The simplified incidence function model which is driven by the colored correlated noises is employed to investigate the extinction time of a metapopulation perturbed by environments. The approximate Fokker-Planck Equa...The simplified incidence function model which is driven by the colored correlated noises is employed to investigate the extinction time of a metapopulation perturbed by environments. The approximate Fokker-Planck Equation and the mean first passage time which denotes the extinction time (Tex) are obtained by virtue of the Novikov theorem and the Fox approach. After introducing a noise intensity ratio and a dimensionless parameter R = D /α (D and a are the multiplicative and additive colored noise intensities respectively), and then performing numerical computations, the results indicate that: (i) The absolute value of correlation strength A and its correlation time τ3 play opposite roles on the Tex; (ii) For the case of 0 〈λ〈 1,α and its correlation time τ2 play opposite roles on the Tex in which R〉 1 is the best condition, and there is one-peak structure on the Tex - D plot; (iii) For the case of-1 〈 λ≤ 0, D and its correlation time τ1 play opposite roles on the Tex in which R 〈 1 is the best condition and there is one-peak structure on the Tex - τ2 plot.展开更多
Development of stable crops cultivars adapted to environmental constraints is very important for food security. Safflower, an oilseed crop which tolerates environmental abiotic stresses, is suitable for marginal lands...Development of stable crops cultivars adapted to environmental constraints is very important for food security. Safflower, an oilseed crop which tolerates environmental abiotic stresses, is suitable for marginal lands relatively dry and deprived from fertilizer inputs or irrigation. A set of Moroccan and introduced cultivars as well as international accessions were conducted at Oujda (Eastern of Morocco) during 2009-2010 for late and conventional sowing under two water regimes, in a field experiment using a completely randomized design, with three replications. The objective was to evaluate the effect of genotype and contrasting environment on safflower behavior and to select genotypes with large adaptation to the contrasted environmental conditions. Morphological, physiological and agronomic traits, as well as the stress susceptibility index (SSI), were recorded in this study. Results showed significant effect of genotype, year (sowing time), water regime and their interaction on most of the studied parameters. Late sowing and drought affected negatively all the parameters except seed oil which lightly increased under drought stress. Number of heads per plant (NHP) had the strongest association with seed yield under both drought and non-drought conditions, and hence could be taken as selection criterion for safflower seed yield improvement. Five accessions showed the highest overall mean seed yield (~ 1,000 kg/ha) and four accessions exhibited the highest overall mean seed oil content (〉 310 g/kg). For late sowing, the accessions P1262421 and PI537604 produced the highest seed yield (〉 800 kg/ha) and the highest seed oil content (〉 290 g/kg). For conventional sowing, the accessions PI250076 and PI250523 were the most performant, with a seed yield 〉 1,300 kg/ha and a seed oil content 〉 330 g/kg. Based on their mean productivity across environments, their SSI and their MDA, P1271073 and P1250076 could be selected and used as promising germplasm in safflower breeding program in Morocco as well as other dry areas throughout the world.展开更多
[Objective] The aim of this study was to compare the morphological char- acteristics of rice (Oryza sativa L.) with different cultivation methods and investigate the dynamics of organ growth and development characte...[Objective] The aim of this study was to compare the morphological char- acteristics of rice (Oryza sativa L.) with different cultivation methods and investigate the dynamics of organ growth and development characteristics of different rice culti- vars. [Method] Based on continuous field observation and destructive sampling over a growing season, detailed organ morphological data were obtained including leaf length, node number, plant height, tiller number, leaf angle, leaf area and specific leaf weight, to compare organ morphological differences among 4 rice cultivars of Baidao (indica), Jinnanfeng (japonica), 9325 (japonica) and 9915 (japonica) with 3 cultivation methods of field planting in Weigang, pot planting in Weigang, and field planting in Jiangpu. [Result] Maximum leaf length of each node gradually increased at the early growth stage and decreased at the later growth stage, the relationship between maximum leaf length and node position can be described by the equations y=a,,-~ and y=ax+b; node number, growth duration, leaf length and plant height of pot planting rice in Weigang were smaller than that of the other two field planting meth- ods; the relationship between plant height and sunshine duration, plant height and GDD (growing degree days) can be described by the equation y=ax+b, 19.23 ℃.d of GDD (≥10 ≥-d) and 8.12 h of sunshine duration were required to increase 1 cm of plant height; plant height, tiller number, and leaf area of Baidao were higher than that of the other 3 laponica rice cultivars, but the specific leaf weight and leaf angle were smaller. [Conclusion] Comparison of morphological characteristic differ- ences among rice cultivars is an important way to select water-saving and drought- tolerant rice varieties. In this study, the experimental results can be integrated into a rice functional-architectural model to simulate rice organ growth dynamics in a three- dimensional space, thereby providing reference for selecting water-saving and drought-tolerant rice cultivars.展开更多
基金Supported by Jiangsu Agricultural Science and Technology Innovation Fund[CX(12)3006]Jiangsu Province Science and Technology Support Program,China(BE2013352)Study on Saving the Cost Facility Cultivation Techniques of High-quality,Safe and Efficient in Fresh Faba Bean(HL2014029)~~
文摘Using Tongxian No.2 as material, the effects of different film-covering time, different sowing time and different planting density on the occurrence of freeze injury and yield of fresh broad beans were investigated. The randomized block design was adopted. The results showed that with the delayed film covering, the incidence of mild freeze injury and number of headless seedlings were increased correspondingly, but the yield was increased; with the delayed sowing, the branch number per plant, effective branch number per plant, incidence of mild freeze injury and number of headless seedlings were all reduced, and the broad beans, sowed on September 30 th, obtained the highest yield; planting density showed on effect on the occurrence of freeze injury, and the yield was increased with the increase of planting density. Under the same film-covering time, the incidence of freeze injury was reduced with the delayed sowing time and it showed no changes when planting density was changed, but the yield was increased with the increase of planting density and it was highest when broad bean seeds were sowed on September 30th;under the same sowing time, the incidence of freeze injury was increased with the delayed film-covering time and it showed no changes when planting density was changed, and the yield was increased with the delayed film-covering time and increased planting density; under the same planting density, the incidence of freeze injury was increased with the delayed film-covering time but was reduced with the delayed sowing time, and the yield was increased with the delayed film-covering time and it was highest when the broad bean seeds were sowed on September30 th. Under same film-covering time and sowing time, the total branch number per plant and effective branch number per plant were reduced, but the yield was increased with the increase of planting density; under same film-covering time and planting density, the incidence of freeze injury was reduced with the delayed sowing time, and the yield was highest when broad bean seeds were sowed on September30th; under same sowing time and planting density, the incidence of freeze injury and the yield were all increased with the delayed film-covering time.
基金Supported by National Science and Technology Support Program of China(2011BAD16B06,2012BAD04B09)~~
文摘Freezing injury is one of the major disasters for the production of winter wheat in the North China Plain, which leads to a significant decrease of wheat yield. This study was conducted to investigate the impact of subfreezing temperature on freezing injury of various winter wheat cultivars at different sowing time. Three wheat cultivars, including Zhengmai 9023, Wanmai 48 and Wanmai 50, were sowed on 25 September and 5 October, respectively. Plant anatomy was applied to investi- gate the impact of subfreezing temperature on cells of three wheat cultivars, results showed that severe plasmolysis occurred in wheat sowed earlier suddenly encoun- tered subfreezing temperature without cold acclimation, compared with wheat sowed at proper sowing time. The degree of plasmolysis of different cultivars and tissues of wheat had significant differences and showed positive correlation with subfreezing temperature. Wanmai 50 had the highest cold resistance compared with Zhengmai 9023 and Wanmai 48, and there was no significant difference between Zhengmai 9023 and Wanmai 48. This study concluded that wheat cold resistance may be im- proved by adopting proper cultivars and sowing dates.
基金Supported by Key Agricultural R&D Program in Guizhou Province dur-ing the Eleventh Five-year Plan[NZ(2005)3001]~~
文摘[ Objective] This study was to understend the optimized combination of planting density, duration of disclosing plastic film and nitrogen fertilization under no-tillage cultivation. [ Method] Quadratic polynomial regression and saturated D-optimal design were employed to investigate the effects of planting density, duration of disclosing plastic film and nitrogen fertilization on the dynamics growth of rapeseed under no-tillage cultivation.[ Result] Within the experimental range, the growth dynamics of no-tillage cultivated rapeseed assumed a rise-fall tend. For the effects to the growth dynamics of no-tillage cultivated rapeseed, nitrogen application amount was higher than planting density and duration of disclosing plastic film. The interaction effect between planting density and duration of disclosing plastic film was higher than that between nitrogen application amount and planting density, and between nitrogen application amount and duration of disclosing plastic film. [ Conclusion] The optimized combination of these factors for dynamic growth of rapeseed under no-tillage cultivation was determined to be: planting density of per hectare 154 925 individuals, duration of disclosing plastic film of 110 d, nitrogen application amount of 315 kg/hm^2.
文摘We examined the competitive ability of larval toads (Bufo gargarizans ) and frogs (Rana kukunoris ) which co-occur in natural pools in the Jiuzhaigou Nature Reserve. We measured the activity level, growth rate, mass at metamorphosis and larval period in a laboratory experiment. Tadpoles of B. gargarizans were significantly more active when food was abundant than scarce, while there was no significant difference in the activity of R. kukunoris tadpoles at different food levels. At low food availability, mass at metamorphosis and growth rate of R. kukunoris were significantly increased in the presence of B. gargarizans, whereas the presence of R. kukunoris had no significant effect on the mass and growth rate of B. gargarizans. In all treatments, the larval period of B. gargarizans at low food availability was the shortest. These results suggest that B. gargarizans can adapt to different food levels by changing their activity rate. At high food level, B. gargarizans increased activity to gain more food. At low food level, B. gargarizans decreased activity and achieved early metamorphosis. However, when food resources were limited, R. kukunoris could gain more food than B.gargarizans .
文摘[Objective] The aim was to improve part of auto-control system of aquatic seedling breeding and to lay foundation for highly-efficient and stable use of the sys- tem. [Method] The executive and drive modules of the auto-control system were im- proved, after which real-time monitor, data display and alarm modules were tested on time. [Result] In the test, for the improved system, stability and sensitivity were enhanced; different components matched better; transmitting electric resistanc6 was reduced. [Conclusion] The research provides references for auto-control of water temperature and dissolved oxygen, and faults clearing in aquatic seedling breeding.
基金the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry(20030917)
文摘This paper considers the travelling wave fronts to a delayed lattice differential equation. The existence of the travelling wave solutions is proved by making use of the technique of the upper and lower solutions developed by J Wu and X Zou in [6]. This work extends that of [4] in a general class of nonlinear terms.
文摘[Objective] This study was conducted to investigate the effects of different gibberellic acid and hydrogen peroxide concentrations and different soaking time on the germination potential and germination rate of Scutellaria baicalensis, so as to improve the breeding efficiency of S. baicalensis. [Method] Dry seeds were divided into 3 groups, each containing 50 grains, which were weighed and put in a culture dish and soaked with distilled water covering the surface of seeds at room temperature. The seed weight was measured by gravimetric method once every 30 min from 30 rain after soaking, until the weight of the seeds no longer changed. [Result] With the increase of the concentration of hydrogen peroxide, the germination rate of S. baicalensis was improved gradually, and reached 32.0% under the concentration of 1.0% at the soaking time of 24 h; and with the increase of the concentration of gibberellic acid, the germination rate of S. baicalensis was improved gradually, and reached 64.0% under the concentration of 600 mg/L at the soaking time of 24 h. [Conclusion] The constant temperature at 25 ℃ in the incubator could also improve the seed germination rate; and the germination rate achieved by treating the seeds with gibbereUic acid was remarkably higher than that achieved by treating the seeds with hydrogen peroxide.
基金Supported by Key Projects of Zhejiang Province(2008C22074)0406 Project in Zhejiang Province+2 种基金Ministry of Agriculture"China's Super Rice Breeding and Experimental Demonstration"Project(2009RG001-5)Operating Expenses of Basic Research of China National Rice Research InstituteAgricultural Science and Technology Across Project
文摘Chunyou 59 is a japonica-indica hybrid rice combination developed from Chunjiang 16A(a late japonica CMS line with dwarfness and early anthesis time)and CH59(an indicaclinous wide compatibility restorer line).It has the characteristics of strong heterosis,strong stem,good lodging resistance,large panicles,good cold tolerance,high yield and wide adaptability.It was registered and released by Jiangxi Provincial Crop Variety Appraisal Committee in March 2009.The breeding procedure,characteristics,major techniques of cultivation and seed production of Chunyou 59 were introduced in the paper.
文摘AIM To evaluate the accuracy of the elastography score combined to the strain ratio in the diagnosis of solid pancreatic lesions(SPL). METHODS A total of 172 patients with SPL identified by endoscopic ultrasound were enrolled in the study to evaluate the efficacy of elastography and strain ratio in differentiating malignant from benign lesions. The semi quantitative score of elastography was represented by the strain ratio method. Two areas were selected, area(A) representing the region of interest and area(B) representing the normal area. Area(B) was then divided by area(A). Sensitivity, specificity, positive predictive value(PPV), negative predictive value(NPV), and accuracy were calculated by comparing diagnoses made by elastography, strain ratio and final diagnoses.RESULTS SPL were shown to be benign in 49 patients and malignant in 123 patients. Elastography alone had a sensitivity of 99%, a specificity of 63%, and an accuracy of 88%, a PPV of 87% and an NPV of 96%. The best cut-off level of strain ratio to obtain the maximal area under the curve was 7.8 with a sensitivity of 92%, specificity of 77%, PPV of 91%, NPV of 80% and an accuracy of 88%. Another estimated cut off strain ratio level of 3.8 had a higher sensitivity of 99% and NPV of 96%, but with less specificity, PPV and accuracy 53%, 84% and 86%, respectively. Adding both elastography to strain ratio resulted in a sensitivity of 98%, specificity of 77%, PPV of 91%, NPV of 95% and accuracy of 92% for the diagnosis of SPL. CONCLUSION Combining elastography to strain ratio increases the accuracy of the differentiation of benign from malignant SPL.
基金supported by the Knowledge Innovation Program of Chinese Academy of Sciences (Grant No. KZCX2-EW-203)the National Basic Research Program of China (Grant No.2013CB430105)the National Department Public Benefit Research Foundation (Grant No.GYHY201006031)
文摘In this research, one-dimensional stratiform a novel dual-model system, cold cloud model (1DSC) coupled to Weather Research and Forecast (WRF) model (WRF-1DSC for short), was employed to investigate the effects of cloud seeding by silver iodide (AgI) on rain enhancement. Driven by changing environmental conditions extracted from the WRF model, WRF-1DSC could be used to assess the cloud seeding effects quantitatively. The employment of WRF- 1DSC, in place of a one-dimen- sional two-moment cloud seeding model applied to a three-dimensional mesoscale cloud-resolving model, was found to result in massive reduction of computational resources. Numerical experiments with WRF-1DSC were conducted for a real stratiform precipitation event ob- served on 4-5 July 2004, in Northeast China. A good agreement between the observed and modeled cloud system ensured the ability of WRF-1DSC to simulate the observed precipitation process efficiently. Sensitivity tests were performed with different seeding times, locations, and amounts. Experimental results showed that the optimum seeding effect (defined as the percentage of rain enhancement or rain enhancement rate) could be achieved through proper seeding at locations of maximum cloud water content when the updraft was strong. The optimum seeding effect was found to increase by 5.61% when the cloud was seeded at 5.5 km above ground level around 2300 UTC 4 July 2004, with the maximum AgI mixing ratio (As) equaling 15 ng kg-1. On the other hand, for an overseeded cloud, a significant reduction occurred in the accumulated precipitation (-12.42%) as Xs reached 100 ng kg^-1. This study demonstrates the potential of WRF- 1DSC in determining the optimal AgI seeding strategy in practical operations of precipitation enhancement.
基金Supported by Project of China Meteorological Administration(2010154)Special Fund for Meteorological Research in the Public Interest(GYHY201206020,GYHY201006025)~~
文摘With super hybrid rice cultivar Y Liangyou 1 as the experimental material, seed-setting rate, abortive grain rate, empty grain rate and 1 000-seed weight were investigated for continuous 10 days since the first day post-harvest to reveal the correlation between differences in seed-setting characters of rice and seed investiga- tion time. The results indicated that seed-setting rate, abortive grain rate, empty grain rate and 1 000-seed weight varied at different seed investigation time. With the postponement of seed investigation, seed-setting rate and 1 000-seed weight showed downward trends, abortive grain rate showed an upward trend, while empty grain rate exhibited a significant correlation with seed investigation time. Seed-setting rate, abortive grain rate and 1 000-seed weight exhibited no significant differences within the first three days after the harvest; since day 4, seed-setting rate and 1000-seed weight declined remarkably, while abortive grain rate increased signifi- cantly. Based on the correlation between seed-setting characters of rice and seed investigation time, the analysis of seed-setting characters of rice and other cereal crops should be completed within the first three days after the harvest, thereby im- proving the accuracy of relative conclusion.
基金Supported by the State Key Development Program for Basic Research of China(2007CB210203)the Special Research Fund for the Doctoral Program of Higher Education of China(20050610013)
文摘A laboratory reactor was designed to test the effect of the interference instant of HY on the pyrolysis of pubescens.The time instant for intermediate species from pyrolysis to contact HY was controlled by varying the position of the catalyst bed relative to the pyrolytic cell.It was found that the effect of the interference instant was significant on the variation of different intermediate species,and the yield and quality of the products.The results also showed that,with the increase in the distance between the pyrolytic cell and the catalyst bed,the yield of liquid and relative content of the organics such as aldehyde,phenols,etc.,decreased,while the yield of residue and relative content of acetic acid increased.The deoxygenation of the intermediate species was favored when the catalyst exerted its performance on them immediately after their formation.
基金Suported by the Spanish Ministry of Science and Technology Project (No. AGL2002-01285)a PhD Scholarship of the University of A Corua
文摘The aim of the study is to examine the influence of the outplanting time on the cultivation of the kelp Laminaria saccharina in the northwestern Spain, close to its southern limit of distribution in the North Atlantic coast. We compared two L. saccharina cultures outplanted in February and December. We found that the starting time of outplanting affects to the yield and the substantiality value, as well as the growth rate. The yield, the substantiality value and the growth rates of L. saccharina sporophytes obtained for the trial outplanted in December were significantly higher than those in February. These results can be mainly explained by the effect of temperature on the growth of L. saccharina sporophytes during cultivation. On the other hand, our results show that even in the southern limit of distribution of L. saccharina, the cultivation of this species was very profitable in high yield and quality.
文摘The simplified incidence function model which is driven by the colored correlated noises is employed to investigate the extinction time of a metapopulation perturbed by environments. The approximate Fokker-Planck Equation and the mean first passage time which denotes the extinction time (Tex) are obtained by virtue of the Novikov theorem and the Fox approach. After introducing a noise intensity ratio and a dimensionless parameter R = D /α (D and a are the multiplicative and additive colored noise intensities respectively), and then performing numerical computations, the results indicate that: (i) The absolute value of correlation strength A and its correlation time τ3 play opposite roles on the Tex; (ii) For the case of 0 〈λ〈 1,α and its correlation time τ2 play opposite roles on the Tex in which R〉 1 is the best condition, and there is one-peak structure on the Tex - D plot; (iii) For the case of-1 〈 λ≤ 0, D and its correlation time τ1 play opposite roles on the Tex in which R 〈 1 is the best condition and there is one-peak structure on the Tex - τ2 plot.
文摘Development of stable crops cultivars adapted to environmental constraints is very important for food security. Safflower, an oilseed crop which tolerates environmental abiotic stresses, is suitable for marginal lands relatively dry and deprived from fertilizer inputs or irrigation. A set of Moroccan and introduced cultivars as well as international accessions were conducted at Oujda (Eastern of Morocco) during 2009-2010 for late and conventional sowing under two water regimes, in a field experiment using a completely randomized design, with three replications. The objective was to evaluate the effect of genotype and contrasting environment on safflower behavior and to select genotypes with large adaptation to the contrasted environmental conditions. Morphological, physiological and agronomic traits, as well as the stress susceptibility index (SSI), were recorded in this study. Results showed significant effect of genotype, year (sowing time), water regime and their interaction on most of the studied parameters. Late sowing and drought affected negatively all the parameters except seed oil which lightly increased under drought stress. Number of heads per plant (NHP) had the strongest association with seed yield under both drought and non-drought conditions, and hence could be taken as selection criterion for safflower seed yield improvement. Five accessions showed the highest overall mean seed yield (~ 1,000 kg/ha) and four accessions exhibited the highest overall mean seed oil content (〉 310 g/kg). For late sowing, the accessions P1262421 and PI537604 produced the highest seed yield (〉 800 kg/ha) and the highest seed oil content (〉 290 g/kg). For conventional sowing, the accessions PI250076 and PI250523 were the most performant, with a seed yield 〉 1,300 kg/ha and a seed oil content 〉 330 g/kg. Based on their mean productivity across environments, their SSI and their MDA, P1271073 and P1250076 could be selected and used as promising germplasm in safflower breeding program in Morocco as well as other dry areas throughout the world.
基金Supported by National Natural Science Foundation of China(31101084)Scientific Research Foundation of the Education Ministry for Returned Chinese Scholars~~
文摘[Objective] The aim of this study was to compare the morphological char- acteristics of rice (Oryza sativa L.) with different cultivation methods and investigate the dynamics of organ growth and development characteristics of different rice culti- vars. [Method] Based on continuous field observation and destructive sampling over a growing season, detailed organ morphological data were obtained including leaf length, node number, plant height, tiller number, leaf angle, leaf area and specific leaf weight, to compare organ morphological differences among 4 rice cultivars of Baidao (indica), Jinnanfeng (japonica), 9325 (japonica) and 9915 (japonica) with 3 cultivation methods of field planting in Weigang, pot planting in Weigang, and field planting in Jiangpu. [Result] Maximum leaf length of each node gradually increased at the early growth stage and decreased at the later growth stage, the relationship between maximum leaf length and node position can be described by the equations y=a,,-~ and y=ax+b; node number, growth duration, leaf length and plant height of pot planting rice in Weigang were smaller than that of the other two field planting meth- ods; the relationship between plant height and sunshine duration, plant height and GDD (growing degree days) can be described by the equation y=ax+b, 19.23 ℃.d of GDD (≥10 ≥-d) and 8.12 h of sunshine duration were required to increase 1 cm of plant height; plant height, tiller number, and leaf area of Baidao were higher than that of the other 3 laponica rice cultivars, but the specific leaf weight and leaf angle were smaller. [Conclusion] Comparison of morphological characteristic differ- ences among rice cultivars is an important way to select water-saving and drought- tolerant rice varieties. In this study, the experimental results can be integrated into a rice functional-architectural model to simulate rice organ growth dynamics in a three- dimensional space, thereby providing reference for selecting water-saving and drought-tolerant rice cultivars.