[Objective] Actinomycetes with high antagonistic effects on alfalfa root rot pathogen was isolated from 10 soil samples in Chifeng Inner Mongolia. [Method] 91 actinomyces were separated from 10 soil samples in Chifeng...[Objective] Actinomycetes with high antagonistic effects on alfalfa root rot pathogen was isolated from 10 soil samples in Chifeng Inner Mongolia. [Method] 91 actinomyces were separated from 10 soil samples in Chifeng Inner Mongolia by gradient dilution separation method. In duel culture tests, all isolates were tested for their antagonism by using 3 strains including Fusarium solani, F. oxysoporum, F. avenaceum of alfalfa root rot pathogenic bacteria as indicator strains. [Result] 5 strains with strong antagonistic effect on tested alfalfa root rot pathogen were obtained from No.1, No.4, No.6 and No.7 soil samples which were numbered 1-3-6, 4-4-2, 6-2-27 and 7-2-13 respectively, accounted for 5.50% in separated strains. [Conclusion] This study laid certain foundation for biological control of alfalfa root rot disease.展开更多
To evaluate the response of alfalfa to water deficit （WD） stress, WD-induced candidates were investigated through a proteomic approach. Alfalfa seedlings were exposed to WD stress for 12 and 15 days respectively, fo...To evaluate the response of alfalfa to water deficit （WD） stress, WD-induced candidates were investigated through a proteomic approach. Alfalfa seedlings were exposed to WD stress for 12 and 15 days respectively, followed by 3 days re-watering. Water deficit increased H202 content, lipid peroxidation, DPPH （1,1-diphenyl-2-picrylhydrazyl）-radical scavenging activity, and the free proline level in alfalfa roots. Root proteins were extracted and separated by two-dimentional polyacrylamide gel electrophoresis （2-DE）. A total of 49 WD-responsive proteins were identified in alfalfa roots; 25 proteins were reproducibly found to be up-regulated and 24 were down-regulated. Two proteins, namely cytosolic ascorbate peroxidase （APx2） and putative F-box protein were newly detected on 2-DE maps of WD-treated plants. We identified several proteins including agamous-like 65, albumin b-32, inward rectifying potassium channel, and auxin-independent growth promoter. The identified proteins are involved in a variety of cellular functions including calcium signaling, abacisic acid （ABA） biosynthesis, reactive oxygen species （ROS） regulation, transcription/translation, antioxidant/detoxification/stress defense, energy metabolism, signal transduction, and storage. These results indicate the potential candidates were responsible for adaptive response in alfalfa roots.展开更多
Regrowth traits of alfalfa （Medicago sativa L.） in spring are closely related to its fall dormancy before winter. In order to determine the relationship between fall dormancy （FD） grade and hormone variation patte...Regrowth traits of alfalfa （Medicago sativa L.） in spring are closely related to its fall dormancy before winter. In order to determine the relationship between fall dormancy （FD） grade and hormone variation pattern and provide academic references for the variety improvement and production of alfalfa, the variations of gibberellins （GA3）, indole-3-acetic acid （IAA）, and abscisic acid （ABA） in alfalfa roots during regrowth period in spring were examined by high performance liquid chromatography （HPLC）. The study involved seven alfalfa cultivars that belonged to four fall dormant grades, i.e., 2, 4, 6, and 8. The results showed that the differences in spring regrowth among the alfalfa cultivars were partially associated with their root hormone levels. The alfalfa cultivars that belonged to the same dormancy grades presented similar variation trends in endogenous hormone content in their roots during the spring regrowth stage. At the early regrowth stage, cultivars with a higher dormant grade had a higher GA3 concent and a lower ABA content in their roots than the cultivars with a lower dormant grade; and IAA content in roots of non- and semi-fall dormancy cultivars was higher than that of fall dormancy cultivars. During the whole period of spring regrowth, the root ABA content of fall dormancy alfalfa cultivar is significantly higher than those of semi- and non-fall dormancy cultivars. GA3 contents in the roots of all cultivars under study showed a double-peak dynamic curve; root IAA contents of the studied cultivars presented a downward trend. But the trend did not significantly differed among the different fall dormant cultivars. The higher GA3 content and lower ABA content in root of non-fall dormancy alfalfa lead to its earlier regrowth. Regrowth time and rate of alfalfa can be regulated by exogenous GA3 or ABA at the early regrowth stage to meet producing requirement.展开更多
Growth traits of root system of 13 autumn-sowing alfalfa cultivars were analyzed. The results indicated that there were significant difference in growth pa- rameters of root system among alfalfa cultivars （ P 〈 0.05...Growth traits of root system of 13 autumn-sowing alfalfa cultivars were analyzed. The results indicated that there were significant difference in growth pa- rameters of root system among alfalfa cultivars （ P 〈 0.05 ）. The cultivars, Prime and WI323, showed the highest root biomass （ higher than 32 g） ; cuhivar WI323 had the largest lateral root number （17.8 branches）. Cultivars Prime, WI323, Super7 and L90 had better root traits than other cultivars based on comprehensive evaluation. Among three times of mowing within a year, root growth and development of alfalfa had mutual promotion with the first and second time growth of abovegraund part, but had competition with the third time growth. Overwintering alfalfa root restricted the grass yield in the following year, especially the third-cut yield in the next year.展开更多
基金Supported by Central Nonprofit Research Institutions Basic Scientific Research Operating Expenses(Grassland Research Institute,Chinese Academy of Agricultural Sciences2006-01-05)~~
文摘[Objective] Actinomycetes with high antagonistic effects on alfalfa root rot pathogen was isolated from 10 soil samples in Chifeng Inner Mongolia. [Method] 91 actinomyces were separated from 10 soil samples in Chifeng Inner Mongolia by gradient dilution separation method. In duel culture tests, all isolates were tested for their antagonism by using 3 strains including Fusarium solani, F. oxysoporum, F. avenaceum of alfalfa root rot pathogenic bacteria as indicator strains. [Result] 5 strains with strong antagonistic effect on tested alfalfa root rot pathogen were obtained from No.1, No.4, No.6 and No.7 soil samples which were numbered 1-3-6, 4-4-2, 6-2-27 and 7-2-13 respectively, accounted for 5.50% in separated strains. [Conclusion] This study laid certain foundation for biological control of alfalfa root rot disease.
基金supported by the National Research Foundation of Korea (NRF) Grant (NRF-2011-616-F00013)supported by post-doctoral grantsupported by the scholarship from BK21Plus program, Ministry of Education, Republic of Korea
文摘To evaluate the response of alfalfa to water deficit （WD） stress, WD-induced candidates were investigated through a proteomic approach. Alfalfa seedlings were exposed to WD stress for 12 and 15 days respectively, followed by 3 days re-watering. Water deficit increased H202 content, lipid peroxidation, DPPH （1,1-diphenyl-2-picrylhydrazyl）-radical scavenging activity, and the free proline level in alfalfa roots. Root proteins were extracted and separated by two-dimentional polyacrylamide gel electrophoresis （2-DE）. A total of 49 WD-responsive proteins were identified in alfalfa roots; 25 proteins were reproducibly found to be up-regulated and 24 were down-regulated. Two proteins, namely cytosolic ascorbate peroxidase （APx2） and putative F-box protein were newly detected on 2-DE maps of WD-treated plants. We identified several proteins including agamous-like 65, albumin b-32, inward rectifying potassium channel, and auxin-independent growth promoter. The identified proteins are involved in a variety of cellular functions including calcium signaling, abacisic acid （ABA） biosynthesis, reactive oxygen species （ROS） regulation, transcription/translation, antioxidant/detoxification/stress defense, energy metabolism, signal transduction, and storage. These results indicate the potential candidates were responsible for adaptive response in alfalfa roots.
基金supported by the Key Technologies R&D Program of China during the 11th Five-Year Plan period (2006BAD29B03)the Special Scientific Research Foundation, China (CX200902)the Tang Zhongying Plant Breeding Special Item of Northwest A&F University, China (09YZ)
文摘Regrowth traits of alfalfa （Medicago sativa L.） in spring are closely related to its fall dormancy before winter. In order to determine the relationship between fall dormancy （FD） grade and hormone variation pattern and provide academic references for the variety improvement and production of alfalfa, the variations of gibberellins （GA3）, indole-3-acetic acid （IAA）, and abscisic acid （ABA） in alfalfa roots during regrowth period in spring were examined by high performance liquid chromatography （HPLC）. The study involved seven alfalfa cultivars that belonged to four fall dormant grades, i.e., 2, 4, 6, and 8. The results showed that the differences in spring regrowth among the alfalfa cultivars were partially associated with their root hormone levels. The alfalfa cultivars that belonged to the same dormancy grades presented similar variation trends in endogenous hormone content in their roots during the spring regrowth stage. At the early regrowth stage, cultivars with a higher dormant grade had a higher GA3 concent and a lower ABA content in their roots than the cultivars with a lower dormant grade; and IAA content in roots of non- and semi-fall dormancy cultivars was higher than that of fall dormancy cultivars. During the whole period of spring regrowth, the root ABA content of fall dormancy alfalfa cultivar is significantly higher than those of semi- and non-fall dormancy cultivars. GA3 contents in the roots of all cultivars under study showed a double-peak dynamic curve; root IAA contents of the studied cultivars presented a downward trend. But the trend did not significantly differed among the different fall dormant cultivars. The higher GA3 content and lower ABA content in root of non-fall dormancy alfalfa lead to its earlier regrowth. Regrowth time and rate of alfalfa can be regulated by exogenous GA3 or ABA at the early regrowth stage to meet producing requirement.
基金Supported by Fundamental Special Project of the Ministry of Science and Technology"Special Investigation of Northeast Grassland Plant Resources"(2014FY210300)Special Investigation of Grassland Plant Resources in Liaoning Province
文摘Growth traits of root system of 13 autumn-sowing alfalfa cultivars were analyzed. The results indicated that there were significant difference in growth pa- rameters of root system among alfalfa cultivars （ P 〈 0.05 ）. The cultivars, Prime and WI323, showed the highest root biomass （ higher than 32 g） ; cuhivar WI323 had the largest lateral root number （17.8 branches）. Cultivars Prime, WI323, Super7 and L90 had better root traits than other cultivars based on comprehensive evaluation. Among three times of mowing within a year, root growth and development of alfalfa had mutual promotion with the first and second time growth of abovegraund part, but had competition with the third time growth. Overwintering alfalfa root restricted the grass yield in the following year, especially the third-cut yield in the next year.
