Hypocotyl segments from aseptic seedlings of two important cultivars of upland cotton ( Gossypium hirsutum L.) in Northwest China, 'Xinluzao_1', 'Jinmian_7', 'Jinmian_12' and 'Jihe_321&#...Hypocotyl segments from aseptic seedlings of two important cultivars of upland cotton ( Gossypium hirsutum L.) in Northwest China, 'Xinluzao_1', 'Jinmian_7', 'Jinmian_12' and 'Jihe_321' were transformed respectively by two efficient plant expression plasmids pBinMoBc and pBinoBc via Agrobacterium tumefaciens . In pBinMoBc, cry 1Ac3 gene, which encodes the Bt toxin, is under the control of chimeric OM promoter. In pBinoBc, it is under control of CaMV 35S promoter. After co_cultivation with Agrobacterium tumefimpfaciens LBA4404 (containing pBinMoBc or pBinoBc), kanamycin_resistant selection, somatic embryos were induced and regenerated plants were obtained. Then the regenerated plantlets were grafted to untransformed stocks in greenhouse to produce descendants. The integration of cry 1Ac3 gene and its expression in T 2 generation of transgenic cotton plants were confirmed by Southern hybridization and Western blotting. The analyses of insect bioassay indicated that the transgenic plants of both constructions have significant resistance to the larvae of cotton bollworm ( Heliothis armigera ) and that cry 1Ac3 gene driven by chimeric OM promoter could endue T 2 generation cotton with high pest_resistant ability, implicating that it has a profound application in genetic engineering to breed new pest_resistant cotton varieties.展开更多
[Objective] This study aimed to investigate the effect of inoculation with various rhizobium strains on growth status, phosphorus uptake, yield and quality of soybean plants. [Method] Using Dongnong 42 and Dongnong 46...[Objective] This study aimed to investigate the effect of inoculation with various rhizobium strains on growth status, phosphorus uptake, yield and quality of soybean plants. [Method] Using Dongnong 42 and Dongnong 46 as experimental soybeans, four treatments were designed, including non-inoculated CK group and three treatment groups inoculated respectively with rhizobium strains R2, R, and Rs, to analysis the effects of rhizobium inoculation on growth status, phosphorus uptake, yield and quality of soybean plants. [Result] Inoculation with different rhizobium strains could significantly increase the biomass and phosphorus content of the roots and shoots of Dongnong 42, to be specific, rhizobium strain R2 showed the best ef- fect, followed by Rs, and those of roots were improved greater than the shoots; in- oculation with rhizobium could significantly increase the yield of Dongnong 42, and R5 showed the best effect, but the yield of Dongnong 46 was decreased; after in- oculated with rhizobium, the protein content and fat content of soybean were signifi- cantly increased, and R2 showed the best effect, but the effects on different varieties varied, to be specific, the protein content of Dongnong 42 was significantly in- creased, while the fat content of Dongnong 46 was significantly increased; different rhizobium strains inoculated to different soybean varieties showed different effects. Inoculation with suitable rhizobium can improve plant growth characteristics, promote phosphorus uptake of plants, increase soybean yield, and effectively improve soy- bean quality. [Conclusion] This study provides theoretical basis for solving the prob- lem of soil phosphorus deficiency, increasing soybean yield and improving soybean quality in the future.展开更多
Alfalfa （Medicago sativa L.） is being grown in harsh environment in Iraq and is mostly subjected to abiotic stresses such as drought, salinity, pH and temperature. Both alfalfa and its nitrogen fixing symbiotic bact...Alfalfa （Medicago sativa L.） is being grown in harsh environment in Iraq and is mostly subjected to abiotic stresses such as drought, salinity, pH and temperature. Both alfalfa and its nitrogen fixing symbiotic bacteria Sinorhizobium meliloti are affected by these environmental stresses. Enhancing nitrogen fixation biologically could be achieved through selection of tolerant strains of S. meliloti to these environmental stresses and inoculating them to the crop, also growing tolerant cultivars. This study examines phenotypic diversity for tolerance to drought, salinity, temperature and pH. Sixty isolates sampled from different areas of Iraq. The results revealed high degree of phenotypic diversity in Sinorhizobium populations. Furthermore, the isolates which showed tolerance to drought stress also showed tolerance to salinity and high degree of temperature, indicating direct relationship between three physiological path ways. Also 58.3% of drought tolerant isolates were alkaline tolerant they tolerated up to pH 9, point to say almost all drought tolerant isolates in this study illustrated strong ＋ positive reaction to catalase enzyme. And 91.6% themes were negative for Gelatinase enzyme test. While only 50% of drought sensitive isolates were negative for drought sensitive isolates could grow at high temperature （42 ℃）.展开更多
A total of 20 rhizobial isolates obtained from root-nodules of Retama raetam （Forsk） and Lupinus various （L.） were studied for their ability to tolerate local environmental and chemical stresses. Six fast and one ...A total of 20 rhizobial isolates obtained from root-nodules of Retama raetam （Forsk） and Lupinus various （L.） were studied for their ability to tolerate local environmental and chemical stresses. Six fast and one slow growing reference strains were included for comparison. Numerical analysis showed that the reference strains were separated from test isolates. The majority of isolates displayed a high tolerance to extreme temperatures; some even grew at 48 ℃ and grew at alkaline and acid pH. Regarding tolerance to salinity on agar medium, the majority of the isolates grew at 6% NaCl, but some isolates from Lupinus various were more resistant, grew even at 8% NaCl. Most isolates were resistant to heavy metals, but were sensitive to most antibiotics tested.展开更多
The objective of this study was to determine the efficiency of biological nitrogen fixation （BNF） of local Bradyrhizobium isolates in soil of various fertility levels using 15N dilution technique. Local isolates wer...The objective of this study was to determine the efficiency of biological nitrogen fixation （BNF） of local Bradyrhizobium isolates in soil of various fertility levels using 15N dilution technique. Local isolates were obtained from cowpea rhizosphere in fields of different Iraqi provinces. Six isolates were selected in this study, which was conducted as a pot experiment under greenhouse conditions. Effects of the following fertility levels were evaluated： at F1, 0 mg N, P and K was added; at F2, 25 mg N/kg soil, 10 mg P/kg soil and 25 mg K/kg soil were added, respectively; the other two levels were F3 at which 50, 20 and 50 mg/kg soil and at F4 75, 30 and 75 mg/kg soil for N, P and K, respectively, were added. Urea, labeled with 15N 10% access atom （aa）, was used as a source of N. The highest BNF was observed under the lowest fertility level, i.e., F1. BNF across all isolates was markedly decreased with the increase of nutrient application to soil, being totally eliminated at the highest fertility level F4. Numbers of nodules per plant root of all isolates were the least under the zero nutrients application and the highest nodules number were found under the highest levels of N, P and K application. Number of nodules does not necessarily reflect the best BNF efficiency of all isolates. However, fertility levels were of significant effect on average nodule number of all isolates. The lowest plant dry weight was under the first fertility level F1 irrelevant of Rhizobium isolates. In general, the highest plant dry weight was under the second soil fertility level F2.展开更多
文摘Hypocotyl segments from aseptic seedlings of two important cultivars of upland cotton ( Gossypium hirsutum L.) in Northwest China, 'Xinluzao_1', 'Jinmian_7', 'Jinmian_12' and 'Jihe_321' were transformed respectively by two efficient plant expression plasmids pBinMoBc and pBinoBc via Agrobacterium tumefaciens . In pBinMoBc, cry 1Ac3 gene, which encodes the Bt toxin, is under the control of chimeric OM promoter. In pBinoBc, it is under control of CaMV 35S promoter. After co_cultivation with Agrobacterium tumefimpfaciens LBA4404 (containing pBinMoBc or pBinoBc), kanamycin_resistant selection, somatic embryos were induced and regenerated plants were obtained. Then the regenerated plantlets were grafted to untransformed stocks in greenhouse to produce descendants. The integration of cry 1Ac3 gene and its expression in T 2 generation of transgenic cotton plants were confirmed by Southern hybridization and Western blotting. The analyses of insect bioassay indicated that the transgenic plants of both constructions have significant resistance to the larvae of cotton bollworm ( Heliothis armigera ) and that cry 1Ac3 gene driven by chimeric OM promoter could endue T 2 generation cotton with high pest_resistant ability, implicating that it has a profound application in genetic engineering to breed new pest_resistant cotton varieties.
基金Supported by Doctoral Scientific Research Start-up Project of Mudanjiang Normal University(MSB200912)"12th Five-Year Plan"Educational Science and Research Project of Heilongjiang Association of Higher Education(HGJXH B1110053)Teaching Reform Project of Mudanjiang Normal University(10-XY01067)~~
文摘[Objective] This study aimed to investigate the effect of inoculation with various rhizobium strains on growth status, phosphorus uptake, yield and quality of soybean plants. [Method] Using Dongnong 42 and Dongnong 46 as experimental soybeans, four treatments were designed, including non-inoculated CK group and three treatment groups inoculated respectively with rhizobium strains R2, R, and Rs, to analysis the effects of rhizobium inoculation on growth status, phosphorus uptake, yield and quality of soybean plants. [Result] Inoculation with different rhizobium strains could significantly increase the biomass and phosphorus content of the roots and shoots of Dongnong 42, to be specific, rhizobium strain R2 showed the best ef- fect, followed by Rs, and those of roots were improved greater than the shoots; in- oculation with rhizobium could significantly increase the yield of Dongnong 42, and R5 showed the best effect, but the yield of Dongnong 46 was decreased; after in- oculated with rhizobium, the protein content and fat content of soybean were signifi- cantly increased, and R2 showed the best effect, but the effects on different varieties varied, to be specific, the protein content of Dongnong 42 was significantly in- creased, while the fat content of Dongnong 46 was significantly increased; different rhizobium strains inoculated to different soybean varieties showed different effects. Inoculation with suitable rhizobium can improve plant growth characteristics, promote phosphorus uptake of plants, increase soybean yield, and effectively improve soy- bean quality. [Conclusion] This study provides theoretical basis for solving the prob- lem of soil phosphorus deficiency, increasing soybean yield and improving soybean quality in the future.
文摘Alfalfa （Medicago sativa L.） is being grown in harsh environment in Iraq and is mostly subjected to abiotic stresses such as drought, salinity, pH and temperature. Both alfalfa and its nitrogen fixing symbiotic bacteria Sinorhizobium meliloti are affected by these environmental stresses. Enhancing nitrogen fixation biologically could be achieved through selection of tolerant strains of S. meliloti to these environmental stresses and inoculating them to the crop, also growing tolerant cultivars. This study examines phenotypic diversity for tolerance to drought, salinity, temperature and pH. Sixty isolates sampled from different areas of Iraq. The results revealed high degree of phenotypic diversity in Sinorhizobium populations. Furthermore, the isolates which showed tolerance to drought stress also showed tolerance to salinity and high degree of temperature, indicating direct relationship between three physiological path ways. Also 58.3% of drought tolerant isolates were alkaline tolerant they tolerated up to pH 9, point to say almost all drought tolerant isolates in this study illustrated strong ＋ positive reaction to catalase enzyme. And 91.6% themes were negative for Gelatinase enzyme test. While only 50% of drought sensitive isolates were negative for drought sensitive isolates could grow at high temperature （42 ℃）.
文摘A total of 20 rhizobial isolates obtained from root-nodules of Retama raetam （Forsk） and Lupinus various （L.） were studied for their ability to tolerate local environmental and chemical stresses. Six fast and one slow growing reference strains were included for comparison. Numerical analysis showed that the reference strains were separated from test isolates. The majority of isolates displayed a high tolerance to extreme temperatures; some even grew at 48 ℃ and grew at alkaline and acid pH. Regarding tolerance to salinity on agar medium, the majority of the isolates grew at 6% NaCl, but some isolates from Lupinus various were more resistant, grew even at 8% NaCl. Most isolates were resistant to heavy metals, but were sensitive to most antibiotics tested.
文摘The objective of this study was to determine the efficiency of biological nitrogen fixation （BNF） of local Bradyrhizobium isolates in soil of various fertility levels using 15N dilution technique. Local isolates were obtained from cowpea rhizosphere in fields of different Iraqi provinces. Six isolates were selected in this study, which was conducted as a pot experiment under greenhouse conditions. Effects of the following fertility levels were evaluated： at F1, 0 mg N, P and K was added; at F2, 25 mg N/kg soil, 10 mg P/kg soil and 25 mg K/kg soil were added, respectively; the other two levels were F3 at which 50, 20 and 50 mg/kg soil and at F4 75, 30 and 75 mg/kg soil for N, P and K, respectively, were added. Urea, labeled with 15N 10% access atom （aa）, was used as a source of N. The highest BNF was observed under the lowest fertility level, i.e., F1. BNF across all isolates was markedly decreased with the increase of nutrient application to soil, being totally eliminated at the highest fertility level F4. Numbers of nodules per plant root of all isolates were the least under the zero nutrients application and the highest nodules number were found under the highest levels of N, P and K application. Number of nodules does not necessarily reflect the best BNF efficiency of all isolates. However, fertility levels were of significant effect on average nodule number of all isolates. The lowest plant dry weight was under the first fertility level F1 irrelevant of Rhizobium isolates. In general, the highest plant dry weight was under the second soil fertility level F2.
