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51.
Application of Bacillus pumilus as a potential biocontrol agent of Fusarium wilt of tomato 总被引:1,自引:0,他引:1
Nahid Heidarzadeh Sareh Baghaee-Ravari 《Archives Of Phytopathology And Plant Protection》2013,46(13-16):841-849
The current study aimed at evaluating the possibility of native Bacillus pumilus species to control Fusarium wilt in tomato and examine its effect on plant growth. Biocontrol traits of B. pumilus strains, biofilm assay, root colonisation and in vivo studies under pot conditions were determined. Strain ToIrMA-KC806242 formed biofilm efficiently and could colonise and survive on tomato rhizosphere (3.1 × 104 CFU/g of root). The amount of auxin production was recorded 29.7 μg/ml at the 96th hour of incubation. Siderophore production was determined positive, while ToIrMA was not able to solubilise phosphate compounds or produce cyanide hydrogen. Statistical analysis of data revealed that the increase in root and shoot length was recorded 60 and 84%, respectively, over control. In addition, about 73% reduction in disease incidence was determined in vivo experiments. In conclusion, this study suggests B. pumilus ToIrMA strain as a possible biocontrol agent in the field experiments. 相似文献
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To obtain bacteria with arsenic accumulation potential that can be used to remove arsenic from contaminated waters, experiments were made to investigate the tolerance and accumulation to arsenic of an indigenous bacterium XZM002 isolated from aquifer sediments of Datong Basin, northern China. The results showed that strain XZM002 belongs to the genus Bacillus and has evolved defense mechanisms to reduce arsenic injury: the change of cellular shape from initial rod to oval and then to round with increment of arsenic toxicity. The effect of arsenate or arsenite on the bacterial growth was also investigated. Results showed that growth of the strain was inhibited under As(III) and high concentration As(V) (over 1200 μg l?1) conditions in the first 2 days and promoted under low concentration As(V) (under 400 μg l?1) condition. Its arsenic bioaccumulation potential was surveyed by monitoring the concentration changes of total arsenic and arsenic speciation in the medium and in the cytoplasm, and those of total arsenic on the membrane. Methylated arsenic species were not detected throughout the experiment. The results indicated that 11.5% of arsenic was removed from liquid medium into the bacterial cells and 9.22% of As(V) in the medium was transformed gradually to As(III) during 4 d of incubation. Approximately 80% of the total accumulated arsenic was adsorbed onto the membrane instead of into cytoplasm; and the arsenic accumulation almost approached saturation after incubation for 72 h. 相似文献
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Caterina Maria Antognazza Demetra Andreou Serena Zaccara Robert J. Britton 《Ecology and evolution》2016,6(5):1280-1292
Anthropogenic activities, including the intentional releases of fish for enhancing populations (stocking), are recognized as adversely impacting the adaptive potential of wild populations. Here, the genetic characteristics of European barbel Barbus barbus were investigated using 18 populations in England, where it is indigenous to eastern‐flowing rivers and where stocking has been used to enhance these populations. Invasive populations are also present in western‐flowing rivers following introductions of translocated fish. Two genetic clusters were evident in the indigenous range, centered on catchments in northeast and southeast England. However, stocking activities, including the release of hatchery‐reared fish, have significantly reduced the genetic differentiation across the majority of this range. In addition, in smaller indigenous rivers, populations appeared to mainly comprise fish of hatchery origin. In the nonindigenous range, genetic data largely aligned to historical stocking records, corroborating information that one particular river (Kennet) in southeast England was the original source of most invasive B. barbus in England. It is recommended that these genetic outputs inform management measures to either restore or maintain the original genetic diversity of the indigenous rivers, as this should help ensure populations can maintain their ability to adapt to changing environmental conditions. Where stocking is considered necessary, it is recommended that only broodstock from within the catchment is used. 相似文献
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Drought is an important environmental factor that can affect rhizobial competition and N2 fixation. Three alfalfa (Medicago sativa L. and M. falcata L.) accessions were grown in pots containing soil from an irrigated (Soil 1) and a dryland (Soil 2) alfalfa field in northern
Utah, USA. Mutants of three strains of Rhizobium meliloti Dang. from Pakistan (UL 136, UL 210, and UL 222) and a commercial rhizobial strain 102F51a were developed with various levels
of resistance to streptomycin. Seeds inoculated with these individual streptomycin-resistant mutants were sown in the two
soils containing naturalized rhizobial populations. Soils in the pots were maintained at −0.03, −0.5, and −1.0 MPa. After
10 weeks, plants were harvested and nodule isolates were cultured on agar medium with and without streptomycin to determine
nodule occupancy (proportion of the nodules occupied by introduced rhizobial strains). Number of nodules, nodule occupancy,
total plant dry weight, and shoot N were higher for Soil 1 than Soil 2. Number of nodules, plant dry weight, and shoot N decreased
as drought increased from −0.03 to −1.0 MPa in the three alfalfa accessions. Rhizobial strains UL 136 and UL 222 were competitive
with naturalized alfalfa rhizobia and were effective at symbiotic N2 fixation under drought. These results suggest that nodulation, growth, and N2 fixation in alfalfa can be improved by inoculation with competitive and drought-tolerant rhizobia and may be one economically
feasible way to increase alfalfa production in water-limited environments.
Joint contribution from USDA-ARS and the Utah Agric. Exp. Sta., Utah State Univ., Logan, UT 84322-4810, USA. Journal Paper
No. 4931.
Joint contribution from USDA-ARS and the Utah Agric. Exp. Sta., Utah State Univ., Logan, UT 84322-4810, USA. Journal Paper
No. 4931. 相似文献
56.
LuJiang Qu Wei Liu FangXi Yang ZhuoCheng Hou JiangXia Zheng GuiYun Xu Ning Yang 《中国科学:生命科学英文版》2009,52(11):1030-1035
In order to elucidate the domestication history of Peking ducks, 190 blood samples from six Chinese indigenous duck breeds were collected with186 individualsgenotyped by 15 microsatellite markers. Both the FST and Nei’s standard genetic distances (Ds) from the microsatellite data indicated high genetic differentiation between Peking duck and other Chinese indigenous breeds. The haplotype network with mtDNA data showed that most of the Peking duck haplotypes were distinctly different from those of other domestic breeds. Although the H01 haplotype was shared by all domesticated duck breeds, Peking ducks displayed 12 specific domestic duck haplotypes, including four similar haplotypes H02, H04, H08 and H22, that formed a single haplogroup (A). Both H02 and H22 haplotypes were also shared by mallard and Peking ducks, indicating that Peking ducks originated from wild mallard ducks. 相似文献
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