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91.
Agrobacterium-mediated high efficiency transformation of tall fescue (Festuca arundinacea) 总被引:3,自引:0,他引:3
Tall fescue (Festuca arundinacea) is the predominant cool-season pasture grass in the USA. Embryogenic calluses were induced from seeds/caryopsis of elite tall fescue cultivars Jesup and Kentucky-31, and were broken up into small pieces and used for Agrobacterium tumefaciens-mediated transformation. Agrobacterium strains LBA4404 and EHA105 harboring pCAMBIA vectors or the super-binary vector pTOK233 were used to infect the embryogenic callus pieces. The number of hygromycin resistant calluses obtained per dish of infected callus pieces was in the range of 2.0-5.8, and the number of transgenic plants recovered per dish of infected callus pieces was in the range of 0.4-1.7. When transformation efficiency was calculated based on the number of transgenic plants recovered and the number of original intact calluses used, the transformation frequency was in the range of 1.9-8.7%. The use of the easily available pCAMBIA vectors could produce equivalent results as the superbinary vector pTOK233. The transgenic nature of the regenerated plants was demonstrated by Southern hybridization analysis using undigested and digested genomic DNA samples. Expression of the transgenes was confirmed by northern hybridization analysis, GUS staining, and detection of GFP signals. Fertile transgenic plants were obtained after vernalization in the greenhouse. Progeny analysis revealed Mendelian inheritance of the transgenes. 相似文献
92.
93.
高羊茅(Festuca arundinacea)因长期多频灌溉往往生长在土壤盐渍化或潜在盐渍化的生境中。采用盆栽试验研究了不同盐生境下添加硅对两个高羊茅品种(抗性强的XD和抗性弱的K31)生物量和渗透调节物质的影响。结果表明:不同盐生境均降低了两个不同抗性高羊茅品种K31和XD的地上生物量和地下生物量。添加硅显著增加了盐浓度小于或等于150 mmol/L时XD的地上和地下生物量,以及盐浓度小于或等于100 mmol/L时K31地下生物量,但对K31地上生物量没有显著影响。添加硅显著增加了盐浓度小于或等于150 mmol/L时XD的地下地上生物量比,以及盐浓度100 mmol/L时K31地上地下生物量比。盐生境降低了XD和K31可溶性糖、可溶性蛋白、脯氨酸和丙二醛含量。添加硅没有显著影响XD的渗透调节物质含量,但显著降低了盐浓度大于或等于200 mmol/L时K31的可溶性糖含量,以及盐浓度250 mmol/L时K31的脯氨酸含量。添加硅均显著降低盐浓度大于或等于150 mmol/L时K31和XD的丙二醛含量,但XD的降低幅度大于K31。结果表明,添加硅对盐生境下高羊茅生长有一定的促进作用,但这种促进作用与品种自身抗性密切相关。 相似文献
94.
Effects of foliar application of nitrogen on the photosynthetic performance and growth of two fescue cultivars under heat stress 总被引:1,自引:0,他引:1
The effects of nitrogen fertilization on the growth, photosynthetic pigment contents, gas exchange, and chlorophyll (Chl)
fluorescence parameters in two tall fescue cultivars (Festuca arundinacea cv. Barlexas and Crossfire II) were investigated under heat stress at 38/30 °C (day/night) for two weeks. Shoot growth rate
of two tall fescue cultivars declined significantly under heat stress, and N supply can improved the growth rates, especially
for the Barlexas. Chl content, leaf net photosynthetic rate, stomatal conductance, water use efficiency, and the maximal efficiency
of photosystem 2 photochemistry (Fv/Fm) also decreased less under heat stress by N supply, especially in Crossfire II. Moreover, cultivar variations in photosynthetic
performance were associated with their different response to heat stress and nitrogen fertilization, which were evidenced
by shoot growth rate and photosynthetic pigment contents. 相似文献
95.
Afforestation resulting from fire suppression, modified grazing, plantation establishment and climate change poses a threat to northern prairie ecosystems. Trees alter the composition and function of plant and soil fauna communities and can compromise the restoration of afforested prairies. To evaluate the hypothesis that legacies of afforestation persist in restored prairie communities and decrease the potential for restoration, we examined the composition, structure, and diversity of plant and seed bank communities along a 20 year chronosequence of plantation tree removal from a northern fescue prairie in Riding Mountain National Park, Manitoba, Canada. Tree removal increased the abundance of weedy species in the plant and seed bank communities of restored prairies and plant diversity peaked and declined over the 20 year period of passive restoration. As a result, time since tree removal and the encroachment of invasive species were key in explaining the composition of restored prairie communities. Low correlation between the species composition of plant and seed bank communities, including the complete absence of Festuca hallii in restored treatments, demonstrated that legacies of afforestation compromised the potential of seed banks to facilitate prairie restoration. We conclude that tree removal alone is insufficient for the restoration of northern fescue prairies and that, in the absence of active management, the persistence of low-diversity plant and seed bank communities constitutes an important legacy of afforestation and an important barrier to future restoration. 相似文献
96.
Effects of Initial Site Treatments on Early Growth and Three-Year Survival of Idaho Fescue 总被引:2,自引:0,他引:2
KernEwing 《Restoration Ecology》2002,10(2):282-288
Prairies in the Pacific Northwest have been actively restored for over a decade. Competition from non‐native woody and herbaceous species has been presumed to be a major cause for the failure of restoration projects. In this research, plugs of the native prairie bunchgrass, Festuca idahoensis Elmer var. roemeri (Pavlick), were grown from seed in a nursery and transplanted into a grassland site dominated by non‐native pasture grasses. The growth of the plants was followed for three years, and biomass of all volunteer plants was measured. Before planting, five treatments were applied to the plots: removal of vegetation by burning, removal of vegetation by an herbicide‐and‐till procedure, soil impoverishment by removal of organic matter, fertilizer application, and compost mulch application. Initial growth of Idaho fescue plugs was greatest with fertilizer and compost mulch. Plants grown in mulched plots were also able to photosynthesize later into the dry summer season. After the first year, plots initially fertilized or composted had the lowest survival rate of Idaho fescue. Impoverished and herbicide‐and‐till plots had the greatest 3‐year survival. Mulched plots supported the greatest weed growth after three years. Stressful environments give a competitive advantage to Idaho fescue in prairie restoration projects. As weedy species increase, growth and survival of Idaho fescue decreases. 相似文献
97.
98.
Jonathan D. Moore Anna E. Carlisle Jim A. Nelson Rebecca L. McCulley 《Restoration Ecology》2019,27(5):1000-1007
Grasslands in North America are increasingly threatened by land conversion and ecological degradation, prompting restoration efforts to increase native plant species diversity and improve wildlife habitat. A major challenge is the removal and management of nonnative invasive species such as tall fescue (Schedonorus arundinaceus), which has a symbiotic association with a fungal endophyte (Epichloë coenophiala) that modifies its ecological interactions. Using transplanted clumps of the cultivar Kentucky‐31, we tested the effects of endophyte infection on tall fescue's survival and performance (tiller production, flowering, and basal area) for 5 years in a central Kentucky reconstructed prairie. We predicted that endophyte infected (E+) clumps would have increased performance compared to endophyte‐free (E?) clumps. Overall, E+ clumps had greater survival, tiller production, flowering tiller production, and basal area, but not reproductive effort (proportion of tillers flowering) as compared to E? clumps. However, survival and trends in tiller number and basal area over the 5‐year period suggested experimental tall fescue populations were in decline in the reconstructed prairie, although the E? population declined more rapidly. Our study provides evidence that endophyte infection improved tall fescue's growth and survival in a postreconstruction plant community, at least in the early years following reconstruction, and may increase the invasive potential of this nonnative species in prairie restorations. 相似文献
99.
《Fungal Ecology》2022
Soil salinization is detrimental to plant growth and yield in agroecosystems worldwide. Epichloë endophytes, a class of clavicipitaceous fungi, enhance the resistance of host plants to saline-alkali stress. This study explored the effects of the systemic fungal endophyte Epichloë coenophiala on the root microbial community and growth performance of tall fescue (Lolium arundinaceum) growing under different saline-alkali stress conditions. Structural equation modeling (SEM) was conducted to analyze the direct and indirect effects (mediated by root microbial community diversity and soil properties) of the endophyte on the growth of tall fescue under saline-alkali stress. The endophyte-infected plants produced higher shoot and root biomass compared to endophyte-free plants under saline-alkali stress (200 and 400 mM). Endophyte infection increased the fungal community diversity and altered its composition in the roots, decreasing the relative abundance of Ascomycota and increasing that of Glomeromycota. Furthermore, endophyte infection decreased the bacterial community diversity and the relative abundance of dominant Proteobacteria. SEM showed that endophyte infection increased the shoot and root biomass under saline-alkali stress (200 and 400 mM) by increasing the arbuscular mycorrhizal fungal diversity in the roots, and soil total nitrogen and phosphorus concentrations. Therefore, it is important to examine aboveground microbes as factors influencing plant growth in saline-alkali stress by affecting belowground microbes and soil chemical properties. 相似文献
100.
H. Thomas 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1987,73(4):551-555
Summary A spontaneous mutation arising in Festuca pratensis has the effect of stabilizing the pigmentproteolipid complexes of thylakoid membranes so that leaf tissue does not turn yellow during senescence. Inheritance of the non-yellowing character was analysed in crosses between the wild-type cultivar Rossa and a mutant line Bf 993. Electrophoretic variants of cytoplasmic phosphoglucoisomerase coded by alleles of the nuclear gene Pgi-2 were used to identify hybrids during intercrossing. About 96% of the F1 progeny were heterozygous and all were phenotypically yellowing. In the F2 generation yellow green segregated in a ratio of 2.141, not significantly different from 31. In the backcross between F1 and Bf 993 the ratio was 11 yellow green. There was no indication of linkage to Pgi-2. Senescence of detached Bf 993 and Rossa leaves was compared with that of the F1 hybrid. The hybrid behaved in an essentially identical fashion to the wildtype parent, and in marked contrast to the mutant, in all aspects of the senescence syndrome investigated, including loss of chlorophyll, carotenoids and the light-harvesting chlorophyll-protein of thylakoid membranes, and elevation of the particulate protein chlorophyll ratio in the terminal stages. It is concluded that there exists in Festuca pratensis a nuclear gene, designated Sid (senescence-induced degradation) which regulates turnover of hydrophobic components of photosynthetic membranes in ageing leaf tissue and which occurs in at least two allelic forms, y (yellow) dominant over g (green).Abbreviations PGI
phosphoglucoisomerase
-
Pgi
nuclear gene coding for PGI
- TSH
tris buffer containing 2-mercaptoethanol
- SDS
sodium dodecyl sulphate
- Chl
chlorophyll
- LHCP
light-harvesting chlorophyll a/b binding protein
- ELISA
enzyme-linked immunosorbent assay 相似文献