A method of Agrobacterium tumefaciens mediated transformation for perennial ryegrass was developed using the calli of ryegrass derived from mature enrbryos. The calli were inoculated with a disarmed A. tumefaciens str...A method of Agrobacterium tumefaciens mediated transformation for perennial ryegrass was developed using the calli of ryegrass derived from mature enrbryos. The calli were inoculated with a disarmed A. tumefaciens strain EHA105 harboring binary vector p2328. Vector p2328 contained transcription factor DREB1B and neomycin phosphotransferase （npt H） genes which were driven by promoters of rd29B and CaMV35S, respectively. The inoculated calli were selected on paromomycin- or kanamycin-containing media till the established plants being transferred to soil. Six tmnsgenic plants with DREB1B had been obtained from perennial ryegrass strain Tove. PCR and Southern-blotting showed that npt Ⅱ and DREBIB genes were integrated in perennial ryegrass genome. Stress treatment confirmed that transgenic plants with higher drought tolerance were obtained.展开更多
Italian ryegrass is an annual/biennial grass that is typically used as a pasture crop or a cover crop along roadsides, rights-of-way, and industrial areas. Glyphosate-resistant (GR) Italian ryegrass populations have b...Italian ryegrass is an annual/biennial grass that is typically used as a pasture crop or a cover crop along roadsides, rights-of-way, and industrial areas. Glyphosate-resistant (GR) Italian ryegrass populations have been documented around the world, mostly in orchard and vineyard situations. The first evidence of evolved GR Italian ryegrass in row/agronomic crops was reported from Washington County, Mississippi in 2005. GR Italian ryegrass populations can jeopardize preplant burndown options in reduced-tillage crop production systems, thereby, delaying planting operations. The effects of competition of Italian ryegrass on crop growth and yield are poorly understood. A field study was conducted in the 2012 growing season and repeated in the 2013 growing season. GR and susceptible (GS) Italian ryegrass populations were established in the greenhouse and transplanted in prepared corn row beds in the fall of 2011 and 2012 at 0, 1, 2, 3, and 4 plants·meter> of crop row. Italian ryegrass plants overwintered and developed over the following spring-summer. Glyphosate was applied at 1.26 kg·ae/ha (1.5× of labeled rate) in the spring to burndown the Italian ryegrass plants and corn was planted into the ryegrass residue 2 - 3 wk later. Current corn production practices were followed. Corn density (early and late season), height (early season), and yield and Italian ryegrass biomass (early-mid season) measurements were recorded during both years. Corn height was greater in 2012 than that in 2013 at comparable stages of the growing season, due to a cooler and wetter early season in 2013 than that in 2012. Averaged across weed densities, corn density (both early and late season) and yield were higher in the GS than those in the GR population, but Italian ryegrass biomass was similar for both populations. Averaged across Italian ryegrass populations, corn density (both early and late season), and yield were inversely proportional to Italian ryegrass density. In summary, Italian ryegrass significantly reduced corn density and yield and reduction was greater with the GR than that with the GS population. Studies are underway to study inter population competition in Italian ryegrass and investigate allelopathic effects of Italian ryegrass on selected crops.展开更多
The paper aimed to study the effects of nitrogen fertilization on the yield and some plant characteristics of perennial ryegrass (Lolium perenne L.). The study was conducted at Agricultural Research and Application Ce...The paper aimed to study the effects of nitrogen fertilization on the yield and some plant characteristics of perennial ryegrass (Lolium perenne L.). The study was conducted at Agricultural Research and Application Center of the Faculty of Agriculture in Igdir University in 2013. In the experiment, eight levels of fertilizers: 0, 10.0, 20.0, 30.0, 40.0, 50.0, 60.0 and 70.0 kg N/ha per month were applied in perennial ryegrass (Lolium perenne L.) during the sixth growing season. A randomized complete block with three replications was used as the experimental design. Nitrogen application affected plant height, green grass yield, plant covering rate, canopy color and turfgrass quality values of perennial ryegrass positively. In both monthly and as the average of nitrogen application, times of application (spring, summer and fall) caused the most uniform turfgrass quality and establishment. Results indicated that although a significant impact was on the character investigated, such as the leaf length, green grass yield, plant cover ratio, canopy color and turfgrass quality, the doses of nitrogen fertilizer have created close to each other in groups. In the stand point of view of all characters, N1, N2 and N3 were located in first group, N4 and N5 in the second group, N6 and N7 in the third group, expect for control (N0). It can be concluded that 40.0-50.0 kg N/ha per month may be more suitable to be used in ryegrass production in the landscape.展开更多
The cultivation of the castor bean plant is prominent and important because of its potential for producing vegetable oils with special properties. However, research on cultivating castor bean plants is scarce, especia...The cultivation of the castor bean plant is prominent and important because of its potential for producing vegetable oils with special properties. However, research on cultivating castor bean plants is scarce, especially in areas with altitudes of 300 m or below. Moreover, the currently available cultivars have not been widely tested in Brazil. Thus, the aim of this study was to evaluate the response of the castor bean cultivar BRS Nordestina to different spacings at low altitudes during two cropping seasons. The study was conducted in the municipality of Itaocara, in the northwest Fluminense region, Brazil, which has an altitude of 60 m. The treatments consisted of five row spacings (1.5, 2.0, 2.5, 3.0 and 3.5 m) with 1 m between plants. The plants were cultivated in the 2007/2008 spring/summer season or in the 2008 autumn/winter season. A randomised block design with four replicates was used. The following parameters were assessed: plant height, height of insertion of primary raceme, number of racemes per plant, raceme length, number of fruits per raceme and grain yield. The spacing of 2.5 m between rows had the highest yield of castor beans during the two cropping seasons. The average yield of the cultivar BRS Nordestina indicates its potential for cultivation in northern Rio de Janeiro, below an altitude of 300 m. The yield was higher during the summer cropping season. The less-dense arrangement of the plant population contributed to the cultivation of plants with more racemes in both growing seasons.展开更多
The market success of perennial ryegrass(Lolium perenne L.) cultivars depends on sufficient seed production, as they are propagated by seed. However, breeding for high quality forage production reduces seed yield, and...The market success of perennial ryegrass(Lolium perenne L.) cultivars depends on sufficient seed production, as they are propagated by seed. However, breeding for high quality forage production reduces seed yield, and breaking the negative correlation would help to overcome the problem. The foliar disease crown rust is another factor affecting reproductive capacity and thereby seed yield. We evaluated seed yield-related traits and resistance to crown rust in a collection of commercial cultivars and ecotypes of perennial ryegrass and identified genome-wide markers associated with the traits. The study revealed high variation between the ecotype and cultivar groups as well as between years. A genome-wide association study identified 17 DNA single-nucleotide polymorphisms(SNPs) of which eight were associated with crown rust and nine with flag-leaf length. The SNP markers were located within or near predicted genes functioning in defense against pathogens. The identified genes are strong candidates for a further in-depth functional study to continue unravel determination of leaf architecture and crown rust resistance in perennial ryegrass.展开更多
基金Supported by the National Natural Science Foundation of China（30170589）and the National Special Project for Research and Industrialization of Transgenic Plants （J-2002-B-006）. Acknowledgements： We are grateful to Dr. Zhang Xiao-dong of Beijing Academy of Agricultural and Forestry Sciences for donating gene DRB1B and Agrobacterium tumefaciens EHA105. We thank Ms. Yang Hong of Chengdu Institute of Biology, Chinese Academy of Sciences, for conducting much work of tissue culture. We also thank Center for Application of Molecular Biology to International A griculture （CAMBIA）, Australia for permission of use pCAMBIA2301.
文摘A method of Agrobacterium tumefaciens mediated transformation for perennial ryegrass was developed using the calli of ryegrass derived from mature enrbryos. The calli were inoculated with a disarmed A. tumefaciens strain EHA105 harboring binary vector p2328. Vector p2328 contained transcription factor DREB1B and neomycin phosphotransferase （npt H） genes which were driven by promoters of rd29B and CaMV35S, respectively. The inoculated calli were selected on paromomycin- or kanamycin-containing media till the established plants being transferred to soil. Six tmnsgenic plants with DREB1B had been obtained from perennial ryegrass strain Tove. PCR and Southern-blotting showed that npt Ⅱ and DREBIB genes were integrated in perennial ryegrass genome. Stress treatment confirmed that transgenic plants with higher drought tolerance were obtained.
文摘Italian ryegrass is an annual/biennial grass that is typically used as a pasture crop or a cover crop along roadsides, rights-of-way, and industrial areas. Glyphosate-resistant (GR) Italian ryegrass populations have been documented around the world, mostly in orchard and vineyard situations. The first evidence of evolved GR Italian ryegrass in row/agronomic crops was reported from Washington County, Mississippi in 2005. GR Italian ryegrass populations can jeopardize preplant burndown options in reduced-tillage crop production systems, thereby, delaying planting operations. The effects of competition of Italian ryegrass on crop growth and yield are poorly understood. A field study was conducted in the 2012 growing season and repeated in the 2013 growing season. GR and susceptible (GS) Italian ryegrass populations were established in the greenhouse and transplanted in prepared corn row beds in the fall of 2011 and 2012 at 0, 1, 2, 3, and 4 plants·meter> of crop row. Italian ryegrass plants overwintered and developed over the following spring-summer. Glyphosate was applied at 1.26 kg·ae/ha (1.5× of labeled rate) in the spring to burndown the Italian ryegrass plants and corn was planted into the ryegrass residue 2 - 3 wk later. Current corn production practices were followed. Corn density (early and late season), height (early season), and yield and Italian ryegrass biomass (early-mid season) measurements were recorded during both years. Corn height was greater in 2012 than that in 2013 at comparable stages of the growing season, due to a cooler and wetter early season in 2013 than that in 2012. Averaged across weed densities, corn density (both early and late season) and yield were higher in the GS than those in the GR population, but Italian ryegrass biomass was similar for both populations. Averaged across Italian ryegrass populations, corn density (both early and late season), and yield were inversely proportional to Italian ryegrass density. In summary, Italian ryegrass significantly reduced corn density and yield and reduction was greater with the GR than that with the GS population. Studies are underway to study inter population competition in Italian ryegrass and investigate allelopathic effects of Italian ryegrass on selected crops.
文摘The paper aimed to study the effects of nitrogen fertilization on the yield and some plant characteristics of perennial ryegrass (Lolium perenne L.). The study was conducted at Agricultural Research and Application Center of the Faculty of Agriculture in Igdir University in 2013. In the experiment, eight levels of fertilizers: 0, 10.0, 20.0, 30.0, 40.0, 50.0, 60.0 and 70.0 kg N/ha per month were applied in perennial ryegrass (Lolium perenne L.) during the sixth growing season. A randomized complete block with three replications was used as the experimental design. Nitrogen application affected plant height, green grass yield, plant covering rate, canopy color and turfgrass quality values of perennial ryegrass positively. In both monthly and as the average of nitrogen application, times of application (spring, summer and fall) caused the most uniform turfgrass quality and establishment. Results indicated that although a significant impact was on the character investigated, such as the leaf length, green grass yield, plant cover ratio, canopy color and turfgrass quality, the doses of nitrogen fertilizer have created close to each other in groups. In the stand point of view of all characters, N1, N2 and N3 were located in first group, N4 and N5 in the second group, N6 and N7 in the third group, expect for control (N0). It can be concluded that 40.0-50.0 kg N/ha per month may be more suitable to be used in ryegrass production in the landscape.
文摘The cultivation of the castor bean plant is prominent and important because of its potential for producing vegetable oils with special properties. However, research on cultivating castor bean plants is scarce, especially in areas with altitudes of 300 m or below. Moreover, the currently available cultivars have not been widely tested in Brazil. Thus, the aim of this study was to evaluate the response of the castor bean cultivar BRS Nordestina to different spacings at low altitudes during two cropping seasons. The study was conducted in the municipality of Itaocara, in the northwest Fluminense region, Brazil, which has an altitude of 60 m. The treatments consisted of five row spacings (1.5, 2.0, 2.5, 3.0 and 3.5 m) with 1 m between plants. The plants were cultivated in the 2007/2008 spring/summer season or in the 2008 autumn/winter season. A randomised block design with four replicates was used. The following parameters were assessed: plant height, height of insertion of primary raceme, number of racemes per plant, raceme length, number of fruits per raceme and grain yield. The spacing of 2.5 m between rows had the highest yield of castor beans during the two cropping seasons. The average yield of the cultivar BRS Nordestina indicates its potential for cultivation in northern Rio de Janeiro, below an altitude of 300 m. The yield was higher during the summer cropping season. The less-dense arrangement of the plant population contributed to the cultivation of plants with more racemes in both growing seasons.
基金the framework of the long-term research program"Genetic determination of the traits of agricultural and forest plants,development of modern cultivars"and"Genome-wide functional analysis of perennial ryegrass for improved growth under water limiting conditions(Grow Gene)"project funded by the Research Council of Lithuania(S-MIP-17-24)。
文摘The market success of perennial ryegrass(Lolium perenne L.) cultivars depends on sufficient seed production, as they are propagated by seed. However, breeding for high quality forage production reduces seed yield, and breaking the negative correlation would help to overcome the problem. The foliar disease crown rust is another factor affecting reproductive capacity and thereby seed yield. We evaluated seed yield-related traits and resistance to crown rust in a collection of commercial cultivars and ecotypes of perennial ryegrass and identified genome-wide markers associated with the traits. The study revealed high variation between the ecotype and cultivar groups as well as between years. A genome-wide association study identified 17 DNA single-nucleotide polymorphisms(SNPs) of which eight were associated with crown rust and nine with flag-leaf length. The SNP markers were located within or near predicted genes functioning in defense against pathogens. The identified genes are strong candidates for a further in-depth functional study to continue unravel determination of leaf architecture and crown rust resistance in perennial ryegrass.
