It is known that cropping causes soil carbon loss, which is a critical issue, especially in tropical agriculture. Nitrogen input generally increases net primary production but does not increase soil carbon content bec...It is known that cropping causes soil carbon loss, which is a critical issue, especially in tropical agriculture. Nitrogen input generally increases net primary production but does not increase soil carbon content because nitrogen input enhances soil organic carbon mineralization by microorganisms. A farmer conducted a trial in which he applied material with a high carbon:nitrogen (C:N) ratio without additional nitrogen fertilizer, and achieved a higher productivity than that of conventional farms. Based on his results, we conducted a survey to evaluate the effects of high C:N ratio organic material on the productivity, soil profile, microbial activity, and carbon and nitrogen balance of soil. Results demonstrate that high C:N ratio organic material enhanced the formation of the soil A horizon and increased soil carbon and nitrogen content. Approximately, 15 - 20 t·ha-1·crop-1 of fresh waste mushroom bed was applied to 15 crops over 4.5 years, and the total input of carbon and nitrogen were 5014 and 129 g·m-2, respectively. The soil nitrate nitrogen concentration was the same as that of the neighboring forest soil, which was lower than the standard limit for conventional agriculture;however, the average productivity of crops was approximately four times that of the national average. The soil Ap horizon increased in thickness by 7 cm, and aggregates reached a thickness of 29 cm in 4.5 years. The output/input ratios of total soil nitrogen and carbon were approximately 2.68 - 6.00 and 1.30 - 2.35, respectively, indicating that this method will maintain the carbon and nitrogen balance of the system. The observed soil microbial activity was one order of magnitude higher than that of a fallow field. The results indicate that this agricultural method remediates soil degradation, and improves food production.展开更多
Many tree planting programmes have long been initiated to increase forest cover to mitigate the effects of global climate change.Successful planting requires careful planning at the project level,including using suita...Many tree planting programmes have long been initiated to increase forest cover to mitigate the effects of global climate change.Successful planting requires careful planning at the project level,including using suitable species with favourable traits.However,there is a paucity of improvement data for tropical tree species.An experimental common garden of Shorea leprosula was established to study traits related to growth performance which are key factors in planting success.Seedlings of S.leprosula were collected from nine geographical forest reserves.To study the effects of genetic variation,seedlings were planted in a common environment following a randomized complete block design.From performance data collected 2017‒2019,one population showed the highest coefficient for relative height growth,significantly higher than most of the other populations.Interestingly,this population from Beserah also exhibited the lowest coefficient for scale insect infestation.This study provides preliminary results on growth performance and susceptibility to scale insect infestation in S.leprosula and the first common garden experiment site conducted on dipterocarp species.It lays a foundation for future genome-wide studies.展开更多
Iron toxicity is a major constraint to rice production, particularly in highly weathered soils of inland valleys in Sub-Saharan Africa where the rice growing area is rapidly expanding. This study aimed to improve the ...Iron toxicity is a major constraint to rice production, particularly in highly weathered soils of inland valleys in Sub-Saharan Africa where the rice growing area is rapidly expanding. This study aimed to improve the productiveness of iron toxicity sensitive’s rice fields as well as in the unsensitive fields by using local phosphate fertilizers. Eighteen (18) rice genotypes were been assessed in a split plot design in two areas: without iron toxicity and with iron toxicity. NPK, NK, Rock Phosphate, Triple super phosphate, Calcined phosphate and Acidulated phosphate were used as fertilizers. Data collection was focused on agronomic traits and yield (g/m<sup>2</sup>). The best fertilizers in the area without iron toxicity were NPK (820.2 g/m<sup>2</sup>) and triple super phosphate (751.7 g/m<sup>2</sup>). In the iron toxicity area, the best yields were performed by NPK (785.5 g/m<sup>2</sup>) and raw calcined phosphate (698.3 g/m<sup>2</sup>). Yet, the Accessions 15, Accessions 225, Accessions 226 and Accessions 270 were rainfed rice genotypes while CC109 A, HB 46 and HB 62 were low-land/irrigated rice genotypes. NPK, NK and acidulated phosphate fertilizers alleviate the best, iron toxicity in both sensitive and unsensitive rice fields.展开更多
This paper estimates a stochastic frontier function using a panel data set that includes 4 961 farmer households for the period of 2005-2009 to decompose the growth of grain production and the total factor productivi...This paper estimates a stochastic frontier function using a panel data set that includes 4 961 farmer households for the period of 2005-2009 to decompose the growth of grain production and the total factor productivity (TFP) growth at the farmer level. The empirical results show that the major contributor to the grain output growth for farmers is input growth and that its average contribution accounts for 60.92% of farmer’s grain production growth in the period of 2006-2009, whereas the average contributions sourced from TFP growth and residuals are only 17.30 and 21.78%, respectively. The growth of intermediate inputs is a top contributor with an average contribution of 44.46%, followed by the planted area (18.16%), investment in fixed assets (1.05%), and labor input (-2.75%), indicating that the contribution from the farmer’s input growth is mainly due to the growth of intermediate inputs and that the decline in labor inputs has become an obstacle for farmers in seeking grain output growth. Among the elements consisting of TFP growth, the contribution of technical progress is the largest (32.04%), followed by grain subsidies (8.55%), the average monthly temperature (4.26%), the average monthly precipitation (-0.88%), the adjusted scale effect (-5.66%), and growth in technical efficiency (-21.01%). In general, the contribution of climate factors and agricultural policy factor are positive and significant.展开更多
To enhance the yield potential of an elite indica rice cultivar,an introgression(BC_3-derived) line of IR64,YTH288,was developed using a new-plant-type cultivar,IR66215-44-2-3,as a donor parent.YTH288 has agronomicall...To enhance the yield potential of an elite indica rice cultivar,an introgression(BC_3-derived) line of IR64,YTH288,was developed using a new-plant-type cultivar,IR66215-44-2-3,as a donor parent.YTH288 has agronomically valuable characteristics such as large panicles,few unproductive tillers,and large leaves inherited from NPT.To identify the genetic basis of these traits,we used 167 F_2 plants derived from a cross between IR64 and YTH288 to conduct QTL analysis for five agronomic traits:days to heading(DTH),culm length(CL),flag leaf length(FLL),flag leaf width(FLW),and filled spikelet number per panicle(FSN).Six putative QTL were detected:four on chromosome4(for CL,FLL,FLW,and FSN) and two on chromosome 2(for DTH and FLL).All QTL with the IR66215-44-2-3 allele,except that for FLL on chromosome 2,had positive effects on each trait.To confirm the effects of these putative QTL,we developed NILs with the IR64 genetic background by marker-assisted selection.We observed significant differences in several agronomic traits between IR64 and NILs that carried these QTL on chromosomes2 and 4.Additionally,four IR64-NILs carrying chromosomal segments derived from different NPT varieties on the long arm of chromosome 4 exhibited similar pleiotropic To enhance the yield potential of an elite indica rice cultivar, an introgression(BC3-derived) line of IR64, YTH288, was developed using a new-plant-type cultivar,IR66215-44-2-3, as a donor parent. YTH288 has agronomically valuable characteristics such as large panicles, few unproductive tillers, and large leaves inherited from NPT.To identify the genetic basis of these traits, we used 167 F2 plants derived from a cross between IR64 and YTH288 to conduct QTL analysis for five agronomic traits: days to heading(DTH), culm length(CL), flag leaf length(FLL), flag leaf width(FLW), and filled spikelet number per panicle(FSN). Six putative QTL were detected: four on chromosome4(for CL, FLL, FLW, and FSN) and two on chromosome 2(for DTH and FLL). All QTL with the IR66215-44-2-3 allele, except that for FLL on chromosome 2, had positive effects on each trait. To confirm the effects of these putative QTL, we developed NILs with the IR64 genetic background by marker-assisted selection. We observed significant differences in several agronomic traits between IR64 and NILs that carried these QTL on chromosomes2 and 4. Additionally, four IR64-NILs carrying chromosomal segments derived from different NPT varieties on the long arm of chromosome 4 exhibited similar pleiotropiceffects for unique agronomic traits. These NILs can be used as research materials for studying each trait and as breeding materials for yield improvement of indica rice cultivars.展开更多
In this study, we developed a computer program for automatic prediction of watering time point by considering the environmental factors such as solar radiation, air temperature and relative humidity based on the multi...In this study, we developed a computer program for automatic prediction of watering time point by considering the environmental factors such as solar radiation, air temperature and relative humidity based on the multiple linear regression equation of leaf area and Penman Method. The experiments were carried out for a year in two watering experimental plots, one of which was controlled by pF value, and the other by the computer program. After comparing the results of the two plots, the following findings were obtained. In the computer program plot, the observed and predicted values of both leaf area and evapotranspiration indicated significant correlation at the 1% level, which suggested that the computer program had high prediction accuracy. In addition, no significant difference was observed between the two experimental plots with respects to the plant height, plant diameter, leaf area, leaf number, fresh weight, and dry weight, which demonstrated that the plants in the computer program plot had normal growth. On the other hand, although the number of flower buds and flowering shoots showed higher values at the end of certain cultivations in the computer program plot than those in pF value plot, we proposed that it was due to the effect of cumulative daily solar radiation in the greenhouse, rather than the watering. Thus, we have reached the conclusion that the computer program for automatic prediction of watering time point developed by this study has high applicability in miniature pot rose production.展开更多
Increasing rice yield potential is a continuous challenge posed by world population growth.To increase yield potential,favorable alleles of valuable genes need to be accumulated in promising germplasm.We conducted com...Increasing rice yield potential is a continuous challenge posed by world population growth.To increase yield potential,favorable alleles of valuable genes need to be accumulated in promising germplasm.We conducted comparative yield trials for two years in Tsukuba,Japan,in a temperate region and at the International Rice Research Institute(IRRI),Philippines,in a tropical region using five high-yielding rice cultivars:Takanari and Hokuriku193,developed in Japan,and IR64,NSIC Rc158,and YTH183,developed in the Philippines.Genotype plus genotype×environment interaction(GGE)biplot analysis across four environments(two regions×two seasons)classified the five cultivars into four categories:Takanari and YTH183 showed high adaptability to both tropical and temperate regions,Hokuriku193 was suitable for temperate regions,NSIC Rc158 was suitable for the tropics,and IR64 was inferior to the other cultivars in both regions.The high yield and adaptability in Takanari and YTH183 were attributed to their large sink capacity with good grain filling.The plant type for high yield was different,however,between the two cultivars;Takanari was a panicle-weight type,whereas YTH183 was a panicle-number type.Evaluations of F2 progeny of a cross between Takanari and YTH183 showed transgressive segregation for number of panicles per plant as well as number of spikelets per panicle,leading some F2 plants to produce more spikelets per plant(corresponding to larger sink size)than the parental cultivars in both regions.These results suggest the possibility of developing rice cultivars with high yield potential in both temperate and tropical regions by crossing temperate with tropical high-yielding cultivars.展开更多
Field performance of whitebacked planthopper (WBPH)-resistance of four phenotypes was evaluated in Chunjiang 06 (C J-06) / TN1 DH rice lines, which were expressed by different combinations of sucking inhibitory an...Field performance of whitebacked planthopper (WBPH)-resistance of four phenotypes was evaluated in Chunjiang 06 (C J-06) / TN1 DH rice lines, which were expressed by different combinations of sucking inhibitory and ovicidal traits inherited independently from C J-06. WBPH established the highest populations in susceptible DH lines that had neither sucking inhibitorynor ovicidal resistance. Both immigration and subsequent population levels were kept below the damage-causing density in the sucking inhibitory DH lines even under a WBPH outbreak. WBPH could not build up populations in the DH lines having both the sucking inhibitory and ovicidal resistance. Although WBPH immigrated preferentially to non-sucking inhibitory DH lines with ovicidal resistance, subsequent population buildup was significantly suppressed. It was concluded that the differential performance to WBPH-resistance in CJ-06 / TN1 DH lines was primarily due to the sucking inhibitory trait, and complementarity to the ovicidal trait.展开更多
The original online version of this article (Noda, I. et al. (2014). Effects of Silvicultural Alternatives on Model-Based Financial Evaluation of Teak (Tectona grandis L.) Farm Forestry Management for Small-Scale Farm...The original online version of this article (Noda, I. et al. (2014). Effects of Silvicultural Alternatives on Model-Based Financial Evaluation of Teak (Tectona grandis L.) Farm Forestry Management for Small-Scale Farmers in Northeast Thailand. Open Journal of Forestry, 4, 558-569. http://dx.doi.org/10.4236/ojf.2014.45060) was published in October. The author wishes to correct Table 5.展开更多
Teak (Tectona grandis L.) plantation management is said to be profitable, but small-scale farmers with teak plantations need to find appropriate and effective choices for plantation management because of their small p...Teak (Tectona grandis L.) plantation management is said to be profitable, but small-scale farmers with teak plantations need to find appropriate and effective choices for plantation management because of their small plots. There have been few studies on how combinations of site quality, rotation and plant spacing affect financial evaluations of teak plantation management quantitatively. In this study, we introduced the yield table for teak plantations in Northeast Thailand, and investigated the effects of site quality with rotation (15-year and 20-year) and spacing (2 m × 4 m and 4 m × 4 m) on the financial evaluation of teak plantation management using discounted cash flow analysis. The equivalent annual incomes (EAI) and benefit/cost ratios (BCR) were negative and <1, respectively, at site indexes (SI) of 14 and 18, but increased ~2 - 3 times as SI rose from 22 (site of medium quality) to 26 and 26 to 30. The 20-year rotation was generally preferable to the 15-year one, especially at SI 22. At SI 30, 2 m × 4 m was more profitable than 4 m × 4 m for both rotations, but at SI 22, 20-year rotation with 4 m × 4 m was the most profitable, followed by 20-year with 2 m × 4 m.展开更多
Substantial potential exists to expand supplies of biomass for energy applications through more systematic collection of agricultural residues, more intensive cultivation of croplands, and reduced waste and losses in ...Substantial potential exists to expand supplies of biomass for energy applications through more systematic collection of agricultural residues, more intensive cultivation of croplands, and reduced waste and losses in the food chain. This study aims to show how the potential can be calculated from public information sources, to put the potential in the context of global needs for liquid transport fuels, and to suggest some practical policy options for bringing part of the potential to market. It finds that if the theoretical potential is fully realized, enough liquid biofuel could be produced to displace the equivalent of all current global liquid fuel use for transport.展开更多
Bromeliaceae are important in ecological restoration, showing easy adaptation to different environments, and constantly interacting with each other through ecological relationships, whose effects may or may not benefi...Bromeliaceae are important in ecological restoration, showing easy adaptation to different environments, and constantly interacting with each other through ecological relationships, whose effects may or may not benefit the species involved. The hypothesis tested whether the population density of Hohenbergia augusta is higher in areas at a more advanced successional stage (brown trail), since the species is typical of more structured forest environments, occurring especially in the lower strata of the forest. Six plots of 10 meters (6 × 10 m) were installed, parallel to the brown and yellow trails, and with a distance of 5 m from the edge. Plots were allocated alternately between the two sides of the trail, 10 meters apart from each other when on the same side. In each plot, all H. augusta (Vell.) E. Morren bromeliads were sampled, without a minimum inclusion criterion, provided they were epiphytic phorophytes. The logarithm of the value was used for data normalization and later, the data were tested in a student’s t-test. The study pointed out that the highest population density of H. augusta occurred in the brown trail because the area is in a more advanced successional stage.展开更多
Objective: The present study consisted of challenging the extract of kombucha and the fungus Ganoderma reported as hypoglycemic and used as alternative treatments against diabetes on the number and morphology of islet...Objective: The present study consisted of challenging the extract of kombucha and the fungus Ganoderma reported as hypoglycemic and used as alternative treatments against diabetes on the number and morphology of islets of Langerhans. Material and Methods: 64 Wistar rats were used in 4 groups: one control, three experimental, streptozotocin, Kombucha y Ganoderma induced diabetes with streptozotocin. Divided into four post-induction stages at 2, 15, 30 and 45 days of treatment, sacrificing 4 rats at each stage, to perform the morphological analysis of the pancreas. Results: A decrease in the islets of Langerhans in size, volume and the number of cells within them was identified for the streptozotocin group from the second stage until almost disappearing due to diabetes, in the groups of Kombucha y Ganoderma the same was observed but they were recovered with the extract treatments and the average number of islets was similar in these groups, the group of Ganoderma. Conclusion: Under the conditions of this work, a protective and regenerative effect of both extracts is identified.展开更多
Epiphytes are plants that use the mechanical support provided by a host tree, called phorophytes, without emitting haustorial structures. Constituting an important component of the flora, playing an important role in ...Epiphytes are plants that use the mechanical support provided by a host tree, called phorophytes, without emitting haustorial structures. Constituting an important component of the flora, playing an important role in the maintenance of ecosystems, such as water and nutrient cycling, in addition to providing resources, sometimes unique, such as food and shelter, for the canopy fauna. However, the epiphytic flora may show high beta diversity, even when compared with different phorophytes, possibly as a response to the dendromorphological characteristics of the phorophyte. Thus, this work aims to: 1) compare whether the species richness of epiphytes differs in trees with different morphological characteristics, and 2) compare species composition among three tree species. For this, 10 individuals of three tree species were selected: Guaria guidonia, Ficus sp., and Roystonea oleracea. In each individual, the number of species (richness) of vascular epiphytes was recorded and obtained from the species composition. To test differences in richness values between the three trees, we used analysis of variance (ANOVA) followed by Tukey’s test. To understand whether the epiphyte community formed separate groups according to the tree species used, we used the available non-metric multidimensional scaling method (NMDS). Thirty-four species of epiphytes were found in the 30 phorophytes surveyed. The three tree species showed significantly different richness, with the highest found in Guarea guidonea and the lowest in Roystonea oleraceae. The NMDS showed that epiphytes group the three tree species into distinct groups, although Ficus sp individuals present a transitional community between the two other species. Thus, the results suggest that the differences in the richness and composition of the epiphytic flora of the different phorophytes are influenced by their distinct morphological characteristics.展开更多
Natural regeneration is the interaction of natural processes to restore the forest ecosystem. Its dynamics are influenced by the intensity and extent of a series of abiotic and biotic factors, which may be intrinsic o...Natural regeneration is the interaction of natural processes to restore the forest ecosystem. Its dynamics are influenced by the intensity and extent of a series of abiotic and biotic factors, which may be intrinsic or extrinsic. Knowing the importance of establishing natural regeneration within forest ecosystems, this work aimed to evaluate whether litter depth and trail distance influenced seedling abundance and richness in a forest fragment undergoing natural restoration. The hypothesis tested in this research was that abiotic factors influence the natural regeneration of this forest since they are factors that are directly linked to seed germination and seedling establishment. 30 plots of 1 m2 were randomly analyzed within the forest located on the brown trail. A millimeter ruler was used to diagnose the litter depth and a measuring tape to measure the distance from the plot to the edge. In each plot the seedlings were morpho-specified and each morphospecies had the number of individuals counted. Linear regression tests were performed to assess the relationships between species richness and trail distance and litter depth. The same was done for species abundance. All results showed that there is no relationship pattern between any of the variables. Other factors also influence the regeneration of a forest, such as luminosity and seed bank. Furthermore, litter depth is related to the successional stage of the forest. It was concluded that the abiotic factors tested do not influence the regeneration of the study area.展开更多
The bioconversion of lignocellulose has attracted global attention,due to the significant potential of agricultural and forestry wastes as renewable zero-carbon resources and the urgent need for substituting fossil ca...The bioconversion of lignocellulose has attracted global attention,due to the significant potential of agricultural and forestry wastes as renewable zero-carbon resources and the urgent need for substituting fossil carbon.The cellulosome system is a multi-enzyme complex produced by anaerobic bacteria,which comprises cellulases,hemicellulases,and associated enzymatic and non-enzymatic components that promote biomass conversion.To enhance their efficiency in degrading recalcitrant lignocellulosic matrices,cellulosomes have been employed to construct biocatalysts for lignocellulose bioconversion,such as consolidated bioprocessing and consolidated bio-saccharification.Hemicelluloses,the second most abundant polysaccharides in plant cell walls,hold valuable application potential but can also induce inhibitory effects on cellulose hydrolysis,thus highlighting the indispensable roles of hemicellulases within the cellulosome complex.This review evaluated current research on cellulosomal hemicellulases,comparing their types,abundance,and regulation,primarily focusing on eight known cellulosome-producing species of different origins.We also reviewed their growth conditions,their hemicellulose-degrading capabilities,and the inhibitory effects of hemicellulose on cellulosome-based lignocellulose saccharification.Finally,we proposed strategies for targeted enhancement of hemicellulase in cellulosomes to improve lignocellulose bioconversion in future studies.展开更多
文摘It is known that cropping causes soil carbon loss, which is a critical issue, especially in tropical agriculture. Nitrogen input generally increases net primary production but does not increase soil carbon content because nitrogen input enhances soil organic carbon mineralization by microorganisms. A farmer conducted a trial in which he applied material with a high carbon:nitrogen (C:N) ratio without additional nitrogen fertilizer, and achieved a higher productivity than that of conventional farms. Based on his results, we conducted a survey to evaluate the effects of high C:N ratio organic material on the productivity, soil profile, microbial activity, and carbon and nitrogen balance of soil. Results demonstrate that high C:N ratio organic material enhanced the formation of the soil A horizon and increased soil carbon and nitrogen content. Approximately, 15 - 20 t·ha-1·crop-1 of fresh waste mushroom bed was applied to 15 crops over 4.5 years, and the total input of carbon and nitrogen were 5014 and 129 g·m-2, respectively. The soil nitrate nitrogen concentration was the same as that of the neighboring forest soil, which was lower than the standard limit for conventional agriculture;however, the average productivity of crops was approximately four times that of the national average. The soil Ap horizon increased in thickness by 7 cm, and aggregates reached a thickness of 29 cm in 4.5 years. The output/input ratios of total soil nitrogen and carbon were approximately 2.68 - 6.00 and 1.30 - 2.35, respectively, indicating that this method will maintain the carbon and nitrogen balance of the system. The observed soil microbial activity was one order of magnitude higher than that of a fallow field. The results indicate that this agricultural method remediates soil degradation, and improves food production.
基金supported by the Government of Malaysia under the 10th and 11th Malaysia Plan.
文摘Many tree planting programmes have long been initiated to increase forest cover to mitigate the effects of global climate change.Successful planting requires careful planning at the project level,including using suitable species with favourable traits.However,there is a paucity of improvement data for tropical tree species.An experimental common garden of Shorea leprosula was established to study traits related to growth performance which are key factors in planting success.Seedlings of S.leprosula were collected from nine geographical forest reserves.To study the effects of genetic variation,seedlings were planted in a common environment following a randomized complete block design.From performance data collected 2017‒2019,one population showed the highest coefficient for relative height growth,significantly higher than most of the other populations.Interestingly,this population from Beserah also exhibited the lowest coefficient for scale insect infestation.This study provides preliminary results on growth performance and susceptibility to scale insect infestation in S.leprosula and the first common garden experiment site conducted on dipterocarp species.It lays a foundation for future genome-wide studies.
文摘Iron toxicity is a major constraint to rice production, particularly in highly weathered soils of inland valleys in Sub-Saharan Africa where the rice growing area is rapidly expanding. This study aimed to improve the productiveness of iron toxicity sensitive’s rice fields as well as in the unsensitive fields by using local phosphate fertilizers. Eighteen (18) rice genotypes were been assessed in a split plot design in two areas: without iron toxicity and with iron toxicity. NPK, NK, Rock Phosphate, Triple super phosphate, Calcined phosphate and Acidulated phosphate were used as fertilizers. Data collection was focused on agronomic traits and yield (g/m<sup>2</sup>). The best fertilizers in the area without iron toxicity were NPK (820.2 g/m<sup>2</sup>) and triple super phosphate (751.7 g/m<sup>2</sup>). In the iron toxicity area, the best yields were performed by NPK (785.5 g/m<sup>2</sup>) and raw calcined phosphate (698.3 g/m<sup>2</sup>). Yet, the Accessions 15, Accessions 225, Accessions 226 and Accessions 270 were rainfed rice genotypes while CC109 A, HB 46 and HB 62 were low-land/irrigated rice genotypes. NPK, NK and acidulated phosphate fertilizers alleviate the best, iron toxicity in both sensitive and unsensitive rice fields.
基金supported by Japan International Research Center for Agricultural Sciences
文摘This paper estimates a stochastic frontier function using a panel data set that includes 4 961 farmer households for the period of 2005-2009 to decompose the growth of grain production and the total factor productivity (TFP) growth at the farmer level. The empirical results show that the major contributor to the grain output growth for farmers is input growth and that its average contribution accounts for 60.92% of farmer’s grain production growth in the period of 2006-2009, whereas the average contributions sourced from TFP growth and residuals are only 17.30 and 21.78%, respectively. The growth of intermediate inputs is a top contributor with an average contribution of 44.46%, followed by the planted area (18.16%), investment in fixed assets (1.05%), and labor input (-2.75%), indicating that the contribution from the farmer’s input growth is mainly due to the growth of intermediate inputs and that the decline in labor inputs has become an obstacle for farmers in seeking grain output growth. Among the elements consisting of TFP growth, the contribution of technical progress is the largest (32.04%), followed by grain subsidies (8.55%), the average monthly temperature (4.26%), the average monthly precipitation (-0.88%), the adjusted scale effect (-5.66%), and growth in technical efficiency (-21.01%). In general, the contribution of climate factors and agricultural policy factor are positive and significant.
基金the results obtained from phases Ⅲ , Ⅳ, Ⅴ, and Ⅵ of the IRRI – Japan Collaborative Research Project, which was supported by the Ministry of Foreign Affairs and the Ministry of Agriculture, Forestry and Fisheries of Japan
文摘To enhance the yield potential of an elite indica rice cultivar,an introgression(BC_3-derived) line of IR64,YTH288,was developed using a new-plant-type cultivar,IR66215-44-2-3,as a donor parent.YTH288 has agronomically valuable characteristics such as large panicles,few unproductive tillers,and large leaves inherited from NPT.To identify the genetic basis of these traits,we used 167 F_2 plants derived from a cross between IR64 and YTH288 to conduct QTL analysis for five agronomic traits:days to heading(DTH),culm length(CL),flag leaf length(FLL),flag leaf width(FLW),and filled spikelet number per panicle(FSN).Six putative QTL were detected:four on chromosome4(for CL,FLL,FLW,and FSN) and two on chromosome 2(for DTH and FLL).All QTL with the IR66215-44-2-3 allele,except that for FLL on chromosome 2,had positive effects on each trait.To confirm the effects of these putative QTL,we developed NILs with the IR64 genetic background by marker-assisted selection.We observed significant differences in several agronomic traits between IR64 and NILs that carried these QTL on chromosomes2 and 4.Additionally,four IR64-NILs carrying chromosomal segments derived from different NPT varieties on the long arm of chromosome 4 exhibited similar pleiotropic To enhance the yield potential of an elite indica rice cultivar, an introgression(BC3-derived) line of IR64, YTH288, was developed using a new-plant-type cultivar,IR66215-44-2-3, as a donor parent. YTH288 has agronomically valuable characteristics such as large panicles, few unproductive tillers, and large leaves inherited from NPT.To identify the genetic basis of these traits, we used 167 F2 plants derived from a cross between IR64 and YTH288 to conduct QTL analysis for five agronomic traits: days to heading(DTH), culm length(CL), flag leaf length(FLL), flag leaf width(FLW), and filled spikelet number per panicle(FSN). Six putative QTL were detected: four on chromosome4(for CL, FLL, FLW, and FSN) and two on chromosome 2(for DTH and FLL). All QTL with the IR66215-44-2-3 allele, except that for FLL on chromosome 2, had positive effects on each trait. To confirm the effects of these putative QTL, we developed NILs with the IR64 genetic background by marker-assisted selection. We observed significant differences in several agronomic traits between IR64 and NILs that carried these QTL on chromosomes2 and 4. Additionally, four IR64-NILs carrying chromosomal segments derived from different NPT varieties on the long arm of chromosome 4 exhibited similar pleiotropiceffects for unique agronomic traits. These NILs can be used as research materials for studying each trait and as breeding materials for yield improvement of indica rice cultivars.
基金supported by the Science Founda-tion of Guangxi Zhuang Autonomous Region, China(0832002)
文摘In this study, we developed a computer program for automatic prediction of watering time point by considering the environmental factors such as solar radiation, air temperature and relative humidity based on the multiple linear regression equation of leaf area and Penman Method. The experiments were carried out for a year in two watering experimental plots, one of which was controlled by pF value, and the other by the computer program. After comparing the results of the two plots, the following findings were obtained. In the computer program plot, the observed and predicted values of both leaf area and evapotranspiration indicated significant correlation at the 1% level, which suggested that the computer program had high prediction accuracy. In addition, no significant difference was observed between the two experimental plots with respects to the plant height, plant diameter, leaf area, leaf number, fresh weight, and dry weight, which demonstrated that the plants in the computer program plot had normal growth. On the other hand, although the number of flower buds and flowering shoots showed higher values at the end of certain cultivations in the computer program plot than those in pF value plot, we proposed that it was due to the effect of cumulative daily solar radiation in the greenhouse, rather than the watering. Thus, we have reached the conclusion that the computer program for automatic prediction of watering time point developed by this study has high applicability in miniature pot rose production.
基金financially supported by the Japan International Research Center for Agricultural Sciences International Rice Research Institute (JIRCAS-IRRI) collaborative breeding projecta grant from the Institute of Crop Science, NARO, Japan
文摘Increasing rice yield potential is a continuous challenge posed by world population growth.To increase yield potential,favorable alleles of valuable genes need to be accumulated in promising germplasm.We conducted comparative yield trials for two years in Tsukuba,Japan,in a temperate region and at the International Rice Research Institute(IRRI),Philippines,in a tropical region using five high-yielding rice cultivars:Takanari and Hokuriku193,developed in Japan,and IR64,NSIC Rc158,and YTH183,developed in the Philippines.Genotype plus genotype×environment interaction(GGE)biplot analysis across four environments(two regions×two seasons)classified the five cultivars into four categories:Takanari and YTH183 showed high adaptability to both tropical and temperate regions,Hokuriku193 was suitable for temperate regions,NSIC Rc158 was suitable for the tropics,and IR64 was inferior to the other cultivars in both regions.The high yield and adaptability in Takanari and YTH183 were attributed to their large sink capacity with good grain filling.The plant type for high yield was different,however,between the two cultivars;Takanari was a panicle-weight type,whereas YTH183 was a panicle-number type.Evaluations of F2 progeny of a cross between Takanari and YTH183 showed transgressive segregation for number of panicles per plant as well as number of spikelets per panicle,leading some F2 plants to produce more spikelets per plant(corresponding to larger sink size)than the parental cultivars in both regions.These results suggest the possibility of developing rice cultivars with high yield potential in both temperate and tropical regions by crossing temperate with tropical high-yielding cultivars.
基金JIRCAS International Collaborative Project Fund(B33102-331)Grant Project of Zhejiang Province for International Collaboration(2002AA217111)supported this work
文摘Field performance of whitebacked planthopper (WBPH)-resistance of four phenotypes was evaluated in Chunjiang 06 (C J-06) / TN1 DH rice lines, which were expressed by different combinations of sucking inhibitory and ovicidal traits inherited independently from C J-06. WBPH established the highest populations in susceptible DH lines that had neither sucking inhibitorynor ovicidal resistance. Both immigration and subsequent population levels were kept below the damage-causing density in the sucking inhibitory DH lines even under a WBPH outbreak. WBPH could not build up populations in the DH lines having both the sucking inhibitory and ovicidal resistance. Although WBPH immigrated preferentially to non-sucking inhibitory DH lines with ovicidal resistance, subsequent population buildup was significantly suppressed. It was concluded that the differential performance to WBPH-resistance in CJ-06 / TN1 DH lines was primarily due to the sucking inhibitory trait, and complementarity to the ovicidal trait.
文摘The original online version of this article (Noda, I. et al. (2014). Effects of Silvicultural Alternatives on Model-Based Financial Evaluation of Teak (Tectona grandis L.) Farm Forestry Management for Small-Scale Farmers in Northeast Thailand. Open Journal of Forestry, 4, 558-569. http://dx.doi.org/10.4236/ojf.2014.45060) was published in October. The author wishes to correct Table 5.
文摘Teak (Tectona grandis L.) plantation management is said to be profitable, but small-scale farmers with teak plantations need to find appropriate and effective choices for plantation management because of their small plots. There have been few studies on how combinations of site quality, rotation and plant spacing affect financial evaluations of teak plantation management quantitatively. In this study, we introduced the yield table for teak plantations in Northeast Thailand, and investigated the effects of site quality with rotation (15-year and 20-year) and spacing (2 m × 4 m and 4 m × 4 m) on the financial evaluation of teak plantation management using discounted cash flow analysis. The equivalent annual incomes (EAI) and benefit/cost ratios (BCR) were negative and <1, respectively, at site indexes (SI) of 14 and 18, but increased ~2 - 3 times as SI rose from 22 (site of medium quality) to 26 and 26 to 30. The 20-year rotation was generally preferable to the 15-year one, especially at SI 22. At SI 30, 2 m × 4 m was more profitable than 4 m × 4 m for both rotations, but at SI 22, 20-year rotation with 4 m × 4 m was the most profitable, followed by 20-year with 2 m × 4 m.
文摘Substantial potential exists to expand supplies of biomass for energy applications through more systematic collection of agricultural residues, more intensive cultivation of croplands, and reduced waste and losses in the food chain. This study aims to show how the potential can be calculated from public information sources, to put the potential in the context of global needs for liquid transport fuels, and to suggest some practical policy options for bringing part of the potential to market. It finds that if the theoretical potential is fully realized, enough liquid biofuel could be produced to displace the equivalent of all current global liquid fuel use for transport.
文摘Bromeliaceae are important in ecological restoration, showing easy adaptation to different environments, and constantly interacting with each other through ecological relationships, whose effects may or may not benefit the species involved. The hypothesis tested whether the population density of Hohenbergia augusta is higher in areas at a more advanced successional stage (brown trail), since the species is typical of more structured forest environments, occurring especially in the lower strata of the forest. Six plots of 10 meters (6 × 10 m) were installed, parallel to the brown and yellow trails, and with a distance of 5 m from the edge. Plots were allocated alternately between the two sides of the trail, 10 meters apart from each other when on the same side. In each plot, all H. augusta (Vell.) E. Morren bromeliads were sampled, without a minimum inclusion criterion, provided they were epiphytic phorophytes. The logarithm of the value was used for data normalization and later, the data were tested in a student’s t-test. The study pointed out that the highest population density of H. augusta occurred in the brown trail because the area is in a more advanced successional stage.
文摘Objective: The present study consisted of challenging the extract of kombucha and the fungus Ganoderma reported as hypoglycemic and used as alternative treatments against diabetes on the number and morphology of islets of Langerhans. Material and Methods: 64 Wistar rats were used in 4 groups: one control, three experimental, streptozotocin, Kombucha y Ganoderma induced diabetes with streptozotocin. Divided into four post-induction stages at 2, 15, 30 and 45 days of treatment, sacrificing 4 rats at each stage, to perform the morphological analysis of the pancreas. Results: A decrease in the islets of Langerhans in size, volume and the number of cells within them was identified for the streptozotocin group from the second stage until almost disappearing due to diabetes, in the groups of Kombucha y Ganoderma the same was observed but they were recovered with the extract treatments and the average number of islets was similar in these groups, the group of Ganoderma. Conclusion: Under the conditions of this work, a protective and regenerative effect of both extracts is identified.
文摘Epiphytes are plants that use the mechanical support provided by a host tree, called phorophytes, without emitting haustorial structures. Constituting an important component of the flora, playing an important role in the maintenance of ecosystems, such as water and nutrient cycling, in addition to providing resources, sometimes unique, such as food and shelter, for the canopy fauna. However, the epiphytic flora may show high beta diversity, even when compared with different phorophytes, possibly as a response to the dendromorphological characteristics of the phorophyte. Thus, this work aims to: 1) compare whether the species richness of epiphytes differs in trees with different morphological characteristics, and 2) compare species composition among three tree species. For this, 10 individuals of three tree species were selected: Guaria guidonia, Ficus sp., and Roystonea oleracea. In each individual, the number of species (richness) of vascular epiphytes was recorded and obtained from the species composition. To test differences in richness values between the three trees, we used analysis of variance (ANOVA) followed by Tukey’s test. To understand whether the epiphyte community formed separate groups according to the tree species used, we used the available non-metric multidimensional scaling method (NMDS). Thirty-four species of epiphytes were found in the 30 phorophytes surveyed. The three tree species showed significantly different richness, with the highest found in Guarea guidonea and the lowest in Roystonea oleraceae. The NMDS showed that epiphytes group the three tree species into distinct groups, although Ficus sp individuals present a transitional community between the two other species. Thus, the results suggest that the differences in the richness and composition of the epiphytic flora of the different phorophytes are influenced by their distinct morphological characteristics.
文摘Natural regeneration is the interaction of natural processes to restore the forest ecosystem. Its dynamics are influenced by the intensity and extent of a series of abiotic and biotic factors, which may be intrinsic or extrinsic. Knowing the importance of establishing natural regeneration within forest ecosystems, this work aimed to evaluate whether litter depth and trail distance influenced seedling abundance and richness in a forest fragment undergoing natural restoration. The hypothesis tested in this research was that abiotic factors influence the natural regeneration of this forest since they are factors that are directly linked to seed germination and seedling establishment. 30 plots of 1 m2 were randomly analyzed within the forest located on the brown trail. A millimeter ruler was used to diagnose the litter depth and a measuring tape to measure the distance from the plot to the edge. In each plot the seedlings were morpho-specified and each morphospecies had the number of individuals counted. Linear regression tests were performed to assess the relationships between species richness and trail distance and litter depth. The same was done for species abundance. All results showed that there is no relationship pattern between any of the variables. Other factors also influence the regeneration of a forest, such as luminosity and seed bank. Furthermore, litter depth is related to the successional stage of the forest. It was concluded that the abiotic factors tested do not influence the regeneration of the study area.
基金supported by the National Natural Science Foundation of China[32070028 and 32370035 to Y.-J.L.,32070125 to Y.F.,and 32170051 to Q.C.]the National Key Research and Development Program of China[2021YFC2103600 to Y.-J.L.and 2023YFC3402304 to Y.F.]+2 种基金the International Partnership Program of Chinese Academy of Sciences[323GJHZ2022004MI to Y.-J.L.and A.K.]Shandong Energy Institute[SEI I202142 to Y.-J.L.,SEI S202106 to Q.C.,SEI I202106 to Y.F.]QIBEBT[Grant No.QIBEBT ICP2023046 to Y.F.].E.A.B.is the incumbent of The Maynard I.and Elaine Wishner Chair of Bio-organic Chemistry.
文摘The bioconversion of lignocellulose has attracted global attention,due to the significant potential of agricultural and forestry wastes as renewable zero-carbon resources and the urgent need for substituting fossil carbon.The cellulosome system is a multi-enzyme complex produced by anaerobic bacteria,which comprises cellulases,hemicellulases,and associated enzymatic and non-enzymatic components that promote biomass conversion.To enhance their efficiency in degrading recalcitrant lignocellulosic matrices,cellulosomes have been employed to construct biocatalysts for lignocellulose bioconversion,such as consolidated bioprocessing and consolidated bio-saccharification.Hemicelluloses,the second most abundant polysaccharides in plant cell walls,hold valuable application potential but can also induce inhibitory effects on cellulose hydrolysis,thus highlighting the indispensable roles of hemicellulases within the cellulosome complex.This review evaluated current research on cellulosomal hemicellulases,comparing their types,abundance,and regulation,primarily focusing on eight known cellulosome-producing species of different origins.We also reviewed their growth conditions,their hemicellulose-degrading capabilities,and the inhibitory effects of hemicellulose on cellulosome-based lignocellulose saccharification.Finally,we proposed strategies for targeted enhancement of hemicellulase in cellulosomes to improve lignocellulose bioconversion in future studies.