With probable center of origin in Brazil, the species Jatropha curcas L., known as physic nut, is a tropical oilseed with potential for cultivation aiming at the production of biodiesel. This study was conducted with ...With probable center of origin in Brazil, the species Jatropha curcas L., known as physic nut, is a tropical oilseed with potential for cultivation aiming at the production of biodiesel. This study was conducted with the objective of investigating the genetic variability regarding the morphology of seeds of physic nut, using biometric analyses to identify variables that have potential for the study of the diversity of the species and the classification of genotypes. Seeds of 22 genotypes of physic nut, from the germplasm bank of Embrapa Agroenergia (Brazil) were evaluated regarding characteristics of size and mass. The genotypes of Jatropha curcas L. selected by the Brazilian breeding program presented high diversity for characteristics of the seeds, allowing the exploration of this genetic variability to classify genotypes in different groups. In addition, variables related to the biomass of the seeds present high relative contributions to the diversity observed in the genotypes.展开更多
The adequate supply of nitrogen is essential for the plant metabolism. This nutrient has an irreplaceable role on the vegetative and reproductive growth of physic nut;therefore the correct management of the fertilizat...The adequate supply of nitrogen is essential for the plant metabolism. This nutrient has an irreplaceable role on the vegetative and reproductive growth of physic nut;therefore the correct management of the fertilization is very important, particularly in tropical regions, which present considerable losses of nitrogen by leaching and volatilization processes. This study was made with the objective of evaluating the growth of genotypes of physic nut conditioned by nitrogen fertilization. The experiment was conducted in controlled environment, following a factorial scheme 12 × 4, with 12 Brazilian genotypes of Jatropha curcas L. and 4 levels of nitrogen fertilization (0%, 50%, 100% and 150% of the recommendation), in completely randomized design, with four replications. The growth of the genotypes was evaluated at 100 days of cultivation. Positive response to the increase in the nitrogen supply was observed in most genotypes, with gain in plant height, stem diameter, number of leaves, leaf area and root volume. The levels of nitrogen fertilization promoted differential growth between genotypes, being possible to identify genotypes with superior growth for each level.展开更多
In addition to the efforts undertaken by research institutions to generate new knowledge and technologies, it is also necessary to promote the results of this research. Specifically, there is a need for an information...In addition to the efforts undertaken by research institutions to generate new knowledge and technologies, it is also necessary to promote the results of this research. Specifically, there is a need for an information system that aggregates, organizes and systematizes information about agro-energy technology and makes it available on the Internet. Despite the abundance of information circulating on the internet in Brazil, a specific method for sharing valid scientific and technological information of practical interest, such as technical guidance and recommendations for processing various materials and production technologies for various forms of agro-energy, has not yet been established. This article presents the Agro-energy Tree of Knowledge, a tool developed by Embrapa to enable web access to comprehensive information about bioenergy production systems applied in different regions and conditions, in addition to texts, publications, statistical data about production and economic markets and information links related to agro-energy.展开更多
Drought is a major environmental factor limiting cotton (Gossypium hirsutum L.) productivity worldwide and projected climate changes could increase their negative effects in the future. Thus, targeting the molecular m...Drought is a major environmental factor limiting cotton (Gossypium hirsutum L.) productivity worldwide and projected climate changes could increase their negative effects in the future. Thus, targeting the molecular mechanisms correlated with drought tolerance without reducing productivity is a challenge for plant breeding. In this way, we evaluated the effects of water deficit progress on AtDREB2A-CA transgenic cotton plant responses, driven by the stress-inducible rd29 promoter. Besides shoot and root morphometric traits, gas exchange and osmotic adjustment analyses were also included. Here, we present how altered root traits shown by transgenic plants impacted on physiological acclimation responses when submitted to severe water stress. The integration of AtDREB2A-CA into the cotton genome increased total root volume, surface area and total root length, without negatively affecting shoot morphometric growth parameters and nor phenotypic evaluated traits. Additionally, when compared to wild-type plants, transgenic plants (17-T0 plants and its progeny) highlighted a gradual pattern of phenotypic plasticity tosome photosynthetic parameters such as photosynthetic rate and stomatal conductance with water deficit progress. Transgene also promoted greater shoot development and root robustness (greater and deeper root mass) allowing roots to grow into deeper soil layers. The same morpho-physiological trend was observed in the subsequent generation (17.6-T2). Our results suggest that the altered root traits shown by transgenic plants are the major contributors to higher tolerance response, allowing the AtDRE2A-CA-cotton plants to maintain elevated stomatal conductance and assimilate rates and, consequently, reducing their metabolic costs involved in the antioxidant responses activation. These results also suggest that these morpho-physiological changes increased the number of reproductive structures retained per plant (26% higher) when compared with its non-transgenic counterpart. This is the first report of cotton plants overexpressing the AtDRE2A-CA transcription factor, demonstrating a morpho-physiological and yield advantages under drought stress, without displaying any yield penalty under irrigated conditions. The mechanisms by which the root traits influenced the acclimation of the transgenic plants to severe water deficit conditions are also discussed. These data present an opportunity to use this strategy in cotton breeding programs in order to improve drought adaptation toward better rooting features.展开更多
文摘With probable center of origin in Brazil, the species Jatropha curcas L., known as physic nut, is a tropical oilseed with potential for cultivation aiming at the production of biodiesel. This study was conducted with the objective of investigating the genetic variability regarding the morphology of seeds of physic nut, using biometric analyses to identify variables that have potential for the study of the diversity of the species and the classification of genotypes. Seeds of 22 genotypes of physic nut, from the germplasm bank of Embrapa Agroenergia (Brazil) were evaluated regarding characteristics of size and mass. The genotypes of Jatropha curcas L. selected by the Brazilian breeding program presented high diversity for characteristics of the seeds, allowing the exploration of this genetic variability to classify genotypes in different groups. In addition, variables related to the biomass of the seeds present high relative contributions to the diversity observed in the genotypes.
文摘The adequate supply of nitrogen is essential for the plant metabolism. This nutrient has an irreplaceable role on the vegetative and reproductive growth of physic nut;therefore the correct management of the fertilization is very important, particularly in tropical regions, which present considerable losses of nitrogen by leaching and volatilization processes. This study was made with the objective of evaluating the growth of genotypes of physic nut conditioned by nitrogen fertilization. The experiment was conducted in controlled environment, following a factorial scheme 12 × 4, with 12 Brazilian genotypes of Jatropha curcas L. and 4 levels of nitrogen fertilization (0%, 50%, 100% and 150% of the recommendation), in completely randomized design, with four replications. The growth of the genotypes was evaluated at 100 days of cultivation. Positive response to the increase in the nitrogen supply was observed in most genotypes, with gain in plant height, stem diameter, number of leaves, leaf area and root volume. The levels of nitrogen fertilization promoted differential growth between genotypes, being possible to identify genotypes with superior growth for each level.
文摘In addition to the efforts undertaken by research institutions to generate new knowledge and technologies, it is also necessary to promote the results of this research. Specifically, there is a need for an information system that aggregates, organizes and systematizes information about agro-energy technology and makes it available on the Internet. Despite the abundance of information circulating on the internet in Brazil, a specific method for sharing valid scientific and technological information of practical interest, such as technical guidance and recommendations for processing various materials and production technologies for various forms of agro-energy, has not yet been established. This article presents the Agro-energy Tree of Knowledge, a tool developed by Embrapa to enable web access to comprehensive information about bioenergy production systems applied in different regions and conditions, in addition to texts, publications, statistical data about production and economic markets and information links related to agro-energy.
基金supported by grants of funds from the Brazilian government(EMBRAPA,CNPq,CAPES and FAPDF).
文摘Drought is a major environmental factor limiting cotton (Gossypium hirsutum L.) productivity worldwide and projected climate changes could increase their negative effects in the future. Thus, targeting the molecular mechanisms correlated with drought tolerance without reducing productivity is a challenge for plant breeding. In this way, we evaluated the effects of water deficit progress on AtDREB2A-CA transgenic cotton plant responses, driven by the stress-inducible rd29 promoter. Besides shoot and root morphometric traits, gas exchange and osmotic adjustment analyses were also included. Here, we present how altered root traits shown by transgenic plants impacted on physiological acclimation responses when submitted to severe water stress. The integration of AtDREB2A-CA into the cotton genome increased total root volume, surface area and total root length, without negatively affecting shoot morphometric growth parameters and nor phenotypic evaluated traits. Additionally, when compared to wild-type plants, transgenic plants (17-T0 plants and its progeny) highlighted a gradual pattern of phenotypic plasticity tosome photosynthetic parameters such as photosynthetic rate and stomatal conductance with water deficit progress. Transgene also promoted greater shoot development and root robustness (greater and deeper root mass) allowing roots to grow into deeper soil layers. The same morpho-physiological trend was observed in the subsequent generation (17.6-T2). Our results suggest that the altered root traits shown by transgenic plants are the major contributors to higher tolerance response, allowing the AtDRE2A-CA-cotton plants to maintain elevated stomatal conductance and assimilate rates and, consequently, reducing their metabolic costs involved in the antioxidant responses activation. These results also suggest that these morpho-physiological changes increased the number of reproductive structures retained per plant (26% higher) when compared with its non-transgenic counterpart. This is the first report of cotton plants overexpressing the AtDRE2A-CA transcription factor, demonstrating a morpho-physiological and yield advantages under drought stress, without displaying any yield penalty under irrigated conditions. The mechanisms by which the root traits influenced the acclimation of the transgenic plants to severe water deficit conditions are also discussed. These data present an opportunity to use this strategy in cotton breeding programs in order to improve drought adaptation toward better rooting features.
