Journal articles 2013
Documents
Relationships of wheat leaf stomatal traits with wheat yield and drought resistance
Wang S-G, Li Z-Q, Jia S-S, Sun D-Z, Shi Y-G, Fan H, Liang Z-H and Jing R-L (2013). Relationships of wheat leaf stomatal traits with wheat yield and drought resistance. Chinese Journal of Applied Ecology 24(6):1609−1614. (G7010.02.01)
Abstract: Taking the DH population of wheat cultivar Hanxuan10/Lumai14 as test object, and by the methods of correlation analysis and path analysis, this paper studied the relationships of the flag leaf stomatal density (SD), stomatal length and width (SL and SW), stomatal conductance (gs), photosynthetic rate (Pn), and transpiration rate (Tr) on the 10th and 20th day after anthesis with the yield and the index of drought-resistance under the conditions of drought stress and normal irrigation. Under the two conditions, most of the test leaf traits on the 10th day after anthesis had less correlation with the yield and the index of drought-resistance, whereas the leaf traits on the 20th day after anthesis had significant positive correlations with thousand kernel weight but less correlation with grain number per ear, grain yield per plant, and index of drought-resistance. Path analysis showed that gs, Pn, and Tr were the main factors affecting the grain yield per plant (YPP) and the index of drought resistance (IDR), and the effects were stronger both in direct and in indirect ways. The direct and indirect effects of SD, SL, and SW on the YPP and IDR were lesser. Under both drought stress and normal irrigation, and on the 10th and 20th day after anthesis, there were significant correlations between SD and SL, and between SL and SW, gs, Pn, and Tr, but the correlations of SD and SL with gs, Pn, and Tr changed with water condition or growth stage. Therefore, it would be not always a good means to select the leaf stomatal density and size as the targets for breeding to improve the leaf stomatal conductance, photosynthetic rate, and transpiration rate, and further, to promote the yield.
Wang S-G, Li Z-Q, Jia S-S, Sun D-Z, Shi Y-G, Fan H, Liang Z-H and Jing R-L (2013). Relationships of wheat leaf stomatal traits with wheat yield and drought resistance. Chinese Journal of Applied Ecology 24(6):1609−1614. (G7010.02.01)
Abstract: Taking the DH population of wheat cultivar Hanxuan10/Lumai14 as test object, and by the methods of correlation analysis and path analysis, this paper studied the relationships of the flag leaf stomatal density (SD), stomatal length and width (SL and SW), stomatal conductance (gs), photosynthetic rate (Pn), and transpiration rate (Tr) on the 10th and 20th day after anthesis with the yield and the index of drought-resistance under the conditions of drought stress and normal irrigation. Under the two conditions, most of the test leaf traits on the 10th day after anthesis had less correlation with the yield and the index of drought-resistance, whereas the leaf traits on the 20th day after anthesis had significant positive correlations with thousand kernel weight but less correlation with grain number per ear, grain yield per plant, and index of drought-resistance. Path analysis showed that gs, Pn, and Tr were the main factors affecting the grain yield per plant (YPP) and the index of drought resistance (IDR), and the effects were stronger both in direct and in indirect ways. The direct and indirect effects of SD, SL, and SW on the YPP and IDR were lesser. Under both drought stress and normal irrigation, and on the 10th and 20th day after anthesis, there were significant correlations between SD and SL, and between SL and SW, gs, Pn, and Tr, but the correlations of SD and SL with gs, Pn, and Tr changed with water condition or growth stage. Therefore, it would be not always a good means to select the leaf stomatal density and size as the targets for breeding to improve the leaf stomatal conductance, photosynthetic rate, and transpiration rate, and further, to promote the yield.
Full article
Plant response to environmental conditions: assessing potential production, water demand, and negative effects of water deficit
Tardieu F (2013). Plant response to environmental conditions: assessing potential production, water demand, and negative effects of water deficit. Frontiers in Plant Physiology 4:17. (DOI: 10.3389/fphys.2013.00017).
This paper reviews methods for analyzing plant performance and its genetic variability under a range of environmental conditions. Biomass accumulation is linked every day to available light in the photosynthetically active radiation (PAR) domain, multiplied by the proportion of light intercepted by plants and by the radiation use efficiency. Total biomass is cumulated over the duration of the considered phase (e.g., plant cycle or vegetative phase). These durations are essentially constant for a given genotype provided that time is corrected for temperature (thermal time). Several ways of expressing thermal time are reviewed. Two alternative equations are presented, based either on the effect of transpiration, or on yield components. Their comparative interests and drawbacks are discussed. The genetic variability of each term of considered equations affects yield under water deficit, via mechanisms at different scales of plant organization and time. The effect of any physiological mechanism on yield of stressed plants acts via one of these terms, although the link is not always straightforward. Finally, I propose practical ways to compare the productivity of genotypes in field environments, and a “minimum dataset”of environmental data and traits that should be recorded for that.
Tardieu F (2013). Plant response to environmental conditions: assessing potential production, water demand, and negative effects of water deficit. Frontiers in Plant Physiology 4:17. (DOI: 10.3389/fphys.2013.00017).
This paper reviews methods for analyzing plant performance and its genetic variability under a range of environmental conditions. Biomass accumulation is linked every day to available light in the photosynthetically active radiation (PAR) domain, multiplied by the proportion of light intercepted by plants and by the radiation use efficiency. Total biomass is cumulated over the duration of the considered phase (e.g., plant cycle or vegetative phase). These durations are essentially constant for a given genotype provided that time is corrected for temperature (thermal time). Several ways of expressing thermal time are reviewed. Two alternative equations are presented, based either on the effect of transpiration, or on yield components. Their comparative interests and drawbacks are discussed. The genetic variability of each term of considered equations affects yield under water deficit, via mechanisms at different scales of plant organization and time. The effect of any physiological mechanism on yield of stressed plants acts via one of these terms, although the link is not always straightforward. Finally, I propose practical ways to compare the productivity of genotypes in field environments, and a “minimum dataset”of environmental data and traits that should be recorded for that.
Plant breeding: Discovery in a dry spell
Eisenstein M.(2013). Plant breeding: Discovery in a dry spell. Nature 501: S7–S9. Published online 25 September 2013. (DOI:10.1038/501S7a). Not open access: view online
Eisenstein M.(2013). Plant breeding: Discovery in a dry spell. Nature 501: S7–S9. Published online 25 September 2013. (DOI:10.1038/501S7a). Not open access: view online
Phenotyping common beans for adaptation to drought
Beebe SE, Rao IM, Blair MW, Acosta-Gallegos JA(2013). Phenotyping common beans for adaptation to drought. Frontiers in Plant Physiology 4:35. (DOI: 10.3389/fphys.2013.00035).
Common beans (Phaseolus vulgaris L.) originated in the New World and are the grain legume of greatest production for direct human consumption. Common bean production is subject to frequent droughts in highland Mexico, in the Pacific coast of Central America, in northeast Brazil, and in eastern and southern Africa from Ethiopia to South Africa. This article reviews efforts to improve common bean for drought tolerance, referring to genetic diversity for drought response, the physiology of drought tolerance mechanisms, and breeding strategies. Different races of common bean respond differently to drought, with race Durango of highland Mexico being a major source of genes. Sister species of P. vulgaris likewise have unique traits, especially P. acutifolius which is well adapted to dryland conditions. Diverse sources of tolerance may have different mechanisms of plant response, implying the need for different methods of phenotyping to recognize the relevant traits. Practical considerations of field management are discussed including: trial planning; water management; and field preparation.
Beebe SE, Rao IM, Blair MW, Acosta-Gallegos JA(2013). Phenotyping common beans for adaptation to drought. Frontiers in Plant Physiology 4:35. (DOI: 10.3389/fphys.2013.00035).
Common beans (Phaseolus vulgaris L.) originated in the New World and are the grain legume of greatest production for direct human consumption. Common bean production is subject to frequent droughts in highland Mexico, in the Pacific coast of Central America, in northeast Brazil, and in eastern and southern Africa from Ethiopia to South Africa. This article reviews efforts to improve common bean for drought tolerance, referring to genetic diversity for drought response, the physiology of drought tolerance mechanisms, and breeding strategies. Different races of common bean respond differently to drought, with race Durango of highland Mexico being a major source of genes. Sister species of P. vulgaris likewise have unique traits, especially P. acutifolius which is well adapted to dryland conditions. Diverse sources of tolerance may have different mechanisms of plant response, implying the need for different methods of phenotyping to recognize the relevant traits. Practical considerations of field management are discussed including: trial planning; water management; and field preparation.
Phenotyping bananas for drought resistance
Ravi I, Uma S, Vaganan MM, Mustaffa MM (2013). Phenotyping bananas for drought resistance. Frontiers in Plant Physiology 4:9. (DOI: 10.3389/fphys.2013.00009).
Drought has emerged as one of the major constraints in banana production. Its effects are pronounced substantially in the tropics and sub-tropics of the world due to climate change. Bananas are quite sensitive to drought; however, genotypes with “B” genome are more tolerant to abiotic stresses than those solely based on “A” genome. In particular, bananas with “ABB” genomes are more tolerant to drought and other abiotic stresses than other genotypes. A good phenotyping plan is a prerequisite for any improvement program for targeted traits. In the present article, known drought tolerant traits of other crop plants are validated in bananas with different genomic backgrounds and presented. Since, banana is recalcitrant to breeding, strategies for making hybrids between different genomic backgrounds are also discussed. Stomatal conductance, cell membrane stability (CMS), leaf emergence rate, rate of leaf senescence, RWC, and bunch yield under soil moisture deficit stress are some of the traits associated with drought tolerance. Among these stress bunch yield under drought should be given top priority for phenotyping. In the light of recently released Musa genome draft sequence, the molecular breeders may have interest in developing molecular markers for drought resistance.
Ravi I, Uma S, Vaganan MM, Mustaffa MM (2013). Phenotyping bananas for drought resistance. Frontiers in Plant Physiology 4:9. (DOI: 10.3389/fphys.2013.00009).
Drought has emerged as one of the major constraints in banana production. Its effects are pronounced substantially in the tropics and sub-tropics of the world due to climate change. Bananas are quite sensitive to drought; however, genotypes with “B” genome are more tolerant to abiotic stresses than those solely based on “A” genome. In particular, bananas with “ABB” genomes are more tolerant to drought and other abiotic stresses than other genotypes. A good phenotyping plan is a prerequisite for any improvement program for targeted traits. In the present article, known drought tolerant traits of other crop plants are validated in bananas with different genomic backgrounds and presented. Since, banana is recalcitrant to breeding, strategies for making hybrids between different genomic backgrounds are also discussed. Stomatal conductance, cell membrane stability (CMS), leaf emergence rate, rate of leaf senescence, RWC, and bunch yield under soil moisture deficit stress are some of the traits associated with drought tolerance. Among these stress bunch yield under drought should be given top priority for phenotyping. In the light of recently released Musa genome draft sequence, the molecular breeders may have interest in developing molecular markers for drought resistance.
Phenotypic approaches to drought in cassava: review
Okogbenin E, Setter TL, Ferguson M, Mutegi R, Ceballos H, Olasanmi B and Fregene M (2013). Phenotypic approaches to drought in cassava: review. Frontiers in Plant Physiology 4:93. (DOI: 10.3389/fphys.2013.00093). (G7009.09/G7010.01.03).
Cassava is an important crop in Africa, Asia, Latin America, and the Caribbean. Cassava can be produced adequately in drought conditions making it the ideal food security crop in marginal environments. Although cassava can tolerate drought stress, it can be genetically improved to enhance productivity in such environments. Drought adaptation studies in over three decades in cassava have identified relevant mechanisms which have been explored in conventional breeding. Drought is a quantitative trait and its multigenic nature makes it very challenging to effectively manipulate and combine genes in breeding for rapid genetic gain and selection process.
Okogbenin E, Setter TL, Ferguson M, Mutegi R, Ceballos H, Olasanmi B and Fregene M (2013). Phenotypic approaches to drought in cassava: review. Frontiers in Plant Physiology 4:93. (DOI: 10.3389/fphys.2013.00093). (G7009.09/G7010.01.03).
Cassava is an important crop in Africa, Asia, Latin America, and the Caribbean. Cassava can be produced adequately in drought conditions making it the ideal food security crop in marginal environments. Although cassava can tolerate drought stress, it can be genetically improved to enhance productivity in such environments. Drought adaptation studies in over three decades in cassava have identified relevant mechanisms which have been explored in conventional breeding. Drought is a quantitative trait and its multigenic nature makes it very challenging to effectively manipulate and combine genes in breeding for rapid genetic gain and selection process.
Performance of nine cassava (Manihot esculanta Crantz) clones across three environments
Peprah BB, Ofori K, Asante IK, Parkes E (2013). Performance of nine cassava (Manihot esculanta Crantz) clones across three environments. Journal of Plant Breeding and Crop Science 5(4):48–53. (DOI:10.5897/JPBCS12.027). (G7010.01.05).
The study was carried out to quantify the genotype × environment interaction (G × E) and to estimate the phenotypic stability by genotype genotype × environment (GGE) biplot of nine cassava clones comprising 5 hybrids, 3 parent checks and 1 improved variety. The study was planted across three different environments; Fumesua, Pokuase and Ejura representing forest, coastal savanna and forest transition zones, respectively. Genotype main effect was significant (P < 0.001) for fresh root yield and dry matter content, G × E interaction effect was significant (P < 0.001) for fresh root yield only and environment main effect was significant (P < 0.01) for only fresh root yield. The most stable clone for fresh root yield with above average performance was La02/026 (hybrid). The high genotype and low environment effects, and the relatively low interaction on dry matter content imply that evaluation and selection can be effectively done in fewer environments to select clones with high performance for the trait whiles fresh root yield requires multiple environments to identify clones with broad and specific adaptation.
Peprah BB, Ofori K, Asante IK, Parkes E (2013). Performance of nine cassava (Manihot esculanta Crantz) clones across three environments. Journal of Plant Breeding and Crop Science 5(4):48–53. (DOI:10.5897/JPBCS12.027). (G7010.01.05).
The study was carried out to quantify the genotype × environment interaction (G × E) and to estimate the phenotypic stability by genotype genotype × environment (GGE) biplot of nine cassava clones comprising 5 hybrids, 3 parent checks and 1 improved variety. The study was planted across three different environments; Fumesua, Pokuase and Ejura representing forest, coastal savanna and forest transition zones, respectively. Genotype main effect was significant (P < 0.001) for fresh root yield and dry matter content, G × E interaction effect was significant (P < 0.001) for fresh root yield only and environment main effect was significant (P < 0.01) for only fresh root yield. The most stable clone for fresh root yield with above average performance was La02/026 (hybrid). The high genotype and low environment effects, and the relatively low interaction on dry matter content imply that evaluation and selection can be effectively done in fewer environments to select clones with high performance for the trait whiles fresh root yield requires multiple environments to identify clones with broad and specific adaptation.
Partitioning coefficient – A trait that contributes to drought tolerance in chickpea
Krishnamurthy L, Kashiwagi J, Upadhyaya HD, Gowda CLL, Gaur PM, Singh S, Purushothaman R, Varshney RK (2013). Partitioning coefficient – A trait that contributes to drought tolerance in chickpea. Field Crops Research 149: 354–365. (ISSN 0378-4290, DOI: http://dx.doi.org/10.1016/j.fcr.2013.05.022). (G4008.12). Not open access: view online
Krishnamurthy L, Kashiwagi J, Upadhyaya HD, Gowda CLL, Gaur PM, Singh S, Purushothaman R, Varshney RK (2013). Partitioning coefficient – A trait that contributes to drought tolerance in chickpea. Field Crops Research 149: 354–365. (ISSN 0378-4290, DOI: http://dx.doi.org/10.1016/j.fcr.2013.05.022). (G4008.12). Not open access: view online
OptiMAS: A decision support tool for marker-assisted assembly of diverse alleles
Valente F, Gauthier F, Bardol N, Blanc G, Joets J, Charcosset A, and Moreau L (2013). OptiMAS: A decision support tool for marker-assisted assembly of diverse alleles. Journal of Heredity published online April 10, 2013. (DOI: 10.1093/jhered/est020). (G8009.03.06.02/Subactivity 2.2.6.2).
Current advances in plant genotyping lead to major progress in the knowledge of genetic architecture of traits of interest. It is increasingly important to develop decision support tools to help breeders and geneticists to conduct marker-assisted selection methods to assemble favorable alleles that are discovered. Algorithms have been implemented, within an interactive graphical interface, to 1) trace parental alleles throughout generations, 2) propose strategies to select the best plants based on estimated molecular scores, and 3) efficiently intermate them depending on the expected value of their progenies. With the possibility to consider a multi-allelic context, OptiMAS opens new prospects to assemble favorable alleles issued from diverse parents and further accelerate genetic gain.
Valente F, Gauthier F, Bardol N, Blanc G, Joets J, Charcosset A, and Moreau L (2013). OptiMAS: A decision support tool for marker-assisted assembly of diverse alleles. Journal of Heredity published online April 10, 2013. (DOI: 10.1093/jhered/est020). (G8009.03.06.02/Subactivity 2.2.6.2).
Current advances in plant genotyping lead to major progress in the knowledge of genetic architecture of traits of interest. It is increasingly important to develop decision support tools to help breeders and geneticists to conduct marker-assisted selection methods to assemble favorable alleles that are discovered. Algorithms have been implemented, within an interactive graphical interface, to 1) trace parental alleles throughout generations, 2) propose strategies to select the best plants based on estimated molecular scores, and 3) efficiently intermate them depending on the expected value of their progenies. With the possibility to consider a multi-allelic context, OptiMAS opens new prospects to assemble favorable alleles issued from diverse parents and further accelerate genetic gain.
Multi-parent advanced generation inter-cross (MAGIC) populations in rice: progress and potential for genetics research and breeding
Bandillo N, Raghavan C, Muyco PA, Sevilla MAL, Lobina IT, Dilla-Ermita CJ, Tung C-w, McCouch S, Thomson M, Mauleon R, Singh RK, Gregorio G, Redoña E and Leung H (2013). Multi-parent advanced generation inter-cross (MAGIC) populations in rice: progress and potential for genetics research and breeding. Rice 2013, 6:11.
This article describes the development of Multi-parent Advanced Generation Inter-Cross populations (MAGIC) in rice and discusses potential applications for mapping quantitative trait loci (QTLs) and for rice varietal development. We have developed 4 multi-parent populations: indica MAGIC (8 indica parents); MAGIC plus (8 indica parents with two additional rounds of 8-way F1 inter-crossing); japonica MAGIC (8 japonica parents); and Global MAGIC (16 parents – 8 indica and 8 japonica). The parents used in creating these populations are improved varieties with desirable traits for biotic and abiotic stress tolerance, yield, and grain quality. The purpose is to fine map QTLs for multiple traits and to directly and indirectly use the highly recombined lines in breeding programs. These MAGIC populations provide a useful germplasm resource with diverse allelic combinations to be exploited by the rice community.
Bandillo N, Raghavan C, Muyco PA, Sevilla MAL, Lobina IT, Dilla-Ermita CJ, Tung C-w, McCouch S, Thomson M, Mauleon R, Singh RK, Gregorio G, Redoña E and Leung H (2013). Multi-parent advanced generation inter-cross (MAGIC) populations in rice: progress and potential for genetics research and breeding. Rice 2013, 6:11.
This article describes the development of Multi-parent Advanced Generation Inter-Cross populations (MAGIC) in rice and discusses potential applications for mapping quantitative trait loci (QTLs) and for rice varietal development. We have developed 4 multi-parent populations: indica MAGIC (8 indica parents); MAGIC plus (8 indica parents with two additional rounds of 8-way F1 inter-crossing); japonica MAGIC (8 japonica parents); and Global MAGIC (16 parents – 8 indica and 8 japonica). The parents used in creating these populations are improved varieties with desirable traits for biotic and abiotic stress tolerance, yield, and grain quality. The purpose is to fine map QTLs for multiple traits and to directly and indirectly use the highly recombined lines in breeding programs. These MAGIC populations provide a useful germplasm resource with diverse allelic combinations to be exploited by the rice community.
