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Midori Okami - One of the best experts on this subject based on the ideXlab platform.
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Agronomic performance of an IR64 introgression line with large leaves derived from New Plant Type rice in Aerobic Culture
European Journal of Agronomy, 2014Co-Authors: Midori Okami, Yoichiro Kato, Nobuya Kobayashi, Junko YamagishiAbstract:Abstract Aerobic Culture is a promising water-saving technology in irrigated rice ecosystems, but the vulnerability of plants to fluctuations in soil moisture constrains leaf expansion and yield. The objective of this study was to examine whether an aboveground architecture with large leaves and reduced tillering is associated with vigorous leaf growth in Aerobic rice Culture. In a series of field experiments, we evaluated the agronomic performance of an IR64 introgression line, YTH323 (IR84640-11-27-1-9-3-2-4-2-2-2-B), with fewer tillers and larger leaves than IR64, derived from New Plant Type rice, under various water and nitrogen conditions. In flooded Culture, YTH323 yielded the same as IR64 and 38% more than IR65564-44-51 (a New Plant Type rice) (9.0 vs. 6.6 t ha −1 ). In Aerobic Culture, in contrast, it yielded 81% more than IR64 in slightly dry soils (5.1 vs. 2.8 t ha −1 ). YTH323 had a higher leaf area index than IR64 and IR65564-44-51 under slightly dry soil conditions and under a range of nitrogen conditions. The higher and more stable yield of YTH323 in Aerobic Culture was attributable to greater early vigor, high specific leaf area, a high ratio of leaf weight to total biomass, and larger leaves, along with the characteristics of high-yield cultivars such as high responsiveness to fertilizers and good grain filling. We conclude that genetic modification of the aboveground architecture of IR64, a typical tropical lowland rice cultivar, to reduce tiller and leaf number improves adaptation to Aerobic Culture.
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Allometric relationship between the size and number of shoots as a determinant of adaptations in rice to water-saving Aerobic Culture
Field Crops Research, 2012Co-Authors: Midori Okami, Yoichiro Kato, Junko YamagishiAbstract:Abstract For efficient canopy expansion, field crops must choose between producing more organs or building larger organs. The objective of this study was to characterize the effects of soil water condition (flooded vs. Aerobic) on the allometric relationship between leaf area on the main stem and tiller number (i.e., shoot size vs. shoot number) in nine rice cultivars representing contrasting plant types ( indica , temperate japonica , and tropical japonica ). We also evaluated individual leaf area and plant leaf area in the middle of the vegetative stage for 91 cultivars. In Aerobic fields, soil water potential at a 20-cm depth averaged between −15 and −30 kPa, but frequently reached −60 kPa. The allometric slope (i.e., the ratio of shoot size to shoot number) was lower in Aerobic than in flooded Culture, and was further reduced by increased soil water deficit. Among the nine cultivars, a slight change in the allometric slope was associated with larger variation in leaf area in Aerobic Culture than in flooded Culture. Consequently, cultivars with larger leaves (shoots), mediated by a higher allometric slope, were advantaged compared to those with smaller leaves with respect to early vigor under limited soil moisture. A significant relationship between leaf size and early vigor was also observed for the 91 cultivars grown in Aerobic Culture. The study confirms the existing perception that tropical japonica cultivars are useful genetic sources for yield stability because of their ability to maintain large shoot size despite fluctuations in hydrological conditions.
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root morphology hydraulic conductivity and plant water relations of high yielding rice grown under Aerobic conditions
Annals of Botany, 2011Co-Authors: Yoichiro Kato, Midori OkamiAbstract:†Background and Aims Increasing physical water scarcity is a major constraint for irrigated rice (Oryza sativa) production. ‘Aerobic rice Culture’ aims to maximize yield per unit water input by growing plants in Aerobic soil without flooding or puddling. The objective was to determine (a) the effect of water management on root morphology and hydraulic conductance, and (b) their roles in plant –water relationships and stomatal conductance in Aerobic Culture. †Methods Root system development, stomatal conductance (gs) and leaf water potential (Cleaf ) were monitored in a high-yielding rice cultivar (‘Takanari’) under flooded and Aerobic conditions at two soil moisture levels [nearly saturated (. – 10 kPa) and mildly dry (. –30 kPa)] over 2 years. In an ancillary pot experiment, whole-plant hydraulic conductivity (soil-leaf hydraulic conductance; Kpa) was measured under flooded and Aerobic conditions. †Key Results Adventitious root emergence and lateral root proliferation were restricted even under nearly saturated conditions, resulting in a 72–85 % reduction in total root length under Aerobic Culture conditions. Because of their reduced rooting size, plants grown under Aerobic conditions tended to have lower Kpa than plants grown under flooded conditions. Cleaf was always significantly lower in Aerobic Culture than in flooded Culture, while gs was unchanged when the soil moisture was at around field capacity. gs was inevitably reduced when the soil water potential at 20-cm depth reached –20 kPa. †Conclusions Unstable performance of rice in water-saving cultivations is often associated with reduction in Cleaf. Cleaf may reduce even if Kpa is not significantly changed, but the lower Cleaf would certainly occur in case Kpa reduces as a result of lower water-uptake capacity under Aerobic conditions. Rice performance in Aerobic Culture might be improved through genetic manipulation that promotes lateral root branching and rhizogenesis as well as deep rooting.
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Role of early vigor in adaptation of rice to water-saving Aerobic Culture: Effects of nitrogen utilization and leaf growth
Field Crops Research, 2011Co-Authors: Midori Okami, Yoichiro Kato, Junko YamagishiAbstract:Abstract Early vigor and rapid canopy development are important characteristics in Aerobic rice Culture, where they are highly susceptible to soil water deficits. To elucidate the response of rice's vegetative growth to water management regimes, we evaluated the leaf growth and the concomitant nitrogen (N) utilization of nine cultivars grown in flooded and Aerobic Culture in 2 years. In Aerobic Culture, the soil water potential at a depth of 20 cm frequently reached −60 kPa in 2007, but remained above −30 kPa in 2008. The average leaf area index (LAI) in the middle of the vegetative growth stage, N uptake and leaf N content per unit leaf area (specific leaf N; SLN) in Aerobic Culture were comparable to those in flooded Culture. However, there was a significant cultivar × water regime interaction in LAI: cultivars with higher LAI during the vegetative growth stage achieved higher yield in Aerobic rice Culture. IR72 and Takanari (high-yielding cultivars of flood-irrigated rice) showed poor leaf growth as well as lower N uptake and higher SLN in Aerobic Culture compared with flooded Culture. Our results show that early vigor is closely associated with yield stability to the soil moisture fluctuations in Aerobic rice Culture, even if weeds are properly controlled. Greater N uptake from Aerobic soil and better balancing between the N demand for leaf growth and the N supply to the leaves under fluctuating soil moisture would be, at least in part, relevant to a rice cultivar's adaptation to Aerobic conditions.
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root growth dynamics and stomatal behaviour of rice oryza sativa l grown under Aerobic and flooded conditions
Field Crops Research, 2010Co-Authors: Yoichiro Kato, Midori OkamiAbstract:Abstract Aerobic rice Culture is a new technology designed to reduce water use, but the vulnerability of rice to Aerobic condition has limited its development. The objective of this study was to characterize the root growth and stomatal behaviour of four rice cultivars grown in flooded and Aerobic Culture for 2 years. In Aerobic Culture, where the soil water potential at 20-cm depth averaged between −15 and −30 kPa, total root biomass was significantly lower than in flooded Culture for the whole growth period, owing to a reduction in root biomass in the surface layer. Dry-matter partitioning to roots decreased, but the ratio of deep root biomass to total root biomass tended to be higher in Aerobic Culture than in flooded Culture. The low root-to-shoot ratio and poor root growth in the surface layer in Aerobic Culture are attributable to the considerable reduction in adventitious root number. As a result, the varietal difference in total root biomass was due largely to individual root growth in Aerobic Culture. Stomatal closure was distinct at the vegetative stage in Aerobic Culture, even when the soil water potential was near field capacity, partly because of the poor rooting vigour. When the soil water potential at 20-cm depth was below −50 kPa, the stomatal behaviour reflected the root growth in the subsurface layer. These results suggest the role of vigorous root growth in soil water uptake and hence, in maintaining transpiration in Aerobic rice Culture.
Yoichiro Kato - One of the best experts on this subject based on the ideXlab platform.
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Agronomic performance of an IR64 introgression line with large leaves derived from New Plant Type rice in Aerobic Culture
European Journal of Agronomy, 2014Co-Authors: Midori Okami, Yoichiro Kato, Nobuya Kobayashi, Junko YamagishiAbstract:Abstract Aerobic Culture is a promising water-saving technology in irrigated rice ecosystems, but the vulnerability of plants to fluctuations in soil moisture constrains leaf expansion and yield. The objective of this study was to examine whether an aboveground architecture with large leaves and reduced tillering is associated with vigorous leaf growth in Aerobic rice Culture. In a series of field experiments, we evaluated the agronomic performance of an IR64 introgression line, YTH323 (IR84640-11-27-1-9-3-2-4-2-2-2-B), with fewer tillers and larger leaves than IR64, derived from New Plant Type rice, under various water and nitrogen conditions. In flooded Culture, YTH323 yielded the same as IR64 and 38% more than IR65564-44-51 (a New Plant Type rice) (9.0 vs. 6.6 t ha −1 ). In Aerobic Culture, in contrast, it yielded 81% more than IR64 in slightly dry soils (5.1 vs. 2.8 t ha −1 ). YTH323 had a higher leaf area index than IR64 and IR65564-44-51 under slightly dry soil conditions and under a range of nitrogen conditions. The higher and more stable yield of YTH323 in Aerobic Culture was attributable to greater early vigor, high specific leaf area, a high ratio of leaf weight to total biomass, and larger leaves, along with the characteristics of high-yield cultivars such as high responsiveness to fertilizers and good grain filling. We conclude that genetic modification of the aboveground architecture of IR64, a typical tropical lowland rice cultivar, to reduce tiller and leaf number improves adaptation to Aerobic Culture.
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rice adaptation to Aerobic soils physiological considerations and implications for agronomy
Plant Production Science, 2014Co-Authors: Yoichiro Kato, Keisuke KatsuraAbstract:AbstractAerobic Culture is a water-saving technique for direct-seeded rice cultivation. Growing rice under continuously unsaturated soil conditions can maximize water-use efficiency and minimize both labor requirements and greenhouse-gas emissions. Under a temperate climate, Aerobic Culture can produce a rice yield greater than 9 t ha–1 especially in central Japan (11.4 t ha–1). Aerobic Culture using large-scale center-pivot sprinklers is being established in the central United States, where yields can surpass 10 t ha–1. However, yields remain at less than 8 t ha–1 in the tropics. The high yield of Japanese Aerobic Culture is mainly attributed to vigorous nitrogen uptake during the reproductive stage, which allows rice plants to produce more spikelets and biomass. Fertilizer management for Aerobic Culture must satisfy both the nitrogen demand and control spikelet density to achieve an appropriate sink–source balance. Unfortunately, the poor development of the root system in rice limits its water uptake fr...
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Allometric relationship between the size and number of shoots as a determinant of adaptations in rice to water-saving Aerobic Culture
Field Crops Research, 2012Co-Authors: Midori Okami, Yoichiro Kato, Junko YamagishiAbstract:Abstract For efficient canopy expansion, field crops must choose between producing more organs or building larger organs. The objective of this study was to characterize the effects of soil water condition (flooded vs. Aerobic) on the allometric relationship between leaf area on the main stem and tiller number (i.e., shoot size vs. shoot number) in nine rice cultivars representing contrasting plant types ( indica , temperate japonica , and tropical japonica ). We also evaluated individual leaf area and plant leaf area in the middle of the vegetative stage for 91 cultivars. In Aerobic fields, soil water potential at a 20-cm depth averaged between −15 and −30 kPa, but frequently reached −60 kPa. The allometric slope (i.e., the ratio of shoot size to shoot number) was lower in Aerobic than in flooded Culture, and was further reduced by increased soil water deficit. Among the nine cultivars, a slight change in the allometric slope was associated with larger variation in leaf area in Aerobic Culture than in flooded Culture. Consequently, cultivars with larger leaves (shoots), mediated by a higher allometric slope, were advantaged compared to those with smaller leaves with respect to early vigor under limited soil moisture. A significant relationship between leaf size and early vigor was also observed for the 91 cultivars grown in Aerobic Culture. The study confirms the existing perception that tropical japonica cultivars are useful genetic sources for yield stability because of their ability to maintain large shoot size despite fluctuations in hydrological conditions.
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root morphology hydraulic conductivity and plant water relations of high yielding rice grown under Aerobic conditions
Annals of Botany, 2011Co-Authors: Yoichiro Kato, Midori OkamiAbstract:†Background and Aims Increasing physical water scarcity is a major constraint for irrigated rice (Oryza sativa) production. ‘Aerobic rice Culture’ aims to maximize yield per unit water input by growing plants in Aerobic soil without flooding or puddling. The objective was to determine (a) the effect of water management on root morphology and hydraulic conductance, and (b) their roles in plant –water relationships and stomatal conductance in Aerobic Culture. †Methods Root system development, stomatal conductance (gs) and leaf water potential (Cleaf ) were monitored in a high-yielding rice cultivar (‘Takanari’) under flooded and Aerobic conditions at two soil moisture levels [nearly saturated (. – 10 kPa) and mildly dry (. –30 kPa)] over 2 years. In an ancillary pot experiment, whole-plant hydraulic conductivity (soil-leaf hydraulic conductance; Kpa) was measured under flooded and Aerobic conditions. †Key Results Adventitious root emergence and lateral root proliferation were restricted even under nearly saturated conditions, resulting in a 72–85 % reduction in total root length under Aerobic Culture conditions. Because of their reduced rooting size, plants grown under Aerobic conditions tended to have lower Kpa than plants grown under flooded conditions. Cleaf was always significantly lower in Aerobic Culture than in flooded Culture, while gs was unchanged when the soil moisture was at around field capacity. gs was inevitably reduced when the soil water potential at 20-cm depth reached –20 kPa. †Conclusions Unstable performance of rice in water-saving cultivations is often associated with reduction in Cleaf. Cleaf may reduce even if Kpa is not significantly changed, but the lower Cleaf would certainly occur in case Kpa reduces as a result of lower water-uptake capacity under Aerobic conditions. Rice performance in Aerobic Culture might be improved through genetic manipulation that promotes lateral root branching and rhizogenesis as well as deep rooting.
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Role of early vigor in adaptation of rice to water-saving Aerobic Culture: Effects of nitrogen utilization and leaf growth
Field Crops Research, 2011Co-Authors: Midori Okami, Yoichiro Kato, Junko YamagishiAbstract:Abstract Early vigor and rapid canopy development are important characteristics in Aerobic rice Culture, where they are highly susceptible to soil water deficits. To elucidate the response of rice's vegetative growth to water management regimes, we evaluated the leaf growth and the concomitant nitrogen (N) utilization of nine cultivars grown in flooded and Aerobic Culture in 2 years. In Aerobic Culture, the soil water potential at a depth of 20 cm frequently reached −60 kPa in 2007, but remained above −30 kPa in 2008. The average leaf area index (LAI) in the middle of the vegetative growth stage, N uptake and leaf N content per unit leaf area (specific leaf N; SLN) in Aerobic Culture were comparable to those in flooded Culture. However, there was a significant cultivar × water regime interaction in LAI: cultivars with higher LAI during the vegetative growth stage achieved higher yield in Aerobic rice Culture. IR72 and Takanari (high-yielding cultivars of flood-irrigated rice) showed poor leaf growth as well as lower N uptake and higher SLN in Aerobic Culture compared with flooded Culture. Our results show that early vigor is closely associated with yield stability to the soil moisture fluctuations in Aerobic rice Culture, even if weeds are properly controlled. Greater N uptake from Aerobic soil and better balancing between the N demand for leaf growth and the N supply to the leaves under fluctuating soil moisture would be, at least in part, relevant to a rice cultivar's adaptation to Aerobic conditions.
Kwok-yung Yuen - One of the best experts on this subject based on the ideXlab platform.
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Reduction of Platelet Transfusion– Associated Sepsis by Short–Term Bacterial Culture
Vox Sanguinis, 1999Co-Authors: Kwok-yung Yuen, Tammy Shui-ying Cheng, Elizabeth Kin-ming Chua, Pak-leung HoAbstract:Background and Objectives: There is as yet no suitable routine laboratory test for a blood transfusion service to detect bacterial contamination in platelets. This study evaluates the effectiveness and the applicability of short-term bacterial Culture for such a purpose. Materials and Methods: Samples from 5-unit platelet pools were inoculated into an Aerobic Culture bottle, then monitored for 48 h at 35°C in an automated monitoring and detection system. Results: 26,210 whole-blood-derived platelet components were tested, of which 14 (0.053%) platelet units were found to be contaminated. In addition, nine of the associated red cell units and 4 fresh-frozen plasma units grew the same organisms on Culture. Conclusion: Short-duration bacterial Culture by an automated system is effective and suitable for routine screening in a regional transfusion center.
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reduction of platelet transfusion associated sepsis by short term bacterial Culture
Vox Sanguinis, 1999Co-Authors: Hingwing Liu, Tammy Shui-ying Cheng, Elizabeth Kin-ming Chua, Kwok-yung Yuen, Kwanbun Lee, C K LinAbstract:Background and Objectives: There is as yet no suitable routine laboratory test for a blood transfusion service to detect bacterial contamination in platelets. This study evaluates the effectiveness and the applicability of short-term bacterial Culture for such a purpose. Materials and Methods: Samples from 5-unit platelet pools were inoculated into an Aerobic Culture bottle, then monitored for 48 h at 35°C in an automated monitoring and detection system. Results: 26,210 whole-blood-derived platelet components were tested, of which 14 (0.053%) platelet units were found to be contaminated. In addition, nine of the associated red cell units and 4 fresh-frozen plasma units grew the same organisms on Culture. Conclusion: Short-duration bacterial Culture by an automated system is effective and suitable for routine screening in a regional transfusion center.
C K Lin - One of the best experts on this subject based on the ideXlab platform.
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reduction of platelet transfusion associated sepsis by short term bacterial Culture
Vox Sanguinis, 1999Co-Authors: Hingwing Liu, Tammy Shui-ying Cheng, Elizabeth Kin-ming Chua, Kwok-yung Yuen, Kwanbun Lee, C K LinAbstract:Background and Objectives: There is as yet no suitable routine laboratory test for a blood transfusion service to detect bacterial contamination in platelets. This study evaluates the effectiveness and the applicability of short-term bacterial Culture for such a purpose. Materials and Methods: Samples from 5-unit platelet pools were inoculated into an Aerobic Culture bottle, then monitored for 48 h at 35°C in an automated monitoring and detection system. Results: 26,210 whole-blood-derived platelet components were tested, of which 14 (0.053%) platelet units were found to be contaminated. In addition, nine of the associated red cell units and 4 fresh-frozen plasma units grew the same organisms on Culture. Conclusion: Short-duration bacterial Culture by an automated system is effective and suitable for routine screening in a regional transfusion center.
Pak-leung Ho - One of the best experts on this subject based on the ideXlab platform.
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Reduction of Platelet Transfusion– Associated Sepsis by Short–Term Bacterial Culture
Vox Sanguinis, 1999Co-Authors: Kwok-yung Yuen, Tammy Shui-ying Cheng, Elizabeth Kin-ming Chua, Pak-leung HoAbstract:Background and Objectives: There is as yet no suitable routine laboratory test for a blood transfusion service to detect bacterial contamination in platelets. This study evaluates the effectiveness and the applicability of short-term bacterial Culture for such a purpose. Materials and Methods: Samples from 5-unit platelet pools were inoculated into an Aerobic Culture bottle, then monitored for 48 h at 35°C in an automated monitoring and detection system. Results: 26,210 whole-blood-derived platelet components were tested, of which 14 (0.053%) platelet units were found to be contaminated. In addition, nine of the associated red cell units and 4 fresh-frozen plasma units grew the same organisms on Culture. Conclusion: Short-duration bacterial Culture by an automated system is effective and suitable for routine screening in a regional transfusion center.
