The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Naoki Yamauchi - One of the best experts on this subject based on the ideXlab platform.
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uv b treatment controls chlorophyll degradation and related gene expression in broccoli brassica oleracea l italica group Florets during storage
Scientia Horticulturae, 2019Co-Authors: Sukanya Aiamlaor, Masayoshi Shigyo, Naoki YamauchiAbstract:Abstract Control of chlorophyll (Chl) degradation and related gene expression in response to UV-B treatment were investigated in broccoli Florets during storage. Reductions in hue angle value and Chl content in broccoli Florets during storage at 4, 15 and 25 °C were delayed with 19 kJ m−2 of UV-B irradiation. Furthermore, up-regulation of BoSGR and BoNYC1, Chl-degrading genes, was found with floret yellowing in the control during storage at 15 °C. In contrast, expression of those genes in UV-B-treated broccoli Florets were effectively suppressed during storage, suggesting that UV-B treatment could be useful for quality maintenance of broccoli Florets during storage.
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effect of reactive oxygen species on quality maintenance of broccoli Florets with electrostatic atomized water particle treatment
Food Chemistry, 2017Co-Authors: Masahiro Nomura, Sukanya Aiamlaor, Masayoshi Shigyo, Shuhei Tanaka, Yukihiro Masuda, Naoki YamauchiAbstract:Abstract The effect of electrostatic atomized water particle (EAWP) treatment on quality maintenance during postharvest storage was determined to clarify a physiological role of reactive oxygen species in broccoli Florets. The EAWP treatment suppressed the floret yellowing of broccoli during storage. The hydrogen peroxide content increased immediately after EAWP treatment but then remained at a low level during storage. Catalase (CAT) activity increased rapidly with EAWP treatment and was higher than that in the control for the first 4 days of storage. The BoCAT gene expression level with EAWP treatment also showed a high trend as compared to the control. The gene expressions of BoRboh, BoCu/ZnSOD, and BoAPX showed almost the same tendency with or without EAWP treatment. These findings suggested that hydrogen peroxide formed by EAWP treatment and regulated by CAT could be relevant to maintaining the quality of broccoli.
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pheophytinase activity and gene expression of chlorophyll degrading enzymes relating to uv b treatment in postharvest broccoli brassica oleracea l italica group Florets
Postharvest Biology and Technology, 2012Co-Authors: Sukanya Aiamlaor, Masayoshi Shigyo, Naoki Yamauchi, Tetsuya NakajimaAbstract:Abstract Pheophytinase (PPH) activity and gene expression of chlorophyll (Chl)-degrading enzymes relating to UV-B treatment in postharvest broccoli (Brassica oleracea L. Italica Group) Florets were determined. PPH is involved in the dephytylation of Mg-free Chl a, pheophytin (Phy) a. However, in vitro chlorophyllase (Chlase, EC.3.1.1.14) also uses Phy a as a substrate to produce pheophorbide (Pheide) a by dephytylation. For an accurate determination of PPH activity, the PPH protein fraction was separated from Chlase protein by ammonium sulfate precipitation. The protein precipitated by 45–60% saturated ammonium sulfate included a little bit of Chlase activity and was suitable for PPH determination. PPH activity in broccoli Florets treated with a UV-B dose of 19 kJ m−2 was repressed for the first 2 d of storage at 15 °C, whereas it increased gradually with senescence of control broccoli Florets. The expression level of BoCLH1 was reduced in broccoli Florets on day 4 of storage, while BoCLH2 and BoCLH3 were up-regulated with UV-B treatment. A high BoPAO expression level was found in senescent broccoli Florets, and the up-regulation of this gene was delayed by UV-B treatment. The highest expression level of BoPPH was found in the control, and its expression was clearly repressed by UV-B treatment on day 2 of storage. We suggest that the up-regulation of Chl-degrading enzyme genes could be delayed by UV-B treatment, resulting in the suppression of floret yellowing in stored broccoli.
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involvement of chlorophyllase on chlorophyll degradation in stored broccoli Florets and its control by uv treatment
Southeast Asia Symposium on Quality and Safety of Fresh and Fresh-Cut Produce Bangkok Thailand., 2010Co-Authors: A Kaosamphan, Sukanya Aiamlaor, Naoki Yamauchi, V Srilaong, C Wongsaree, A UthairatanakijAbstract:Yellowing is the most visible deterioration in broccoli (Brassica oleracea L. Italica Group) that usually occurs with the progress of chlorophyll (Chl) degradation. This study deals with the control of floret yellowing in stored broccoli by using UV-B irradiation at 0 (control) and 8.8 kJ.m -2 . The application of UV-B at 8.8 kJ.m -2 effectively delayed yellowing of broccoli Florets. Chl a derivatives including chlorophyllide (Chlide) a, C13 2 -hydroxychlorophyll (C13 2 -OHChl) a and pheophytin (Phy) a levels in broccoli Florets were decreased concomitantly with the enhancement of pheophorbide (Pheide) a and pyropheophorbide (Pyropheide) a levels especially in the control treatment. On the other hand, Chlide a, C13 2 -OHChl a and Phy a levels were increased in 8.8 kJ.m -2 UV-B treated broccoli during storage at 15°C. Two types of chlorophyllase (Chlase) were identified by molecular exclusion chromatography. Type I was suppressed in UV-B treated broccoli on day 4, and the Km value of Type I was lower than that of Type II. Thus, the Chlase activity, especially Type I, was effectively suppressed by UV-B treatment, whereas Type II Chlase may take in part of Chl degradation in stored broccoli Florets.
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effects of heat treatment on an ascorbate glutathione cycle in stored broccoli brassica oleracea l Florets
Postharvest Biology and Technology, 2005Co-Authors: Tetsuya Shigenaga, Masayoshi Shigyo, Naoki Yamauchi, Yoshio FunamotoAbstract:Abstract Effects of heat treatment on an ascorbate–glutathione cycle in stored broccoli (Brassica oleracea L. cv Erude) Florets were measured. Floret yellowing during storage at 15 °C was effectively retarded by hot air treatment at 50 °C for 2 h. Hydrogen peroxide contents in heat-treated broccoli Florets were higher than in control Florets. Ascorbic acid content with or without heat treatment decreased during storage, but the decrease in the control was faster than in heat-treated broccoli. Additionally, the reduced glutathione content in heat-treated Florets showed almost no change during storage, whereas that in control Florets decreased gradually. In heat-treated Florets, both dehydroascorbate reductase and glutathione reductase activities were maintained for the first 2 days and then decreased slightly, while they decreased considerably in the control Florets during storage. Cytosolic ascorbate peroxidase activity in heat-treated Florets increased slightly during storage, whereas that in control Florets showed almost no change. However, chloroplastic ascorbate peroxidase activity with or without heat treatment greatly decreased during 4 days of storage. These results indicate that hydrogen peroxide, which is generated by the heat treatment, might induce activation of enzymes related to the ascorbate–glutathione cycle, and the enhancement of the action of the cycle might relate to the suppression of senescence in heat-treated broccoli Florets.
Masayoshi Shigyo - One of the best experts on this subject based on the ideXlab platform.
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uv b treatment controls chlorophyll degradation and related gene expression in broccoli brassica oleracea l italica group Florets during storage
Scientia Horticulturae, 2019Co-Authors: Sukanya Aiamlaor, Masayoshi Shigyo, Naoki YamauchiAbstract:Abstract Control of chlorophyll (Chl) degradation and related gene expression in response to UV-B treatment were investigated in broccoli Florets during storage. Reductions in hue angle value and Chl content in broccoli Florets during storage at 4, 15 and 25 °C were delayed with 19 kJ m−2 of UV-B irradiation. Furthermore, up-regulation of BoSGR and BoNYC1, Chl-degrading genes, was found with floret yellowing in the control during storage at 15 °C. In contrast, expression of those genes in UV-B-treated broccoli Florets were effectively suppressed during storage, suggesting that UV-B treatment could be useful for quality maintenance of broccoli Florets during storage.
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effect of reactive oxygen species on quality maintenance of broccoli Florets with electrostatic atomized water particle treatment
Food Chemistry, 2017Co-Authors: Masahiro Nomura, Sukanya Aiamlaor, Masayoshi Shigyo, Shuhei Tanaka, Yukihiro Masuda, Naoki YamauchiAbstract:Abstract The effect of electrostatic atomized water particle (EAWP) treatment on quality maintenance during postharvest storage was determined to clarify a physiological role of reactive oxygen species in broccoli Florets. The EAWP treatment suppressed the floret yellowing of broccoli during storage. The hydrogen peroxide content increased immediately after EAWP treatment but then remained at a low level during storage. Catalase (CAT) activity increased rapidly with EAWP treatment and was higher than that in the control for the first 4 days of storage. The BoCAT gene expression level with EAWP treatment also showed a high trend as compared to the control. The gene expressions of BoRboh, BoCu/ZnSOD, and BoAPX showed almost the same tendency with or without EAWP treatment. These findings suggested that hydrogen peroxide formed by EAWP treatment and regulated by CAT could be relevant to maintaining the quality of broccoli.
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pheophytinase activity and gene expression of chlorophyll degrading enzymes relating to uv b treatment in postharvest broccoli brassica oleracea l italica group Florets
Postharvest Biology and Technology, 2012Co-Authors: Sukanya Aiamlaor, Masayoshi Shigyo, Naoki Yamauchi, Tetsuya NakajimaAbstract:Abstract Pheophytinase (PPH) activity and gene expression of chlorophyll (Chl)-degrading enzymes relating to UV-B treatment in postharvest broccoli (Brassica oleracea L. Italica Group) Florets were determined. PPH is involved in the dephytylation of Mg-free Chl a, pheophytin (Phy) a. However, in vitro chlorophyllase (Chlase, EC.3.1.1.14) also uses Phy a as a substrate to produce pheophorbide (Pheide) a by dephytylation. For an accurate determination of PPH activity, the PPH protein fraction was separated from Chlase protein by ammonium sulfate precipitation. The protein precipitated by 45–60% saturated ammonium sulfate included a little bit of Chlase activity and was suitable for PPH determination. PPH activity in broccoli Florets treated with a UV-B dose of 19 kJ m−2 was repressed for the first 2 d of storage at 15 °C, whereas it increased gradually with senescence of control broccoli Florets. The expression level of BoCLH1 was reduced in broccoli Florets on day 4 of storage, while BoCLH2 and BoCLH3 were up-regulated with UV-B treatment. A high BoPAO expression level was found in senescent broccoli Florets, and the up-regulation of this gene was delayed by UV-B treatment. The highest expression level of BoPPH was found in the control, and its expression was clearly repressed by UV-B treatment on day 2 of storage. We suggest that the up-regulation of Chl-degrading enzyme genes could be delayed by UV-B treatment, resulting in the suppression of floret yellowing in stored broccoli.
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effects of heat treatment on an ascorbate glutathione cycle in stored broccoli brassica oleracea l Florets
Postharvest Biology and Technology, 2005Co-Authors: Tetsuya Shigenaga, Masayoshi Shigyo, Naoki Yamauchi, Yoshio FunamotoAbstract:Abstract Effects of heat treatment on an ascorbate–glutathione cycle in stored broccoli (Brassica oleracea L. cv Erude) Florets were measured. Floret yellowing during storage at 15 °C was effectively retarded by hot air treatment at 50 °C for 2 h. Hydrogen peroxide contents in heat-treated broccoli Florets were higher than in control Florets. Ascorbic acid content with or without heat treatment decreased during storage, but the decrease in the control was faster than in heat-treated broccoli. Additionally, the reduced glutathione content in heat-treated Florets showed almost no change during storage, whereas that in control Florets decreased gradually. In heat-treated Florets, both dehydroascorbate reductase and glutathione reductase activities were maintained for the first 2 days and then decreased slightly, while they decreased considerably in the control Florets during storage. Cytosolic ascorbate peroxidase activity in heat-treated Florets increased slightly during storage, whereas that in control Florets showed almost no change. However, chloroplastic ascorbate peroxidase activity with or without heat treatment greatly decreased during 4 days of storage. These results indicate that hydrogen peroxide, which is generated by the heat treatment, might induce activation of enzymes related to the ascorbate–glutathione cycle, and the enhancement of the action of the cycle might relate to the suppression of senescence in heat-treated broccoli Florets.
Daniel J Miralles - One of the best experts on this subject based on the ideXlab platform.
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more fertile Florets and grains per spike can be achieved at higher temperature in wheat lines with high spike biomass and sugar content at booting
Functional Plant Biology, 2014Co-Authors: Fernanda M Dreccer, Matthew P Reynolds, Kimberley Wockner, Jairo A Palta, Lynne C Mcintyre, Gabriela M Borgognone, Maryse Bourgault, Daniel J MirallesAbstract:An understanding of processes regulating wheat floret and grain number at higher temperatures is required to better exploit genetic variation. In this study we tested the hypothesis that at higher temperatures, a reduction in floret fertility is associated with a decrease in soluble sugars and this response is exacerbated in genotypes low in water soluble carbohydrates (WSC). Four recombinant inbred lines contrasting for stem WSC were grown at 20/10 degrees C and 11 h photoperiod until terminal spikelet, and then continued in a factorial combination of 20/10 degrees C or 28/14 degrees C with 11 h or 16 h photoperiod until anthesis. Across environments, High WSC lines had more grains per spike associated with more Florets per spike. The number of fertile Florets was associated with spike biomass at booting and, by extension, with glucose amount, both higher in High WSC lines. At booting, High WSC lines had higher fixed C-13 and higher levels of expression of genes involved in photosynthesis and sucrose transport and lower in sucrose degradation compared with Low WSC lines. At higher temperature, the intrinsic rate of floret development rate before booting was slower in High WSC lines. Grain set declined with the intrinsic rate of floret development before booting, with an advantage for High WSC lines at 28/14 degrees C and 16 h. Genotypic and environmental action on floret fertility and grain set was summarised in a model.
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autophagy regulated by day length determines the number of fertile Florets in wheat
Plant Journal, 2008Co-Authors: Hernan Ghiglione, Fernanda G Gonzalez, Daniel J Miralles, Roman Augusto Serrago, Sara Maldonado, Charles Chilcott, Jose A Cura, Tong Zhu, Jorge J CasalAbstract:The wheat spikelet meristem differentiates into up to 12 floret primordia, but many of them fail to reach the fertile floret stage at anthesis. We combined microarray, biochemical and anatomical studies to investigate floret development in wheat plants grown in the field under short or long days (short days extended with low-fluence light) after all the spikelets had already differentiated. Long days accelerated spike and floret development and greening, and the expression of genes involved in photosynthesis, photoprotection and carbohydrate metabolism. These changes started while the spike was in the light-depleted environment created by the surrounding leaf sheaths. Cell division ceased in the tissues of distal Florets, which interrupted their normal developmental progression and initiated autophagy, thus decreasing the number of fertile Florets at anthesis. A massive decrease in the expression of genes involved in cell proliferation, a decrease in soluble carbohydrate levels, and an increase in the expression of genes involved in programmed cell death accompanied anatomical signs of cell death, and these effects were stronger under long days. We propose a model in which developmentally generated sugar starvation triggers floret autophagy, and long days intensify these processes due to the increased carbohydrate consumption caused by the accelerated plant development. © 2008 The Authors.
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radiation effects on potential number of grains per spike and biomass partitioning in two and six rowed near isogenic barley lines
Field Crops Research, 2008Co-Authors: Sebastian Arisnabarreta, Daniel J MirallesAbstract:Abstract The critical period for yield determination in barley ( Hordeum vulgare L.) is situated in the pre-heading phases. During the latest part of the critical period one of the most important yield components (i.e. the number of grains per spike) is set in two- and six-rowed barley. In wheat, much is known about the role of the spike in assimilate acquisition for the establishment of grains per spike, but not in barley. This paper evaluates how biomass partitioning between vegetative and reproductive organs impacts floret development and primordia survival in response to radiation during different periods in the crop cycle, in barley lines. Field experiments were carried out using two- and six-rowed near isogenic barley lines differing only in spike type. Shading treatments were applied at different periods during the crop cycle (from 60 to 15 days before and after heading) reducing the intercepted radiation (ca. 70%). Dynamics of floret primordia initiation and mortality and of floret development for different spikelet positions along the spike were measured, and biomass partitioning between vegetative and reproductive structures was calculated. Pre-heading shading reduced fertile Florets per spike ( P The amount of assimilates partitioned to the spike at heading affected the number of fertile Florets per spike in both barley types. However, when spike biomass at heading was corrected by nitrogen concentration, the fitness of the relationship did not improve in relation to the first one. In relative terms, radiation restrictions during the immediate pre-heading phase increased the amount of biomass partitioned to the growing spike.
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pre anthesis development and number of fertile Florets in wheat as affected by photoperiod sensitivity genes ppd d1 and ppd b1
Euphytica, 2006Co-Authors: Fernanda G Gonzalez, Gustavo A. Slafer, Daniel J MirallesAbstract:Lengthening the late reproductive phase (LRP) of stem elongation in wheat (Triticum aestivumL.), by changing its photoperiod sensitivity independently of the preceding phases, would improve the yield potential through increasing spike weight and the number of fertile Florets at anthesis. This paper presents results of a two-year field experiment designed to determine the impact of Ppd-D1and Ppd-B1on (i) the duration of three pre-anthesis developmental phases, and (ii) spike weight and the number of fertile Florets at anthesis under two photoperiods during the LRP (natural and an extension of six hours over that). Near isogenic lines of Mercia and single chromosome recombinant lines of Cappelle Desprez were used. Under natural photoperiod, Ppd-D1hastened time to anthesis ca. 500∘C d in both backgrounds by reducing each of the three pre-anthesis phases. Ppd-B1hastened the time to anthesis under natural photoperiod by 178∘C d, mainly by reducing the early reproductive phase. The response to photoperiod of the LRP under extended daylength depended on the Ppdlocus present: Ppd-D1was insensitive while Ppd-B1and the recessive controls were sensitive. For all lines, photoperiod treatments and years, the number of fertile Florets was associated with spike dry weight at anthesis (R 2≅ 80%, p< 0.01) which, in turn, was positively related to the intercepted radiation accumulated during the LRP (R 2 45%, p< 0.05). Changing the duration of the LRP through extended photoperiod or through Ppd-D1produced similar results in both backgrounds and years. Thus, altering the duration of the LRP by manipulating photoperiod sensitivity may be an alternative to changing the fertile floret number in wheat. Nevertheless, as no particular allele was responsible for the photoperiod sensitivity only during the LRP, new alleles should be studied to identify the control of photoperiod sensitivity of individual phases to fine-tune the pre-anthesis wheat development.
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floret development and survival in wheat plants exposed to contrasting photoperiod and radiation environments during stem elongation
Functional Plant Biology, 2005Co-Authors: Fernanda G Gonzalez, Gustavo A. Slafer, Daniel J MirallesAbstract:Wheat breeding has improved yield potential increasing floret survival through higher dry matter partitioning to the spikes during the stem elongation phase (from terminal spikelet initiation to anthesis). We studied survival of floret primodia in different spikelet positions along the spike in relation to dynamics of spike growth, when dynamics of dry matter partitioning to the spike was altered by photoperiod and shading treatments applied during the stem elongation phase. The cultivar Buck Manantial was exposed to (1) NP+0 un-shaded (natural photoperiod and incoming radiation of the growing season), (2) NP+0 shaded (natural photoperiod but only 33% of the incoming radiation), and (3) NP+6 un-shaded (natural photoperiod extended 6 h and natural incoming radiation). Floret survival increased, depending on spikelet position, 1.1–2.5 fold under un-shaded v. shaded treatments (both under NP+0), and 1.3–1.8 fold under NP+0 v. NP+6 treatments (both un-shaded), without any impact of treatments on the total number of initiated floret primordia. The fate of the floret primordia and its final stage at anthesis were associated with duration of floret development within the stem elongation phase (R2 = 82%, P<0.0001). Florets may be classified into three groups: (i) those that were fertile at anthesis under all treatments (mostly the two Florets F1 and F2, proximal to the rachis within the spikelet), (ii) those that reached different stages at anthesis, depending on treatment, and that contributed differentially to the number of fertile Florets at anthesis (mostly the Florets F3, F4 and F5, positioned in the middle of the spikelet), and (iii) those that did not contribute to the number of fertile Florets under any treatment (mostly the Florets ≥ F6). Degeneration of Florets in group (ii) was associated with spike growth at maximum rate, explaining the strong relationship observed between spike dry weight at anthesis and number of fertile Florets. However, degeneration of Florets in group (iii) seemed to occur before spike growth at maximum rate. Survival of Florets positioned in the middle of the spikelets could be improved by increasing spike growth through manipulation of photoperiod sensitivity during stem elongation.
Gustavo A. Slafer - One of the best experts on this subject based on the ideXlab platform.
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floret development and spike fertility in wheat differences between cultivars of contrasting yield potential and their sensitivity to photoperiod and soil n
Field Crops Research, 2020Co-Authors: Ariel Ferrante, Roxana Savin, Gustavo A. SlaferAbstract:Abstract In a previous paper (Field Crops Res. 203, 114–127), we showed that the difference in yield potential between a contemporary and a traditional cultivar was due to differences in fruiting efficiency, likely derived from differences in spike fertility (fertile Florets per spike) while having similar spike dry weights at anthesis. In this study, we determined the mechanistic bases of these genotypic differences in spike fertility analysing the initiation of all floret primordia per spike (up to 8), the maximum number of Florets initiated per spikelet, and the associated floret developmental rates and their fate to become fertile Florets under contrasting photoperiod (natural vs extended) and nitrogen availability (50 or 200 kg N ha−1) during the stem elongation phase. Under potential growing conditions (natural photoperiod, high nitrogen availability), the contemporary cultivar owed its higher spike fertility to the improved rate of floret development, which mainly determined an improved level of floret primordia survival to produce fertile Florets. The sensitivity of the floret developmental patterns to faster development due to exposure to an extended photoperiod and, to a larger extent, a reduction in N availability was similar for both cultivars, providing a basis for the consistent differences in spike fertility across a range of environments. The response again determined a main effect through increasing floret mortality reducing therefore the level of fertile Florets per spikelet in these conditions.
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genotypic variation in spike fertility traits and ovary size as determinants of floret and grain survival rate in wheat
Journal of Experimental Botany, 2016Co-Authors: Zifeng Guo, Gustavo A. Slafer, Thorsten SchnurbuschAbstract:Spike fertility traits are critical attributes for grain yield in wheat (Triticum aestivum L.). Here, we examine the genotypic variation in three important traits: maximum number of floret primordia, number of fertile Florets, and number of grains. We determine their relationship in determining spike fertility in 30 genotypes grown under two contrasting conditions: field and greenhouse. The maximum number of floret primordia per spikelet (MFS), fertile Florets per spikelet (FFS), and number of grains per spikelet (GS) not only exhibited large genotypic variation in both growth conditions and across all spikelet positions studied, but also displayed moderate levels of heritability. FFS was closely associated with floret survival and only weakly related to MFS. We also found that the post-anthesis process of grain set/abortion was important in determining genotypic variation in GS; an increase in GS was mainly associated with improved grain survival. Ovary size at anthesis was associated with both floret survival (pre-anthesis) and grain survival (post-anthesis), and was thus believed to 'connect' the two traits. In this work, proximal Florets (i.e. the first three Florets from the base of a spikelet: F1, F2, and F3) produced fertile Florets and set grains in most cases. The ovary size of more distal Florets (F4 and beyond) seemed to act as a decisive factor for grain setting and effectively reflected pre-anthesis floret development. In both growth conditions, GS positively correlated with ovary size of Florets in the distal position (F4), suggesting that assimilates allocated to distal Florets may play a critical role in regulating grain set.
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dynamics of floret development determining differences in spike fertility in an elite population of wheat
Field Crops Research, 2015Co-Authors: Matthew P Reynolds, Oscar E Gonzaleznavarro, Simon Griffiths, Gemma Molero, Gustavo A. SlaferAbstract:Abstract Further increases in wheat yield potential could be achieved through a better understanding of the dynamics of floret primordia generation/degeneration, a process which has received little attention. We quantified genotypic variation among elite genotypes of the CIMCOG panel assembled by CIMMYT for its usefulness for wheat breeding. Ten genotypes, representing the range of variation for yield and its components of the whole panel, were grown under high-yielding conditions in NW Mexico for two growing seasons. The stage of development of floret primordia was determined 2–3 times weekly during stem elongation for apical, central and basal spikelets within the spike. The dynamics of floret initiation/death, and the resulting number of fertile Florets, were determined for each spikelet position. We found that the variation in number of fertile Florets within this elite germplasm was much more related to the survival of floret primordia than to the maximum number of Florets initiated. As the two floret primordia most proximal to the rachis were almost always fertile and most distal Florets (Florets 6–8) were never fertile, the differences in number of fertile Florets were clearly attributed to the differential developmental patterns of intermediate Florets (floret primordia 3, 4 and 5, counted from the rachis, depending on the spikelet position). We found significant differences among elite germplasm in dynamics of floret development. Differences in floret survival seemed positively related to those in the length of the period of floret development: the longer the duration of floret development the higher the likelihood of that floret becoming fertile. It is proposed that this type of study may be instrumental for identifying prospective parents for further raising yield potential wheat breeding programmes.
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pre anthesis development and number of fertile Florets in wheat as affected by photoperiod sensitivity genes ppd d1 and ppd b1
Euphytica, 2006Co-Authors: Fernanda G Gonzalez, Gustavo A. Slafer, Daniel J MirallesAbstract:Lengthening the late reproductive phase (LRP) of stem elongation in wheat (Triticum aestivumL.), by changing its photoperiod sensitivity independently of the preceding phases, would improve the yield potential through increasing spike weight and the number of fertile Florets at anthesis. This paper presents results of a two-year field experiment designed to determine the impact of Ppd-D1and Ppd-B1on (i) the duration of three pre-anthesis developmental phases, and (ii) spike weight and the number of fertile Florets at anthesis under two photoperiods during the LRP (natural and an extension of six hours over that). Near isogenic lines of Mercia and single chromosome recombinant lines of Cappelle Desprez were used. Under natural photoperiod, Ppd-D1hastened time to anthesis ca. 500∘C d in both backgrounds by reducing each of the three pre-anthesis phases. Ppd-B1hastened the time to anthesis under natural photoperiod by 178∘C d, mainly by reducing the early reproductive phase. The response to photoperiod of the LRP under extended daylength depended on the Ppdlocus present: Ppd-D1was insensitive while Ppd-B1and the recessive controls were sensitive. For all lines, photoperiod treatments and years, the number of fertile Florets was associated with spike dry weight at anthesis (R 2≅ 80%, p< 0.01) which, in turn, was positively related to the intercepted radiation accumulated during the LRP (R 2 45%, p< 0.05). Changing the duration of the LRP through extended photoperiod or through Ppd-D1produced similar results in both backgrounds and years. Thus, altering the duration of the LRP by manipulating photoperiod sensitivity may be an alternative to changing the fertile floret number in wheat. Nevertheless, as no particular allele was responsible for the photoperiod sensitivity only during the LRP, new alleles should be studied to identify the control of photoperiod sensitivity of individual phases to fine-tune the pre-anthesis wheat development.
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floret development and survival in wheat plants exposed to contrasting photoperiod and radiation environments during stem elongation
Functional Plant Biology, 2005Co-Authors: Fernanda G Gonzalez, Gustavo A. Slafer, Daniel J MirallesAbstract:Wheat breeding has improved yield potential increasing floret survival through higher dry matter partitioning to the spikes during the stem elongation phase (from terminal spikelet initiation to anthesis). We studied survival of floret primodia in different spikelet positions along the spike in relation to dynamics of spike growth, when dynamics of dry matter partitioning to the spike was altered by photoperiod and shading treatments applied during the stem elongation phase. The cultivar Buck Manantial was exposed to (1) NP+0 un-shaded (natural photoperiod and incoming radiation of the growing season), (2) NP+0 shaded (natural photoperiod but only 33% of the incoming radiation), and (3) NP+6 un-shaded (natural photoperiod extended 6 h and natural incoming radiation). Floret survival increased, depending on spikelet position, 1.1–2.5 fold under un-shaded v. shaded treatments (both under NP+0), and 1.3–1.8 fold under NP+0 v. NP+6 treatments (both un-shaded), without any impact of treatments on the total number of initiated floret primordia. The fate of the floret primordia and its final stage at anthesis were associated with duration of floret development within the stem elongation phase (R2 = 82%, P<0.0001). Florets may be classified into three groups: (i) those that were fertile at anthesis under all treatments (mostly the two Florets F1 and F2, proximal to the rachis within the spikelet), (ii) those that reached different stages at anthesis, depending on treatment, and that contributed differentially to the number of fertile Florets at anthesis (mostly the Florets F3, F4 and F5, positioned in the middle of the spikelet), and (iii) those that did not contribute to the number of fertile Florets under any treatment (mostly the Florets ≥ F6). Degeneration of Florets in group (ii) was associated with spike growth at maximum rate, explaining the strong relationship observed between spike dry weight at anthesis and number of fertile Florets. However, degeneration of Florets in group (iii) seemed to occur before spike growth at maximum rate. Survival of Florets positioned in the middle of the spikelets could be improved by increasing spike growth through manipulation of photoperiod sensitivity during stem elongation.
Sukanya Aiamlaor - One of the best experts on this subject based on the ideXlab platform.
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uv b treatment controls chlorophyll degradation and related gene expression in broccoli brassica oleracea l italica group Florets during storage
Scientia Horticulturae, 2019Co-Authors: Sukanya Aiamlaor, Masayoshi Shigyo, Naoki YamauchiAbstract:Abstract Control of chlorophyll (Chl) degradation and related gene expression in response to UV-B treatment were investigated in broccoli Florets during storage. Reductions in hue angle value and Chl content in broccoli Florets during storage at 4, 15 and 25 °C were delayed with 19 kJ m−2 of UV-B irradiation. Furthermore, up-regulation of BoSGR and BoNYC1, Chl-degrading genes, was found with floret yellowing in the control during storage at 15 °C. In contrast, expression of those genes in UV-B-treated broccoli Florets were effectively suppressed during storage, suggesting that UV-B treatment could be useful for quality maintenance of broccoli Florets during storage.
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effect of reactive oxygen species on quality maintenance of broccoli Florets with electrostatic atomized water particle treatment
Food Chemistry, 2017Co-Authors: Masahiro Nomura, Sukanya Aiamlaor, Masayoshi Shigyo, Shuhei Tanaka, Yukihiro Masuda, Naoki YamauchiAbstract:Abstract The effect of electrostatic atomized water particle (EAWP) treatment on quality maintenance during postharvest storage was determined to clarify a physiological role of reactive oxygen species in broccoli Florets. The EAWP treatment suppressed the floret yellowing of broccoli during storage. The hydrogen peroxide content increased immediately after EAWP treatment but then remained at a low level during storage. Catalase (CAT) activity increased rapidly with EAWP treatment and was higher than that in the control for the first 4 days of storage. The BoCAT gene expression level with EAWP treatment also showed a high trend as compared to the control. The gene expressions of BoRboh, BoCu/ZnSOD, and BoAPX showed almost the same tendency with or without EAWP treatment. These findings suggested that hydrogen peroxide formed by EAWP treatment and regulated by CAT could be relevant to maintaining the quality of broccoli.
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pheophytinase activity and gene expression of chlorophyll degrading enzymes relating to uv b treatment in postharvest broccoli brassica oleracea l italica group Florets
Postharvest Biology and Technology, 2012Co-Authors: Sukanya Aiamlaor, Masayoshi Shigyo, Naoki Yamauchi, Tetsuya NakajimaAbstract:Abstract Pheophytinase (PPH) activity and gene expression of chlorophyll (Chl)-degrading enzymes relating to UV-B treatment in postharvest broccoli (Brassica oleracea L. Italica Group) Florets were determined. PPH is involved in the dephytylation of Mg-free Chl a, pheophytin (Phy) a. However, in vitro chlorophyllase (Chlase, EC.3.1.1.14) also uses Phy a as a substrate to produce pheophorbide (Pheide) a by dephytylation. For an accurate determination of PPH activity, the PPH protein fraction was separated from Chlase protein by ammonium sulfate precipitation. The protein precipitated by 45–60% saturated ammonium sulfate included a little bit of Chlase activity and was suitable for PPH determination. PPH activity in broccoli Florets treated with a UV-B dose of 19 kJ m−2 was repressed for the first 2 d of storage at 15 °C, whereas it increased gradually with senescence of control broccoli Florets. The expression level of BoCLH1 was reduced in broccoli Florets on day 4 of storage, while BoCLH2 and BoCLH3 were up-regulated with UV-B treatment. A high BoPAO expression level was found in senescent broccoli Florets, and the up-regulation of this gene was delayed by UV-B treatment. The highest expression level of BoPPH was found in the control, and its expression was clearly repressed by UV-B treatment on day 2 of storage. We suggest that the up-regulation of Chl-degrading enzyme genes could be delayed by UV-B treatment, resulting in the suppression of floret yellowing in stored broccoli.
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involvement of chlorophyllase on chlorophyll degradation in stored broccoli Florets and its control by uv treatment
Southeast Asia Symposium on Quality and Safety of Fresh and Fresh-Cut Produce Bangkok Thailand., 2010Co-Authors: A Kaosamphan, Sukanya Aiamlaor, Naoki Yamauchi, V Srilaong, C Wongsaree, A UthairatanakijAbstract:Yellowing is the most visible deterioration in broccoli (Brassica oleracea L. Italica Group) that usually occurs with the progress of chlorophyll (Chl) degradation. This study deals with the control of floret yellowing in stored broccoli by using UV-B irradiation at 0 (control) and 8.8 kJ.m -2 . The application of UV-B at 8.8 kJ.m -2 effectively delayed yellowing of broccoli Florets. Chl a derivatives including chlorophyllide (Chlide) a, C13 2 -hydroxychlorophyll (C13 2 -OHChl) a and pheophytin (Phy) a levels in broccoli Florets were decreased concomitantly with the enhancement of pheophorbide (Pheide) a and pyropheophorbide (Pyropheide) a levels especially in the control treatment. On the other hand, Chlide a, C13 2 -OHChl a and Phy a levels were increased in 8.8 kJ.m -2 UV-B treated broccoli during storage at 15°C. Two types of chlorophyllase (Chlase) were identified by molecular exclusion chromatography. Type I was suppressed in UV-B treated broccoli on day 4, and the Km value of Type I was lower than that of Type II. Thus, the Chlase activity, especially Type I, was effectively suppressed by UV-B treatment, whereas Type II Chlase may take in part of Chl degradation in stored broccoli Florets.