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H.m. Rawson - One of the best experts on this subject based on the ideXlab platform.
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Quantitative developmental response to the length of exposure to long photoperiod in wheat and barley
The Journal of Agricultural Science, 2003Co-Authors: Daniel J. Miralles, Gustavo A. Slafer, Richard A. Richards, H.m. RawsonAbstract:The present study was designed to analyse the effect of the length of exposure to a long photoperiod imposed c. 3 weeks after sowing in spring wheat (cv. UQ189) and barley (cv. Arapiles) to (i) establish whether the response to the number of cycles of exposure is quantitative or qualitative, (ii) determine the existence of a commitment to particular stages well before the stage has been observable, and (iii) study the interrelationships between the effects on final leaf number and Phyllochron when the stimulus is provided several days after seedling emergence. Both wheat and barley seemed to respond quantitatively to the number of long-day cycles they were exposed to. However, wheat showed a requirement of approximately 4 long-day cycles to be able to produce a significant response in time to heading. The barley cultivar used in the study was responsive to the minimum length of exposure. The response to extended photoperiod cycles during the stem elongation phase was due to the ‘ memory’ photoperiod effects being related, in the case of wheat, to the fact that the pre-terminal spikelet appearance phase saturated its photoperiod response well before that stage was reached. Therefore, the commitment to the terminal spikelet appearance in wheat may be reached well before this stage could be recognized. As the response in duration to heading exceeded that of the final leaf number, and the stem elongation phase responded to memory effects of photoperiod, the Phyllochron of both cereals was responsive to the treatments accelerating the average Phyllochron when exposed to longer periods of long days. The response in average Phyllochron was due to a switch from bi-linear to linear models of leaf number v. time when the conditions were increasingly inductive, with the Phyllochron of the initial (6–8) leaves being similar for all treatments (within each species), and from then on increased.
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Phyllochron in Wheat as Affected by Photoperiod Under Two Temperature Regimes
Functional Plant Biology, 1997Co-Authors: Gustavo A. Slafer, H.m. RawsonAbstract:In this paper we describe the effects of photoperiod (9, 12, 15, 17, 19 and 21 h) and temperature (21/17 and 16/12°C) on rate of leaf appearance and Phyllochron in two spring wheats, a semi-winter wheat, and a winter wheat. Under long photoperiods only, all leaves on the main culm of a cultivar emerged at a common rate within a temperature regime, so it was acceptable to assign a specific Phyllochron to leaves irrespective of their level of insertion. Increased temperature significantly decreased Phyllochron, but the degree of this effect differed between cultivars. As photoperiod was shortened below the optimum, Phyllochron lengthened marginally and similarly in all varieties (by approximately 0.1 days per hour change in photoperiod). For very short photoperiods this was true only for the first six leaves, whilst for leaves at higher insertions there was a major effect of reducing photoperiod on lengthening Phyllochron. The actual daylength required for producing this major effect on Phyllochron was cultivar-dependent. These results suggest that, when making predictions of heading date using Phyllochron, it may not be acceptable to assume that leaf number and time are always linearly related at shorter photoperiods, particularly when considering leaves at higher insertions.
Francesco Giunta - One of the best experts on this subject based on the ideXlab platform.
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Dual-purpose use affects phenology of triticale
Field Crops Research, 2015Co-Authors: Francesco Giunta, Adriana Virdis, Agnese Cabigliera, Rosella MotzoAbstract:Abstract Treating cereals as a dual-purpose crop (grazing and grain production) can modify the timing of anthesis, but which among the main determinants of the timing of anthesis – namely leaf number, the Phyllochron and the length of the flag leaf emergence to anthesis interval – are affected is unclear. Eight field experiments conducted in triticale, designed to vary both sowing date (October through January), growth habit (vernalization requiring vs non-requiring) and to simulate grazing by clipping at the terminal spikelet stage (TS), were performed to monitor plant development. Clipping delayed anthesis by 2–7 days in four cultivar/environment combinations. The slower rate of leaf emergence after clipping delayed the appearance of the flag leaf ligule (FLA). When a delayed FLA was not accompanied by a proportional reduction in the duration of the FLA-anthesis interval, anthesis occurred later. The impact of an increase in the Phyllochron can be expected to be wider than just a delay to anthesis. A higher Phyllochron can also result in a slower recovery of leaf area, with a knock-on effect on the duration of the most critical period for grain number determination.
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Genetic variation for the duration of pre-anthesis development in durum wheat and its interaction with vernalization treatment and photoperiod
Journal of Experimental Botany, 2014Co-Authors: Gavino Sanna, Francesco Giunta, Rosella Motzo, Anna M. Mastrangelo, Pasquale De VitaAbstract:A recombinant inbred durum wheat population was grown under three contrasting regimes: long days following vernalization (LDV), long days without vernalization (LD), and short days following vernalization (SDV). The length of several pre-anthesis stages and the number of leaves and the Phyllochron were measured. Different groups of genes were involved in determining the phenology in the three treatments, as demonstrated by a quantitative trait locus (QTL) analysis. The length of the period required to reach the terminal spikelet stage was correlated with the time to anthesis only in the case of LDV- and LD-grown plants where the timing of anthesis depended on the final leaf number. However, for SDV-grown plants, anthesis date was more dependent on the length of the period between the terminal spikelet stage and anthesis and was independent of leaf number. The involvement of the Phyllochron in determining the duration of pre-anthesis development was also treatment-dependent. QTL mapping of the various flowering time associated traits uncovered some novel loci (such as those associated with the Phyllochron), in addition to confirming the presence of several well-established loci.
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The phenology of seed‐propagated globe artichoke
Annals of Applied Biology, 2013Co-Authors: Adriana Virdis, Rosella Motzo, Francesco GiuntaAbstract:The ability of globe artichoke to produce inflorescences (capitula) during the autumn when the market price is highest is lost when plants are propagated from seed, as are most F1 hybrid cultivars. To gain an understanding of the phenology of seed-propagated globe artichoke, both vernalised and non-vernalised seedlings grown from open pollinated progeny of ‘Spinoso sardo’ plants were transplanted into the field at two monthly intervals covering a whole year. Final leaf number and the date of unfolding of each leaf were used to calculate the Phyllochrons. The average final leaf number increased from 24 to 88 in response to increasing daylength above an approximately 11 h threshold during the first 30 days after emergence, and this variate explained about 90% of the variation in the thermal time taken to reach the bolting stage. The average Phyllochron ranged from 56 to 96°Cd among the six emergence dates and was the major underlying physiological cause of the loss of early flowering shown by seed-propagated plants. Genotypic variation for Phyllochron within an emergence date was strongly associated with variation for the length of the emergence to bolting stage period. The limited effect of vernalisation on development indicated that the late flowering tendency of seed-propagated plants cannot be attributed to an unfulfilled cold requirement.
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Key phenological events in globe artichoke (Cynara cardunculus var.scolymus) development
Annals of Applied Biology, 2009Co-Authors: Adriana Virdis, Rosella Motzo, Francesco GiuntaAbstract:A priority for the field vegetable grower is to be able to schedule a regular supply of product throughout the growing season. This requires a predictive framework, based on the identification of key developmental events of the crop, and an understanding of how genotypic and environmental factors interact to determine plant development. Four globe artichoke (Cynara cardunculus var. scolymus) cultivars, representing the existing phenological range, were grown in a field experiment, and a range of environmental conditions was imposed by varying both the timing of the first irrigation (which determines the initiation of regrowth) and by repeating the experiment across two locations and 2 years. The timing of the appearance of the main stem capitulum was sensitive to both the growing environment and the cultivar. These differences persisted till flowering and were correlated with final leaf number. As the plant developed, the Phyllochron decreased, resulting in three values of Phyllochron, each of which was responsive to genotype, and hardly to environment. The timing of the first change in Phyllochron was associated with the final leaf number and the appearance of the capitulum. For all the cultivars, the rate of development fell and the final leaf number increased as the length of the photoperiod increased. The later flowering cultivars shared a similar vernalisation requirement, but 'Spinoso sardo' did not require a cold period to flower. Leaf length reached a peak before the beginning of stem elongation, and maximum leaf length was correlated with final leaf number. The sensitiveness of the Phyllochron to the genotype, and of the number of leaves and the timing of the appearance of the capitulum to both genotype and environment makes them suitable as variables in developmental models. The importance of the final number of leaves is not only because of its phenological significance, but also because of its effect on the ability of the canopy to intercept radiation.
Rosella Motzo - One of the best experts on this subject based on the ideXlab platform.
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Dual-purpose use affects phenology of triticale
Field Crops Research, 2015Co-Authors: Francesco Giunta, Adriana Virdis, Agnese Cabigliera, Rosella MotzoAbstract:Abstract Treating cereals as a dual-purpose crop (grazing and grain production) can modify the timing of anthesis, but which among the main determinants of the timing of anthesis – namely leaf number, the Phyllochron and the length of the flag leaf emergence to anthesis interval – are affected is unclear. Eight field experiments conducted in triticale, designed to vary both sowing date (October through January), growth habit (vernalization requiring vs non-requiring) and to simulate grazing by clipping at the terminal spikelet stage (TS), were performed to monitor plant development. Clipping delayed anthesis by 2–7 days in four cultivar/environment combinations. The slower rate of leaf emergence after clipping delayed the appearance of the flag leaf ligule (FLA). When a delayed FLA was not accompanied by a proportional reduction in the duration of the FLA-anthesis interval, anthesis occurred later. The impact of an increase in the Phyllochron can be expected to be wider than just a delay to anthesis. A higher Phyllochron can also result in a slower recovery of leaf area, with a knock-on effect on the duration of the most critical period for grain number determination.
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Genetic variation for the duration of pre-anthesis development in durum wheat and its interaction with vernalization treatment and photoperiod
Journal of Experimental Botany, 2014Co-Authors: Gavino Sanna, Francesco Giunta, Rosella Motzo, Anna M. Mastrangelo, Pasquale De VitaAbstract:A recombinant inbred durum wheat population was grown under three contrasting regimes: long days following vernalization (LDV), long days without vernalization (LD), and short days following vernalization (SDV). The length of several pre-anthesis stages and the number of leaves and the Phyllochron were measured. Different groups of genes were involved in determining the phenology in the three treatments, as demonstrated by a quantitative trait locus (QTL) analysis. The length of the period required to reach the terminal spikelet stage was correlated with the time to anthesis only in the case of LDV- and LD-grown plants where the timing of anthesis depended on the final leaf number. However, for SDV-grown plants, anthesis date was more dependent on the length of the period between the terminal spikelet stage and anthesis and was independent of leaf number. The involvement of the Phyllochron in determining the duration of pre-anthesis development was also treatment-dependent. QTL mapping of the various flowering time associated traits uncovered some novel loci (such as those associated with the Phyllochron), in addition to confirming the presence of several well-established loci.
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The phenology of seed‐propagated globe artichoke
Annals of Applied Biology, 2013Co-Authors: Adriana Virdis, Rosella Motzo, Francesco GiuntaAbstract:The ability of globe artichoke to produce inflorescences (capitula) during the autumn when the market price is highest is lost when plants are propagated from seed, as are most F1 hybrid cultivars. To gain an understanding of the phenology of seed-propagated globe artichoke, both vernalised and non-vernalised seedlings grown from open pollinated progeny of ‘Spinoso sardo’ plants were transplanted into the field at two monthly intervals covering a whole year. Final leaf number and the date of unfolding of each leaf were used to calculate the Phyllochrons. The average final leaf number increased from 24 to 88 in response to increasing daylength above an approximately 11 h threshold during the first 30 days after emergence, and this variate explained about 90% of the variation in the thermal time taken to reach the bolting stage. The average Phyllochron ranged from 56 to 96°Cd among the six emergence dates and was the major underlying physiological cause of the loss of early flowering shown by seed-propagated plants. Genotypic variation for Phyllochron within an emergence date was strongly associated with variation for the length of the emergence to bolting stage period. The limited effect of vernalisation on development indicated that the late flowering tendency of seed-propagated plants cannot be attributed to an unfulfilled cold requirement.
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Key phenological events in globe artichoke (Cynara cardunculus var.scolymus) development
Annals of Applied Biology, 2009Co-Authors: Adriana Virdis, Rosella Motzo, Francesco GiuntaAbstract:A priority for the field vegetable grower is to be able to schedule a regular supply of product throughout the growing season. This requires a predictive framework, based on the identification of key developmental events of the crop, and an understanding of how genotypic and environmental factors interact to determine plant development. Four globe artichoke (Cynara cardunculus var. scolymus) cultivars, representing the existing phenological range, were grown in a field experiment, and a range of environmental conditions was imposed by varying both the timing of the first irrigation (which determines the initiation of regrowth) and by repeating the experiment across two locations and 2 years. The timing of the appearance of the main stem capitulum was sensitive to both the growing environment and the cultivar. These differences persisted till flowering and were correlated with final leaf number. As the plant developed, the Phyllochron decreased, resulting in three values of Phyllochron, each of which was responsive to genotype, and hardly to environment. The timing of the first change in Phyllochron was associated with the final leaf number and the appearance of the capitulum. For all the cultivars, the rate of development fell and the final leaf number increased as the length of the photoperiod increased. The later flowering cultivars shared a similar vernalisation requirement, but 'Spinoso sardo' did not require a cold period to flower. Leaf length reached a peak before the beginning of stem elongation, and maximum leaf length was correlated with final leaf number. The sensitiveness of the Phyllochron to the genotype, and of the number of leaves and the timing of the appearance of the capitulum to both genotype and environment makes them suitable as variables in developmental models. The importance of the final number of leaves is not only because of its phenological significance, but also because of its effect on the ability of the canopy to intercept radiation.
Denise Schmidt - One of the best experts on this subject based on the ideXlab platform.
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Phyllochron and Productive Performance of Strawberry Cultivars: Impact of Different Regions of Origin in a Conventional Cultivation System
Journal of Agricultural Science, 2018Co-Authors: Leonardo Antonio Thiesen, Braulio Otomar Caron, Marcos Vinícius Marques Pinheiro, Maria Inês Diel, Carine Cocco, Daniele Cristina Fontana, Evandro Holz, Denise SchmidtAbstract:The seedlings selection and the strawberry cultivars choice are fundamental to the productive success of a cultivation. Thus, the objective of this work was to evaluate the production of two strawberry cultivars with seedlings from different origins, in a conventional cultivation system under the low tunnel. The experiment was conducted in a randomized complete block design, in a 2 × 3 factorial scheme, two cultivars (Albion and San Andreas) and three different nurseries (Low altitude region/BR, High altitude region/BR and seedlings imported from the of Patagonia Region/AR) totaling six treatments, with four replicates and eight plants per plot. Phyllochron, number and production of commercials and non commercial fruits were determined. To the qualitative analysis, the acidity, total soluble solids and the relation total soluble solids/titratable acidity were determined. It was possible to observe that the Albion cultivar from all sources and the San Andreas of high altitude/BR presented the highest Phyllochron values. The production of commercial fruits was higher for the Albion cultivar from high altitude/BR and Patagonia/AR, and to San Andreas cultivar of low altitude/BR. It was concluded that the Phyllochron varies according to the cultivar and place of origin of the seedlings, being San Andreas cultivar of the low altitude/BR the one that requires less amounts of degree-days to emit a leaf. The Albion (high altitude/BR) cultivar has higher Phyllochron, high productive potential and less production of non-commercial fruits, and can be used as a substitute for imported seedlings (Patagonia/AR), which will reflect in the costs reduction to the implantation of strawberry crops.
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Yield and Quality Performance of Italian and American Strawberry Genotypes in Brazil
Journal of Agricultural Science, 2018Co-Authors: Maria Inês Diel, Braulio Otomar Caron, Marcos Vinícius Marques Pinheiro, Carine Cocco, Daniele Cristina Fontana, Daniela Meira, Leonardo Antonio Thiesen, Denise SchmidtAbstract:The strawberry cultivars show variation in agronomic performance when grown in different regions of the world, due to the genotype × environment interaction. The aim of the study was to evaluate the yield performance and quality of Italian and American strawberry cultivars. We evaluated the Phyllochron, which measures the time required for the emission of successive leaves in a plant, the number and commercial and non-commercial fruit yield, titratable acidity and total soluble solids (obtained from evaluations of the Brix degree of the fruit). The experimental design was a randomized complete block with 11 treatments, which were composed of the Italian strawberry cultivars (CREA-FRF PIR 29, CREA-FRF PA3, CREA-FRF CE 51, CREA-FRF CE 56, CREA-FRF Jonica and CREA-FRF Pircinque) and American (Albion, Camarosa, San Andreas, Camino Real and Aromas), with four replications per treatment, eight plants per plot, giving a total 32 plants per cultivar. Analysis of variance showed differences for Phyllochron, marketable fruits yield and total soluble solids content. The American cultivar Albion showed higher Phyllochron, the cultivar CREA-FRF Pircinque the lowest Phyllochron. The highest yields of marketable fruits were found in American cultivars Camino Real and CREA-FRF Pircinque. The higher solids soluble was observed in Italian cultivars. Thus, we highlight the Italian strawberry cultivars, because they reflect good yield when compared to the American cultivars.
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estimated Phyllochron in low tunnel cultivated strawberry cultivars
Ciencia Rural, 2016Co-Authors: K L T Cocco, Braulio Otomar Caron, Daniele Cristina Fontana, Denise Schmidt, Velci Queiroz De Souza, Gizelli Moiano De PaulaAbstract:The aim of this study was to determine Phyllochron in strawberry cultivars, from two origins during two crop years, conducted in low tunnel. Experiments were conducted at the Universidade Federal de Santa Maria, campus Frederico Westphalen (CESNORS/UFSM), Brazil, evaluating 'Camarosa', 'Camino Real' and 'Albion' strawberry cultivars. During the 2012 crop year, seedlings from Chile and Pelotas/RS, Brazil were evaluated, for the 2013 crop year, only seedlings from Chile were submitted to evaluations. In order to determine the Phyllochron, twice a week the numbers of leaves (NL) of the main crown were counted and a regression between NL and accumulated thermal time (ATT) was held. The experimental design was a complete randomized block, with three repetitions with the evaluation of 12 plants per experimental unity, consisting of a factorial. For 2012 and 2013 crop years, it is possible to conclude that 'Camarosa' and 'Camino Real' cultivars required higher accumulation of degree-days (oC day-1) to issue each successive leaf than cv. 'Albion', which, in turn, presented higher rates of leaf emergence, being considered earlier. Regarding to origin, seedlings from cv. 'Albion' from Chile presented lower total Phyllochron values and for samples from Pelotas, no difference among cultivars was observed.
Jorge Alberto Tognetti - One of the best experts on this subject based on the ideXlab platform.
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Low temperature differentially affects tillering in spring and winter wheat in association with changes in plant carbon status
Annals of Applied Biology, 2014Co-Authors: M. Lorenzo, Silvia G. Assuero, Jorge Alberto TognettiAbstract:The higher tillering potential of winter wheat cultivars as compared to spring ones has been attributed to an earlier tillering onset in the former. Tillering in grasses is known to depend on temperature and light environment, and may be mediated by plant C status. The aim of this work was to elucidate whether differences in carbohydrate accumulation between wheat types at low temperature may contribute to differences in tillering potential. A set of experiments with contrasting temperatures was conducted in both field enclosures (high irradiance, three experiments) and growth chambers (low irradiance, two experiments). The relative tiller production rate (RTR) was the highest in winter cultivars grown in cool field enclosures, and the lowest in spring cultivars in growth chambers, either cool or warm. Plant C status was inversely related to temperature the response being more pronounced in winter cultivars. Components of RTR, site filling and Phyllochron, responded differently to environment and plant C status. Phyllochron increased with temperature, and was inversely correlated to sugar concentration irrespective of cultivar type. Site filling increased with irradiance in both cultivar types while sugar concentration contributed additively to its promotion solely in winter cultivars. Nevertheless, variation in site filling was larger in percentage than variation in Phyllochron (200% and 41%, respectively, between most contrasting treatments). Thus, differences in tillering potential between winter and spring wheats may be attributed not only to the earlier tillering onset in the former but also to their differential response to environment and C status.