Phyllochron in Wheat as Affected by Photoperiod Under Two Temperature Regimes

1997 ◽  
Vol 24 (2) ◽  
pp. 151 ◽  
Author(s):  
Gustavo A. Slafer ◽  
H. M. Rawson
Keyword(s):  
Winter Wheat ◽  
Temperature Regime ◽  
Heading Date ◽  
Major Effect ◽  
Leaf Number ◽  
Increased Temperature ◽  
Temperature Regimes ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance ◽  
Two Temperature

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.

scholarly journals Insights into the Genetic Architecture of Phenotypic Stability Traits in Winter Wheat

Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 368 ◽  
Author(s):  
Dennis Lozada ◽  
Arron Carter
Keyword(s):  
Winter Wheat ◽  
Pacific Northwest ◽  
Genetic Architecture ◽  
Heading Date ◽  
Major Effect ◽  
Snp Markers ◽  
Genetic Loci ◽  
Phenotypic Stability ◽  
Trait Stability ◽  
Genetic Complexity

Examining the architecture of traits through genomics is necessary to gain a better understanding of the genetic loci affecting important traits to facilitate improvement. Genomewide association study (GWAS) and genomic selection (GS) were implemented for grain yield, heading date, and plant height to gain insights into the genetic complexity of phenotypic stability of traits in a diverse population of US Pacific Northwest winter wheat. Analysis of variance using the Additive Main Effect and Multiplicative Interaction (AMMI) approach revealed significant genotype and genotype by environment interactions. GWAS identified 12 SNP markers distributed across 10 chromosomes affecting variation for both trait and phenotypic stability, indicating potential pleiotropic effects and signifying that similar genetic loci could be associated with different aspects of stability. The lack of stable and major effect loci affecting phenotypic variation supports the complexity of stability of traits. Accuracy of GS was low to moderate, between 0.14 and 0.66, indicating that phenotypic stability is under genetic control. The moderate to high correlation between trait and trait stability suggests the potential of simultaneous selection for trait and trait stability. Our results demonstrate the complex genetic architecture of trait stability and show the potential for improving stability in winter wheat using genomic-assisted approaches.

The effect of aerobic soil conditions, soil volume and sowing date on the development of four tropical rice varieties grown in the greenhouse

2013 ◽  
Vol 40 (1) ◽  
pp. 79 ◽  
Author(s):  
Benoit Clerget ◽  
Crisanta Bueno
Keyword(s):  
Heading Date ◽  
Sowing Date ◽  
Soil Conditions ◽  
Rice Varieties ◽  
Pot Size ◽  
A Chain ◽  
Leaf Appearance ◽  
Aerobic Soil ◽  
Kinetics Of ◽  
Rate Of Leaf Appearance

Rice has generally been reported to yield less in aerobic soil conditions than in flooded soil conditions, in association with delayed anthesis and a reduction in height. A greenhouse experiment was conducted and repeated twice with four rice varieties grown in either flooded or nearly-saturated aerobic soil, in either large or small pots. The rate of leaf appearance was recorded weekly until heading time, when plants were harvested for shoot and root biomass. The kinetics of leaf appearance was generally trilinear with longer phyllochrons in the May sowing. Pot size had only a small effect whereas aerobic soil conditions slowed down the rate of leaf initiation, which consequently delayed panicle initiation and heading date and thus increased the duration of the tillering phase and finally the number of tillers. Surprisingly, the four varieties showed a significant response to sowing date, especially IR72, which headed 21 days later and after the expansion of two more leaves in the May sowing. The aerobic soil conditions and sowing date have thus changed the rate of development of rice plants and this trait has appeared to be the initial link of a chain of consequences in a series of traits known to be affected by these factors.

scholarly journals Barley development as affected by rate of change of photoperiod

1995 ◽  
Vol 124 (3) ◽  
pp. 379-388 ◽  
Author(s):  
G. C. Kernich ◽  
G. A. Slafer ◽  
G. M. Halloran
Keyword(s):  
Spring Barley ◽  
Seedling Emergence ◽  
Rate Of Change ◽  
Leaf Number ◽  
Spikelet Number ◽  
Photoperiod Regime ◽  
Leaf Emergence ◽  
Linear Relationships ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

SUMMARYThe rate of leaf appearance of barley varies substantially with time of sowing. This variation has been related to both the length and the rate of change of photoperiod at the time of plant emergence. An outdoor pot experiment was conducted to test if rate of change of photoperiod directly affects phasic development and rate of leaf emergence of spring barley. Two photoperiod-sensitive cultivars (Bandulla and Galleon) were subjected to five photoperiod regimes: two constant photoperiods, of 14 and 15·5 h, and three different rates of change of photoperiod of c. 2, 9 and 13 min/day from seedling emergence to awn initiation.Photoperiod treatments significantly affected the duration from seedling emergence to awn initiation in both cultivars. Rate of change of photoperiod did not affect the rate of development towards awn initiation independently of the absolute daylength it produced. Although Bandulla had a longer duration than Galleon at any photoperiod regime, the cultivars did not vary in their sensitivity to photoperiod. When this phase was divided into the leaf initiation (LI) and spikelet initiation (SI) phases, it was evident that the sensitivity to photoperiod was not constant, being in general higher during the SI than during the LI phase. However, the magnitude of the change in sensitivity was cultivar-dependent, indicating that sensitivity to photoperiod during the different phases could be under independent genetic control.Final numbers of primordia (leaves together with maximum spikelet number) were negatively affected by increasing photoperiods, but once again, there was no evidence of any effect of the rate of change of photoperiod which was independent of the average photoperiod. Both cultivars showed similar sensitivities for final leaf number but maximum spikelet number was more sensitive to photoperiod in Galleon than in Bandulla.Highly significant linear relationships between leaf number and thermal time were found for all combinations of cultivars and photoperiod regimes (r2 > 0·98). The rate of leaf appearance (RLA) was similar for both cultivars (c. 0·0185 leaves/°Cd) and did not alter during plant development or in response to the change in photoperiod at awn initiation. The range in RLA was greater for Galleon (0·0170–0·0205 leaves/°Cd) than for Bandulla (0·0173–0·0186 leaves/°Cd). Neither of these cultivars exhibited a significant relationship between rate of leaf emergence and photoperiod or rate of change of photoperiod. The lack of significant relationships between RLA and length or rate of change of photoperiod is in contrast with previous reports using time of sowing as a main treatment.

scholarly journals Production Temperatures Influence Growth and Physiology of Leatherleaf Fern

HortScience ◽  
1994 ◽  
Vol 29 (2) ◽  
pp. 67-70 ◽  
Author(s):  
Robert H. Stamps ◽  
Terril A. Nell ◽  
James E. Barrett
Keyword(s):  
Temperature Regime ◽  
Dark Respiration ◽  
Soluble Sugars ◽  
Light Saturation ◽  
Temperature Regimes ◽  
Use Efficiency ◽  
Carbohydrate Levels ◽  
Rumohra Adiantiformis ◽  
Mass Basis ◽  
Two Temperature

Leatherleaf fern [Rumohra adiantiformis (Forst.) Ching] fronds produced under a high-temperature regime (HTR, 30 day/25C night) grew faster and produced sori earlier than those in a low-temperature regime (LTR, 20 day/15C night). Abaxial diffusive conductance was lower for HTR-grown fronds. Light-saturated net CO2 assimilation rates (Pn) and dark respiration were lower for HTR fronds, but light-saturated Pn efficiencies (chlorophyll basis); light compensation points; and soluble sugars, starch, and nonstructural carbohydrate levels were similar for the two regimes. Transpiration and water-use efficiency (mass basis) at light saturation were similar for fronds from both temperature treatments. Comparison of physiological characteristics of fronds from the two temperature regimes revealed no differences that might account for reduced postharvest longevity of fronds produced at the higher temperatures.

scholarly journals CO2Effects on Phasic Development, Leaf Number and Rate of Leaf Appearance in Wheat

1997 ◽  
Vol 79 (1) ◽  
pp. 75-81 ◽  
Author(s):  
G SLAFER
Keyword(s):  
Leaf Number ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

Modelling the effects of vernalization on progress to final leaf appearance in winter wheat

1995 ◽  
Vol 124 (3) ◽  
pp. 369-377 ◽  
Author(s):  
J. Craigon ◽  
J. G. Atherton ◽  
N. Sweet
Keyword(s):  
Winter Wheat ◽  
Treatment Duration ◽  
Development Rate ◽  
Post Treatment ◽  
Leaf Number ◽  
Optimum Temperature ◽  
Original Experiment ◽  
Data Set ◽  
Initial Development ◽  
Leaf Appearance

SUMMARYA simple model of vernalization, originally developed to quantify the vernalization response of fieldgrown carrots, was fitted to previously published experimental results for winter wheat cv. Norin 27. The optimum temperature for vernalization indicated by the model was c. 5·2 °C, as this induced the fastest progress to final leaf appearance, expressed as the reciprocal of number of days from sowing to final leaf. This rate decreased linearly with temperature rise or fall on either side of the optimum, extrapolating to zero at –4·8 °C (Tmin) and 26·6 °C (Tmax). When all the treatment temperatures and durations were expressed as vernalizing degree days > –4·8 °C (V °C d), there was a linear increase in post-treatment development rate with increasing vernalization up to c. 275 V °C d. Ending the effective treatment duration for vernalization at the estimated time of initiation of the final leaf primordia brought many of the data points closer to the linear trend which described the rest of the data.Effects of using leaf number, which is linearly related to thermal time, instead of days as the unit of time to compensate for temperature differences in the original experiment were examined. Unvernalized plants had the potential to produce 18 leaves before flowering and therefore rates were expressed as the fraction of the potential total leaf number that each new leaf represented. All plants were assumed to have an initial development rate of 1/18 per leaf. This rate was assumed to increase linearly with time during the vernalizing treatment periods and then remain constant after treatment until the final leaf appeared. Leaf numbers reported from the original experiment were used with these assumptions to estimate the rate at the end of each treatment. The relationship between these rates and treatment temperatures was similar to that for rates based on post-treatment durations. There was an optimum temperature c. 5·5 °C and Tmin and Tmax of –5·1 and 18·8 °C estimated by extrapolating the decreasing linear trends to the base rate of 1/18. When plotted against V °C d calculated from these temperatures, the rates from the full data set were well represented by the model line which had been fitted to the data from just one treatment duration.

Seedling Vigor Evaluation of Four Birdsfoot Trefoil Varieties Grown Under Two Temperature Regimes 1

Crop Science ◽  
1968 ◽  
Vol 8 (6) ◽  
pp. 756-757 ◽  
Author(s):  
Clee S. Cooper ◽  
Mickey Qualls
Keyword(s):  
Birdsfoot Trefoil ◽  
Seedling Vigor ◽  
Temperature Regimes ◽  
Two Temperature

scholarly journals O-linked N-acetylglucosamine transferase is involved in fine regulation of flowering time in winter wheat

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Min Fan ◽  
Fang Miao ◽  
Haiyan Jia ◽  
Genqiao Li ◽  
Carol Powers ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Flowering Time ◽  
Heading Date ◽  
Wheat Cultivars ◽  
Gene Encoding ◽  
Constitutive Overexpression ◽  
Winter Wheat Cultivars ◽  
Fine Regulation ◽  
Trait Locus ◽  
Glcnac Transferase

AbstractVernalization genes underlying dramatic differences in flowering time between spring wheat and winter wheat have been studied extensively, but little is known about genes that regulate subtler differences in flowering time among winter wheat cultivars, which account for approximately 75% of wheat grown worldwide. Here, we identify a gene encoding anO-linkedN-acetylglucosamine (O-GlcNAc) transferase (OGT) that differentiates heading date between winter wheat cultivars Duster and Billings. We clone thisTaOGT1gene from a quantitative trait locus (QTL) for heading date in a mapping population derived from these two bread wheat cultivars and analyzed in various environments. Transgenic complementation analysis shows that constitutive overexpression ofTaOGT1bfrom Billings accelerates the heading of transgenic Duster plants.TaOGT1 is able to transfer anO-GlcNAc group to wheat proteinTaGRP2. Our findings establish important roles forTaOGT1in winter wheat in adaptation to global warming in the future climate scenarios.

scholarly journals Properties of Extruded Snacks Prepared from Corn and Carrot Powder with Ascorbic Acid Addition

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1367
Author(s):  
Valentina Obradović ◽  
Jurislav Babić ◽  
Verica Dragović-Uzelac ◽  
Antun Jozinović ◽  
Đurđica Ačkar ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Temperature Regime ◽  
External Source ◽  
Single Screw Extruder ◽  
Functional Value ◽  
Temperature Regimes ◽  
Starting Point ◽  
Extruded Snacks ◽  
New Type ◽  
Corn Snacks

The objective of this research was to investigate the potentiality of carrot powder (CP) utilization at levels 4, 6, or 8% as ingredient of corn snacks and evaluation of the extrusion influence on functionally important ingredients such as carotenoids (color), polyphenols, fiber, fat, and antioxidant activity. The influence of ascorbic acid (AA) as an external source at levels 0.5 and 1% on this particular extrusion was also investigated. A single-screw extruder at two temperature regimes (135/170/170 °C (E1) and 100/150/150 °C (E2)) carried out extrusion. The E1 temperature regime acted favorably on total polyphenol content and crude fiber, but fat preferred the E2 regime. Extrusion, especially the E1 temperature regime, increased the extractability of carotenoids. Ascorbic acid degraded during extrusion, but it still provided protection to carotenoids and color attributes of extrudates. Snacks with increased nutritional and functional value due to carrot powder addition were successfully produced, which is a starting point for production of a new type of extruded snacks.

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