scholarly journals Interactions between two QTLs for time to anthesis on spike development and fertility in wheat

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Priyanka A. Basavaraddi ◽  
Roxana Savin ◽  
Luzie U. Wingen ◽  
Stefano Bencivenga ◽  
Alexandra M. Przewieslik-Allen ◽  
...  
Keyword(s):  
Physiological Effect ◽  
Fine Tuning ◽  
Appearance Rate ◽  
Spike Development ◽  
Before And After ◽  
Leaf Appearance Rate ◽  
Allelic Status ◽  
Per Se ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

AbstractEarliness per se (Eps) genes are reported to be important in fine-tuning flowering time in wheat independently of photoperiod (Ppd) and vernalisation (Vrn). Unlike Ppd and Vrn genes, Eps have relatively small effects and their physiological effect along with chromosomal position are not well defined. We evaluated eight lines derived from crossing two vernalisation insensitive lines, Paragon and Baj (late and early flowering respectively), to study the detailed effects of two newly identified QTLs, Eps-7D and Eps-2B and their interactions under field conditions. The effect of both QTLs was minor and was affected by the allelic status of the other. While the magnitude of effect of these QTLs on anthesis was similar, they are associated with very different profiles of pre-anthesis development which also depends on their interaction. Eps-7D affected both duration before and after terminal spikelet while not affecting final leaf number (FLN) so Eps-7D-early had a faster rate of leaf appearance. Eps-2B acted more specifically in the early reproductive phase and slightly altered FLN without affecting the leaf appearance rate. Both QTLs affected the spike fertility by altering the rate of floret development and mortality. The effect of Eps-2B was very small but consistent in that -late allele tended to produce more fertile florets.

scholarly journals Interactions between two QTLs for time to anthesis on spike development and fertility in wheat

2020 ◽  
Author(s):  
Priyanka A. Basavaraddi ◽  
Roxana Savin ◽  
Luzie U Wingen ◽  
Stefano Bencivenga ◽  
Alexandra M. Przewieslik-Allen ◽  
...  
Keyword(s):  
Physiological Effect ◽  
Fine Tuning ◽  
Appearance Rate ◽  
Spike Development ◽  
Before And After ◽  
Leaf Appearance Rate ◽  
Allelic Status ◽  
Per Se ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

AbstractEarliness per se (Eps) genes are reported to be important in fine-tuning flowering time in wheat independently of photoperiod (Ppd) and vernalisation (Vrn). Unlike Ppd and Vrn genes, Eps have relatively small effects and their physiological effect along with chromosomal position are not well defined. We evaluated eight lines derived from crossing Paragon and Baj (late and early flowering respectively), vernalisation insensitive, to study the detailed effects of two newly identified QTLs, Eps-7D and Eps-2B and their interactions under field conditions. The effect of both QTLs were minor but their effect was modulated by the allelic status of the other. While the magnitude of effect of these QTLs on anthesis was similar, they are associated with very different profiles of pre-anthesis development which also depends on their interaction. Eps-7D affected both duration before and after terminal spikelet while not affecting final leaf number (FLN) so Eps-7D-early had a faster rate of leaf appearance. Eps-2B acted more specifically in the early reproductive phase and slightly altered FLN without affecting the leaf appearance rate. Both Eps-7D and 2B affected the spike fertility by altering the rate of floret development and mortality. The effect of the latter was very small but consistent in that the -late allele tended to produced more fertile florets.

Temperature response function for leaf appearance rate in wheat and corn

1999 ◽  
Vol 79 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Y. W. Jame ◽  
H. W. Cutforth ◽  
J. T. Ritchie
Keyword(s):  
Response Function ◽  
Plant Development ◽  
Full Range ◽  
Beta Function ◽  
Temperature Response ◽  
Base Temperature ◽  
Appearance Rate ◽  
Leaf Appearance Rate ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

The ability to predict leaf appearance would enhance our capability of modeling plant development and the rate of leaf area expansion. Many crop models use the constant thermal time for successive leaf tip appearance (which is often termed a phyllochron) as one model parameter to predict total number of leaves and date of anthesis. However, many researchers have found that phyllochron is not constant, but is dependent upon environment. The problem could be related to the simplified assumption that the daily leaf appearance rate is linearly related to temperature (and hence, phyllochron is constant, independent of temperature). In reality, the temperature response function for the development of a biological system is nonlinear. Thus, we fitted daily leaf appearance rate–temperature relationships obtained from growth room studies for both wheat (Triticum aestivum) and corn (Zea mays L.) to a nonlinear beta function with 0 °C as the base temperature and 42 °C as the upper critical temperature. The function described the relationships very well over the full range of temperatures for plant development. Other variables that are used to describe the duration and rate of leaf appearance, such as calendar days, phyllochron, and thermal rate of leaf appearance, are related to the daily leaf appearance rate, eliminating the need to develop various mathematical functions to independently describe the response of these variables to temperature. Because of the nonlinear nature of the temperature response function, we demonstrated that more accurate determinations of daily leaf appearance rates can be achieved by calculating rates over relatively short periods (i.e., hourly) and summing these to get the mean daily rate. Many environmental factors other than temperature also affect leaf appearance rate. However, once the proper temperature response function for leaf appearance rate is determined, it is much easier to determine when and how other factors are involved to modify the leaf appearance rate under a given environment.Key words: Temperature, leaf appearance rate, phyllochron, wheat, corn, beta function

Leaf appearance rate and associated characters in some Mexican and Australian wheats

1974 ◽  
Vol 25 (1) ◽  
pp. 1 ◽  
Author(s):  
JR Syme
Keyword(s):  
Yield Potential ◽  
High Yield ◽  
Leaf Production ◽  
Polygenic Control ◽  
Appearance Rate ◽  
Leaf Appearance Rate ◽  
Backcross Populations ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance ◽  
High Yield Potential

Three Mexican cultivars of high yield potential were compared in four field sowings with three Australian varieties of similar flowering time. The cultivars had different numbers of leaves on the main stem, associated mainly with differences in rate of leaf appearance rather than duration of leaf production. The Mexican cultivars produced leaves more quickly throughout growth, and this was repeated under glasshouse conditions. A fast rate of leaf appearance was associated with more spikelets and with faster tillering. Analysis of parental, F1, F2 and backcross populations of one cross showed leaf production rate to be under polygenic control with moderate heritability.

Sowing date and photoperiod effects on leaf appearance in field-grown wheat

1997 ◽  
Vol 77 (1) ◽  
pp. 23-31 ◽  
Author(s):  
G. K. Hotsonyame ◽  
L. A. Hunt
Keyword(s):  
Air Temperature ◽  
Sowing Date ◽  
Rate Of Change ◽  
Wheat Field ◽  
Sowing Dates ◽  
Appearance Rate ◽  
Leaf Appearance Rate ◽  
Supported Work ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

Rate of leaf appearance is a characteristic that can impact on the rate of development of a crop canopy. For wheat (Triticum aestivum L.), it is generally thought to be constant within a sowing date, but to vary among sowing dates. Such variation has been variously attributed to differences in the rate of change of photoperiod, the absolute photoperiod, or the mean air temperature. This study was undertaken to provide further information on the photoperiod and temperature effects on rate of leaf appearance in wheat. Field studies were conducted at Elora, Ontario at five sowing dates under natural and extended (20 h) photoperiod conditions. Two genotypes each of spring and winter wheat were grown under 0 and 150 kg ha−1 nitrogen fertilization. The results indicated that variations in rate of leaf appearance were not due to rate of change in photoperiod or absolute photoperiod at emergence. The change in rate of leaf appearance during a growth cycle was constant when mean air temperature during growth varied in a narrow range (less than 10 °C), but varied when there were wider ranges (over 10 °C) of temperature variation. Rate of leaf appearance was lower for the September seeding, at which time temperatures were around 5 °C, but were quite similar for May, June, July and August seedings even though temperatures ranged from approximately 15 °C (May) to 23 °C (June). The results suggested that the leaf appearance rate–temperature response curve is curvilinear, as found in some growth room studies, and supported work indicating that the phyllochron would depend on the temperature at the time of measurement. Key words: Wheat, photoperiod, temperature, nitrogen, sowing date, leaf appearance rate

scholarly journals Modeling leaf appearance rate for Canada Western Red Spring wheat cultivars

2010 ◽  
Vol 90 (4) ◽  
pp. 399-402 ◽  
Author(s):  
H. Wang ◽  
H. Cutforth ◽  
R M DePauw ◽  
T. McCaig ◽  
G. McLeod ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Triticum Aestivum L ◽  
Wheat Cultivars ◽  
Canadian Prairies ◽  
Semiarid Environment ◽  
Appearance Rate ◽  
Wheat Leaf ◽  
Leaf Appearance Rate ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

The rate of leaf appearance [LAR (d-1)] was observed for two older (Marquis and Neepawa) and two newer (AC Barrie and AC Elsa) Canada Western Red Spring (CWRS) wheat (Triticum aestivum L.) cultivars grown in a semiarid environment on the Canadian prairies for four years. Although the newer cultivars significantly increased yield LAR did not change when compared with the older cultivars. A simulation model developed by Jame et al. (1998a), and using coefficients for Neepawa determined from a previous study adequately predicted LAR for all four cultivars.Key words: Wheat, leaf appearance rate, temperature, daylength, model

Rate of leaf appearance in sugarcane, including a comparison of a range of varieties

1998 ◽  
Vol 25 (7) ◽  
pp. 829 ◽  
Author(s):  
G. D. Bonnett
Keyword(s):  
Power Law ◽  
Large Change ◽  
Thermal Time ◽  
Linear Polynomial ◽  
Appearance Rate ◽  
Biological Explanation ◽  
Leaf Appearance Rate ◽  
Number Of Leaves ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

Leaf appearance rate is a major determinant of canopy establishment, radiation interception and therefore yield. The effect of genotype on leaf appearance rate in sugarcane is largely unknown. Leaf appearance rate was recorded for the mainstems of pot grown sugarcane plants of nine commercial varieties, over 10 months in Townsville, Australia. Bi-phasic linear, polynomial and power-law models were fitted to data describing leaf appearance with thermal time. The bi-phasic model (previously used for sugarcane) had a single large change in phyllochron for which no biological explanation is apparent. Polynomials were less likely to predict leaf appearance accurately outside the range of fitted data. The power-law model gave a continuously increasing thermal time between the appearance of successive leaves (phyllochron) and was used to compare the varieties. An increasing phyllochron for the first 15 leaves could be explained, in part, by the increasing length of lamina each successive leaf had to grow through. However, an explanation for an increasing phyllochron throughout ontogeny has yet to be found. The rate of leaf appearance was significantly different between the varieties. After 5000˚Cd the number of leaves predicted to have appeared ranged from 35 to 46. These variety specific parameters make an important contribution to describing how different varieties produce leaf area.

GENETIC CONTROL OF VARIATION IN A SELECTED POPULATION OF ALTAI WILD RYEGRASS (ELYMUS ANGUSTUS)

1979 ◽  
Vol 59 (1) ◽  
pp. 7-13 ◽  
Author(s):  
T. LAWRENCE
Keyword(s):  
Dry Matter ◽  
Direct Selection ◽  
Adult Plant ◽  
Dry Matter Yield ◽  
Appearance Rate ◽  
Leaf Appearance Rate ◽  
Seedling Characters ◽  
Leaf Appearance ◽  
Additive Control ◽  
Rate Of Leaf Appearance

Progenies from a six-genotype diallel cross in Altai wild ryegrass (Elymus angustus Trin.) were studied to assess the pattern of genetic control for F1 seed weight and a number of seedling and adult plant characters. Variation in F1 seed weight was largely determined by the maternal parent, but some control by the pollen parent was apparent. Gene action was additive, but some nonadditive genetic effects were also present. All of the seedling characters, days to emerge, rate of leaf appearance, rate of tiller appearance and seedling dry matter yield showed additive control which is amenable to direct selection. Diallel analyses indicated that the adult plant characters, days to inflorescence appearance, digestible organic matter, total dry matter yield and total seed yield were controlled by strong additive control which is amenable to direct selection. The seedling characters, rate of leaf appearance, rate of tiller appearance and seedling dry matter yield were interrelated but only rate of tiller appearance was associated with adult plant yield.

scholarly journals Morphogenetic characteristics of three Brachiaria brizantha cultivars submitted to nitrogen fertilization

2013 ◽  
Vol 85 (1) ◽  
pp. 371-377 ◽  
Author(s):  
Marcos F Silva ◽  
Edson M. V Porto ◽  
Dorismar D Alves ◽  
Cláudio M.T Vitor ◽  
Ignacio Aspiazú
Keyword(s):  
Nitrogen Fertilization ◽  
Leaf Blade ◽  
Elongation Rate ◽  
Leaf Elongation ◽  
Brachiaria Brizantha ◽  
Nitrogen Levels ◽  
Appearance Rate ◽  
Leaf Elongation Rate ◽  
Leaf Appearance Rate ◽  
Leaf Appearance

This study aims to evaluate the morphogenetic characteristics of three cultivars of Brachiaria brizantha subjected to nitrogen fertilization. The design was a randomized block in factorial arrangement 4x3; three cultivars of B. brizantha - Marandu, Piatã, Xaraés and four nitrogen levels - 0, 80, 160 and 240 kg/ha, with three replications. The experimental units consisted of plastic pots filled with 5 dm3 of soil. Thereupon the establishment fertilization, varieties were sowed directly in the pots, leaving, after thinning, five plants per pot. Forty-five days after planting, it was done a standardization cut at 10 cm tall. Nitrogen levels were distributed according to the treatments, divided in three applications. The morphogenetic characteristics were evaluated in three tillers per sampling unit and data were submitted to analysis of variance and regression. For all evaluated characteristics there was no interaction between factors cultivar and nitrogen levels, verifying only the effects of nitrogen on the variables leaf appearance rate and phyllochron. The dose 240 kg/ha of N corresponds to the greater leaf appearance rate. Cultivar Marandu shows the higher leaf blade: pseudostem and ratio of leaf elongation rate and elongation pseudostem, which favors higher forage quality.

scholarly journals Contrasting phenotypes emerging from stable rules: A model based on self-regulated control loops captures the dynamics of shoot extension in contrasting maize phenotypes

2019 ◽  
Vol 126 (4) ◽  
pp. 615-633 ◽  
Author(s):  
T Vidal ◽  
B Andrieu
Keyword(s):  
Initial Conditions ◽  
Growth Conditions ◽  
Internal Variables ◽  
Model Parameters ◽  
Crop Models ◽  
Control Loops ◽  
Modelling Framework ◽  
Appearance Rate ◽  
Leaf Appearance Rate ◽  
Leaf Appearance

Abstract Background and Aims The dynamics of plant architecture is a central aspect of plant and crop models. Most models assume that whole shoot development is orchestrated by the leaf appearance rate, which follows a thermal time schedule. However, leaf appearance actually results from leaf extension and taking it as an input hampers our ability to understand shoot construction. The objective of the present study was to assess a modelling framework for grasses, in which the emergence of leaves and other organs is explicitly calculated as a result of their extension. Methods The approach builds on a previous model, which uses a set of rules co-ordinating the timing of development within and between phytomers. We first assessed rule validity for four experimental datasets, including different cultivars, planting densities and environments, and accordingly revised the equations driving the extension of the upper leaves and of internodes. We then fitted model parameters for each dataset and evaluated the ability to simulate the measured phenotypes across time. Finally, we carried out a sensitivity analysis to identify the parameters that had the greatest impact and to investigate model behaviour. Key Results The modified version of the model simulated correctly the contrasting maize phenotypes. Co-ordination rules accounted for the observations in all studied cultivars. Factors with major impact on model output included extension rates, the time of tassel initiation and initial conditions. A large diversity of phenotypes could be simulated. Conclusions This work provides direct experimental evidence for co-ordination rules and illustrates the capacity of the model to represent contrasting phenotypes. These rules play an important role in patterning shoot architecture and some of them need to be assessed further, considering contrasting growth conditions. To make the model more predictive, several parameters could be considered in the future as internal variables driven by plant status.

Leaf tissue remaining after cutting and regrowth in perennial ryegrass

1974 ◽  
Vol 82 (1) ◽  
pp. 165-172 ◽  
Author(s):  
Alison Davies
Keyword(s):  
Growth Rate ◽  
Perennial Ryegrass ◽  
Plant Material ◽  
Shoot Growth ◽  
Leaf Tissue ◽  
Relative Growth ◽  
Appearance Rate ◽  
Leaf Appearance Rate ◽  
Leaf Appearance ◽  
Increased Activity

SUMMARYWhen one or two leaves were removed out of the three or sometimes four present on each tiller of five genotypes of perennial ryegrass grown in nutrient solution, it was found that the relative growth rate (RGR) was not much less than that of untreated plants. The removal of lower leaves had no effect on RGR. Removal of all leaf blades depressed RGR. It is suggested that the results obtained indicate that the plant has the capacity to compensate for loss of leaf tissue by increased activity in the remaining leaves. Leaf appearance rate and tiller production were found to be the attributes most sensitive to the defoliation treatments imposed, and the degree to which leaf appearance rates were affected by defoliation was found to be a good indicator of the regrowth capacity of the different genotypes. Evidence was obtained linking high regrowth potential with high relative increases in the proportion of plant material allocated to new shoot growth.

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