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 GENETIC CONTROL OF VARIATION IN A SELECTED POPULATION OF RUSSIAN WILD RYEGRASS (ELYMUS JUNCEUS)

1976 ◽  
Vol 56 (2) ◽  
pp. 275-280
Author(s):  
T. LAWRENCE
Keyword(s):  
Genetic Control ◽  
Seed Yield ◽  
Seed Weight ◽  
Dry Matter ◽  
Recurrent Selection ◽  
Direct Selection ◽  
Adult Plant ◽  
Dry Matter Yield ◽  
Seedling Characters ◽  
Additive Control

Progenies from a five-genotype diallel cross in Russian wild ryegrass, Elymus junceus Fisch., 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. Of the seedling characters, days to emerge, rate of leaf appearance, rate of tiller appearance, and seedling dry matter yield, only days to emerge showed additive variance which is amenable to direct selection. The other three characters could be most easily exploited by a recurrent selection program. The adult plant characters, date of inflorescence appearance, P content of the forage, and organic matter digestibility indicated strong additive control which is amenable to direct selection. Dry matter yield and seed yield also showed strong additive control which was accompanied by specific combining ability and weak maternal effects suggesting good progress should be possible by direct selection methods but crossing the selections in a diallel fashion prior to formation of synthetics might be desirable. The seedling characters, rate of leaf and tiller appearance and seedling dry matter yield were interrelated and associated with adult plant yield, thus offering the possibility of screening seedlings for these characters in a recurrent selection program for improved forage or seed yield.

scholarly journals Attributes related to seasonal herbage growth in white clover

2009 ◽  
Vol 66 (1) ◽  
pp. 20-27 ◽  
Author(s):  
Omar Scheneiter ◽  
Beatriz Rosso ◽  
Mauro Corletto
Keyword(s):  
White Clover ◽  
Dry Matter ◽  
Leaf Size ◽  
Growth Patterns ◽  
Dry Matter Accumulation ◽  
Seasonal Growth ◽  
Local Populations ◽  
Appearance Rate ◽  
Leaf Appearance Rate ◽  
Leaf Appearance

When breeding temperate forage species is investigated, some attributes such as herbage accumulation and seasonal growth patterns have to be considered. To modify some of these traits, knowledge of the detailed process might be useful. In order to evaluate seasonal growth of contrasting white clover populations an experiment was carried out. Treatments were five cultivars and three local populations collected in Argentina. Weekly measures were taken during each season to calculate leaf appearance and flower appearance rates, stolon growing rate and dry matter (DM) net accumulation. Different germplasm of this species have different mechanisms for DM accumulation. Leaf size, more than leaf appearance rate, was the variable with most differences among germplasm and mostly related to dry matter accumulation. During spring and summer, inflorescences production had important effects on growing stolon rate, and differences among germplasm were evident. Some local populations showed favourable attributes that could be useful for breeding.

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

The effect of photoperiod and temperature on the first crop and ratoon growth of Pennisetum purpureum Schum

1978 ◽  
Vol 29 (5) ◽  
pp. 941 ◽  
Author(s):  
R Ferraris
Keyword(s):  
Dry Matter ◽  
Stem Elongation ◽  
Main Stem ◽  
Pennisetum Purpureum ◽  
Short Day ◽  
Long Day ◽  
Appearance Rate ◽  
Leaf Appearance Rate ◽  
Higher Temperature ◽  
Leaf Appearance

Elephant grass (Pennisetum purpureum Schum.) was grown in phytotron cabinets for 60 days at 30/25° or 21/16°C (daylnight) in either 8 or 16 hr photoperiods. During the juvenile phase the higher temperature increased the leaf appearance rate, tillering rate and main stem elongation rate. Once plants in the 8 hr photoperiod became reproductive, the stem elongation, tillering rate and leaf appearance rate increased. The higher temperature continued to stimulate development. At harvest at 60 days plants grown at 30/25° had higher leaf, stem and total dry matter yields, a greater leaf area but lower carbohydrate content in the stubble. The 16 hr photoperiod produced higher dry matter yields at harvest than the 8 hr photoperiod. A comparison pot experiment grown in short day and long day photoperiods under field conditions in north Queensland produced similar findings to the phytotron experiment. After harvest, stubbles were ratooned into either short day (8 hr) or long day (16 hr) photoperiods, the temperature difference being maintained. Leaf number per main stem and main stem elongation were similar to those of the first crop, but more tillers and higher yields were produced in the ratoon crop. Temperature and photoperiod effects were similar in both crops. It was concluded that low temperatures rather than reduced photoperiod would be the greatest limitation to the adaptation of the species as an industrial or forage crop where yearround production is required.

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.

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 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.

SELECTION FOR DRY MATTER YIELD IN LOLIUM PERENNE L. II. CORRELATED RESPONSES UNDER TWO CUTTING REGIMES

1980 ◽  
Vol 60 (2) ◽  
pp. 501-508 ◽  
Author(s):  
S. CECCARELLI ◽  
M. FALCINELLI ◽  
F. DAMIANI
Keyword(s):  
Lolium Perenne ◽  
Dry Matter ◽  
Leaf Size ◽  
Dry Matter Yield ◽  
Correlated Responses ◽  
Lolium Perenne L ◽  
Selection For ◽  
Cutting Regimes ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

The correlated responses to divergent selection for dry matter yield within an ecotype of Lolium perenne L. were evaluated in two experiments under different cutting regimes. Both experiments showed that selection for dry matter yield did not affect leaf size and caused asymmetrical correlated responses on the rate of tiller production and the rate of leaf appearance. Selection for high dry matter yield resulted in an increased rate of tiller production without change in the rate of leaf appearance. Selection for low dry matter yield did reduce both the rate of leaf appearance and the rate of tiller production.

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

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