scholarly journals Photoperiod-sensitivity genes (Ppd-1): Quantifying their effect on the photoperiod response model in wheat

2019 ◽  
Author(s):  
Thomas I Pérez-Gianmarco ◽  
Alan D Severini ◽  
Fernanda G González
Keyword(s):  
Stem Elongation ◽  
Flag Leaf ◽  
Triticum Aestivum L ◽  
Photoperiod Sensitivity ◽  
Yield Potential ◽  
Photoperiod Response ◽  
Potential Development ◽  
Wide Range ◽  
Photoperiod Sensitive ◽  
Photoperiod Sensitivity Genes

Abstract Coupling anthesis date to the best environment is critical for wheat (Triticum aestivum L.) adaptation and yield potential. Development to anthesis is controlled by temperature and photoperiod. Response to photoperiod is chiefly modulated by Ppd-1 genes, but their effect on the quantitative response of i) time to anthesis, and ii) pre-anthesis phases to photoperiod remains largely unknown. A photoperiod-sensitive spring cultivar, Paragon, and near-isogenic lines of it carrying different combinations of Ppd-1a insensitivity alleles were tested under a wide range of photoperiods, including switches in photoperiod at the onset of stem elongation. Using multimodel inference we found that Ppd-1a alleles reduced photoperiod sensitivity from a) emergence to anthesis and b) emergence to onset of stem elongation, both in a less than additive manner, while threshold photoperiod and intrinsic earliness were unaffected. Sensitivity to current photoperiod from onset of stem elongation to flag leaf and from then to anthesis was milder than for previous phases and was not related to variability in Ppd-1. But ‘memory’ effects of previously experienced photoperiod on the duration from onset of stem elongation to flag leaf, was. The characterisation and quantification provided here of Ppd-1 allelic combinations’ effects on development should help increase genotype-to-phenotype models’ accuracy for predicting wheat phenology.

scholarly journals Expected genetic gains from mono trait and indexbased selection in advanced bread wheat (Triticum aestivum L.) populations

2020 ◽  
Vol 73 (2) ◽  
pp. 9131-9141
Author(s):  
Zine El Abidine Fellahi ◽  
Abderrahmane Hannachi ◽  
Hamenna Bouzerzour
Keyword(s):  
Grain Yield ◽  
Bread Wheat ◽  
Flag Leaf ◽  
Block Design ◽  
Triticum Aestivum L ◽  
Research Unit ◽  
Kernel Weight ◽  
Wide Range ◽  
Wheat Lines ◽  
Selection Of

This study aimed at evaluating the expected gains from selection obtained based upon direct, indirect, and index-based selection in a set of 599 bread wheat lines. The experiment was carried out at the experimental field of INRAA institute, Setif research unit (Algeria), in a Federer augmented block design including three controls. A wide range of genetic variability was observed among lines for the eleven traits assessed. The results indicated that index-based selection and selection based on grain yield expressed higher expected genetic gain than direct and indirect mono-trait-based selection. The best 15 selected lines exhibited higher grain yield than the control varieties, and they were clustered in three groups that contrasted mainly for the flag-leaf area, thousand-kernel weight, biomass, and harvest index. The index-based selection appears as a useful tool for the rapid selection of early filial generations, enriching selected breeding materials with desirable alleles and reducing the number of years required to combine these traits in elite varieties.

Identification of quantitative trait loci for traits conferring weed competitiveness in wheat (Triticum aestivum L.)

2001 ◽  
Vol 52 (12) ◽  
pp. 1235 ◽  
Author(s):  
R. K. Coleman ◽  
G. S. Gill ◽  
G. J. Rebetzke
Keyword(s):  
Triticum Aestivum ◽  
Quantitative Trait Loci ◽  
Grain Yield ◽  
Quantitative Trait ◽  
Morphological Traits ◽  
Competitive Ability ◽  
Stem Elongation ◽  
Flag Leaf ◽  
Triticum Aestivum L ◽  
Ryegrass Growth

As weeds develop resistance to a broad range of herbicides, wheat (Triticum aestivum L.) cultivars with superior weed competitive capacity are needed to complement integrated weed management strategies. In this study, agronomic and morphological traits that enable wheat to compete effectively with weeds were identified. Halberd, Cranbrook, and 161 Cranbrook x Halberd doubled haploid (DH) lines were examined in field experiments conducted over two growing seasons. The weed species Lolium rigidum L. (annual ryegrass) was sown in strips perpendicular to the direction of wheat seeding. Various traits were measured during each season with competitive ability determined by both percent loss in wheat grain yield and suppression of ryegrass growth. Width of leaf 2, canopy height, and light interception at early stem elongation (Z31), and tiller number, height at maturity, and days to anthesis were important for competitive ability in 1999. In the previous year, length of leaf 2 and size of the flag leaf contributed to competitiveness. Seasonal effects appeared to have some impact on the relative contribution of crop traits to competitive ability. The morphological traits involved in maintaining grain yield differed from those that contributed to the suppression of ryegrass growth. Development of the Cranbrook x Halberd chromosomal linkage map enabled the putative identification of quantitative trait loci (QTL) associated with competitive ability in the DH population. Many of the QTL were mapped to similar positions in both years. Further, several traits, including time to anthesis, flag leaf size, height at stem elongation, and the size of the first 2 leaves, were mapped to similar positions on chromosomes 2B and 2D. Narrow-sense heritabilities on an entry-mean basis were typically high within each year for traits associated with weed competitive ability. However, large genotype x year interactions reduced these heritabilities, making genetic gain through phenotypic selection difficult. The identification of QTL repeatable over seasons indicates the potential for marker-assisted selection in a wheat breeding program selecting for improved grain yield and weed competitiveness.

VERNALIZATION AND PHOTOPERIOD RESPONSE CHARACTERISTICS OF A RECIPROCAL SUBSTITUTION SERIES OF RESCUE AND CADET HARD RED SPRING WHEAT

1985 ◽  
Vol 65 (1) ◽  
pp. 33-39 ◽  
Author(s):  
DAVID J. MAJOR ◽  
E. D. P. WHELAN
Keyword(s):  
Triticum Aestivum ◽  
Triticum Aestivum L ◽  
Photoperiod Sensitivity ◽  
Day Length ◽  
Photoperiod Response ◽  
Vernalization Response ◽  
Vegetative Phase ◽  
Hard Red Spring Wheat ◽  
Response Characteristics ◽  
Chromosome 3B

A reciprocal substitution series between Rescue and Cadet hard red spring wheats was used to identify chromosomal differences for vernalization response, basic vegetative phase, and photoperiod sensitivity. A greenhouse technique was used to provide estimates of these variables. Genes affecting vernalization were found on chromosomes 2A, 5A and 5B. Chromosomes 2A and 5B also affected the length of the basic vegetative phase. A gene on chromosome 3B affected photoperiod sensitivity.Key words: Day length, Triticum aestivum L., basic vegetative phase

scholarly journals Wheat pre-anthesis development as affected by photoperiod sensitivity genes (Ppd-1) under contrasting photoperiods

2018 ◽  
Vol 45 (6) ◽  
pp. 645 ◽  
Author(s):  
Thomas I. Pérez-Gianmarco ◽  
Gustavo A. Slafer ◽  
Fernanda G. González
Keyword(s):  
Developmental Time ◽  
Fine Tuning ◽  
Yield Potential ◽  
Genetic Constitution ◽  
Qualitative Response ◽  
Photoperiod Sensitive ◽  
Photoperiod Sensitivity Genes ◽  
Leaf Appearance ◽  
Developmental Responses ◽  
Rate Of Leaf Appearance

Fine tuning wheat phenology is of paramount importance for adaptation. A better understanding of how genetic constitution modulates the developmental responses during pre-anthesis phases would help to maintain or even increase yield potential as temperature increases due to climate change. The photoperiod-sensitive cultivar Paragon, and four near isogenic lines with different combinations of insensitivity alleles (Ppd-A1a, Ppd-B1a, Ppd-D1a or their triple stack) were evaluated under short (12 h) and long (16 h) photoperiods. Insensitivity alleles decreased time to anthesis and duration of the three pre-anthesis phases (vegetative, early reproductive and late reproductive), following the Ppd-D1a > Ppd-A1a > Ppd-B1a ranking of strength. Stacking them intensified the insensitivity, but had no additive effect over that of Ppd-D1a. The late reproductive phase was the most responsive, even exhibiting a qualitative response. Leaf plastochron was not affected but spikelet plastochron increased according to Ppd-1a ranking of strength. Earlier anthesis resulted from less leaves differentiated and a fine tuning effect of accelerated rate of leaf appearance. None of the alleles affected development exclusively during any particular pre-anthesis phase, which would be ideal for tailoring time to anthesis with specific partitioning of developmental time into particular phases. Other allelic variants should be further tested to this purpose.

Influence of photoperiod response on the expression of cold hardiness in wheat and barley

2000 ◽  
Vol 80 (4) ◽  
pp. 721-724 ◽  
Author(s):  
S. Mahfoozi ◽  
A. E. Limin ◽  
P. M. Hayes ◽  
P. Hucl ◽  
D. B. Fowler
Keyword(s):  
Triticum Aestivum ◽  
Hordeum Vulgare ◽  
Low Temperature ◽  
Cold Hardiness ◽  
Developmental Regulation ◽  
Triticum Aestivum L ◽  
Temperature Tolerance ◽  
Photoperiod Sensitivity ◽  
Photoperiod Response ◽  
Hordeum Vulgare L

Vernalization and photoperiod requirements regulate the timing of the vegetative/reproductive transition in plants. Cereals adapted to cold winter climates regulate this developmental transition mainly through vernalization requirements, which delay transition from the vegetative to the reproductive growth stage. Recent research indicates that vernalization requirements also influence the expression of low-temperature (LT) tolerance genes in cereals exposed to acclimating temperatures. The objective of the present study was to determine if LT tolerance expression was also developmentally regulated by photoperiod response. The nonhardy, short day (SD) sensitive, wheat (Triticum aestivum L. em Thell) cultivar AC Minto, the LT tolerant, highly SD sensitive barley (Hordeum vulgare L.) cultivar Dicktoo, and a barley selection with very low sensitivity to SD were subjected to 8-h (SD) and 20-h (LD) days at cold acclimating temperatures over a period of 98 d. Final leaf number (FLN) was used to measure photoperiod sensitivity and determine the vegetative/reproductive transition point. The LT tolerance of the less SD sensitive barley genotype was similar for LD and SD treatments. In contrast, a delay in the transition from the vegetative to the reproductive stage in AC Minto and Dicktoo grown under SD resulted in an increased level and/or longer retention of LT tolerance. These results support the hypothesis that not only the level, but also the duration of gene expression determines the degree of LT tolerance in cereals. Consequently, any factor that lengthens the vegetative stage, such as vernalization or photoperiod sensitivity, also increases the duration of expression of LT tolerance genes. Key words: Triticum aestivum L., Hordeum vulgare L., low-temperature tolerance, photoperiod, developmental regulation

scholarly journals Distribution of Assimilate During Stem Elongation in Wheat

1972 ◽  
Vol 25 (3) ◽  
pp. 455 ◽  
Author(s):  
JW Patrick
Keyword(s):  
Triticum Aestivum ◽  
Vascular System ◽  
Stem Elongation ◽  
Flag Leaf ◽  
Dry Weight ◽  
Triticum Aestivum L ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Stem Extension

During the phase of stem extension in plants of Triticum aestivum L. cv. Stewart, the distribution of assimilated 14C appeared to be related to sink size, proximity to the source, and a canalizing effect imposed by the vascular system on the movement between leaves. Evidence was found of a greater resistance to export from a leaf in the upward than in the downward direction and this is consistent with the observed arrangement of the sieve elements linking the bundles at the nodes. The cross� sectional area of the phloem did not appear to impose a limitation on the amount of material transported to the apex. The bulk of carbon imported by a growing leaf was consistently transported from the second lamina below. Import from other leaves continued after the emergence of a lamina and accounted for some 80% of its final dry weight and 50% of that in the attached sheath. The elongating inter-nodes 81ther side of the leaf formed large sinks for its photosynthate. Ear growth, prior to its emergence, was supported by the upper three leaves. After emergence the flag leaf was the main supplier.

scholarly journals A Sheathed Spike Gene, TaWUS-like Inhibits Stem Elongation in Common Wheat by Regulating Hormone Levels

2021 ◽  
Vol 22 (20) ◽  
pp. 11210
Author(s):  
Xuemei Si ◽  
Wanxin Wang ◽  
Ke Wang ◽  
Yunchuan Liu ◽  
Jiangping Bai ◽  
...  
Keyword(s):  
Plant Architecture ◽  
Molecular Mechanisms ◽  
Stem Elongation ◽  
Flag Leaf ◽  
Longitudinal Section ◽  
Triticum Aestivum L ◽  
Wild Type ◽  
Spike Gene ◽  
Transgenic Lines ◽  
Tiller Angle

The elongation and development of wheat (Triticum aestivum L.) stem play an important role in plant architecture. The shortened stem would result in a sheathed spike and a low yield in crops. Unraveling the molecular mechanisms underlying a sheathed spike would be beneficial for plant architecture and yield improvement. We identified a novel gene, TaWUS-like (WUSCHEL-related homeobox-like), which regulated sheathed spike and plant architecture in wheat. The plant height of overexpression transgenic lines was significantly decreased and the spike was not completely elongated and enclosed in flag leaf sheaths. Moreover, the increase in tiller angle resulted in loose plant architecture and lower yield. The statistical and cytological analysis demonstrated that the length of the uppermost and secondary internode was significantly shortened, especially the uppermost internode which was only half the length of the wild-type. The size of parenchyma cells was obviously reduced and cell length on the longitudinal section was elongated insufficiently compared with wild-type. The analysis of hormone content showed that there was a lack of gibberellin A 3 (GA3) in internodes but a higher brassinosteroid (BR) content. TaWUS-like may inhibit the synthesis of GA3 and/or BR, thus affecting the function of signal transduction of these hormones, which further caused stem shortening and plant dwarfing in wheat.

scholarly journals Effect of exogenous salicylic acid under irrigation withholding at different growth stages in wheat (Triticum aestivum L.)

2016 ◽  
Vol 4 (2) ◽  
pp. 28-33 ◽  
Author(s):  
MA Dabzad ◽  
HRT Moghadam ◽  
H Zahedi
Keyword(s):  
Salicylic Acid ◽  
Foliar Application ◽  
Stem Elongation ◽  
Triticum Aestivum L ◽  
Water Deficit Stress ◽  
Growth Stages ◽  
Wide Range ◽  
Protein Peroxidation ◽  
Positive Effect ◽  
Different Growth Stages

Salicylic acid (SA), an endogenous plant growth regulator has been found to generate a wide range of metabolic and physiological responses in plants affecting their growth and development. In order to study effect of salicylic acid foliar application and limited irrigation on quantitative and qualitative characteristics of wheat, this experiment was conducted at Varamin, Iran during 2014 growing season. The experimental design was laid out in a randomized complete block with a split plots arrangement of treatments in three replications. Main plots included four different levels of irrigation (complete irrigation, irrigation withholding at stem elongation stage, irrigation withholding at flowering stage and irrigation withholding at seed filling period stage) and different concentration of foliar application of salicylic acid (0, 150 and 300 ?M) were allocated to subplots. The results showed that irrigation withholding conditions in different growth stages significantly decreased seed yield, RWC and total chlorophyll but by contrast increased membrane stability, proline content, SOD and CAT enzymes activity and also lipid and protein peroxidation. Salicylic acid foliar application had positive effect on all attributes in this experiment. In general, the results of the present study indicate that usage of salicylic acid reduces the harmful effects of water deficit stress and increases resistance to drought stress in wheat plant.International Journal of Natural Sciences (2014), 4(2) 28-33

Towards the Reliable Prediction of Time to Flowering in Six Annual Crops. II. Soyabean (Glycine Max)

1993 ◽  
Vol 29 (3) ◽  
pp. 253-289 ◽  
Author(s):  
R. J. Summerfield ◽  
R. J. Lawn ◽  
A. QI ◽  
R. H. Ellis ◽  
E. H. Roberts ◽  
...  
Keyword(s):  
Glycine Max ◽  
Sowing Date ◽  
Natural Environments ◽  
Mean Values ◽  
Air Temperatures ◽  
Maximum Delay ◽  
Wide Range ◽  
Critical Photoperiod ◽  
Photoperiod Sensitive ◽  
Photoperiod Sensitivity Genes

SUMMARYEleven genotypes of soyabean (Glycine max) of tropical, sub-tropical and temperate origin and one accession of G. soja were grown in six locations in Australia during 1986–88, and at one location in Australia and two in Taiwan during 1989–91. Dates of sowing were varied within and among locations so as to expose plants to as many as 32 environments of widely different diurnal temperature and daylength. Times from sowing to flowering (f) were recorded, from which rates of progress towards flowering (1/f) were calculated. These derived data were then related to mean pre-flowering values of temperature (T¯) and photoperiod (P) using a three-plane linear model developed from controlled environment data. Among genotypes, mean values of f varied between 24–49 d and between 139–291 d in the most- and least-inductive environments, respectively. These differences were associated with variations in P from about 11 to 16 h d-1, in daily mean maximum temperatures from about 17° to 36°C, in daily mean minimum temperatures from about 5° to 25°C, and in T¯ from about 11° to 30°C, that is, a very wide range of photothermal regimes. The relations of 1/f to T¯ and P can be described in photoperiod-insensitive genotypes by a thermal plane defined by two constants, a and b, and additionally by a photothermal plane defined by three constants, a′, b′ and c′, in the more numerous photoperiod-sensitive genotypes. If photoperiod-sensitive genotypes are grown in sufficiently long days then a third photoperiod and temperature-insensitive plane is exposed, defined by a constant, d′; this plane indicates the maximum delay in flowering of which the genotype is capable. The constants a′, b′, c′ and d′ define the delay in flowering caused by photoperiod-sensitivity genes. The two intercepts between the three planes define, respectively, the critical photoperiod, Pc, above which increase in daylength delays flowering, and the ceiling photoperiod, Pcc, above which there is no further delay. The values of the six constants for any genotype can be estimated from observations of fin several natural environments. Comparisons between years in Australia and between Australia and Taiwan show that these genotypic constants can predict 1/f, and so the time taken to flower, given data on latitude, sowing date and daily values of maximum and minimum air temperatures. This model is more accurate than an alternative logistic model; we also believe that all six constants in the three-plane rate model described here have biological meaning. They indicate separate genetic control of flowering responses to P and T¯ and could form a rational basis for the genetic characterization and analysis of these responses in the soyabean germplasm.Pronóstico del momento de floración II

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