scholarly journals The impact of source or sink limitations on yield formation of winter wheat (Triticum aestivum L.) due to post-anthesis water and nitrogen deficiencies

2010 ◽  
Vol 56 (No. 5) ◽  
pp. 218-227 ◽  
Author(s):  
A. Madani ◽  
A. Shirani-Rad ◽  
A. Pazoki ◽  
G. Nourmohammadi ◽  
R. Zarghami ◽  
...  
Keyword(s):  
Grain Yield ◽  
Triticum Aestivum L ◽  
Grain Weight ◽  
Grain Number ◽  
Water Regimes ◽  
N Supply ◽  
Nitrogen Deficiencies ◽  
Rainfed Wheat ◽  
Source Sink ◽  
The Impact

The experiments were laid out to understand the mechanisms causing yield limitations imposed by post-anthesis water and nitrogen deficiencies in plants with modified source-sink ratios. Two soil-water regimes were allotted to the main plots. At anthesis, three levels of N were applied: none, 25% and 50% of total the N supply. Spike-halving caused reduction in grain yield at both water regimes and all N supply levels, showing that the reduction in grain number can not be compensated by a higher individual grain weight. Sink reduction by trimming 50% of the spikelets reduced grain number per ear by 38.5% and increased individual grain weight by 12.0%, which shows the plasticity in grain weight and grain set of wheat if sufficient assimilates are available. Additional nitrogen supply at anthesis had no significant effect on the total aboveground biomass, but increased grain yield through more allocation of dry matter to grains. Our findings suggest that for rainfed wheat with optimum N supply and supplemental irrigation, wheat growers should choose cultivars with a high grain number per ear and manage the crop to increase grain number per unit of land (sink capacity).

Yield and grain quality of wheat in response to increased temperatures at key periods for grain number and grain weight determination: considerations for the climatic change scenarios of Chile

2012 ◽  
Vol 151 (2) ◽  
pp. 209-221 ◽  
Author(s):  
X. C. LIZANA ◽  
D. F. CALDERINI
Keyword(s):  
Grain Yield ◽  
Climatic Change ◽  
High Temperatures ◽  
Grain Weight ◽  
Quality Traits ◽  
Grain Number ◽  
Average Temperature ◽  
Increased Temperature ◽  
The Impact ◽  
Days After Anthesis

SUMMARYAgricultural systems are challenged by global climatic change in a scenario of increasing food demand by a growing population. The increase in average temperature will be the main environmental factor affecting the crop development and productivity worldwide, although changes in carbon dioxide (CO2) concentration and rainfall are also expected. Global warming in the range of moderately high temperatures (15–32°C) is projected for temperate environments such as that of central-southern Chile, where grain crops such as wheat are widely grown. The present study assessed the impact of moderately high temperatures on both yield and quality traits of wheat during key stages for grain number and grain weight determination. Two cultivars of spring wheat (Pandora INIA and Huayún INIA) were grown under field conditions during two cropping seasons (2006/07 and 2007/08) under different thermal regimes, consisting of a combination of three temperatures (a control at ambient temperature and two increased temperature treatments, ranging from 2·6 to 11·7°C above the control) and two (3–15 and 20–32 days after anthesis) or three (booting to anthesis (Bo-At), 3–15 and 20–32 days after anthesis) timing regimes. The data recorded showed that the extent of yield reduction was strongly dependent on the timing of the heat treatments. Increased temperature at pre- (Bo-At) or early post-anthesis (3–15 days after anthesis) affected grain yield the most (reducing it by 8–30%). In light of these results, yield reductions of up to 18% can be expected when the crop undergoes average temperature increase of 2·8°C at Bo-At. In this study, the negative effect of increasing temperature on grain yield was associated with both grain number and grain weight reductions; however, different sensitivities to higher temperatures were found between cultivars. Although protein concentration of grains was not affected by higher temperatures, other negative effects on industrial quality traits are important, considering the impact of thermal treatments on grain size of both cultivars.

scholarly journals Canaryseed (Phalaris canariensis L.) accessions from nineteen countries show useful genetic variation for agronomic traits

2011 ◽  
Vol 91 (1) ◽  
pp. 37-48 ◽  
Author(s):  
M. Cogliatti ◽  
F. Bongiorno ◽  
H. Dalla Valle ◽  
W J Rogers
Keyword(s):  
Genetic Variation ◽  
Grain Yield ◽  
Harvest Index ◽  
Agronomic Traits ◽  
Grain Weight ◽  
Environment Interaction ◽  
Grain Number ◽  
Harvest Maturity ◽  
Phalaris Canariensis ◽  
Late Sowing

Fifty-seven accessions of canaryseed (47 populations and 10 cultivars) from 19 countries were evaluated for agronomic traits in four field trials sown over 3 yr in the province of Buenos Aires, Argentina. Genetic variation was found for all traits scored: grain yield and its components (grain weight, grain number per square meter, grain number per head and head number per square meter), harvest index, percent lodging, and phenological characters (emergence to heading, emergence to harvest maturity and heading to harvest maturity). Although genotype × environment interaction was observed for all traits, the additive differences between accessions were sufficient to enable promising breeding materials to be identified. Accessions superior in performance to the local Argentinean population, which in general gave values close to the overall mean of the accessions evaluated, were identified. For example, a population of Moroccan origin gave good yield associated with elevated values of the highly heritable character grain weight, rather than with the more commonly observed grain number per square meter. This population was also of relatively short stature and resistant to lodging, and, although it performed best when sown within the normal sowing date, tolerated late sowing fairly well. Other accessions were also observed with high grain weight, a useful characteristic in itself, since large grains are desirable from a quality point of view. Regarding phenology, the accessions showed a range of 160 degree days (8 calendar days in our conditions) in maturity, which, while not large in magnitude, may be of some utility in crop rotation management. Some accessions were well adapted to late sowing. Grain yield in general was strongly correlated with grain number per square meter. Principal components analysis (PCA) carried out for all characteristics provided indications of accessions combining useful characteristics and identified three components that explained approximately 70% of the phenotypic variation. Furthermore, a second PCA plus regression showed that approximately 60% of the variation in grain yield could be explained by a component associated with harvest index and grain number per square meter. Pointers were provided to possible future breeding targets.Key words: Phalaris canariensis, canaryseed, accessions, yield, phenology, genetics, breeding

Source - sink effects on grain weight of bread wheat, durum wheat, and triticale at different locations

2006 ◽  
Vol 57 (2) ◽  
pp. 227 ◽  
Author(s):  
Daniel F. Calderini ◽  
M. P. Reynolds ◽  
G. A. Slafer
Keyword(s):  
Grain Yield ◽  
Durum Wheat ◽  
Bread Wheat ◽  
Grain Filling ◽  
Grain Weight ◽  
The Other ◽  
Field Conditions ◽  
Breeding Strategies ◽  
Source Sink ◽  
Source Limitation

Source limitation during grain filling is important for both management and breeding strategies of grain crops. There is little information on the sensitivity of grain weight of temperate cereals to variations in source–sink ratios, and no studies are available on the comparative behaviour of temperate cereals growing together in the same experiment. The objective of the current study was to evaluate, under field conditions, the response of grain weight to different source–sink ratios during grain filling in high-yielding cultivars of bread wheat, durum wheat, and triticale at 2 contrasting locations. Two experiments were carried out at C. Obregon and El Batan in Mexico. In each location, 6 genotypes (2 bread wheat, 2 durum wheat, 2 triticale) were evaluated. A week after anthesis, 2 source–sink (control and halved spikes) treatments were imposed. Location and genotype significantly (P < 0.01) affected grain yield and components. Significant grain weight increases (P < 0.05) were found only in 2 cases in El Batan. The highest response of 17% was found in triticale, with less than 10% in most of the other genotypes. The effect of genotype and location is discussed.

scholarly journals Correlation, Regression and Path analysis among yield and yield traits in Triticum dicoccum

1970 ◽  
pp. 24-27
Author(s):  
Maysoun M. Saleh ◽  
Dyab S. Moussa ◽  
Nader I. Alkaraki ◽  
Abbas Lateef Abdurahman
Keyword(s):  
Grain Yield ◽  
Path Analysis ◽  
Selection Criteria ◽  
Agricultural Research ◽  
Grain Weight ◽  
Individual Plant ◽  
Grain Number ◽  
Triticum Dicoccum ◽  
Grain Number Per Spike ◽  
Significant Regression

Seven wheat genotypes (Triticum dicoccum) and the local check sham5 were planted all at Al-Ghab and Izra Research centers in The General Commission for Scientific Agricultural Research in Syria during growing season 2010/2011. Yield components (number of total and fertile tillers per plant, number and weight of grains per spike, weight of thousand grain and individual plant grain yield) were studied in two sites in order to predict their effect and to determine their effects on grain yield in order to define selection criteria for grain yield. Results revealed all studied traits except total tillers number were positively correlated with grain yield, and only (fertile tillers number and grain number per spike and grain weight per spike) had a significant regression with grain yield and these traits can explain about (27.6, 67.7, 62.2)% respectively of the variation final grain yield. Results of path analysis indicated that the direct effect of fertile tillers per plant and grain weight per spike on grain yield was positive and high (0.6178, 0.7563) respectively, so that we can depend on them in breeding program as selection criteria to increase grain yield in plant.

scholarly journals EFFECT OF REGULATION OF SOURCE-SINK RELATIONSHIP ON GRAIN YIELD AND ITS COMPONENT OF DIFFERENT BREAD WHEAT CULTIVARS

2016 ◽  
Vol 47 (2) ◽  
Author(s):  
Jaddoa & Kadom
Keyword(s):  
Growth Rate ◽  
Grain Yield ◽  
Bread Wheat ◽  
Flag Leaf ◽  
Grain Weight ◽  
Abu Ghraib ◽  
Research Station ◽  
Wheat Cultivars ◽  
Source Sink ◽  
1000 Grain Weight

A field trial was conducted at Abu-Ghraib Research Station-Agricultural Research Directorate-Ministry of Agriculture during the growing seasons of 2012-2013 and 2013-2014. The objective was to investigate the effect of source-sink Regulation on grain yield  and its companents of five bread wheat cultivars (Triticum aestivum L.). Randomized complete block design with the arrangement of split-plots with three replicates was used. Bread wheat cultivars (Bohooth-22, IPA 99, Abu-Ghraib-3,Al-Fath and Al-Rasheed) occupied the main plots while treatments of source-sink relationship regulation occupied the sub-plots. They included eight treatments: Con. control (Con.), S1 (removal of lamina of the flag leaf of main stem), S2 (removal of laminas of the leaf  beneath the flag leaf), S3 (removal of both lamina of the leaf  and the leaf under flag leaf), S4 (removal of upper third spikelets),S5 (removal of median third spikelets), S6 (removal of lower third spikelets) and S7 (removal all spikelets from one side of spike) . Characteristics of plant height, flag leaf area, spike length, no of spikelet per spike, spike weight, and grain yield and its components were measured and estimated. Results of the present study indicated the followings:  Cultivar (Bohooth-22) gave the highest 1000 grain weight (35.70 and 35.31 g) the highest grain yield (5.467 and 5.148 t.ha-1) in both seasons, respectively compared with Abu-Ghraib3 and Al-Rasheed cultivars which gave lowest grain yield (4.918,4.364, 4.239 and 4.352 t.ha-1) in both seasons, respectively and then less 1000 grain weight (30.15, 32.66, 32.61 and 32.77 g), in both seasons, respectively. Treatment (Con.) i.e no modification of source-sink relationship gave the highest grain yield (5.93 and 5.66 t.ha-1) in both seasons, respectively. Treatments of regulation source (S1 and S3)gave grain yield (4.909, 4.698, 4.621and 4.356 t.ha-1), respectively while (S5) treatment gave the lowest grain yield (4.203 t.ha-1) in the first season and (4.061 t.ha-1) in the second season. This indicates that sink regulation treatment was the most influencial in reducing grain yield than the source regulation treatment, especially, treatment (S5) in both seasons where the  median third of spikelets had been removed due to the reduction of spike growth rate (3.18 and 2.49 g.day-1) in both seasons compared with the (Con) treatment which gave the highest values of spike growth rate (3.91 and 3.12 g.day-1) in both seasons, respectively which resulted in the reduction of dry matter translocation in the (S5) treatment (1.87 and 1.74 g.day -1) and consequently in the reduction of 1000 grain weight (30.09 and 31.199) compared with (34.99 and 37.12 g) in the (Con.) treatment in both seasons, respectively.

scholarly journals Genetic variation of several bread wheat (Triticum aestivum L.) genotypes based on some morphological traits

2014 ◽  
Vol 69 (1) ◽  
pp. 44-54
Author(s):  
NASER SABAGHNIA ◽  
MOHSEN JANMOHAMMADI ◽  
ADEL BASHIRI ◽  
REZA ASGHARI-SHIRGHAN
Keyword(s):  
Cluster Analysis ◽  
Triticum Aestivum ◽  
Grain Yield ◽  
Bread Wheat ◽  
Seed Weight ◽  
Agronomic Traits ◽  
Triticum Aestivum L ◽  
Grain Number ◽  
The Mean ◽  
Thousand Seed Weight

The genetic diversity among 56 bread wheat (Triticum aestivum L.) genotypes was evaluated by 18 agronomical traits in the experimental field at Maragheh, Iran. Significant differences among bread wheat genotypes in all of the measured traits i.e. stem diameter, plant height, leaf number, leaf length, leaf width, tiller number, internode length, peduncle length, spike length, floret number, spikelet number, grain number, length of awn, grain diameter, grain length, the number of days to flowering, thousand seed weight and grain yield. The coefficient of variation (CV) was high for grain yield (25.61%), number of tillers per plant (22.06%) and number of grains per spike (21.45). The other remaining traits recorded moderate to low CV estimates from 14.30% in grain number per spike to 4.81% in days to flowering. The largest thousand seed weight was 45.93 g, the lowest thousand seed weight was 26.16 g and the mean thousand seed weight was 37.85 g. The mean performance of grain yield was 5031.2 kg ha-1, the minimum grain yield was 2835.0 kg ha-1 and the maximum grain yield was 7125.3 kg ha-1. Ward’s minimum variance cluster analysis based on squared Euclidian distance on the raw data of 18 agronomic traits clearly separated five clusters. In general, cluster analysis of the 56 genotypes based on the selected agronomic traits was consistent with known information. Our plant materials could be important germplasm resources for enriching the genetic background of commercial cultivars. Such genetic differences of bread wheat traits studied in this investigation can be applied as a new source of variation in other breeding programs and crossing nurseries in breeding program

scholarly journals Grain number and grain weight as determinants of triticale, wheat, two-rowed and six-rowed barley yield in the Pannonian environment

2018 ◽  
Vol 16 (3) ◽  
pp. e0903 ◽  
Author(s):  
Milan Mirosavljević ◽  
Vojislava Momčilović ◽  
Srbislav Denčić ◽  
Sanja Mikić ◽  
Dragana Trkulja ◽  
...  
Keyword(s):  
Grain Yield ◽  
Crop Production ◽  
Large Scale ◽  
Heading Date ◽  
Growing Season ◽  
Grain Weight ◽  
Scale Production ◽  
Grain Number ◽  
Winter Cereal ◽  
Growing Seasons

Climate significantly affects cropping systems across Europe. Knowledge of the variability in grain number per unit area and grain weight across different growing seasons and its association with grain yield is important for further improving small grain crop production. The main aim of this study was to compare grain yield and its numerical components among triticale, wheat, two-rowed and six-rowed barley cultivars across different growing seasons in a typical Pannonian location (south-eastern part of Central Europe). Trials with twelve winter cereal genotypes (three two-rowed barley, three six-rowed barley, three wheat and three triticale genotypes) were carried out in four successive seasons in Novi Sad, Serbia. Results of this study showed that growing season, species, cultivar, and species × growing season interaction significantly (p<0.01) affected grain yield and its determinants. Generally, triticale had higher average grain yield, while the lowest grain yield was recorded in six-rowed barleys. Grain yield was more associated with the number of grains/m2 than with grain weight. Heading date was recognized as one of the important adaptive traits in crop development and yield determination. Short duration of the pre-anthesis phase in early cultivars and delayed anthesis in late cultivars significantly decreased the number of grains/spike in different species/spike types, reducing the final grain yield. Medium early cultivars had the highest number of grains/spike due to optimal duration of the pre-anthesis period and heading date and are suggested as recommendable for large scale production in the Pannonian environments.

scholarly journals Effects of Potassium Availability on Growth and Development of Barley Cultivars

Agronomy ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2269
Author(s):  
Widad Al Azzawi ◽  
Muhammad Bilal Gill ◽  
Foad Fatehi ◽  
Meixue Zhou ◽  
Tina Acuña ◽  
...  
Keyword(s):  
Crop Production ◽  
Dry Weight ◽  
Major Effect ◽  
Grain Weight ◽  
Grain Number ◽  
Barley Cultivars ◽  
Shoot Dry Weight ◽  
Spike Number ◽  
Potassium Supply ◽  
The Impact

Potassium deficiency is one of the major issues affecting crop production around the globe. Giving the high cost of potassium fertilizers and environmental concerns related to inappropriate fertilization practices, developing more potassium use efficient (KUE) varieties is critical for sustainable food production in agricultural systems. In this study, we analysed the impact of potassium availability on agronomical attributes of thirty barley genotypes grown at four different levels of potassium (0.002 mM, 0.02 mM, 2 mM, 20 mM) under glasshouse conditions. The results showed that the availability of potassium in the soil had a major effect on yield components i.e., spike number, grain number and grain weight. Furthermore, grain weight showed a strong correlation with grain number and spike number at all levels of potassium supply. Although an increase in potassium supply led to an increase in plant height in all genotypes, the correlation with grain weight was very weak at all levels. Potassium supplementation caused an increase in shoot dry weight, which also showed a weak correlation with grain weight at the 0.002 mM potassium supply level. The genotypes Gebeina, Skiff, YF374, Flagship and YF374 were highly efficient in performing at suboptimal K supply levels and, thus, can be recommended to be grown in K-impoverished soils. We also suggest that grain and spike numbers could be used as proxies for KUE studies, to construct DH lines and identify QTL to improve low potassium tolerance and KUE in barley.

scholarly journals Trehalose 6-phosphate signalling and impact on crop yield

2020 ◽  
Vol 48 (5) ◽  
pp. 2127-2137
Author(s):  
Matthew J. Paul ◽  
Amy Watson ◽  
Cara A. Griffiths
Keyword(s):  
Resource Allocation ◽  
Grain Yield ◽  
Green Revolution ◽  
Regulatory System ◽  
Grain Filling ◽  
Stem Height ◽  
Grain Number ◽  
Plant Resource ◽  
Whole Plant ◽  
Source Sink

The domestication and breeding of crops has been a major achievement for mankind enabling the development of stable societies and civilisation. Crops have become more productive per unit area of cultivated land over the course of domestication supporting a current global population of 7.8 billion. Food security crops such as wheat and maize have seen large changes compared with early progenitors. Amongst processes that have been altered in these crops, is the allocation of carbon resources to support larger grain yield (grain number and size). In wheat, reduction in stem height has enabled diversion of resources from stems to ears. This has freed up carbon to support greater grain yield. Green revolution genes responsible for reductions in stem height are known, but a unifying mechanism for the active regulation of carbon resource allocation towards and within sinks has however been lacking. The trehalose 6-phosphate (T6P) signalling system has emerged as a mechanism of resource allocation and has been implicated in several crop traits including assimilate partitioning and improvement of yield in different environments. Understanding the mode of action of T6P through the SnRK1 protein kinase regulatory system is providing a basis for a unifying mechanism controlling whole-plant resource allocation and source-sink interactions in crops. Latest results show it is likely that the T6P/SnRK1 pathway can be harnessed for further improvements such as grain number and grain filling traits and abiotic stress resilience through targeted gene editing, breeding and chemical approaches.

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