Genetic variation in osmoregulation in bread and durum wheats and its relationship to grain yield in a range of field environments

1986 ◽  
Vol 37 (5) ◽  
pp. 449 ◽  
Author(s):  
JM Morgan ◽  
RA Hare ◽  
RJ Fletcher
Keyword(s):  
Grain Yield ◽  
Full Range ◽  
Selection Criterion ◽  
Field Trials ◽  
Wheat Breeding ◽  
Grain Yields ◽  
Class Differences ◽  
Wide Range ◽  
One Year ◽  
Common Parent

The association between osmoregulation and grain yield was examined using measurements of osmoregulation made on wheat plants grown in pots in a glasshouse and measurements of grain yields made in a wide range of field environments. Osmoregulation was determined from measurements of relative water contents and osmotic potentials made on the flag leaves of plants droughted near anthesis. The genotypes were advanced lines from two distinct breeding programs - one for bread wheats and one for durum wheats. All the genotypes in each program (27 bread and 14 durum) were closely related in having a common parent. The grain yields of the bread wheats were evaluated in 56 field trials covering a period of 4 years, and those of the durum wheats were evaluated in seven field trials in one year. Both droughted and irrigated sites were represented. Four field environments were also included for F4 segregating lines reported previously. Considerable variation in osmoregulation occurred which was positively associated with grain yield over the full range of environments sampled for each genotype group. The yields of genotypes which were high in osmoregulation were 11-17% higher in bread wheats and 7% higher in durum wheats than those which were low in osmoregulation, when class differences were based on rnaximising the average yield differences between osmoregulation groups. These results add further evidence favouring the use of glasshouse measurements of osrnoregulation as a selection criterion in wheat breeding.

Field evaluation of early vigour for genetic improvement of grain yield in wheat

2002 ◽  
Vol 53 (10) ◽  
pp. 1137 ◽  
Author(s):  
T. L. Botwright ◽  
A. G. Condon ◽  
G. J. Rebetzke ◽  
R. A. Richards
Keyword(s):  
Grain Size ◽  
Grain Yield ◽  
Biomass Production ◽  
Field Evaluation ◽  
Field Trials ◽  
Wheat Breeding ◽  
Growth And Yield ◽  
Seeding Density ◽  
Recurrent Parent ◽  
Early Vigour

Improved early vigour in wheat (Triticum aestivum L.) has been proposed as an important trait for increasing grain yield through greater water-use efficiency in rainfed, Mediterranean-type environments. Three years of field trials were undertaken in Western Australia at 2 sites, Merredin (low rainfall, 244 mm in the growing season) and Wongan Hills (medium rainfall, 308 mm), to examine the influence of increased early vigour on crop growth and yield. The effect of breeding for greater early vigour was tested in 1998 and 1999 using 3 high vigour and 3 low vigour BC2:F5 lines of the cultivar Amery backcrossed to a 'high vigour' donor. Averaged across environments, the high vigour backcross lines had a 10% increase in early vigour (i.e. leaf area/plant) at 50 DAS compared with the low vigour lines. Differences in yield across environments were associated with variation in total rainfall, rainfall distribution, and soil properties. In the wetter of the 2 years (1999), greater early vigour translated to increased yield of c. 12%, averaged across environments, but there was no difference in yield in either environment in the drier year (1998). Potential deleterious effects of the recurrent parent on yield were eliminated in field trials in 1999 and 2000 by manipulating early vigour through varying grain size (25, 35, or 50 mg) or seeding density (50, 200, or 400 plants/m2) of Amery at sowing. Large grain increased the embryo size and early vigour at 50 DAS in both environments in 1999. This translated to greater biomass production at anthesis and maturity to increase grain yield at Wongan Hills in 1999. In contrast, there was no relationship between grain size, biomass production, and yield at Merredin in 1999 or at either site in 2000. Sowing density treatments also had no effect on yield in 2000. In conclusion, there is potential to increase yield of wheat by selecting for greater early vigour in a wheat breeding program. The expression of vigour in field conditions and the translation of this improvement to higher yields is, however, dependent on the environment. Current yield limitations arising through backcrossing with a high vigour, yet poor yielding donor, need to be addressed.

Variation in south Asian wheat germplasm for seedling drought tolerance traits

2009 ◽  
Vol 7 (1) ◽  
pp. 88-93 ◽  
Author(s):  
Umesh R. Rosyara ◽  
Amrit A. Ghimire ◽  
Sushil Subedi ◽  
Ram C. Sharma
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Wheat Breeding ◽  
Dwarfing Genes ◽  
Seedling Vigour ◽  
Coleoptile Length ◽  
Wide Range ◽  
Dry Conditions ◽  
Breeding Programmes ◽  
Positive Correlations

Higher seedling vigour and greater coleoptile length are important for early establishment of wheat crops and subsequently higher grain yield in many dry environments. Seedling vigour includes those seed properties that determine the potential for rapid, uniform emergence and development of normal seedlings under a wide range of field conditions. Genotypes with the widely used gibberellic acid (GA)-insensitive dwarfing genes Rht-B1b and Rht-D1b have good partitioning and grain yield under optimal conditions, but may perform poorly under stressed conditions due to poor crop establishment. Breeding programmes are in search of GA-sensitive dwarfing genes that do not affect seedling vigour under dry conditions. This study evaluated 40 genotypes currently used in wheat breeding programmes of south Asia for seedling vigour-related traits in greenhouse and field experiments during 2006–2007 at IAAS, Rampur, Nepal. Wide variation in coleoptile length, seedling vigour, as well as sensitivity to GA was observed. Among the genotypes studied, there were positive correlations among coleoptile length, leaf width and plant height. Genotypes, SW89-5193, SW89-5422/NL251 and SW89-5422, were found to have longer coleoptile, higher seedling vigour and response to GA application. This shows a promise for their further applications in the breeding programmes.

HARVEST INDEX AS A SELECTION CRITERION FOR GRAIN YIELD IN TWO SPRING WHEAT CROSSES GROWN AT TWO POPULATION DENSITIES

1980 ◽  
Vol 60 (4) ◽  
pp. 1141-1146 ◽  
Author(s):  
H. G. NASS
Keyword(s):  
Population Density ◽  
Grain Yield ◽  
Spring Wheat ◽  
Harvest Index ◽  
Plant Density ◽  
Selection Criterion ◽  
Triticum Aestivum L ◽  
Wheat Breeding ◽  
Seeding Rate ◽  
Population Densities

The use of harvest index as a selection criterion for grain yield in F2 populations of spring wheat (Triticum aestivum L.) grown at two population densities was investigated. Harvest index was useful in delineating yield differences between lines for both crosses. The F4 lines selected in F2 for a high harvest index yielded about 9% more per plot in 1978 than F4 lines having a low harvest index in F2. Generally, lines selected at the higher commercial seeding rate yielded more than lines selected at the lower plant density. In 1979, a heavy Fusarium infection reduced the mean grain yield of the F6 lines and suppressed any significant response to selection resulting from population density and harvest index in F2. While selection based on high harvest index at low population density can be used to select higher yielding plants it was not as effective as selection at high population density which more closely approximates commercial crop densities. Additional research is needed before the use of harvest index as a selection tool in wheat breeding programs can be recommended for use in Atlantic Canada.

scholarly journals Phenotypic characterization of wheat landraces from mid and far western districts of Nepal

2015 ◽  
Vol 4 (4) ◽  
pp. 32-44
Author(s):  
Sangharash Raj Dangi ◽  
Ramesh Raj Puri ◽  
Nutan Raj Gautam
Keyword(s):  
Grain Yield ◽  
Plant Height ◽  
Phenotypic Variability ◽  
Block Design ◽  
Wheat Breeding ◽  
Phenotypic Characterization ◽  
Improvement Program ◽  
Wide Range ◽  
Wheat Landraces

The study was conducted to evaluate phenotypic variation in one hundred and sixty six wheat landraces from mid and far western districts of Nepal. They were sown in randomized complete block design with two replications at National Wheat Research Program in 2014/15. The observed traits were analyzed using descriptive statistics and multivariate analysis using MINITAB v. 14. The results showed a wide range of phenotypic variability in observed parameters. The results also showed that the highest value of the standard deviation from mean (Sd) was for grain yield (±290.10) followed by plant height (±7.21). Among the traits the lowest deviation from mean (Sd) was for thousand grain weight TGW (±2.68). Wheat landraces grouped in four clusters depending on similarity of the studied traits. The results in this cluster, showed that days to maturity ranged from 97 to111 days, TGW ranged from 16 to17 gm, plant height ranged from 76 to 85 cm, and grain yield ranged from 2800 to 3000 Kg ha-1. Wheat landraces under study are grouped depending on specific traits useful for wheat improvement program. Results of this study can be supportive to detect wheat landraces within species with similar traits. In addition it can be useful for sampling in successive studies and parental selection in wheat breeding program.International Journal of Environment Vol.4(4) 2015: 32-44

scholarly journals Genotype and environment interaction of drought tolerant rice genotypes evaluated in drought prone areas of Bangladesh

2016 ◽  
Vol 14 (1) ◽  
pp. 23-30
Author(s):  
RR Majumder ◽  
TR Hore ◽  
MA Kader ◽  
TL Aditya
Keyword(s):  
Grain Yield ◽  
Block Design ◽  
Principal Component ◽  
Field Trials ◽  
High Yield ◽  
Environment Interaction ◽  
Growth Duration ◽  
Yield Data ◽  
Wide Range ◽  
Rice Genotypes

Field trials were conducted using ten rice genotypes including four national and international check varieties under drought prone rainfed environments of Rangpur, Nilphamari, Kurigram and Lalmonirhat districts of Bangladesh in Transplant Aman 2012 season to evaluate the growth duration and grain yield stability as well as adaptability. The experiment used randomized complete block design with three replications. Growth duration and Grain yield data were subjected to Additive Main effects and Multiplicative Interaction (AMMI) analysis. The mean growth duration of 10 genotypes over four environments showed that the longest growth duration was found for IR83383-B-B-129-4 (115.6 days) and the lowest growth duration was found for BRRI dhan56 (Ck) (113.4 days). IR82635-B-B-145-1 produced maximum 4.28 t/ha grain yield followed by 4.28 t/ha in IR82589-B-B-84-3 and the lowest grain yield was recorded for IR83376-B-B-130-2 with 3.24 t/ha. It was evident from the AMMI 1 biplot analysis that IR83377-B-B-93- 3, IR83383-B-B-129-4, IR82635-B-B-145-1, IR82635-B-B-75-2 and BRRI dhan56 (Ck) generally exhibited high yield with high main (additive) effects showing positive first principal component of the interaction (IPCA1), but IR82635-B-B-145-1 being the overall best. Hence, IR82635-B-B-145-1 was identified as specially adapted to Lalmonirhat and this environment was considered as the wide range suitable environment for the genotype. Lalmonirhat could be regarded as a good selection site for rice improvement due to stable yields. IR83377-B-B-93-3, IR82635-B-B-145-1, IR83383-B-B-129-4, IRRI 123 (Ck), BRRI dhan57 (Ck) and BINA dhan7 (Ck) were hardly affected by the G × E interaction and would perform well across a wide range of environments. In AMMI 2 biplot, IR82635-B-B-145-1 and IRRI 123 (Ck) was more responsive since they were away from the origin whereas other genotypes were nearer to the origin and hence they were more stable to different environments. IR83383-B-B-129-4 was very close to the origin, so it was more stable to different environments. Similarly Rangpur Sadar and Lalmonirhat showed similar potentiality over IR83383-B-B-129-4. The study it revealed that IR83377-B-B-93-3, IR83383-B-B-129-4, IR82635-B-B-145-1, IR82635-B-B-75-2 and IR82589-B-B-84-3 has the potentiality to show drought tolerance for the regions and might be suitable for releasing as a variety after conducting proper yield evaluation trials and Distinction, Uniformity and Stability (DUS) tests.J. Bangladesh Agril. Univ. 14(1): 23-30, June 2016

Early sowing with wheat cultivars of suitable maturity increases grain yield of spring wheat in a short season environment

1992 ◽  
Vol 32 (6) ◽  
pp. 717 ◽  
Author(s):  
NJ Kerr ◽  
KHM Siddique ◽  
RJ Delane
Keyword(s):  
Dry Matter ◽  
Current Practice ◽  
Field Trials ◽  
Kernel Weight ◽  
Wheat Cultivars ◽  
Kernel Number ◽  
Developmental Patterns ◽  
Grain Yields ◽  
Wide Range ◽  
Short Season

Eleven field trials were sown in the northeastern wheatbelt of Western Australia to test the hypothesis that if wheat cultivars with suitable maturity are sown earlier than current practice, then higher grain yields will be achieved. The experiments included time of sowing treatments that ranged from early May to late June in 1988, 1989 and 1990. Seven commercial cultivars with a wide range of developmental patterns and maturities were used. Sowing between mid May and early June produced the highest grain yields. For plantings after early June, yields declined by approximately 250 kg/ha (15%) per week. Delayed sowing caused a decrease in dry matter and kernel number (per m2). In general this reduction in kernel number was not compensated by an improvement in kernel weight. At early times of sowing, the medium-long season cultivars generally had higher yields than short season cultivars. The short season cultivars were the highest yielding cultivars at the late times of sowing. These results suggest that cultivars should be chosen to suit the seasonal break, which may vary from late April to mid June. As a consequence, farmers should be encouraged to retain a number of cultivars with differing maturities suited to a range of planting times.

Genetic variation for wheat spike fertility in cultivars and early breeding materials

2015 ◽  
Vol 154 (1) ◽  
pp. 13-22 ◽  
Author(s):  
N. E. MIRABELLA ◽  
P. E. ABBATE ◽  
I. A. RAMIREZ ◽  
A. C. PONTAROLI
Keyword(s):  
Grain Yield ◽  
Genotypic Variation ◽  
Selection Criterion ◽  
Dry Weight ◽  
Wheat Breeding ◽  
Environment Interaction ◽  
Grain Number ◽  
Narrow Sense Heritability ◽  
Frequency Distributions ◽  
Commercial Cultivars

SUMMARYGrain yield in bread wheat is often tightly associated with grain number/m2. In turn, spike fertility (SF), i.e., the quotient between grain number and spike chaff dry weight, accounts for a great proportion of the variation in grain number among cultivars. In order to examine the potential use of SF as a breeding target, (1) variation for the trait was assessed in six datasets combining commercial cultivars under different environmental conditions, (2) trait heritability was estimated in a set of F1 hybrids derived from controlled crosses between cultivars with contrasting SF and (3) SF distribution pattern was analysed in two F2 segregating populations. Analysis of commercial cultivars revealed considerable variation for SF, under both optimal and sub-optimal conditions. In addition, genotypic variation was consistently larger than genotype × environment interaction variation in all datasets. Narrow sense heritability, estimated by the mid-parent-offspring regression of 20 F1 hybrids and their respective parents, was 0·63. Data from two F2 populations exhibited bell-shaped and symmetric frequency distributions of SF, with a SF mean intermediate between the parental values. Substantial transgressive segregation was detected in both F2 populations. In conclusion, SF appears to be a heritable trait with predominantly additive effects. This warrants further investigation on the feasibility of using SF as an early selection criterion in wheat breeding programs aimed at increasing grain yield.

The grain yield of winter-grazed crops

1977 ◽  
Vol 17 (86) ◽  
pp. 452 ◽  
Author(s):  
PR Dann ◽  
A Axelsen ◽  
CBH Edwards
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Grain Production ◽  
Winter Rape ◽  
Dual Purpose ◽  
Grain Yields ◽  
One Year ◽  
Better Than

In six years of experiments various grazing treatments were applied to a range of crops and subsequent grain yields measured. Spring rapes, lupins and peas showed little potential for dual purpose grazing/grain use, generally producing less herbage and grain than wheat, oats, barley and rye. Winter rape performed as well as barley and wheat in one year. Oats and barley were overall better than wheat which was generally better than rye. Comparison of late-sown grain-only crops with early sown grazed ones indicated that with some crops in some years the dual-purpose enterprise was the more profitable. The experiments suggested that the most biologically profitable combination of herbage and grain production would be obtained by delaying grazing until about 4t of crop dry matter per ha were available in winter.

SEEDING RATE EFFECTS ON LOW-TILLERING SPRING WHEATS IN A SEMIARID ENVIRONMENT

1990 ◽  
Vol 70 (1) ◽  
pp. 9-17 ◽  
Author(s):  
P. HUCL ◽  
R. J. BAKER
Keyword(s):  
Grain Yield ◽  
Maximum Yield ◽  
Triticum Aestivum L ◽  
Field Trials ◽  
Main Stem ◽  
Seeding Rate ◽  
Grain Yields ◽  
Rate Effects ◽  
High Tillering ◽  
Plot Design

To determine if increased seeding rates would alter relative yields of traditional and low-tillering genotypes, a high-tillering (Neepawa), a low-tillering (Siete Cerros), and an oligoculm (M1417) spring wheat (Triticum aestivum L.) genotype were seeded in replicated field trials at two locations in 1984 and 1985. A four-replication split-plot design, with genotypes assigned to main plots and seeding rates (40, 80 160, 320 and 640 seeds m−2) to subplots, was used for each experiment. Grain yield and its components were measured on individual plots or on main stems of five plants in each plot. All three genotypes expressed maximum yield at the same seeding rate (640 seeds m−2 in 1984 and 320 seeds m−2 in 1985) in the semiarid conditions of these experiments. Despite diverse tillering habits, the relative yields of these three genotypes could not be altered by changing seeding rates. On average, Siete Cerros (low-tillering) yielded 15% more than Neepawa and 17% more than M1417. Neepawa had lower grain yields than M1417 at all seeding rates in 1984, but higher grain yields in 1985. A similar change in relative performance of these two genotypes was observed for harvest index of the main stem but not for main stem grain yield kernels spike −1 on the main stem or kernel weight.Key words: Wheat (spring), oligoculm, yield components, genotype-environmental interaction.

scholarly journals Multi-trait genomic-enabled prediction enhances accuracy in multi-year wheat breeding trials

2021 ◽  
Author(s):  
Abelardo Montesinos-López ◽  
Daniel E Runcie ◽  
Maria Itria Ibba ◽  
Paulino Pérez-Rodríguez ◽  
Osval A Montesinos-López ◽  
...  
Keyword(s):  
Grain Yield ◽  
Prediction Accuracy ◽  
Prediction Models ◽  
Wheat Breeding ◽  
Data Sets ◽  
Bivariate Model ◽  
Pearson’S Correlation ◽  
Pearson's Correlation ◽  
Predicted Values ◽  
One Year

Abstract Implementing genomic-based prediction models in genomic selection requires an understanding of the measures for evaluating prediction accuracy from different models and methods using multi-trait data. In this study we compared prediction accuracy using six large multi-trait wheat data sets (quality and grain yield). The data was used to predict one year (testing) from the previous year (training) to assess prediction accuracy using four different prediction models. The results indicated that the conventional Pearson’s correlation between observed and predicted values underestimated the true correlation value, whereas the corrected Pearson’s correlation calculated by fitting a bivariate model was higher than the division of the Pearson’s correlation by the squared root of the heritability across traits, by 2.53 to 11.46%. Across the datasets, the corrected Pearson’s correlation was higher than the uncorrected by 5.80 to 14.01%. Overall, we found that for grain yield the prediction performance was highest using a multi-trait compared to a single-trait model. The higher the absolute genetic correlation between traits the greater the benefits of multi-trait models for increasing the genomic-enabled prediction accuracy of traits.

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