Genetic control of mineral concentration and yield in perennial ryegrass (Lolium perenne L.), with special emphasis on minerals related to grass tetany

1999 ◽  
Vol 50 (1) ◽  
pp. 79 ◽  
Author(s):  
K. F. Smith ◽  
G. J. Rebetzke ◽  
H. A. Eagles ◽  
M. W. Anderson ◽  
H. S. Easton
Keyword(s):  
Genetic Correlation ◽  
Genetic Control ◽  
Perennial Ryegrass ◽  
Early Spring ◽  
Family Selection ◽  
Mineral Concentration ◽  
Sib Families ◽  
Selection For ◽  
Mineral Concentrations ◽  
Low K

Grass tetany is a common metabolic disorder of ruminants in southern Australia. To investigate the genetic control of mineral concentrations leading to this disorder, replicate populations of perennial ryegrass half-sib families were grown at Hamilton and Timboon in southern Australia. Variation in herbage yield, and Mg, P, K, Ca, Na, Cl, S, Mn, Fe, Cu, Zn, and K/(Mg+Ca) (tetany ratio) concentrations in the herbage of these families was measured in the early spring of 1994. Large environmental effects on herbage mineral concentration were detected, with location differences accounting for 60–80% of the total variance. Both the mean and range for mineral concentration were similar for each population. As expected, Mg, Ca, and K were significantly correlated with tetany ratio; however, the concentrations of other minerals were not consistently associated with tetany ratio. Tetany ratio and Mg showed a negative genetic correlation in both groups. The genetic correlation for tetany ratio with K or Ca was less repeatable across groups. Significant family variance components (σ2f) were detected for yield, Mg, Ca, K, and tetany ratio, and narrow-sense heritabilities for these traits were moderate to high (h2 = 0·46–0·81). However, family location interactions were also significant, with σ2fl often >σ2f. A large proportion of the family location interaction for K and Mg concentration was associated with non-rank family changes indicating that family selection for low K or high Mg concentration would be effective across environments. However, family × location effects for Ca and tetany ratio were associated with substantial rank changes across locations. Selection for increased Mg concentration would appear the most suitable strategy for reducing the tetany ratio of perennial ryegrass, with possibly different cultivars required for the environments represented by Hamilton and Timboon.

Genetic control of wood density profile in young Douglas-fir

1991 ◽  
Vol 21 (6) ◽  
pp. 935-939 ◽  
Author(s):  
J. A. Loo-Dinkins ◽  
J. S. Gonzalez
Keyword(s):  
Relative Density ◽  
Genetic Control ◽  
Density Profile ◽  
Douglas Fir ◽  
Breast Height ◽  
Cambial Age ◽  
Sib Families ◽  
Progeny Tests ◽  
Selection For ◽  
The Difference

The relative density profile from pith to bark was examined in young Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stems at 1.3, 0.7, and 0.4 m above the ground. The trees represented 22 half-sib families growing at two progeny test locations. The objective was to evaluate the reliability of wood samples taken from below breast height (1.3 m) for selection for relative density in young coastal Douglas-fir progeny tests. The relative density profile appeared to be different for the first 6 or 7 years from the pith at the different sampling heights, but the difference decreased with cambial age. Genetic correlation estimates were sufficiently high to indicate identical genetic control at the three sampling heights, but heritability estimates were higher at 1.3 and 0.7 m than at 0.4 m. Sampling at 0.7 m is as effective as at 1.3 m. This allows reliable selection 1 to 2 years earlier than by sampling at 1.3 m.

Genetic resistance of spruce to gall-forming adelgids (Hemiptera: Adelgidae)

2009 ◽  
Vol 39 (12) ◽  
pp. 2536-2541 ◽  
Author(s):  
B. Bains ◽  
F. Isik ◽  
W.B. Strong ◽  
B. Jaquish ◽  
J.A. McLean ◽  
...  
Keyword(s):  
Genetic Control ◽  
Genetic Resistance ◽  
Gall Formation ◽  
Narrow Sense Heritability ◽  
Seed Loss ◽  
Interior Spruce ◽  
High Heritability ◽  
Sib Families ◽  
Selection For ◽  
Partial Diallel

Adelgids (Hemiptera: Adelgidae) gall vegetative and reproductive shoots of interior spruce (Picea spp.), causing growth impairment, seed loss, and aesthetic decline. We tested the theory that susceptibility to galling is under genetic control in spruce. We assessed natural galling incidence in a spruce progeny test located in southern British Columbia. The experiment was composed of a replicated 13-parent incomplete, partial diallel with 42 full-sib families. Moderate evidence of genetic control of susceptibility–resistance was observed with individual narrow-sense heritability of 0.17. We observed considerable genetic variation among parents for resistance to gall formation as shown by high heritability (0.87) of family means. Breeding values for parental susceptibility to adelgid attack ranged between 0.25 and 0.76, indicating that selection for reduced susceptibility would be successful. The benefits of screening for resistance to adelgid attack are discussed in relation to adelgid pest management, insect’s life-cycle, and tree health.

Evaluation of Three Cycles of Full‐Sib Family Selection for Yield in the Colus o2 Variety of Maize 1

Crop Science ◽  
1982 ◽  
Vol 22 (1) ◽  
pp. 10-12 ◽  
Author(s):  
Hugo L. Zorrilla ◽  
P. L. Crane
Keyword(s):  
Family Selection ◽  
Selection For

scholarly journals EFFECTS OF POPULATION SIZE AND SELECTION INTENSITY ON SHORT-TERM RESPONSE TO SELECTION FOR POSTWEANING GAIN IN MICE

Genetics ◽  
1973 ◽  
Vol 73 (3) ◽  
pp. 513-530
Author(s):  
J P Hanrahan ◽  
E J Eisen ◽  
J E Legates
Keyword(s):  
Population Size ◽  
Selection Response ◽  
Selection Intensity ◽  
Realized Heritability ◽  
Family Selection ◽  
Effective Population ◽  
Population Sizes ◽  
Selection For ◽  
Selection Intensities ◽  
Term Response

ABSTRACT The effects of population size and selection intensity on the mean response was examined after 14 generations of within full-sib family selection for postweaning gain in mice. Population sizes of 1, 2, 4, 8 and 16 pair matings were each evaluated at selection intensities of 100% (control), 50% and 25% in a replicated experiment. Selection response per generation increased as selection intensity increased. Selection response and realized heritability tended to increase with increasing population size. Replicate variability in realized heritability was large at population sizes of 1, 2 and 4 pairs. Genetic drift was implicated as the primary factor causing the reduced response and lowered repeatability at the smaller population sizes. Lines with intended effective population sizes of 62 yielded larger selection responses per unit selection differential than lines with effective population sizes of 30 or less.

Feature selection for genomic prediction of perennial ryegrass forage quality

2021 ◽  
Author(s):  
Agnieszka Konkolewska ◽  
Patrick Conaghan ◽  
Dan Milbourne ◽  
Michael Dineen ◽  
Susanne Barth ◽  
...  
Keyword(s):  
Feature Selection ◽  
Perennial Ryegrass ◽  
Genomic Prediction ◽  
Forage Quality ◽  
Selection For

scholarly journals Genetic correlation between traits in the ESALQ-PB1 maize population divergently selected for tassel size and ear height

2001 ◽  
Vol 58 (1) ◽  
pp. 119-123 ◽  
Author(s):  
Austeclínio Lopes Farias Neto ◽  
José Branco de Miranda Filho
Keyword(s):  
Genetic Correlation ◽  
Correlation Coefficients ◽  
Divergent Selection ◽  
Phenotypic Correlation ◽  
Base Population ◽  
Branch Number ◽  
Maize Population ◽  
Tassel Branch Number ◽  
Ear Height ◽  
Selection For

Full-sib and selfed (S1) progenies were obtained from sub-populations of ESALQ-PB1, divergently selected for tassel size (T+ and T-) and ear height (E+ and E-), and used for estimating genetic and phenotypic correlation coefficients between traits. The analyzed traits were: EW- total ear weight (g/plant), PH- plant height (cm), EH- ear height (cm), TB- tassel branch number and TL- tassel length. The highest genetic (rG) and phenotypic (rF) correlation was observed for the combination PH x EH, as expected, with average of 0.800 and 0.778, respectively over sub-populations and locations. It is apparent that divergent selection for tassel size did not affect greatly the correlation between PH and EH in the full sib progenies, but in the inbred progenies the correlation was smaller in the sub-population selected for larger tassels. Genetic correlation between PH and EH with tassel traits was always positive but ranged from 0.020 to 0.668 in Piracicaba and from 0.06 to 0.309 in Rio Verde. Genetic correlation between PH and EH with yield (EW) also was positive in the range of 0.087 to 0.503. EH showed higher correlation with EW in relation to PH x EW and differences were larger in the sub-populations divergently selected for ear height. Correlation between tassel traits with other traits was positive in most of instances and a lack of consistency was observed among sub-populations. Generally the coefficients of genetic and phenotypic correlation differed substantially from the estimates in the base population ESALQ-PB1 before divergent selection for tassel size and ear placement. Divergent selection affected the correlation between traits under unpredicted and varying magnitudes.

Early spring and late autumn response to applied nitrogen in four grasses

1980 ◽  
Vol 94 (2) ◽  
pp. 443-453 ◽  
Author(s):  
D. Wilman ◽  
A. A. Mohamed
Keyword(s):  
Perennial Ryegrass ◽  
Leaf Blade ◽  
Unit Area ◽  
Total Yield ◽  
Early Spring ◽  
Late Winter ◽  
Number Of Leaves ◽  
Four Levels ◽  
Leaf Extension ◽  
Applied Nitrogen

SummaryThe regrowth of Aberystwyth S. 23 perennial ryegrass, S. 24 perennial ryegrass, S. 59 red fescue and S. 170 tall fescue was studied in field swards, comparing four levels of applied nitrogen, for 8 weeks following a clearing cut. The clearing cuts were in mid-October, mid-February and mid-March in each of 3 years, different plots being used on each occasion.The application of N increased the number of leaf primordia, the number of un-emerged leaves, the rate of leaf emergence and death, leaf blade length, width and weight, sheath length, number of leaves per unit area of ground and proportion of green tissue in total yield. The application of N had little effect on the number of leaves per tiller and tended to reduce weight per unit area of leaf blade. The increase in size, weight and number of leaf blades appeared to be major reasons for the positive effect of applied N on yield, previously reported; and the increase in sheath length contributed to the increase in proportion of yield above 4 cm. Rate of leaf extension was not closely related to yield and was more sensitive to temperature than was yield. Changes during regrowth in blade and sheath length helped to explain changes in weight per tiller, previously reported. The effects of improving weather conditions in late winter/early spring were similar to the effects of applied N: larger, heavier leaf blades, longer sheaths, a taller canopy, a lower proportion of dead material, younger leaves. The length of shoot apex per leaf primordium was relatively constant. Leaves continued to emerge, at a slow rate, in the period December–February. S. 170 had the biggest leaves, particularly in May, and the slowest rate of leaf turnover. Rate of leaf extension was increased by applied N more, on average, in the ryegrasses than in the fescues.

scholarly journals Survey of fruit nutrient removal by mango (Mangifera indica L.) cultivars for the export market in various producing regions of Mexico

2019 ◽  
Vol 37 (4) ◽  
pp. 437
Author(s):  
Adriana Mellado-Vázquez ◽  
Samuel Salazar-García ◽  
Ricardo Goenaga ◽  
Alfredo López-Jiménez
Keyword(s):  
Nutrient Removal ◽  
Mangifera Indica ◽  
Export Market ◽  
Mineral Concentration ◽  
Mango Fruit ◽  
Physiological Maturity ◽  
Production Region ◽  
Thin Slices ◽  
Forced Air ◽  
Mineral Concentrations

In Mexico there are more than 201 400 ha grown with different mango (Mangifera indica L.) cultivars. This may cause variations in mineral requirement, fruit mineral concentrations and nutrient removal. The objective of this research was to make a survey of mineral concentration in fruit tissues and calculate nutrient removal by fruit tissues during harvest of the most important mango cultivars (Ataulfo, Kent and Tommy Atkins) from several production regions (Campeche, Chiapas, Oaxaca, Nayarit, and Sinaloa) of Mexico. Fruit at physiological maturity were harvested from commercial mango orchards and concentration of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), iron (Fe), copper (Cu), manganese (Mn), zinc (Zn) and boron (B) was determined for skin, mesocarp, endocarp, and seed tissues. Each tissue was cut into thin slices and they were dehydrated in a forced air oven at 70 °C, after that, were pulverized and they were analyzed: nitrogen by semi-microKjeldahl digestion, phosphorus with the ascorbic acid method and the other nutrients with atomic absorption. The removal of nutrients was calculated considering the weight of the fruit and the content of nutrients in each tissue. Signif icant differences in the concentration of N, K, Mg, and Zn were found among cultivars and tissues. Concentration of P, S, Cu, and Mn in the skin, Ca, Cu, and Mn in the mesocarp, Ca, S, Mn, and B in endocarp, and S, Fe, and Mn in the seed were not affected by mango cultivar. Production region affected concentration of minerals in ‘Ataulfo’ fruit more than in ‘Tommy Atkins’ and ‘Kent’. Nutrient removal by mango fruit tissues was little affected in cvs. Ataulfo, Tommy Atkins and Kent. The regions with the greatest nutrient removal were Oaxaca, Campeche and Sinaloa for ‘Ataulfo’, ‘Tommy Atkins’ and ‘Kent’, respectively.

scholarly journals PSVIII-38 Late-Breaking Abstract: Estimating genetic parameters of feed efficiency traits in American mink

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 347-347
Author(s):  
Pourya Davoudi ◽  
Duy Ngoc Do ◽  
Guoyu Hu ◽  
Siavash Salek Ardestani ◽  
Younes Miar
Keyword(s):  
Body Weight ◽  
Genetic Correlation ◽  
Feed Intake ◽  
Feed Efficiency ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
American Mink ◽  
Genetic Correlations ◽  
Final Body Weight ◽  
Selection For

Abstract Feed cost is the major input cost in the mink industry and thus improvement of feed efficiency through selection for high feed efficient mink is necessary for the mink farmers. The objective of this study was to estimate the heritability, phenotypic and genetic correlations for different feed efficiency measures, including final body weight (FBW), daily feed intake (DFI), average daily gain (ADG), feed conversion ratio (FCR) and residual feed intake (RFI). For this purpose, 1,088 American mink from the Canadian Center for Fur Animal Research at Dalhousie Faculty of Agriculture were recorded for daily feed intake and body weight from August 1 to November 14 in 2018 and 2019. The univariate models were used to test the significance of sex, birth year and color as fixed effects, and dam as a random effect. Genetic parameters were estimated via bivariate models using ASReml-R version 4. Estimates of heritabilities (±SE) were 0.41±0.10, 0.37±0.11, 0.33±0.14, 0.24±0.09 and 0.22±0.09 for FBW, DFI, ADG, FCR and RFI, respectively. The genetic correlation (±SE) was moderate to high between FCR and RFI (0.68±0.15) and between FCR and ADG (-0.86±0.06). In addition, RFI had low non-significant (P > 0.05) genetic correlations with ADG (0.04 ± 0.26) and BW (0.16 ± 0.24) but significant (P < 0.05) high genetic correlation with DFI (0.74 ± 0.11) indicating that selection for lower RFI will reduce feed intake without adverse effects on the animal size and growth rate. The results suggested that RFI can be implemented in genetic/genomic selection programs to reduce feed intake in the mink production system.

scholarly journals Genetic characterization of carrot root shape and size using genome-wide association analysis and genomic-estimated breeding values

2021 ◽  
Author(s):  
Scott H. Brainard ◽  
Shelby L. Ellison ◽  
Philipp W. Simon ◽  
Julie C. Dawson ◽  
Irwin L. Goldman
Keyword(s):  
Image Analysis ◽  
Genetic Control ◽  
Digital Image Analysis ◽  
Genome Wide Association ◽  
Carrot Root ◽  
Size And Shape ◽  
Genome Wide ◽  
Market Class ◽  
Selection For ◽  
Estimated Breeding Values

Abstract Key message The principal phenotypic determinants of market class in carrot—the size and shape of the root—are under primarily additive, but also highly polygenic, genetic control. Abstract The size and shape of carrot roots are the primary determinants not only of yield, but also market class. These quantitative phenotypes have historically been challenging to objectively evaluate, and thus subjective visual assessment of market class remains the primary method by which selection for these traits is performed. However, advancements in digital image analysis have recently made possible the high-throughput quantification of size and shape attributes. It is therefore now feasible to utilize modern methods of genetic analysis to investigate the genetic control of root morphology. To this end, this study utilized both genome wide association analysis (GWAS) and genomic-estimated breeding values (GEBVs) and demonstrated that the components of market class are highly polygenic traits, likely under the influence of many small effect QTL. Relatively large proportions of additive genetic variance for many of the component phenotypes support high predictive ability of GEBVs; average prediction ability across underlying market class traits was 0.67. GWAS identified multiple QTL for four of the phenotypes which compose market class: length, aspect ratio, maximum width, and root fill, a previously uncharacterized trait which represents the size-independent portion of carrot root shape. By combining digital image analysis with GWAS and GEBVs, this study represents a novel advance in our understanding of the genetic control of market class in carrot. The immediate practical utility and viability of genomic selection for carrot market class is also described, and concrete guidelines for the design of training populations are provided.

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