Achieving higher heritabilities through improved design and analysis of clonal trials

2006 ◽  
Vol 36 (9) ◽  
pp. 2148-2156 ◽  
Author(s):  
Salvador A Gezan ◽  
Timothy L White ◽  
Dudley A Huber
Keyword(s):  
Approximate Method ◽  
Confidence Intervals ◽  
Environmental Variability ◽  
Clonal Selection ◽  
Broad Sense ◽  
Experimental Designs ◽  
Residual Variance ◽  
Block Designs ◽  
Broad Sense Heritability ◽  
Heritability Estimates

Clonal testing was studied under different environmental patterns and experimental designs through simulation with the criteria of maximizing broad-sense heritability estimates and genetic gain from clonal selection. Several experimental designs were studied together with three patterns of environmental variability. In addition, empirical 95% confidence intervals for heritability estimates were compared with Dickerson's approximate method. Other elements studied included (i) conditions under which different environmental patterns yield high or low heritabilities and (ii) effects of varying the number of ramets per clone. Row-column designs produced the highest mean individual broad- sense heritability, but these designs were only slightly more efficient than incomplete block designs with small block sizes. For all experimental designs, Dickerson's approximate method for estimating the variance of heritability estimates produced reasonable 95% confidence intervals but overestimated the upper confidence limit of complex designs. Larger heritabilities were found with higher tree-to-tree spatial correlations and lower amounts of microsite residual variance, and varying gradients had negligible influence. The effect of implementing Latinization was significant on increasing heritability, but small in practical terms, and was more important for patchy surfaces. Experiments with more ramets per clone yielded higher clonal mean heritabilities, and using between four and six ramets per clone per site is recommended.

scholarly journals Genetic variation and correlation of agronomic traits in meadow bromegrass (Bromus riparius Rehm) clones

2004 ◽  
Vol 34 (2) ◽  
pp. 505-510 ◽  
Author(s):  
Marcelo Renato Alves de Araújo ◽  
Bruce Coulman
Keyword(s):  
Genetic Variation ◽  
Crude Protein ◽  
Genetic Correlations ◽  
Neutral Detergent Fiber ◽  
Broad Sense ◽  
Grass Species ◽  
Broad Sense Heritability ◽  
Bromus Riparius ◽  
Heritability Estimates ◽  
Meadow Bromegrass

Meadow bromegrass (Bromus riparius Rehm.) is a recently introduced pasture grass in western Canada. Its leafy production and rapid regrowth have made it a major grass species for pasturing beef animals in this region. As relatively little breeding work has been done on this species, there is little information on its breeding behaviour. The main objective of this study was to estimate total genetic variability, broad-sense heritability, phenotypic and genetic correlations. Forty-four meadow bromegrass clones were evaluated for agronomic characters. Genetic variation for dry matter yield, seed yield, fertility index, harvest index, plant height, plant spread, crude protein, neutral detergent fiber and acid detergent fiber, was significant. Broad-sense heritability estimates exceeded 50% for all characters. Heritability estimates were at least 3.5 times greater than their standard errors. Phenotypic and genetic correlation between all possible characters were measured. There was general agreement in both sign and magnitude between genetic and phenotypic correlations. Correlations between the different characters demonstrated that it is possible to simultaneously improve seed and forage yield. Based on the results, it appears that the development of higher yielding cultivars with higher crude protein, and lower acid and neutral detergent fibers concentration should be possible.

Clonal testing efficiency: the trade-offs between clones tested and ramets per clone

1986 ◽  
Vol 16 (5) ◽  
pp. 925-930 ◽  
Author(s):  
J. H. Russell ◽  
W. J. Libby
Keyword(s):  
Clonal Selection ◽  
Simulation Models ◽  
Radiata Pine ◽  
Fixed Number ◽  
Broad Sense ◽  
Optimum Level ◽  
Broad Sense Heritability ◽  
Selection Intensity ◽  
Trade Offs ◽  
Clonal Testing

Three contrasting simulation models were developed to investigate testing efficiencies in a clonal selection program. The variables investigated were number of total plants tested, number of candidate clones tested, number of ramets per clone, number of clones selected, selection intensity, and broad-sense heritability. The model deemed appropriate to most clonal forestry situations selected a fixed number of clones in an experiment with the total number of plants in the test held constant. In this model, as the number of ramets per clone was varied, the number of candidate clones tested and the selection intensity necessarily also varied. This model indicates that cloning individuals for testing is useful when selection is based on a characteristic or index with broad-sense heritability less than about 0.6. At the lower heritabilities, two to six ramets per clone per site usually produces the optimum level of cloning, the exact number depending upon the selection intensity and heritability. Predictions generated by this fixed number of selected clones model were compared with average phenotypic values of selections using different subsamples of data for 8-year height and for 8-year diameter in a radiata pine (Pinusradiata D. Don) clonal experiment. Agreement between predictions and average phenotypic values in both these two comparisons was close.

scholarly journals Heritability of Simulated Wear and Traffic Tolerance in Three Fine Fescue Species

HortScience ◽  
2018 ◽  
Vol 53 (4) ◽  
pp. 416-420 ◽  
Author(s):  
Austin L. Grimshaw ◽  
Yuanshuo Qu ◽  
William A. Meyer ◽  
Eric Watkins ◽  
Stacy A. Bonos
Keyword(s):  
Broad Sense ◽  
Potential Candidate ◽  
Single Individual ◽  
Broad Sense Heritability ◽  
The North ◽  
Heritability Estimates ◽  
Traffic Tolerance ◽  
Fine Fescue ◽  
Selection Of ◽  
Wear Tolerance

In recent years, turfgrass breeders have given increased attention to the development of lower maintenance turfgrass cultivars. Fine fescues (Festuca spp.) have been identified as potential candidate species for low-maintenance lawns because of their reduced need for water, mowing, and fertilizer. Unfortunately, these species have some weaknesses that must be improved to facilitate their use; perhaps, the most important of these is tolerance to wear and traffic. For this trait to be improved in new cultivars, there must be sufficient heritable variation available for plant breeders to exploit; however, little is known about the heritability of this complex trait in fine fescue species. Therefore, the objective of this study was to determine the heritability of wear and traffic tolerance in three fine fescue species. Replicated field studies were established in North Brunswick, NJ, and St. Paul, MN, and each included 157 Chewing’s fescue (Festuca rubra L. subsp. fallax), 155 hard fescue (Festuca brevipilia), and 149 strong creeping red fescue (F. rubra L. subsp. rubra) genotypes. Wear tolerance was evaluated in North Brunswick and traffic tolerance was evaluated in St. Paul during 2015 and 2016 using different simulators to determine both plant performance and broad-sense heritability estimates for wear and traffic tolerance. Broad-sense heritability estimates for the three species when calculated on a clonal basis was between 0.69 and 0.82 for wear tolerance in the North Brunswick location and between 0.49 and 0.60 for traffic tolerance in the St. Paul location. On a single-plant basis, broad-sense heritability estimates for the three species were between 0.31 and 0.45 for wear tolerance in the North Brunswick location and 0.09 and 0.12 for traffic tolerance in St. Paul. However, this research does indicate that improvement of wear and traffic tolerance in fine fescues is possible through recurrent breeding methods based on selection of replicated clonally propagated genotypes rather than selection of single individual plants of a population. This was the first study to determine the genetic effects of wear and traffic tolerance in any turfgrass species.

scholarly journals Inheritance of Resistance to Colletotrichum Species in Strawberry

1991 ◽  
Vol 116 (4) ◽  
pp. 724-727 ◽  
Author(s):  
Creighton L. Gupton ◽  
Barbara J. Smith
Keyword(s):  
Recurrent Selection ◽  
Major Gene ◽  
Broad Sense ◽  
Inheritance Of Resistance ◽  
Broad Sense Heritability ◽  
Narrow Sense ◽  
Narrow Sense Heritability ◽  
Genetic Variances ◽  
Heritability Estimates ◽  
Selection Of

Experiments were conducted to estimate the relative importance of additive and dominance genetic variances and non-allelic interactions in the inheritance of resistance to Colletotrichum spp. in strawberry (Fragaria × ananassa Duch.). Progeny of 40 parents crossed in a Comstock and Robinson Design II Mating scheme were inoculated with three isolates of C. fragariae and one isolate of C. acutatum. Disease development on each plant was rated visually. Variance components were estimated and converted to genetic variances. Estimates of were six to 10 times higher than those for Within-family variance not accounted for by equaled 35% and 38% of the total genetic variance in females and males, respectively, indicating probable epistatic effects. The frequency distribution of disease severity ratings was bimodal in both experiments, suggesting major gene action. Narrow-sense heritability estimates were 0.37 and 0.26, and broad-sense heritability estimates were 0.87 and 0.85 for females and males, respectively. Narrow-sense heritability estimates are probably sufficient to produce gains from recurrent selection. Gains from selection of clonal value should be possible because of the high broad sense heritability estimates. It appears feasible to establish a broad genetic-based population resistant to Colletotrichum spp. from which selections could be evaluated per se and/or recombined to produce improved populations.

scholarly journals Broad-sense Heritability Estimates of Turfgrass Performance Characteristics in Native Prairie Junegrass Germplasm

HortScience ◽  
2012 ◽  
Vol 47 (9) ◽  
pp. 1228-1233 ◽  
Author(s):  
Matthew D. Clark ◽  
Eric Watkins
Keyword(s):  
Block Design ◽  
Performance Characteristics ◽  
Broad Sense ◽  
Lateral Spread ◽  
Broad Sense Heritability ◽  
Native Prairie ◽  
Crown Density ◽  
Koeleria Macrantha ◽  
Heritability Estimates ◽  
Positive Correlations

Prairie junegrass [Koeleria macrantha (Ledeb.) Shultes] is a perennial, short-grass prairie species distributed throughout the Northern Hemisphere that is being evaluated for use as a low-input turf. In June 2007, 300 genotypes representing collection locations derived from Colorado, Nebraska, and Minnesota germplasm were grown and evaluated 3 years for turfgrass performance characteristics in a randomized complete block design with five clonal replications at two locations (St. Paul, MN, and Becker, MN). After establishment, plots received no supplemental irrigation or fertility and were mowed weekly to a height of 6.4 cm. Broad-sense heritability estimates were calculated on a clonal mean (Hc) and single-plant (Hsp) basis for turf quality (Hc = 0.62, Hsp = 0.13), crown density (Hc = 0.55, Hsp = 0.09), mowing quality (Hc = 0.59, Hsp = 0.09), and genetic color (Hc = 0.45, Hsp = 0.06). The heritability estimates indicate that selection for these traits should result in significant gains in germplasm improvement. Differences were observed in the means and variances among clones, collection locations, and/or collection regions for many of the traits evaluated including rust severity (Puccinia spp.), spring green-up, plant height, lateral spread, vertical regrowth, and flowering traits. The positive correlations among some of these traits and those with moderate heritability estimates should allow for multi-trait selection in cultivar development.

THE INHERITANCE OF OZONE INSENSITIVITY IN SELECTED Phaseolus vulgaris L. POPULATIONS

1982 ◽  
Vol 62 (4) ◽  
pp. 861-865 ◽  
Author(s):  
P. HUCL ◽  
W. D. BEVERSDORF
Keyword(s):  
Phaseolus Vulgaris ◽  
Broad Sense ◽  
Field Conditions ◽  
Broad Sense Heritability ◽  
Phaseolus Vulgaris L ◽  
Selection For ◽  
Heritability Estimates ◽  
Two Populations

Broad sense heritability estimates (H) for ozone (O3) insensitivity in four P. vulgaris F2 populations were high (0.66–0.88) under artifical fumigation conditions. In the F3, under field conditions, broad sense H in two populations had declined to 0.16 and 0.21, probably as a result of the interaction of maturity and injury. The results suggest that selection for O3 insensitivity in early generations should be conducted under controlled fumigation conditions followed by field evaluations as lines approach homozygosity.

scholarly journals Broad-sense Heritability Estimates for Fruit Color and Morphological Traits from Open-pollinated Half-sib Mango Families

HortScience ◽  
2009 ◽  
Vol 44 (6) ◽  
pp. 1552-1556 ◽  
Author(s):  
J. Steven Brown ◽  
Raymond J. Schnell ◽  
Tomás Ayala-Silva ◽  
J. Michael Moore ◽  
Cecile L. Tondo ◽  
...  
Keyword(s):  
Fruits And Vegetables ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Broad Sense ◽  
Broad Sense Heritability ◽  
Quality Factors ◽  
Visual Appearance ◽  
Good Potential ◽  
Resistance Trait ◽  
Heritability Estimates

The visual appearance of mangos is a primary factor in determining consumer acceptance and sale, similar to other fruit and vegetable commodities. Even if the appeal of visual appearance is based on consumer perception rather than on established quality factors, breeders must usually select within the range of acceptance, at least in some countries. Mango selection using multiyear breeding programs is slowly replacing the former method by which most earlier cultivars were selected, namely from chance seedlings either from planned or unplanned crosses. The knowledge of heritability of traits as they are controlled by genetics and experimental design and the effects and interaction of these two sets of factors on achieved gain have become more critical. The use of portable colorimeters has been shown to give repeatable scores in a quantitative, three-dimensional space for fruits and vegetables. In this experiment, we calculated broad-sense heritability estimates for five color traits, three morphological fruit traits, and one disease resistance trait (anthracnose expressed on the fruit). Estimates were found to be relatively high, indicating good potential for improvement through breeding. For nearly all traits measured, variance within families was greater than that among families, illustrating the likely importance of heterozygosity, dominance, and epistasis in these crosses. The careful estimation of heritability and repeatability will help prioritize and increase the efficiency of trait improvement as breeding methods become more sophisticated and competition for funding increases.

scholarly journals Kemajuan Genetik dan Heritabilitas Karakter Agronomi Padi Beras Hitam pada Populasi F2

2016 ◽  
Vol 35 (2) ◽  
pp. 119 ◽  
Author(s):  
Kristamtini Kristamtini ◽  
Sutarno Sutarno ◽  
Endang Wisnu Wiranti ◽  
Setyorini Widyayanti
Keyword(s):  
Plant Height ◽  
Flag Leaf ◽  
Leaf Length ◽  
Broad Sense ◽  
Broad Sense Heritability ◽  
Genetic Advance ◽  
Black Rice ◽  
White Rice ◽  
Panicle Number ◽  
Heritability Estimates

Black rice is a local rice variety with some advantages and weaknesses. The desirable character of black rice is its high anthocyanin content, while the weaknesses are late maturing, tall plant stature and low grain yield. Crosses were made between two parents aimed to recombine the superior traits. The effectiveness and efficiency of selection would be determined by the magnitude of the heritability of traits and the selection progress. This study was aimed to determine the heritability estimates in a broad sense and the genetic advance of agronomic characters of F2 generation, from crosses of local black rice and high yielding variety of white rice. The experiment was conducted in Padasan, Pakembinangun, Pakem, Sleman, Yogyakarta from January to May 2013. The F2 population derived from crosses of black rice x white rice, with the morphological traits of hairless black rice (S) crossed with Situbagendit (G) white rice, Cempo ireng (C) with Situbagendit (G) and Cempo ireng (C) with Inpari 6 (I). The F2 plants population were planted without replication. Genetic parameters estimated were calculated for broad sense heritability and genetic advance from selection. Results showed that the F2 population had high broad sense heritability estimates for all characters observed, including: plant height, flag leaf length, number of productive tillers, panicle length, number of filled grains per panicle, number of empty grains per panicle, maturity and rice color, in the three F2 populations obtained from crosses of S x G, C x G and C x I. Only the plant height of S x G cross had a medium broad sense heritability estimate. The large heritability estimates indicated that the respective character was controlled by genetic factor more than environmental ones. High genetic advance would be obtained in the flag leaf length, number of productive tillers, panicle length, number of filled grains/panicle, number of empty grains/panicle and rice color from S x G, C x G and C x I crosses. Genetic advance of plant height was medium (at S x G and C x I crosses) to high (C x G crosses). The maturity trait had low genetic advance on cross S x G; C x G; and Cx I. The high value of genetic advance of character would suggest that selection on the character’s appearance would be successful.

High Heritability of Glycyrrhizic Acid, Glabridin, Liquiritin and Liquiritigenin in Licorice (Glycyrrhiza Glabra L.) Populations of Iran

2021 ◽  
Author(s):  
Ghasem Eghlima ◽  
Mohsen Sanikhani ◽  
Azizollah Kheiry ◽  
Javad Hadian
Keyword(s):  
Coefficient Of Variation ◽  
Morphological Traits ◽  
Glycyrrhizic Acid ◽  
Correlation Coefficients ◽  
Glycyrrhiza Glabra ◽  
Broad Sense ◽  
Phenotypic Correlation ◽  
Broad Sense Heritability ◽  
Narrow Sense Heritability ◽  
Perennial Plant

Abstract Glycyrrhiza glabra L. is an herbaceous, perennial plant with high distribution in Iran. Genetic variability, heritability and correlation among characters in 22 populations of G. glabra L. were studied. The genetic parameters among the traits including phenotypic variances, genotypic variances, genotype by environment variances, broad-sense heritability and genotypic and phenotypic correlation coefficients were studied. Variance components analysis showed that the extent of phenotypic coefficient of variation (PCV) was fairly higher for all the examined traits compared with genotypic coefficient of variation (GCV). Glabridin (GLA) exhibited high GCV and PCV (156.07% and 156.68%, respectively). The broad sense heritability varied from 38.92–99.79% and narrow sense heritability ranged from 9.70 % to 24.94%. Heritability of GLA, glycyrrhizic acid (GLY), liquiritin (LI), liquiritigenin (LIQ), rutin (RU) and rosmarinic acid (RA) were very high, exhibiting more than 97% heritability. Therefore, these critical characteristics can efficiently be selected and inherited in breeding programs. In most traits, the genotypic correlations showed the same direction as the phenotypic correlations. The contents of GLA and LIQ showed a positive correlation with majority of morphological traits. Therefore, selecting individual plants having desired morphological traits can be correlated with high contents of bioactive compounds in the harvested root.

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