Genetic parameters of pure and hybrid populations ofEucalyptus grandisandE. urophyllaand implications for hybrid breeding strategy

2009 ◽  
Vol 71 (2) ◽  
pp. 133-140 ◽  
Author(s):  
ECL Retief ◽  
TK Stanger
Keyword(s):  
Genetic Parameters ◽  
Breeding Strategy ◽  
Hybrid Breeding

scholarly journals Genetic Parameters of Interspecific Hybrids of Eucalyptus grandis and E. urophylla Seedlings and Cuttings

2015 ◽  
Vol 64 (1-6) ◽  
pp. 291-308 ◽  
Author(s):  
G. J. van den Berg ◽  
S. D. Verryn ◽  
P. W. Chirwa ◽  
F. Van Deventer
Keyword(s):  
Genetic Variation ◽  
Growth Performance ◽  
Hybrid Material ◽  
Genetic Parameters ◽  
Breeding Strategy ◽  
Hybrid Breeding ◽  
Additive Variance ◽  
Breeding Values ◽  
Additive Genetic Variation ◽  
Hybrid Seedling

Abstract The current E. grandis × E. urophylla hybrid breeding strategy of South Africa’s Forestry Industry is to maintain large breeding populations of both parental species in which parents are selected based on their general combining ability (GCA) estimates or predicted individual tree breeding values and are used for interspecific hybrid crosses. The hybrid material is first screened in seedling progeny trials after which superior individuals are selected and tested as clones. Although this strategy has delivered superior clones for commercial production in South Africa, it is a time consuming strategy to follow and more cost effective strategies are being investigated. In order to review the current hybrid breeding strategy, information on the genetic control of the traits of interest is needed for E. grandis × E. urophylla seedling and clonal populations. The main objectives of this study were therefore to firstly estimate genetic parameters for E. grandis × E. urophylla hybrid seedling and clonal populations; secondly to investigate the correlation between E. grandis and E. urophylla parental (GCA) or individual breeding values and their general hybridising ability (GHA); and lastly to determine the correlation between E. grandis × E. urophylla hybrid seedling ortets and their ramets. Results of our study indicated that non-additive genetic variation explained the majority of the total genetic variation in E. grandis × E. urophylla seedling and clonal populations. Due to the pre-eminence of non-additive variance, the pure-hybrid correlations were weak, especially for clonal populations. It would therefore seem that GCA or predicted individual breeding values are not good predictors of GHA for growth performance in the observed populations. Our study also indicated a weak coefficient of correlation between the growth performance of seedling ortets and their ramets. These results suggest that: firstly a hybrid breeding strategy to capture non-additive genetic variation should be adopted; and secondly that the first phase of screening E. grandis × E. urophylla hybrid material as seedlings should be revisited.

Initial productivity and genetic parameters of three Corymbia species in Brazil: designing a breeding strategy

2021 ◽  
Vol 51 (1) ◽  
pp. 25-30
Author(s):  
Marcio José de Araujo ◽  
David John Lee ◽  
Evandro Vagner Tambarussi ◽  
Rinaldo Cesar de Paula ◽  
Paulo Henrique Müller da Silva
Keyword(s):  
Genetic Parameters ◽  
Breeding Strategy ◽  
Hybrid Breeding ◽  
Forward Selection ◽  
Annual Increment ◽  
Narrow Sense Heritability ◽  
Species Survival ◽  
Species Population ◽  
The Mean ◽  
Corymbia Citriodora

The survival, initial productivity, and the genetic parameters of Corymbia citriodora subsp. citriodora (CCC), Corymbia citriodora subsp. variegata (CCV), and Corymbia torelliana (CT) were used to develop a breeding strategy for the Corymbia species. Survival, height, and diameter at breast height (DBH) data were assessed 24 and 36 months after planting, and the mean annual volume increment was estimated in three trials. Longitudinal DBH data analysis was applied individually to each trial to identify the best and the poorest families at both ages. The mortality ranged from 5% in CT to 27% in CCC, and the mean annual increment varied from 17.8 to 20 m3·ha−1·year−1 at 36 months after planting. The 36-month narrow-sense heritability [Formula: see text] was high for CCV (0.69 ± 0.17), moderate for CCC (0.41 ± 0.11), and low for CT (0.21 ± 0.09). The genetic parameters indicated the need for different breeding strategies for each species. Selecting the best families while roguing the poor families allowed forward selection of CCC and CCV. It was possible to select good CT trees for hybrid breeding; however, improving the species population requires focusing on increasing the effective size and expanding the genetic variability in the CT population.

Genetic parameters and genotype–environment interactions of Chinese fir (Cunninghamia lanceolata) in Fujian Province

2014 ◽  
Vol 44 (6) ◽  
pp. 582-592 ◽  
Author(s):  
Liming Bian ◽  
Jisen Shi ◽  
Renhua Zheng ◽  
Jinhui Chen ◽  
Harry X. Wu
Keyword(s):  
Genetic Parameters ◽  
Breeding Strategy ◽  
Chinese Fir ◽  
Breeding Program ◽  
Cunninghamia Lanceolata ◽  
Environment Interaction ◽  
Fujian Province ◽  
The Third ◽  
Genotype Environment Interaction ◽  
Sib Families

Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) is the most commercially important conifer in China, and the Nanjing Forestry University – Fujian Province Chinese fir Cooperation (NJFU – Fujian Cooperation) breeding program has advanced it into the third cycle of selection and breeding. In this paper, we estimated genetic parameters from four sites for 80 half-sib families and summarized previous estimates of genetic parameters in Chinese fir with an objective to propose optimal breeding strategy. Heritability averaged 0.20 and 0.14 for height and diameter at breast height (DBH), respectively, for the four sites. A significant genotype–environment interaction (G × E) for growth was also observed among the four sites, with the greatest interactions between a marginal site and the three central sites in the Fujian Province Chinese fir plantation region. The average estimated type-B genetic correlation between the marginal site and the three central sites was 0.08 for height and –0.09 for DBH. However, the highly productive families were among the most stable across the four sites. The results from this study in combination with summarized genetic parameters from literature were used to discuss and propose an optimal breeding strategy for the third generation of the breeding program for Chinese firs in Fujian Province.

scholarly journals Design of an F1 hybrid breeding strategy for ryegrasses based on selection of self-incompatibility locus-specific alleles

2015 ◽  
Vol 6 ◽  
Author(s):  
Luke W. Pembleton ◽  
Hiroshi Shinozuka ◽  
Junping Wang ◽  
German C. Spangenberg ◽  
John W. Forster ◽  
...  
Keyword(s):  
Breeding Strategy ◽  
Hybrid Breeding ◽  
Self Incompatibility ◽  
F1 Hybrid ◽  
Incompatibility Locus ◽  
Selection Of

Genetic parameter estimates for interspecific Eucalyptus hybrids and implications for hybrid breeding strategy

New Forests ◽  
2011 ◽  
Vol 44 (1) ◽  
pp. 63-84 ◽  
Author(s):  
Tasiyiwa Madhibha ◽  
Ruramai Murepa ◽  
Cossy Musokonyi ◽  
Washington Gapare
Keyword(s):  
Genetic Parameter ◽  
Breeding Strategy ◽  
Hybrid Breeding ◽  
Parameter Estimates

scholarly journals Genomic Selection for F1 Hybrid Breeding in Strawberry (Fragaria × ananassa)

2021 ◽  
Vol 12 ◽  
Author(s):  
Eiji Yamamoto ◽  
Sono Kataoka ◽  
Kenta Shirasawa ◽  
Yuji Noguchi ◽  
Sachiko Isobe
Keyword(s):  
Genomic Selection ◽  
Agronomic Traits ◽  
Inbred Lines ◽  
Breeding Strategy ◽  
Hybrid Breeding ◽  
Single Nucleotide ◽  
F1 Hybrid ◽  
Hybrid Seeds ◽  
Pericarp Color ◽  
Model Training

Cultivated strawberry is the most widely consumed fruit crop in the world, and therefore, many breeding programs are underway to improve its agronomic traits such as fruit quality. Strawberry cultivars were vegetatively propagated through runners and carried a high risk of infection with viruses and insects. To solve this problem, the development of F1 hybrid seeds has been proposed as an alternative breeding strategy in strawberry. In this study, we conducted a potential assessment of genomic selection (GS) in strawberry F1 hybrid breeding. A total of 105 inbred lines were developed as candidate parents of strawberry F1 hybrids. In addition, 275 parental combinations were randomly selected from the 105 inbred lines and crossed to develop test F1 hybrids for GS model training. These populations were phenotyped for petiole length, leaf area, Brix, fruit hardness, and pericarp color. Whole-genome shotgun sequencing of the 105 inbred lines detected 20,811 single nucleotide polymorphism sites that were provided for subsequent GS analyses. In a GS model construction, inclusion of dominant effects showed a slight advantage in GS accuracy. In the across population prediction analysis, GS models using the inbred lines showed predictability for the test F1 hybrids and vice versa, except for Brix. Finally, the GS models were used for phenotype prediction of 5,460 possible F1 hybrids from 105 inbred lines to select F1 hybrids with high fruit hardness or high pericarp color. These F1 hybrids were developed and phenotyped to evaluate the efficacy of the GS. As expected, F1 hybrids that were predicted to have high fruit hardness or high pericarp color expressed higher observed phenotypic values than the F1 hybrids that were selected for other objectives. Through the analyses in this study, we demonstrated that GS can be applied for strawberry F1 hybrid breeding.

scholarly journals Genetic parameters estimate for plant characters of a particular carrot population in two different agroecologic cultivation systems

2020 ◽  
Vol 36 ◽  
Author(s):  
Michelle Souza Vilela ◽  
José Ricardo Peixoto ◽  
Jairo Vidal Vieira ◽  
Giovani Olegário Da Silva ◽  
Daiane da Silva Nóbrega ◽  
...  
Keyword(s):  
Genetic Parameters ◽  
Cropping Systems ◽  
Block Design ◽  
Breeding Strategy ◽  
Root Tip ◽  
Environment Interaction ◽  
Randomized Block Design ◽  
National Market ◽  
New Varieties ◽  
The Individual

Carrots are among the most planted vegetables in Brazil, which represents importance in the national market. This crop can be grown in conventional and agroecological systems, and studies to improve productivity, disease resistance and root quality in agroecological cropping systems are important. The aim of the present work was to estimate genetic parameters that provide a breeding strategy in the search for the development of new varieties of carrot adapted to the conditions of Distrito Federal’s agroecology cultivation. Considering data from tests performed in areas of agroecology cultivation (Natural Agriculture-NA and Organic Agriculture-OA), the following characteristics were evaluated: incidence of leaf blight-LB, incidence of root cracking-CRACK, root length-COMP, format of root tip-TP, format of root shoulder-TO, measure of the color of the a* xylem parameter-a*X, measure of the color of the a* phloem parameter-a*F. Traits were evaluated in 100 half-sib progenies derived from Brasília cultivar, using a completely randomized block design. For the characters COMP, a*X, a*F, TP and TO, the treatment X environment interaction was significant according to the results from test F. The values of the individual variance analyses presented significant effect for the following characteristics: COMP, a*X, TP, TO, LB for NA system, and COMP, a*X, a*F, TP for OA system. In NA system, the values of heritability estimates-ha² for the plant characters fluctuated from 65.66 to 25.52% and, in the OA system, the ha² of the characters a*X, was 81.13%. Estimates of genetic gain per cycle for the characters a*X and a*F were lower in NA system than the estimates observed in OA system.  

scholarly journals Inbreeding in Pinus Radiata – V. The Effects of Inbreeding on Fecundity

2004 ◽  
Vol 53 (1-6) ◽  
pp. 80-88 ◽  
Author(s):  
H. X. Wu ◽  
J.V. Owen ◽  
A. Abarquez ◽  
A. C. Matheson
Keyword(s):  
Inbreeding Depression ◽  
Radiata Pine ◽  
Inbred Lines ◽  
Breeding Strategy ◽  
Young Age ◽  
Reproductive Age ◽  
Early Selection ◽  
Hybrid Breeding ◽  
Reproductive Ability ◽  
Adult Trees

Abstract A successful inbreeding and hybrid breeding strategy in tree improvement requires that 1) inbreeding (selfing) can produce superior inbred lines (effective purging of deleterious alleles), 2) there is heterosis among crosses of inbred lines, 3) early selection between lines is effective, and 4) inbreeding will not substantially reduce reproductive ability. We have previously reported that inbreeding depression on growth was lower in radiata pine relative to other conifers and segregation in the first two-generations of selfs generated superior inbred trees. In addition, we have observed that early selection among inbred trees (lines) was more effective than in out-crossed populations and there was an apparent heterosis in radiata pine. In this study, the effect of inbreeding on the reproductive ability in young and adult trees of radiata pine has been quantified from five populations of varied inbreeding levels (F =0, 0.125, 0.25, 0.5, and 0.75). It was observed that the effects of inbreeding depression on fecundity was higher at a young age than at older age and inbreeding depression at a young age is due to two factors: 1) a delay of reproductive age (about 8.3, and 8.5% of trees delayed for F =0.5 and F =0.75 populations, respectively) and 2) a true reduction of flowering trees (6.7 and 13.1% more trees having no flowers for F =0.5 and F =0.75 populations than F =0 population, respectively). Despite significant inbreeding depression on the percentage of female reproductive trees and the number of cones on adult trees, overall inbreeding depression on fecundity was low in radiata pine. One founder clone contributed most of the significant inbreeding depression observed for the population of eight founder clones. It was observed that fecundity varied more widely among the eight clones than among the inbreeding level (self and outcross).

scholarly journals Comparative Performance of Corymbia Hybrids and Parental Species in Subtropical Queensland and Implications for Breeding and Deployment

2009 ◽  
Vol 58 (1-6) ◽  
pp. 205-212 ◽  
Author(s):  
David J. Lee ◽  
J. R. Huth ◽  
J. T. Brawner ◽  
G. R. Dickinson
Keyword(s):  
Pilot Scale ◽  
Genotype By Environment Interaction ◽  
Breeding Strategy ◽  
Hybrid Breeding ◽  
Environment Interaction ◽  
Comparative Performance ◽  
F1 Hybrid ◽  
Stem Straightness ◽  
Corymbia Citriodora ◽  
Branch Size

AbstractEighty six full-sib Corymbia F1 hybrid families (crosses between C. torelliana and four spotted gum taxa: C. citriodora subsp. variegata, C. citriodora subsp. citriodora, C. henryi and C. maculata), were planted in six trials across six disparate sites in south-eastern Queensland to evaluate their productivity and determine their potential utility for plantation forestry. In each trial, the best-growing 20% of hybrid families grew significantly faster (P = 0.05) than open-pollinated seedlots of the parent species Corymbia citriodora subsp. variegata, ranging from 107% to 181% and 127% to 287% of the height and diameter respectively. Relative performance of hybrid families growing on more than one site displayed consistency in ranking for growth across sites and analysis showed low genotype-by-environment interaction. Heritability estimates based on female and male parents across two sites at age six years for height and diameter at breast height, were high (0.62 ± 0.28 to 0.64 ± 0.35 and 0.31 ± 0.21 to 0.69 ± 0.37 respectively), and low to moderate (0.03 ± 0.04 to 0.33 ± 0.22) for stem straightness, branch size, incidence of ramicorns, and frost and disease resistance traits at ages one to three years. The proportion of dominance variance for height and diameter had reduced to zero by age six years. Based on these promising results, further breeding and pilot-scale family forestry and clonal forestry deployment is being undertaken. These results have also provided insights regarding the choice of a future hybrid breeding strategy.

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