scholarly journals Hybridizing ability and heterosis between Eucalyptus urophylla and E. tereticornis for growth and wood density over two environments

2014 ◽  
Vol 63 (1-6) ◽  
pp. 15-23 ◽  
Author(s):  
Q. Weng ◽  
X. He ◽  
F. Li ◽  
M. Li ◽  
X. Yu ◽  
...  
Keyword(s):  
Wood Density ◽  
Genetic Correlations ◽  
Female Parent ◽  
Hybrid Breeding ◽  
Eucalyptus Urophylla ◽  
Narrow Sense Heritability ◽  
Gene Effects ◽  
Additive Gene ◽  
Factorial Mating ◽  
Hybrid Growth

Abstract Interspecific hybrids of Eucalyptus urophylla × E. tereticornis in a factorial-mating design were used to analyze general hybridizing ability (GHA), specific hybridizing ability (SHA) and heterosis for height (H; 0.5, 1.5, 2.5, 4 and 7.5 years in age), diameter at breast height (D; ages 1.5, 2.5, 4 and 7.5) and wood density (WD; age 7.5) across two environments. The GHA variances were significant for all traits, and those of the SHA were also significant for most of the traits but with less magnitude, indicating the greater importance of additive gene effects in explaining the phenotypic variation among hybrids. The narrow-sense heritability (h2) and dominance (d2) estimates with hybrid growth and wood density ranged between 0.02±0.05 (d2 in D7.5) and 0.23±0.10 (d2 in H1.5) over the different ages, suggesting weak additive and dominant effects on these traits. Additive genetic correlations of growth with wood density were weak at age 7.5. Female general combining ability (GCA) based on maternal open-pollinated families was not necessarily a good indicator of GHA as their correlations were 0.48 (P=0.17), 0.65 (P=0.04) and -0.56 (P=0.10) for H7.5, D7.5 and WD7.5, respectively. A great proportion of hybrids showed positive female-parent heterosis (FPH) at age 7.5, with the highest relative FPH of 47.2% in D7.5. This study demonstrates the heterosis between inter-sectional species and could have implications for E. urophylla × E. tereticornis hybrid breeding.

scholarly journals Evaluating Genetic Parameters and Combining Ability of Starch Viscosity Parameters in Rice Cultivars (Oryza sativa L.)

2019 ◽  
Vol 7 (4) ◽  
pp. 665
Author(s):  
Alireza Haghighi Hasanalideh ◽  
Mehrzad Allahgholipour ◽  
Ezatollah Farshadfar
Keyword(s):  
Combining Ability ◽  
Gene Action ◽  
Oryza Sativa L ◽  
Block Design ◽  
Breeding Methods ◽  
Narrow Sense ◽  
Narrow Sense Heritability ◽  
Gene Effects ◽  
Diallel Mating Design ◽  
Additive Gene

This study was undertaken to assess the combining ability of 6 rice varieties, for viscosity parameters and determining gene action controlling Rapid Visco Analyser (RVA) characters. F2 progenies derived from a 6×6 half diallel mating design with their parents were grown in a randomized complete block design with three replications at the research farm of Rice Research Institute of Iran (RRII) in 2015. The diallel analysis by Griffing`s method indicated the involvement of additive and non-additive gene actions controlling RVA traits. For traits PV and FV RI18447-2 and IR50 were the best combiners for increasing and decreasing, respectively. Deylamani and IR50 were the best combiners for increasing and decreasing BV, respectively. Beside, due to more portion of non-additive gene action in controlling trait SV, The Gilaneh × RI18430-46, and Deylamani × RI18430-46 crosses were the best for increasing and decreasing SV, respectively. The high estimates of broad sense heritability and narrow sense heritability for BV and FV, indicated the importance of additive effects in expression of these traits. Therefore, selection base breeding methods will be useful to improve these traits and selection in the early generations could be done to fix the favourable genes. Low estimate of narrow sense heritability for SV revealed that non-additive gene effects play important role in controlling setback viscosity. So, hybrid base breeding methods will be useful to improve this trait.

Implications of selection history on genetic architecture of growth, form, and wood-quality traits in Pinus radiata

2008 ◽  
Vol 38 (9) ◽  
pp. 2372-2381 ◽  
Author(s):  
S. Kumar ◽  
R. D. Burdon ◽  
G. T. Stovold ◽  
L. D. Gea
Keyword(s):  
Wood Density ◽  
Pinus Radiata ◽  
Wood Quality ◽  
Genetic Correlations ◽  
Wood Properties ◽  
Radiata Pine ◽  
Single Pair ◽  
Narrow Sense Heritability ◽  
Tree Form ◽  
Selection History

Clonal trials of Pinus radiata D. Don (radiata pine), representing two populations (or breeds), one selected for growth and form (GF) and the other selected for high wood density as well as growth and form (HD), were replicated on two low-altitude New Zealand sites: Tarawera (pumice soil, 38°08′S) and Woodhill (coastal dune, 36°42′S). The GF material comprised 33 pair-crosses (19 parents) × 10 clones, and the HD material comprised 19 single-pair crosses (35 parents) × 10 clones, with six ramets per clone per site. Diameter (DBH), two tree-form variables, and needle retention (NRA) were assessed 8 years after planting, and wood density (DEN), acoustic velocity, and collapse were assessed 9 years after planting. The site differences were generally expressed more strongly in the GF population. Estimated genetic parameters were mostly similar for the two breeds, except that genotypic correlation between DBH and DEN was apparently zero in the HD population. Estimated broad-sense heritabilities (H2) were generally markedly higher than narrow-sense heritability estimates (h2), except with DEN. Estimated between-site type-B clonal genotypic correlations were generally high (>0.8) for wood properties. Overall, DBH showed adverse genetic correlations with wood properties. The Elite/Breed strategy appeared to be helpful in combating adverse genetic correlations.

INHERITANCE OF PERICARP THICKNESS IN SHORT SEASON MAIZE INBREDS

1975 ◽  
Vol 17 (4) ◽  
pp. 621-629 ◽  
Author(s):  
L. C. Ho ◽  
L. W. Kannenberg ◽  
R. B. Hunter
Keyword(s):  
Heritability Estimate ◽  
Narrow Sense Heritability ◽  
Gene Effects ◽  
Partial Dominance ◽  
Epistasis Analysis ◽  
Graphic Analysis ◽  
Additive Gene ◽  
Short Season ◽  
High Level ◽  
Pericarp Thickness

Pericarp thickness of 16 short-season inbred lines of corn (Zea mays L.) ranged from 35 to 126 μm with an overall mean of 82 ± 5 μm. The mode of inheritance of this trait was studied in two experiments. Two inbreds representing the extremes of pericarp thickness, their F1 and F2 generations, and both first generation backcrosses were included in Experiment 1. The inheritance of pericarp thickness proved to be quantitative in nature. All gene effects were significant, but epistatic effects, particularly dominance × dominance, were the largest in this particular cross. This could have resulted from bias due to linkage disequilibrium. Experiment 2 was a diallel set of 5 inbreds to include the parents and all possible single crosses, but not reciprocals. Diallel graphic analysis of these data indicated partial dominance for thin pericarp with minimal epistasis. Analysis II of Gardner and Eberhart showed that the mean square for line effects was several times larger than the heterosis estimates, indicating a high level of additive gene effects. The narrow sense heritability estimate was 72%. Thus selection for specific pericarp thickness should be effective and relatively rapid.

scholarly journals DIALLEL ANALYSIS OF ROUGH BLOSSOM-END SCARRING IN TOMATO

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1172e-1172
Author(s):  
J. H. M. Barten ◽  
J. W. Scott ◽  
J. Elkind ◽  
N. Kedar
Keyword(s):  
Gene Action ◽  
Dominant Gene ◽  
Fruit Size ◽  
Diallel Analysis ◽  
Genetic System ◽  
Narrow Sense Heritability ◽  
Gene Effects ◽  
Breeding Programs ◽  
Additive Gene ◽  
Half Diallel

A half diallel including 11 parents was conducted under high temp. conditions in Florida and low temp. conditions in Israel. Blossom scar (BS) size was measured relative to the fruit size for 20 mature fruits per plot. Griffing's analysis showed that both GCA and SCA effects were highly significant at both locations (p< 0.0001). Analysis according to Hayman indicated no epistatic effects. In both environments, additive and dominant gene action was significant (p < 0.0005), although the additive gene effects were most important. Averaged over all loci, the incomplete dominance was in the direction of small BS. Narrow sense heritability estimates were 0.62 and 0.57 for Florida and Israel, respectively. Combined analysis showed that the genetic system was unstable over the 2 environments, as both additive and dominant gene effects interacted significantly with environment (p < 0.0001). The implication for breeding programs is that hybrid performance should be tested at several locations to insure stability of small BS.

EPISTATIC BIAS IN ADDITIVE AND DOMINANCE VARIATION AND GENETIC ASSOCIATIONS BETWEEN TWO QUALITY TRAITS IN BREAD WHEAT

1972 ◽  
Vol 14 (1) ◽  
pp. 49-55 ◽  
Author(s):  
K. S. Bains ◽  
K. S. Gill ◽  
K. L. Sehgal
Keyword(s):  
Grain Protein ◽  
Asymmetric Distribution ◽  
Quality Traits ◽  
Genetic Associations ◽  
Narrow Sense Heritability ◽  
Gene Effects ◽  
Epistatic Interactions ◽  
Additive Component ◽  
Additive Gene ◽  
Dominance Variation

Grain protein and Pelshenke value in 8 × 8 diallel crosses and after eliminating the interacting arrays were genetically analysed. All the dominance variation for grain protein was due to epistatic interactions. The dominance component for Pelshenke value was considerably inflated by epistasis. For both characters, the dominance component was affected more by the epistatic bias than the additive component of genetic variance, resulting in considerably low narrow-sense heritability estimates. Covariance between grain protein and Pelshenke value was primarily due to additive gene effects and was attributed to pleiotropic relationships in the absence of genetic linkage. An ambidirectional trend of dominance with an asymmetric distribution of dominant and recessive alleles among the cultivars was observed for grain protein, whereas preponderance of the dominant decreasing genes with more isodirectional gene distribution was operative for Pelshenke value. Correlated responses of these quality traits to selection due to high additive genetic correlation and degree of co-inheritance in relation to their gene action is stressed.

scholarly journals Genetic analysis of some agronomic traits in groundnut (Arachis hypogaea L.)

2014 ◽  
Vol 3 (2) ◽  
pp. 31-35
Author(s):  
MK Alam ◽  
UK Nath ◽  
MAK Azad ◽  
MA Alam ◽  
AA Khan
Keyword(s):  
Arachis Hypogaea ◽  
Harvest Index ◽  
Agronomic Traits ◽  
Kernel Weight ◽  
Narrow Sense Heritability ◽  
Additive Variance ◽  
Gene Effects ◽  
Degree Of Dominance ◽  
Arachis Hypogaea L ◽  
Additive Gene

A 10×10 half diallel experiment was conducted on groundnut (Arachis hypogaea L.) to ascertain the gene action and genetic parameters of ten traits including 50% flowering, no. of pods per plant, plant height, harvest index, pod index, 100 pod weight, 100 kernel weight, pod size, diseases infection and yield per plot. The experiments were carried out in the Department of Genetics and Plant Breeding, Bangladesh Agricultural University (BAU), Mymensingh during the cropping season of 2010-2011. The estimates of gene effects indicated that significance of both additive and non-additive variance for pod size, 100 pod weight and diseases infection among the traits and presence of over dominance satisfying assumptions of diallel except dormancy. However, both the additive and non-additive gene affects together importance to control of most quantitative traits in the groundnut. The average degree of dominance (H1/D) 1/2 (H1 = dominance variance, D = additive variance) was higher than one, indicating over dominance for all the traits. The narrow-sense heritability was high for 50% flowering (38%), harvest index (35%), pod size (52%), 100 pod weight (35%) and yield per plot (41%) indicating that great genetic gain could be achieved for them. DOI: http://dx.doi.org/10.3329/ijarit.v3i2.17841 Int. J. Agril. Res. Innov. & Tech. 3 (2): 31-35, December, 2013

scholarly journals Genetics of angular leaf spot (ALS) resistance in South African market class dry bean (Phaseolus vulgaris) cultivars

2020 ◽  
pp. 1589-1594
Author(s):  
Josephine T. Pasipanodya ◽  
Rob Melis ◽  
Deidre Fourie
Keyword(s):  
Leaf Spot ◽  
Angular Leaf Spot ◽  
Additive Effects ◽  
Narrow Sense ◽  
Narrow Sense Heritability ◽  
Gene Effects ◽  
Dry Bean ◽  
Best Management ◽  
Additive Gene ◽  
Pseudocercospora Griseola

Angular leaf spot (ALS) caused by Pseudocercospora griseola (Sacc.) is one of the serious fungal diseases affecting dry bean in Africa, including South Africa. Host plant resistance is the best management strategy, of which its effectiveness requires knowledge of the genetics underlying the resistance in guiding breeding efforts. In this study, the inheritance of ALS resistance was studied through the generation mean analysis biometrical procedure. Six generations consisting of the two parents Ukulinga and Gadra, and its cross derived filial progenies (F1), second-generation (F2), and backcrosses of F1 to Ukulinga (BCP1) and Gadra (BCP2) were planted in a net-house and later inoculated using a mixture of P. griseola isolates. Leaf lesions (% disease severity) were rated using a CIAT 1-9 scale and analysed using SAS macros in Proc GLM of SAS version 9.3. Results of ANOVA for a full model displayed significant additive effects (P<0.05) and highly significant (P<0.001) additive x dominance effects. Segregation analysis indicated 9:7 ratio, implying the involvement of complementary gene effects. The number of genes was estimated to be 1.79; however, due to epistasis two or more genes possibly govern the resistance in this cross. Broad and narrow sense heritabilities were 0.40 and 0.33, respectively. Therefore, the estimated narrow-sense heritability, additive gene effects, and epistatic interaction imply that it is prudent to delay selections until later stages, in which homozygosity could be achieved and additive effects fixed.

scholarly journals Age trends in genetic parameters of wood density components in 46 half-sibling families of Pinus pinaster

2008 ◽  
Vol 38 (6) ◽  
pp. 1470-1477 ◽  
Author(s):  
Maria João Gaspar ◽  
José Luís Louzada ◽  
Maria Emília Silva ◽  
Alexandre Aguiar ◽  
Maria Helena Almeida
Keyword(s):  
Wood Density ◽  
Pinus Pinaster ◽  
Wood Quality ◽  
Genetic Correlations ◽  
Ring Width ◽  
Seed Orchard ◽  
Narrow Sense Heritability ◽  
Clonal Seed Orchard ◽  
Ring Number ◽  
Latewood Density

This study contributes to the Pinus pinaster Ait. breeding programme, which is reaching the third generation by adding information on wood quality of 46 open-pollinated families from a progeny trial located in Leiria, Portugal, that originated from seed collected in a clonal seed orchard. A total of 552 seventeen-year-old trees were sampled at 2 m height. Trends were studied from the pith outward in variance components and narrow-sense heritability (h2) of wood density components and ring-width characteristics as well as genetic correlations between cambial ages. Mean ring density (RD), minimum density (MND), maximum density (MXD), earlywood density (EWD), latewood density (LWD), earlywood width, latewood width, ring width, latewood percentage, and heterogeneity index were determined using X-ray densitometry procedures. RD had higher genetic control (h2 = 0.63), and heritability values of earlywood components (h2MND = 0.54, h2EWD = 0.60) exceeded those of latewood components (h2MXD = 0.34, h2LWD = 0.26). Heritabilities increased with ring number from pith for almost all wood density components, and there were high age–age genetic correlations for wood density traits (rg > 0.98).

scholarly journals Association of Pedicel Length and Diameter with Fruit Length and Diameter and Ease of Fruit Detachment in Pepper

1990 ◽  
Vol 115 (4) ◽  
pp. 677-681 ◽  
Author(s):  
Ridwan Setiamihardja ◽  
Dean E. Knavei
Keyword(s):  
Capsicum Annuum ◽  
Genetic Correlations ◽  
Fruit Characteristics ◽  
Gene Effects ◽  
Fruit Length ◽  
Detachment Force ◽  
Additive Gene Effects ◽  
Pedicel Length ◽  
Additive Gene ◽  
Fruit Diameter

Genetic correlations for pedicel length and diameter, fruit length and diameter, and fruit detachment force (FDF) were determined in three pepper (Capsicum annuum L.) families from crosses of `Serrano Chili' (low FDF) with three cultivars (`Anaheim Chili', `Keystone Resistant Giant', and `Red Cherry Small') characterized by high FDF and different fruit characteristics. Pedicel and fruit length means of F1 generations were nearly intermediate, while pedicel and fruit diameter means were shifted toward `Serrano Chili'. Progeny distributions in F2 generations were continuous and F2 means slightly less than the F1 means. Generation mean analyses indicated gene effects for pedicel and fruit length to be mostly additive. Gene effects for pedicel and fruit diameter were also mostly additive. Pedicel length was positively correlated genetically with fruit length, and pedicel diameter was positively correlated with fruit diameter. FDF means were positively correlated with pedicel and fruit length and diameter in most segregating generations. In BCP2 (`Serrano Chili' × `Red Cherry Small'), FDF was negatively correlated with pedicel and fruit length. Pendant fruit in BCP2 (`Serrano Chili' × `Red Cherry Small') were longer and narrower than upright fruit and FDF decreased with increased length of both pedicel and fruit.

scholarly journals Genetic inheritance of photoperiod sensitivity in Runner bean (Phaseolus coccineous L.)

2019 ◽  
pp. 1511-1519
Author(s):  
Mable. M. Mulanya ◽  
Paul. M. Kimani ◽  
Rama D. Narla ◽  
Pascal Okwiri Ojwang
Keyword(s):  
Female Parent ◽  
Photoperiod Sensitivity ◽  
Day Length ◽  
Dominance Model ◽  
Gene Effects ◽  
Short Day ◽  
Long Day ◽  
Runner Bean ◽  
Additive Gene ◽  
Bulk Breeding

Lack of information on the mode of inheritance of photoperiod sensitivity is a constraint to genetic improvement of tropically adapted vegetable runner bean. This study was conducted to determine the inheritance of short-day photoperiod in runner beans. Seven single crosses between female parent; White Emergo (long day imported variety) and seven short day local landraces (Kin 1, Kin 2, Kin 3, Nyeri, Dwarf1, Dwarf 2 and Dwarf 3) were developed in Kenya. The parents, F1, F2 and backcrosses were evaluated at Kabete (warm conditions) and Ol Joro-Orok (cool condtions) under the natural short-day length of 12hrs. From the results, short day parents flowered earlier (within 40-48 days) and formed more racemes (on average 10 racemes/plant) and pods (at least 25pods/plant) than long day parent (White Emergo) at both locations. The populations in the seven cross combinations flowered earlier at the warmer location (Kabete) than cooler one (Ol Joro Orok). In all crosses, F1 and F2 means of days to flowering and number of racemes were within parental range while the backcrosses’ showed means that were close to their recurrent parents. The additive-dominance model [m+a+d] was found to adequately explain the genetic influence on studied traits with additive gene effects accounting for about 90% of the genetic action. The predominance of additive gene action indicates that improvement of this crop for short day adaptation can be easily achieved by trait integration through hybridization followed by pure selection methods such as single seed descent, bulk breeding or pedigree.

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