Keywords : Heritability


Estimation of Phenotypic Variance Components, Heritability, Average Degree of Dominance and Genetic Advance for Early Generation in Bread Wheat (Triticum aestivum L.)

Mohammed H. Ayoob

Rafidain Journal of Science, 2019, Volume 28, Issue 1, Pages 11-23
DOI: 10.33899/rjs.2019.159406

Six early generation (B2,B1,F2,F1,P2,P1) of two crosses of bread wheat (Triticum aestivum L.) the first (Intesar × Rabbeaa) and the second (Abo-Greab-3 × Adnanyi) were used to estimate the components of phenotypic variance, heritability, average degree of dominance and expected genetic advance for plant height, number of tillers per plant, grain yield and its components for each cross. The result revealed that additive genetic variance was significant for number of grains per spike, 100 grain weight and grain yield in both crosses while the dominance genetic variance was significant for spike length in the first cross. The studied traits revealed all types of dominance heterosis can be utilized for improve number of tillers per plant in both crosses, plant height, spike length in first cross, number of spike per plant in second cross. The values of broad sense heritability was high for all studied traits in both crosses, the values of narrow sense heritability were high and significant for number of grains per spike, 100 grain weight and grain gield per plant in both crosses, number of spike per plant in first cross, spike length in second cross, medium for plant height and number of tillers per plant in both crosses. The values of expected genetic advance as a percentage of the mean were for number of spikes per plant, 100 grains weight and grain yield per plant in both crosses which indicated that selection in the second filial generation will be effective to improved those traits..

Estimates of Heritability and Average Degree of Dominance by Complete Diallel Crosses Analysis in Hexaploid Wheat (Triticum aestivum L.)

Manal A. AL-Hayali; Najeeb K. Yousif

Rafidain Journal of Science, 2019, Volume 28, Issue 1, Pages 45-52
DOI: 10.33899/rjs.2019.159403

Seven varieties of hexaploid wheat (Triticum aestivum L.) JAWAHIR-20, REYNA-27, ACHTAR, REBWAH-12, REBWAH-12, Ibaa 99and Abo-Gharaib and their full dialed crosses were used in this study. Grains of parental varieties and their hybrids were planted at the college of Agricultural and Forestry University of Mosul using randomized complete block design with four replications, during the growing season (2013-2014), depending on rain fed conditions. Genetical analysis was performed to determine the genetic systems for each of plant height, Number of spikes per plant, biological yield, grain yield, weight of (100) grains and number of grains per spike, and also to estimate, genetical variance components average degree of dominance, heritability. Estimation of genetical parameters ratios indicated that there were different degrees of dominance on the studied traits, and irregular distributions of dominat and receive allels among parents for all traits except for (100) grains weight. There were three groups of dominant genes controlled for (100) grains weight and one for other traits. the broad sense heritability estimate were low for 100 grains weight and height for other traits, however narrow sense heritability estimates were: low for number of spikes, grain yield, and medium for others traits.

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Gene Action, Heritability and Average Degree of Dominanc for Grain Yield and its Components in Durum Wheat

Najeeb K. Yousif; Waleed S. Hamdoon

Rafidain Journal of Science, 2013, Volume 24, Issue 2, Pages 1-8
DOI: 10.33899/rjs.2013.67457

Four cultivars of durum wheat (Triticum durum Desf) were used in two crosses, the first, Leeds x Waha and the second Azeghar x Om rabi-3. The parent generations, first and second filial generations and first and second back crosses from each cross were used to study gene action, heritability, average degree of dominance and expected genetic advance for plant height, number of spikes, grain yield, weight of 100 grains and number of grains per spike. The results revealed that additive dominance model was adequate for weight of 100 grains in the two crosses, while additive, dominance and epistatic gene action played a significant role in the inheritance of other traits. Most of the studied traits revealed over dominance and high to medium narrow sense heritability. The values of expected genetic advance as percentage of the mean indicated that selection in the second filial generation will be effective to improve most of the studied traits.

Keywords: Gene

Genetical Analysis of Self-Fertilized Generation Variances in Two Durum Wheat Crosses

Nabeel T. Al-Badrany; Najeeb K. Yousif; Ghada A. Al-Hamdany

Rafidain Journal of Science, 2012, Volume 23, Issue 6, Pages 68-82
DOI: 10.33899/rjs.2012.59623

Phenotypic variance in parents and third generation were analyzed to estimate the additive genetic variance, dominance genetic variance, environmental variance, average degree of dominance, heritability in broad sense, heritability in narrow sense and expected genetic advance from selection in F3 generation, of two crosses in durum wheat (Triticum durum Desf.), the first cross between Azeghar-1 and Um-Rabie-5 and the second cross between Leeds and Waha for traits, heading time, flag leaf venation, plant height, peduncle length, number of spike, spike length, grain yield, 100 grains weight and number of grains per spike. Average degree of dominance revealed the different types of dominance for the studied traits, the values of narrow sense heritability were high for plant height, peduncle length, number of spikes, grain yield and number of grains per spikes in both crosses, spike length and weight of 100 grains in first cross, and flag leaf venation in second cross.

Estimation of Genetic Parameters and Stability Analysis for Durum Wheat Entries (Triticum durum Desf.)

Arshad T. AL-Nuaimi; Ahmed A. Ahmed

Rafidain Journal of Science, 2011, Volume 22, Issue 2, Pages 37-48
DOI: 10.33899/rjs.2011.31612

Eight durum wheat entries obtained from ICARDA were sown in three seed rates (120,150 and 180 kg/ha) using split plot arrangement according to randomized complete block design with three replications in season 2004 , phenotypic and genetic variances were significant for all traits at the seeding rates. Stability parameters for entries indicated that the entry Azul-5 responds to an un appropriate environments for the number of spikes/m2 and the number of grains/spike , the entry 1346/Lahn/Bcr/Lks4 respond to an un appropriate environments for 1000- grains weight.

The Estimates of Heritability and Expected Genetic Advance by Using Analysis Generation Variances of Self – fertilizing Generations in Bread Wheat

Manal A. Hayalye

Rafidain Journal of Science, 2011, Volume 22, Issue 2, Pages 100-108
DOI: 10.33899/rjs.2011.32392

Four generations (F2 , F3 , Bs5 and Bs3) of two crosses in bread wheat , the first (S3- 69, S6 – 35) and the second (Germany X pandas), were used to study the components of variances , average degree of dominance , heritability and expected genetic advance form selction in the generations F2 , F3 , B1s and B2s for the quantitative traits : grain yield , number of per spikes , weight of 100 grains and number of grains per spike . The results of this study showed that the polygenes revealed over dominance for :
(1) number of spikes and weight of 100 grains in the two crosses . (2) grain yield and number of grains per spike in the first cross .
Broad and narrow sense heritabilities and expected genetic advance were high magnitude for some traits in the studied generations . Selection could used in the four generations to increase the frequency of desirable alleles for weight of 100 grains in the two crosses and recurrent selection could suggested to increase the frequency of desirable alleles for other traits .