scholarly journals Combining Ability and Gene Action Estimates of Eight Parent Diallel Crosses of Chickpea for Ascochyta Blight

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Mohamed Labdi ◽  
Samia Ghomari ◽  
Samia Hamdi

Ascochyta blight resistance was studied in half-diallel cross involving eight genotypes of chickpea at seedling and adult stages. The disease was rated in the greenhouse with a modified scale from 0 to 100%. The diallel analysis was performed on 28 F1 and their F2. The results were analyzed with the Hayman and Griffing methods. The general combining ability is most important for two generations, is highly significant for the two stages, and is more important than specific combining ability. This result reflects a strong preponderance of additive effects and epistasis additive × additive with respect to dominance effects in this material for the two generations, which shows the predominance of additive versus dominance. Estimates of heritability are very high. The additive effects have the highest value indicating the importance of this component for resistance toAscochyta. For seedling stage, the negative sign of F for both generations indicates that there are much more recessive alleles that affect resistance to the disease. In adult stage, F is positive in both generations and shows more dominant alleles that control plant reaction to pathogen. H2is positive in both generations which show that dominant genes are acting mostly towards the susceptibility.

1970 ◽  
Vol 12 (3) ◽  
pp. 484-489 ◽  
Author(s):  
Bronius Povilaitis

The eight tobacco cultivars Delcrest, Hicks Broadleaf, Yellow Gold and Jamaica Wrapper of the flue-cured type and Burley 1, Burley 21, Virginia B29 and Kentucky 12 of the burley type and their crosses and reciprocals were grown in an 8 × 8 diallel-cross experiment. Diallel analyses were completed according to procedures described by Hayman, Griffing and Robinson.The mean squares for general combining ability and for Hayman's a made up a considerably higher proportion of the total variability than the other subdivisions. The variances for special combining ability were in all instances smaller than those for general combining ability, although there were differences in size and in levels of significance between Griffing's and Robinson's methods. The statistic due to additive effects of genes (Hayman's D) was significant for days to flower, height, and number of leaves, and the statistic due to dominance effects significant for days to flower and height. The greatest effect in decreasing the number of days to flower was exhibited by the cultivar Delcrest, and the greatest effect in increasing the number of days to flower was by Yellow Gold and Kentucky 12. Kentucky 12 showed the greatest effect in increasing height and number of leaves.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 772F-772
Author(s):  
Cheryld L. Emmons ◽  
J.W. Scott

To investigate the genetic control of rain check (cuticle cracking) in tomato (Lycopersicon esculentum), a full diallel cross including five parents ranging from very resistant to very susceptible was grown in late spring 1994. A randomized complete-block design with four replications was used and the proportion of fruit showing check was measured on all mature fruit from eight plants per replication at three harvests. Analysis of variance indicated significant (P < 0.0001) variation for line, harvest, and line by harvest interaction. The proportion of fruit affected increased with each successive harvest. Reciprocal differences were tested on a by-harvest basis and found to be nonsignificant. Reciprocals were combined and a Hayman's analysis was performed on a by-harvest basis on the means. Additive effects on variance were significant (P < 0.05) for all harvests. Under high environmental stress (harvest 3), dominance effects were negative and significant (P < 0.05). Narrow-sense heritability ranged from 0.54 to 0.67 and increased with increasing environmental stress. General combining ability was significant for all harvests, whereas specific combining ability was significant only for harvest 3 (P < 0.05).


2016 ◽  
Vol 41 (3) ◽  
pp. 565-577 ◽  
Author(s):  
MZA Talukder ◽  
ANM S Karim ◽  
S Ahmed ◽  
M Amiruzzaman

Combining ability and heterosis were studied in a 7×7 half diallel cross in maize for grain yield and yield contributing characters. Significant general and specific combining ability variances were observed for all the characters studied. The significant estimates of GCA and SCA variances suggested the importance of both additive and non-additive gene actions for the expression studied traits. In these studies, variances due to SCA were higher than GCA for all charactesr, which revealed the predominance of non additive gene action (dominance and epistasis) for controlling these traits. Parents P1 and P4 were excellent general combiner for days to tasseling and silking while P1 and P5 for early maturity. P4 for short height and, P4 and P7 for higher thousand kernel weight. The parents P4 and P6 having good combining abilities for yield. Heterosis estimation was carried out using two commercial varieties NK40 and 900MG. When standard commercial check NK40 was used, the percent heterosis for kernel yield varied from -51.39 to 12.53%. Among the 21 F1s, 3crosses exhibited significant positive heterosis for kernel yield. The highest heterosis was exhibited by the cross P4×P6 (12.43%), P6×P7 (10.89%) and P2×P3 (9.87%) respectively. Compared with 900MG as check, the percent heterosis for kernel yield varied from -53.73 to 7.01%. Among the 21 F1s, none of the crosses exhibited significant positive heterosis for kernel yield. The highest heterosis were exhibited by the crosses P4×P6 (7.01%), P6 x P7 (5.55%) and P2×P3 (4.57%). The crosses showed significant positive SCA values could be used for variety development after verifying them across the agro-ecological zones of Bangladesh.Bangladesh J. Agril. Res. 41(3): 565-577, September 2016


1999 ◽  
Vol 133 (4) ◽  
pp. 371-377 ◽  
Author(s):  
X. G. ZHANG ◽  
R. S. JESSOP ◽  
F. ELLISON

Root re-growth, following aluminium (Al) stress, has been used as an indicator of Al stress tolerance. Genetic variation in root re-growth characteristics among eight triticale genotypes was investigated by a diallel analysis. Highly significant variation due to both general combining ability (GCA) effects and specific combining ability (SCA) effects indicated that both additive effects and non-additive effects were important in explaining the genetic variation for Al tolerance. The high estimates of heritability and the predictability ratio for root re-growth revealed the preponderance of additive genetic variance in the inheritance of Al tolerance. Differences in patterns of GCA effects and SCA effects among the parents provided strong evidence that the genetic control of variation for Al tolerance as assessed by root re-growth was a complex polygenic system. Three Al-tolerant genotypes, Tahara, Abacus, and 19th ITSN 70–4, were found to be the best general combiners for larger root re-growth, and they could be used in hybridization programmes to improve Al stress tolerance by following a simple pedigree method of selective breeding.


2018 ◽  
Vol 31 (1) ◽  
pp. 40-47 ◽  
Author(s):  
ERINA VITÓRIO RODRIGUES ◽  
KAESEL JACKSON DAMASCENO-SILVA ◽  
MAURISRAEL DE MOURA ROCHA ◽  
EDSON ALVES BASTOS ◽  
ADRIANO DOS SANTOS

ABSTRACT The low use of technologies by farmers and the occurrence of biotic and abiotic stresses are limiting factors for cowpea production in the Brazilian Northeast region. The tolerance of genotypes to drought is an alternative to decrease the negative effects of stresses on cowpea production. Thus, the objective of this work was to identify parents and combinations of cowpea genotypes with high probability of generating segregating populations with tolerance to drought. Six cowpea genotypes were crossed in a complete diallel cross design, totaling 30 F2 populations, which were evaluated together with their parents in an experiment under water deficit at the experimental field of the Embrapa Mid-North, Teresina, State of Piauí, Brazil. A triple lattice incomplete block experiment design was used, with three replications, with experimental plot consisting of six 2-m plant rows. Fifteen plants per plot were sampled to evaluate their agronomic characteristics, whose results were subjected to analysis of variance and means were used to estimate the general and specific combining abilities. The genotypes showed significant differences in all characteristics evaluated, denoting the genetic variability of the population. The additive effects were more important than the non-additive effects, and maternal inheritance was detected. The genotypes BRS Xiquexique, Pingo-de-Ouro-1-2 and MNC99-510F-16-1 were the most promising for use in recurrent selection programs for tolerance to water deficit. The hybrid combinations (1) BRS Paraguaçu X (4) CNCx-698-128G, (2) Pingo-de-Ouro-1-2 X (3) BRS Xiquexique, (3) BRS Xiquexique X (5) Santo-Inácio, (4) CNCx-698-128G X (6) MNC99-510F-16-1 and (5) Santo-Inácio X (4) CNCx-698-128G showed potential for generating superior lineages regarding bean production and tolerance to water deficit.


1979 ◽  
Vol 21 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Wai-Koon Tan ◽  
Geok-Yong Tan ◽  
P. D. Walton

Twenty-one progenies and the parents of a 7 × 7 half diallel cross of smooth bromegrass (Bromus inermis Leyss.) were evaluated at four locations in Alberta in each of two years, for genetic variation and genetic by environment interactions in the expression of their yield potentials. Years, locations and their interactions were highly significant in the combined analysis of variance. Combining ability analysis revealed that general combining ability (GCA) and specific combining ability (SCA) were both important in the expression of yield, including spring, fall and annual yield, whereas GCA was more important than SCA for yield per area. Although the genotype × environment interactions were all highly significant, variation accounted for by combining ability effects was generally higher than the interaction effects of GCA and SCA respectively, with environments. High average GCA effects for spring, fall and annual yield were demonstrated for the clones UA5, UA9 and B42. These together with the high average SCA effects suggested that the three clones could be included in a synthetic to develop high yielding cultivars. The results suggested that recurrent selections involving multi-location and multi-year testing seems necessary in breeding for high yielding bromegrass cultivars in Alberta.


2021 ◽  
Vol 117 (2) ◽  
pp. 1
Author(s):  
Liudmila Andreevna RUDAS ◽  
Mariya Viktorivna TORBANYUK ◽  
Zinovy Deonizovich SYCH

<p> Five parental forms of tomato (Solanum lycopersicum L.) and twenty hybrids F1, were studied which were obtained by the complete diallel scheme (5 x 5). For genetic analysis (by Hayman, 1954; Jinks,1954) was used line №477 (sp,u), variety Alya (sp) with reduced  duration of vegetation period and three collection samples with the high lycopene content in fruits: Dark Green (hp-2dg), МО 112 (hp), Т˗3627 (Bc). The effects of the general (GCA) and specific combining ability (SCA) of the duration of vegetation period were determined and established character of inheritance. According to the results of research, the duration of vegetation period is controlled by additive-dominant genetic system. Inheritance occurs by type of over dominance, and in dry and hot summers which led to the prolongation of the duration of vegetation period, there is a tendency to incomplete dominance, but it is apocryphal. In genetic control a major role play non-additive effects of genes. The best reliable effects of the general combining ability (GCA) had line №477 and variety Alya. They can be recommended for the creation of heterotic hybrids and varieties.</p>


2020 ◽  
Vol 50 (2) ◽  
Author(s):  
José Galdino Cavalcante Neto ◽  
Karmita Thainá Correia Ferreira ◽  
Fernando Antonio Souza de Aragão ◽  
Rafaela Priscila Antônio ◽  
Glauber Henrique de Sousa Nunes

ABSTRACT: Melon or muskmelon (Cucumis melo L.) is of considerable economic importance in Brazil. Nearly all the cultivars currently grown are hybrids. Heterosis has been used to advantage in the melon plant, and the use of uniform hybrids is one of the reasons for successful cultivation. The aim of the present study was to evaluate the agronomic potential of yellow melon lines and hybrids. An experiment was conducted in randomized blocks with three replications to evaluate 24 hybrids generated by crosses among three elite lines used as female parents (AF-01, AF-02, and AF-03) and eight lines used as male parents (LAM-01, LAM-02, LAM-03, LAM-04, LAM-05, LAM-06, LAM-07, and LAM-08). Yield and fruit quality traits were evaluated. Partial diallel analysis was carried out to estimate general combining ability and specific combining ability. Additive and non-additive effects were observed for the yield, mean fruit weight, and pulp thickness traits. The lines AF-02, LAM-02, and LAM-03 are the most promising as parents as they more frequently have favorable alleles. The most prominent hybrids in diallel analysis were AF-02 x LAM-02, AF-02 x LAM-03, AF-02 x LAM-04, and AF-03 x LAM-06.


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