Heterotic performance and combining ability in a diallel cross among spring wheats (Triticum aestivum L.)

1971 ◽  
Vol 22 (3) ◽  
pp. 359 ◽  
Author(s):  
GM Bhatt

Levels of hybrid vigour for earliness, plant height, four components of yield, and yield were examined in the F1 generation of a diallel cross of eight cultivars of spring wheat. Kernel weight and kernels per spike exhibited high levels of heterosis effects. The analysis for general combining ability indicated that a large part of the total genetic variation observed for six out of seven traits was associated with genes which were additive in their effects. The estimates for specific combining ability were highly significant for five out of seven traits. These estimates were lower than those of general combining ability for six out of seven traits. The combining ability analysis helped in classifying the parents in terms of their hybrid performance and in gaining greater understanding of the nature of quantitatively inherited traits. The importance of genetic diversity in relation to heterosis was also assessed.

1971 ◽  
Vol 51 (5) ◽  
pp. 377-383 ◽  
Author(s):  
L. P. S. SPANGELO ◽  
R. WATKINS ◽  
C. S. HSU ◽  
S. O. FEJER

General and specific combining abilities were analyzed for total, marketable, early, and late yield, and for flower stalk number in a diallel cross of eight strawberry cultivars. Data were recorded from individual seedlings restricted to two runner plants, thereby eliminating variability resulting from differences in plant density. General and specific combining abilities for the five characters were highly significant. Estimates of general combining ability effects taken alone were, in general, of little value in predicting the order of desirability of individual crosses.


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.


1974 ◽  
Vol 54 (4) ◽  
pp. 605-609 ◽  
Author(s):  
K. G. BRIGGS

Grain protein percentage was assessed in F1 and F2 populations in two experiments involving a complete diallel cross among the barley (Hordeum vulgare L.) cultivars Bonanza, Conquest, Olli, Galt and Jubilee. Heterosis was absent in all crosses and a Griffing combining ability analysis showed that specific combining ability was nonsignificant in both F1 and F2 populations. General combining ability (GCA) for protein percentage was highly significant in both generations, with Conquest and Olli having major positive GCA effects. Galt produced a large negative GCA effect, while Jubilee and Bonanza caused small negative GCA effects. Significant differences between the hybrids were found only in F1. Broad sense heritabilities for protein differences between the parents were 0.57 and 0.72 in the two experiments, and were significant at the 5 and 1% levels of significance, respectively. Conquest had significantly higher protein than Bonanza, with Olli being intermediate. Galt had lower protein than Jubilee, but this difference was significant in only one experiment. The differences among the five cultivars for mean grain protein percentage and general combining ability are significant in relation to breeding for malting and feed type barleys.


1974 ◽  
Vol 10 (4) ◽  
pp. 241-245 ◽  
Author(s):  
K. P. Sinolinding ◽  
A. Rehman Chowdhry

SUMMARYAnalysis of a 4-parent diallel cross showed marked heterosis for yield and its components in two crosses (Mexipak × Dirk and C273 × AU49) under irrigation, while little or negative heterosis occurred under moisture stress. A large part of the genetic variation among crosses for yield, and most components of yield, was attributed to the general combining ability, indicating that the additive effects were important. Reciprocal effects and various interactions were insignificant except for kernel weight, which suggests that effective selection could be made under irrigation of genotypes adaptable to moisture stress.


1976 ◽  
Vol 86 (3) ◽  
pp. 537-542 ◽  
Author(s):  
H. G. Nasr ◽  
W. Khayrallah

SummaryThe F1 and F2 generations of a diallel cross of six-row barley involving the parents, Beecher, Athenais, Atlas 46, 3130-4564-3, and 3130-864-4 were studied and heterosis, inbreeding depression, and combining abilities were measured for grain yield, number of tillers per plant, number of kernels per plant, kernel weight, and plant height. Significant heterosis was detected for grain yield in two of the ten crosses, for number of tillers per plant in one cross, for number of kernels per plant in two crosses, for plant height in three crosses, and for kernel weight in none of the crosses. The inbreeding depression of the F2 generation was present in most cases but significantly so in a few. Atlas 46 x 3130-4564-3 exhibited inbreeding depression for grain yield, number of kernels per plant, and plant height.The general combining ability (GCA) mean squares of both generations were significant for all characters studied except number of kernels per plant in the F1 generation. The specific combining ability (SCA) mean squares were significant for only plant height in the F1 generation and all characters studied except number of tillers per plant in the F2 generation.The GCA effects indicated that Beecher and Athenais are good general combiners for grain yield and its components. The latter parent produced good yielding hybrids with slightly shorter plants than the remaining hybrids.The SCA effects revealed that Athenais × 3130-4564-3, Athenais × 3130-864-4, and Beecher × Atlas 46 seem good specific combinations for high grain yield. Also, the former two crosses tend to produce shorter plants.


2018 ◽  
Vol 49 (6) ◽  
Author(s):  
Hussain & Hussen

The study was carried out  using full diallel cross between six inbred lines of maize, parents and their F1 including reciprocals were planted in 19th march 2014 at field of agriculture college, Duhok University. All treatments arranged in randomized complete block design (RCBD) with three replications to estimate the general and specific combining ability of maize traits in single cross hybrids. According to the mean square values of The results showed that the general combining ability, specific combining ability, and reciprocal combining ability, the general combining ability exhibited significant variance for all traits except days to 75% tasseling and number of kernels row-1, whereas, specific combining ability was non significant for leaf area though its prerogative  for all other traits. The reciprocal combining ability was remarkable  for days to 75% tasseling, plant and ear height, leaf area, ear diameter, ear length, number of rows ear-1, number of kernels row-1, 300- kernel weight and yield plant-1. The hybrid IK8xTH613 displayed the best value for yield plant-1 and IK58XTH613 for days to 75% tasseling, while the reciprocal HSxIK8 was the best for yield plant-1.


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


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