COMBINING ABILITY FOR YIELD OF SYNTHETIC HEXAPLOID WHEATS

1974 ◽  
Vol 54 (2) ◽  
pp. 235-239 ◽  
Author(s):  
R. J. BAKER ◽  
P. L. DYCK

Four hexaploid spring wheats (Triticum aestivum L.), which differ only in their D genomes, were crossed in all combinations. Heterosis was expressed in F1 and F2 for number of spikes, kernel weight, and seed yield. Failure to detect significant specific combining ability among F1 progeny suggests that only additive genetic variance is involved in the inheritance of these traits. Competition between single-spaced plants was detected.

Author(s):  
Ranjana Patial ◽  
R. K. Mittal ◽  
V. K. Sood ◽  
Shahnawaz Ahmed

An experiment was carried out in blackgram using line x tester mating design to estimate the GCA effect of parents and SCA effect of 54 hybrids for yield and its traits using 27 lines and two testers. The relative estimates of variance due to specific combining ability (SCA) were higher than general combining ability (GCA) variances for all twelve traits, indicating predominance of non-additive gene action. Combining ability estimates showed significant genetic variance in lines for all traits whereas testers had significant genetic variance for nine traits. On the basis of GCA effects, among the lines and testers IC-436910, IC-413306, IC-398973, IC-343885 and HPBU-111 respectively, were good combiners for most of the traits and can be used in future breeding programme. Specific combining ability studies indicated cross IC-436910 x HPBU-111 as best specific combiner for the economically important traits viz., plant height, branches per plant, seed yield per plant and days to 75% maturity. Such crosses could be further exploited to obtain transgressive segregants in future breeding programme.


2014 ◽  
Vol 39 (2) ◽  
pp. 283-291 ◽  
Author(s):  
MN Amin ◽  
M Amiruzzaman ◽  
A Ahmed ◽  
MR Ali

Combining ability was studied for kernel yield and yield components in a 8×8 diallel cross of waterlogged tolerant maize. Significant general and specific combining ability variances were observed for all the characters studied. Additive genetic variance was preponderant in plant height, ear height, ear length, ear diameter, and kernel weight and non-additive gene action was involved in days to silking, number of kernels per ear and kernel yield. The parental lines E-31 and E-79 were found to be the best general combiners for yield. The good combining parents for different traits could be used in hybridization to improve yield and other desirable traits as donor parents for the accumulation of favourable genes. The cross combinations, E 31× E 40, E 31× E 64, E 31× E 79, E 38× E 40, E 58× E 79, E 63× E 79, E 64 × E 79 showing significant and positive sca effects can be used for commercial hybrid variety development after verifying them at different locations. DOI: http://dx.doi.org/10.3329/bjar.v39i2.20430 Bangladesh J. Agril. Res. 39(2): 283-291, June 2014


2015 ◽  
Vol 3 (2) ◽  
pp. 118-127 ◽  
Author(s):  
Habtamu Zeleke

Combining ability analysis for grain yield and yield component traits in maize were carried out in 8×8 diallel cross. The analysis of variance showed there is highly significant variation between the genotypes for all the traits considered. Year of testing was significant only for days to maturity and grain yield per hectare. The highest percentage of heterosis for grain over the standard varieties (BH 660) was observed by the cross L1 x L4 (29.3%) followed by crosses L1 x L5 (28.3%), L3 x L5 (21.7%) and L1 x L7 (20.8%). Mid-parent heterosis for days to maturity ranged from -2.5 to -23.9%, whereas that of better parent heterosis ranged from 0 to -13% indicating that the hybrids tend to be earlier in maturity than the parents. The mean squares due to GCA for days to maturity, ear diameter, member of kernels per row, 1000 kernel weight and grain yield were significant, indicating the importance of additive genetic variance in controlling these traits. The mean squares due to SCA were also significant for days to maturity, ear length, member of kernels per row and 1000 kernel weight indicating the importance of non-additive genetic variance in controlling these traits. The inbred lines L1, L3, and L4 were good general combiners for grain yield.


1966 ◽  
Vol 8 (1) ◽  
pp. 129-135 ◽  
Author(s):  
J. C. Bowman ◽  
J. S. Broadbent

This paper reports a paternal half sib analysis of data collected over 3 years to estimate additive genetic variance of growth between birth and 16 weeks in crossbred progeny derived from Down rams. The data were divided into two groups and pooled estimates of parameters obtained by two methods. The paternal half sib intra-class correlations varied between 0·017 and 0·057 depending on pooling group and method. It is suggested that such low correlations arise because (a) most of the lambs in the study were still sucking at slaughter, close to 16 weeks of age, and the trait measured is thus largely influenced by maternal milking ability (b) the selection practised in the Down breeds may have been effective and reduced genetic variation and (c) there is considerable inbreeding in the Down breeds.In further analysis of data from four farms involving rams mated to more than one breed of ewe there was limited evidence of specific combining ability of growth between birth and 16 weeks of age for Welsh ewes compared to ewes of other breeds.


1971 ◽  
Vol 13 (1) ◽  
pp. 110-114 ◽  
Author(s):  
P. D. Walton

A diallel cross among eight spring wheat cultivars examined the inheritance of yield, its components, certain developmental stages and morphological characters above the flag leaf node. Additive genetic variance was important for all the characters studied. For yield, kernels per ear, ear volume and for the developmental stages considered dominance was also present. Results presented here agreed with the main conclusions drawn in four other diallels crosses which were reported previously.


Crop Science ◽  
2016 ◽  
Vol 56 (3) ◽  
pp. 1025-1035 ◽  
Author(s):  
Juthamas Fakthongphan ◽  
R.A. Graybosch ◽  
P.S. Baenziger

Sign in / Sign up

Export Citation Format

Share Document