Diallel crosses of honeybees. II A note presenting an estimate of the heritability of honey production under Australian conditions

1987 ◽  
Vol 38 (3) ◽  
pp. 651 ◽  
Author(s):  
BP Oldroyd ◽  
C Moran ◽  
FW Nicholas

A partial diallel cross of honeybees (Apis mellifera L.) was formed. Combining ability analysis of variance was used to estimate additive and non-additive genetic variance in seasonal colony weight gain for the artificial 'population' studied. The values determined were: general combining ability variance, 12.14 kg2 (s.e., 11.42); specific combining ability variance, 11 -96 kg2 (s.e., 13.71); environmental variance, 21.65 kg2 (s.e., 8.84); heritability of honey production, 0.42 (s.e., 0.24). The phenotypic standard deviation was 7.6 kg.The results suggest that selection for colony weight gain would be successful.

1987 ◽  
Vol 40 (1) ◽  
pp. 57 ◽  
Author(s):  
BP Oldroyd ◽  
C Moran

Nine lines of honeybees were used to form a 9 x 9 partial diallel cross. Hamuli number was determined for samples of worker offspring. One set of workers was reared in non-maternal colonies which had been made uniform, as far as possible, with respect to colony strength (number of workers), while another set was sampled directly from the combs of each maternal colony. Combining ability analysis of variance revealed significant additive and non-additive genetic effects for both sets of data, regardless of whether inbred parentals were included or excluded from the analysis. Uniform rearing removed average heterosis and reciprocal effects.


1970 ◽  
Vol 33 (3) ◽  
pp. 375-379 ◽  
Author(s):  
AKMM Alam ◽  
S Ahmed ◽  
M Begum ◽  
MK Sultan

Combining ability analysis for grain yield and its contributing characters in maize were carried out in 5×5 diallel cross. The highest percentage of heterosis for grain per ear over mid parent and better parent were observed by the cross P2×P3. Crosses P1×P3 and P1×P5 showed significant negative heterosis for days to maturity. Significant general and specific combining ability variances were observed for all the characters except ear height. Almost equal role of additive and non-additive gene actions was observed for days to maturity. Additive genetic variance was preponderant for grains per ear and 1000-grain weight and non-additive gene action was involved in plant height, ear height, days to silking, and days to maturity. The inbred lines P2 and P5 were found to be best general combiner for 1000-grain weight. Key Words: Heterosis, combining ability, grain yield, maize. doi:10.3329/bjar.v33i3.1596 Bangladesh J. Agril. Res. 33(3) : 375-379, September 2008


1985 ◽  
Vol 12 (2) ◽  
pp. 55-57 ◽  
Author(s):  
S. N Nigam ◽  
S. L Dwivedi ◽  
P. T. C Nambiar ◽  
R. W Gibbons ◽  
P. J Dart

Abstract Analysis of a six parent diallel cross involving high and low nitrogen fixing peanut (Arachis hypogaea L.) genotypes revealed the predominant nature of non-additive genetic variance for nitrogenase activity and other traits. Germplasm line, NC Ac 2821 had the highest general combining ability for nitrogenase activity, total nitrogen, leaf area, and top weight, and therefore, it should be a good parent for use in breeding programs. Nitrogenase activity was significantly and positively correlated with nodule number, nodule mass, total nitrogen, top weight, and root weight. This evidence suggests the possibility of breeding for increased nitrogen fixation and thus yield in peanut.


Genetika ◽  
2017 ◽  
Vol 49 (3) ◽  
pp. 1001-1014 ◽  
Author(s):  
Hasanalideh Haghighi ◽  
Ezatollah Farshadfar ◽  
Mehrzad Allahgholipour

In order to study the combining ability, genetic parameters and gene actions of yield, yield components and quality characters in rice, fifteen F2 generation of a 6?6 diallel cross, excluding reciprocals, was grown in a randomized complete block design (RCBD) with three replications. The results of analysis of variance showed significant differences between the genotypes for grain yield (GY), 100-grain weight (HGW), number of panicles per plant (PN), panicle length (PL), number of full grains per panicle (FGN) and for quality characters including amylose content (AC) and gel consistency (GC). The results of combining ability analysis revealed that general combining ability (GCA) and specific combining ability (SCA) were significant for characters GY, FGN, GC, AC, HGW and PN indicating the involvement of additive and non-additive effects in their inheritance, however high amounts of Bakers ratio remarked that additive gene effect had more portion in controlling these traits. The best combiners for GY, HGW, FGN, PN and PL, were RI18447-2, IR 50, Daylamani, RI18430-46 and Daylamani respectively. For AC and GC, the best combiner was Daylamani. Hayman's graphs showed that regression line passed below the origin cutting Wr axis in the negative region for HGW, PN, PL and GC, indicating the presence of over dominance. Estimates of genetic parameters showed significant amount of H1 and H2, and non-significant amount of D for the characters GY, PN, PL and GC, which confirmed the existence of dominance in the inheritance of these traits.


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.


1983 ◽  
Vol 42 (2) ◽  
pp. 207-217 ◽  
Author(s):  
Hidenori Tachida ◽  
Muneo Matsuda ◽  
Shin-Ichi Kusakabe ◽  
Terumi Mukai

SUMMARYUsing the 602 second chromosome lines extracted from the Ishigakijima population of Drosophila melanogaster in Japan, partial diallel cross experiments (Design II of Comstock & Robinson, 1952) were carried out, and the additive genetic variance and the dominance variance of viability were estimated. The estimated value of the additive genetic variance is 0·01754±0·00608, and the dominance variance 0·00151±0·00114, using a logarithmic scale. Since the value of the additive genetic variance is much larger than expected under mutation–selection balance although the dominance variance is compatible with it, we speculate that in the Ishigakijima population some type of balancing selection must be operating to maintain the genetic variability with respect to viability at a minority of loci. As candidates for such selection, overdominance, frequency-dependent selection, and diversifying selection are considered, and it is suggested that diversifying selection is the most probable candidate for increasing the additive genetic variance.


2017 ◽  
Vol 9 (1) ◽  
pp. 324-331
Author(s):  
Y. A. Lyngdoh ◽  
R. Mulge ◽  
A. Shadap ◽  
Jogendra Singh ◽  
Seema Sangwan

Line × tester analysis was carried out with the objective of identifying the good combiners and to decide the breeding strategies for developing potential and productive genotypes or cultivars. Parents and hybrids differed significantly for GCA and SCA effects for all the characters respectively. Specific combining ability (SCA) variance was higher than the general combining ability (GCA) variance which shows the predominance of non-additive gene action for the improvement of all the characters studied. The parents and crosses having highest and significant GCA and SCA effects viz., KO-18 (13.69), KO-6 (9.54) and KO-2 × Parbhani Kranti (19.28) for plant height; KO-12 (0.34), KO-14 (0.19) and KO-5 × V5 (0.60) for number of branches per plant; KO-14 (-0.66) and KO-15 × Arka Anamika(-1.66) for days to first flowering; KO-1(1.10), Arka Anamika (0.46) and KO-9 × VRO-5 (3.28) for fruit length; KO-7 (7.91), VRO-5(1.68) and KO-18 × VRO-6 (8.64) for average fruit weight; KO-2 (1.18) and KO-17 × Arka Anamika (2.80) for number of fruits per plant; KO-9(0.05), VRO-6 (0.01) and KO-11 × VRO-6 (0.10) for total yield per plant were identified as good general and specific combiners. The results establish the worth of heterosis breeding for effective usage of non-additive genetic variance in okra.


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