A STUDY OF COMBINING ABILITY FOR GRAIN PROTEIN PERCENTAGE IN A DIALLEL CROSS OF FIVE SIX-ROW BARLEY CULTIVARS

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.

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.


2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Fernando Lisboa Guedes ◽  
Rafael Parreira Diniz ◽  
Marcio Balestre ◽  
Camila Bastos Ribeiro ◽  
Renato Barbosa Camargos ◽  
...  

The objective of our study was to characterize and determine the patterns of genetic control in relation to tolerance and efficiency of nitrogen use by means of a complete diallel cross involving contrasting inbred progenies of tropical maize based on a univariate approach within the perspective of a multivariate mixed model. Eleven progenies, previously classified regarding the tolerance and responsiveness to nitrogen, were crossed in a complete diallel cross. Fifty-five hybrids were obtained. The hybrids and the progenies were evaluated at two different nitrogen levels, in two locations. The grain yield was measured as well as its yield components. The heritability values between the higher and lower nitrogen input environment did not differ among themselves. It was observed that the general combining ability values were similar for both approaches univariate and multivariate, when it was analyzed within each location and nitrogen level. The estimate of variance of the specific combining ability was higher than general combining ability estimate and the ratio between them was 0.54. The univariate and multivariate approaches are equivalent in experiments with good precision and high heritability. The nonadditive genetic effects exhibit greater quantities than the additive genetic effects for the genetic control of nitrogen use efficiency.


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.


1981 ◽  
Vol 23 (3) ◽  
pp. 373-378 ◽  
Author(s):  
Shri Dhar Lal ◽  
Jitendra Nath Seth

A 10 × 10 complete diallel cross was carried out in the strawberry (Fragaria × ananassa Duch.). Significant general (gca) and specific combining ability (sea) effects were recorded. The variances due to general combining ability exceeded the variances due to specific combining ability. Cytoplasmic effects were also noted. The variety Kalimpong Local was found to be a good general combiner for number of inflorescences, number of flowers and number of fruits. The variety Albritton had highest gca effect for number of inflorescences. The variety Premier was a good general combiner for number of flowers. The Redcoat showed highest gca effect for days to maturity. The best specific combination for number of inflorescences was Phenomenal × Jeolikote Local in F1 and Premier × Kalimpong Local in F2. For number of fruits Albritton × Kalimpong Local and Premier × Cavalier were the best.


1974 ◽  
Vol 54 (1) ◽  
pp. 29-34 ◽  
Author(s):  
K. G. BRIGGS

A complete diallel cross of Bonanza, Conquest, Galt, Jubilee, and Olli barley was made and the parents, F1 and F2 bulks, were subjected to a kernel-sizing procedure, using five different standard sieves. Mean values for the P, F1, and F2 were obtained and heritabilities and estimates of general (GCA) and specific (SCA) combining ability were calculated. Reciprocal effects were not significant in either F1 or F2. For the F1 data significant differences could only be found on the 19 × 2.4-mm (3/4 × 6/64-inch) sieve. Only GCA was significant for the F1, suggesting additive gene action. By contrast, in the F2 GCA was highly significant for all sieve sizes from 19 × 2.2 mm (3/4 × 11/128 inch) upwards, and SCA was significant on those of size 19 × 2.4 mm (3/4 × 6/64 inch) upwards. For the F2 on the 2.4-mm (6/64-inch) screen, the SCA effect exceeded the GCA effect in magnitude, and was in a negative direction, contributing to the two cases of negative heterosis for kernel plumpness. No significant positive heterosis was found in F2, and F2 bulks were normally intermediate in value to their parents. The amount of SCA effect was unrelated to the degree of similarity of the parents by pedigree, or to whether they were malting or feed types. Bonanza, Conquest, and Jubilee were significantly plumper than Galt and Olli, and Olli transmitted its less plump kernel type to the F2 generation, as indicated by its large negative GCA effect. None of the other cultivars exhibited significant GCA effects. Little progress in increasing kernel plumpness can be expected from crosses between these cultivars, as heritabilities were also generally low.


1966 ◽  
Vol 46 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Eric D. Putt

Heterosis occurred for the eight plant and seed characters studied. It was most frequent for yield of seed and height of plant. Mean squares for general combining ability (gca) and specific combining ability (sca) were significant (P =.01) for all characters. The estimated components for gca were greater than for sca for days to mature, weight per bushel, and percent oil in the seed; less for height and yield of seed; and essentially the same for days to bloom, diameter of head, and weight per 1000 seeds.The yield of seed and percent oil in the seed, for the highest ranking 100 synthetics that could be composed from the 10 lines, was predicted in F6 assuming 50 and 60% outcrossing between F2 and F6. Virtually all values exceeded the mean performance of four check samples of commercial hybrids. Many exceeded the highest rank check for oil content in the seed. Fourteen of the highest ranking 100 synthetics for yield and 30 for oil content consisted of two or three lines. It was concluded that synthetics can be superior to the present hybrids in heterosis and that desirable synthetics can be made from only a few lines.


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.


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