Heterosis and combining ability in a diallel cross of chilli (Capsicum annum L.)

1976 ◽  
Vol 87 (2) ◽  
pp. 447-449 ◽  
Author(s):  
A. C. Soh ◽  
T. C. Yap ◽  
K. M. Graham

SummaryIn a 7×7 diallel-cross experiment utilizing parents with varying resistance to mosaic virus disease and of different horticultural types significant heterosis over the better parent was found in number of days between sowing and flowering and over the mean of the two parents in other characters. The combining ability analysis revealed that genetic control of most character variation was due to additive effects.It is suggested that pedigree and/or backcross methods are most appropriate for improving this chilli population.

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.


2011 ◽  
Vol 24 (2) ◽  
pp. 01-08
Author(s):  
B. Kumar ◽  
N. K. Patra

Opium poppy (Papaver somniferum L.) is an important medicinal plant produces more than 80 alkaloids obtained from the capsules and straw of the plant. The estimate of combining ability gives an indication of the genetic behaviour of the parental material. It is therefore, desirable to select the parents for hybridization on the basis of their per se performance and combining ability effects. The F1, F2 and their reciprocals of an eight parent diallel cross in opium poppy were studied for combining ability of seven economic traits. The mean sum of squares due to GCA, SCA and reciprocals were significant for all the traits. The magnitude of GCA variances were invariably higher than those of SCA and thus indicating the preponderance of non-additive genetic variances, which was further affirmed by the measure of average degree of dominance i.e. ?(?2s/? 2g).  Among the parents VN35I for plant height, Sanchita and VG26 for capsules per plant, VN23, VN35I and Vivek for capsule index, VG26 and Sanchita for seed and straw yield per plant, and VN35I and VG20 for morphine content were found good general combiners. Earliness being a desired trait, parent VG20 having significant negative GCA estimates coupled with per se performance can be considered as good general combiner for early flowering. Inclusion of good general combiners in a multiple crossing program or an inter-mating population involving all possible crosses among them subjected to bi-parental mating may be expected to offer maximum promise in breeding for economic traits.DOI: http://dx.doi.org/10.3329/bjpbg.v24i2.17000


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.


1990 ◽  
Vol 115 (3) ◽  
pp. 509-512 ◽  
Author(s):  
Geok Yong Tan

Six Trinitario females of cacao (Theobroma cacao L.) were crossed with nine Amazonian males in a factorial crossing design. The 54 hybrid progenies were used to estimate genetic variability due to general combining ability (GCA) and specific combining ability (SCA) for yield, pod production, pod weight, husk content, number of beans per pod, average bean weight, and pod value. The results demonstrated that GCA differed significantly for all characteristics from all three sources (Le., female + male, female, and male). SCA (female × male) was also significantly different for all characteristics. The ratio of GCA to SCA ranged from 7.1 for number of beans per pod to 25.7 for pod weight. This result suggested that a major portion of the genetic variability was additive in nature for these characteristics. Among the six Trinitarios, KA2-106 was the best female parent; it contributed high yield and all the desirable pod and bean characteristics into the hybrid progenies. Trinitario KA2-101 combined high pod production and yield, but tended to transmit below-average pod and bean characteristics to its progenies. Amazonians KEE6 and KEE12 were the two highest-yielding male parents, but had below-average bean number per pod and average bean weight. KEE42 and KEE43 combined high yield and transmitted good pod and bean characteristics to their progenies. Based on the GCA effects and the mean performance of the hybrid progenies, a multi-line cultivar consisting of 20 high-yielding crosses with good pod and bean characteristics is being produced in seed gardens for commercial planting.


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.


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.


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