scholarly journals The partial circulant diallel cross at the interpopulation level

1999 ◽  
Vol 22 (2) ◽  
pp. 249-255 ◽  
Author(s):  
José B. Miranda Filho ◽  
Roland Vencovsky

The partial circulant diallel cross mating scheme of Kempthorne and Curnow (Biometrics 17: 229-250, 1961) was adapted for the evaluation of genotypes in crosses at the interpopulation level. Considering a random sample of n lines from base population I, and that each line is crossed with s lines from opposite population II, there will be ns sampled crosses that are evaluated experimentally. The means of the ns sampled crosses and the remaining n(n - s) crosses can be predicted by the reduced model <img src="http:/img/fbpe/gmb/v22n2/0291e1.gif" align="absmiddle"> where Yij is the mean of the cross between line i (i = 1,2,...,n) of population I and line j (j = 1',2',...,n') of population II; µ is the general mean, and gi and gj refer to general combining ability effects of lines from populations I and II, respectively. Specific combining ability (Sij) is estimated by the difference <img src="http:/img/fbpe/gmb/v22n2/0291e2.gif" align="absmiddle">. The sequence of crosses for each line (i) is [i x j], [i x (j + 1)], [i x (j + 2)], ..., [i x (j + s -1)], starting with i = j = 1 for convenience. Any j + s -1 > n is reduced by subtracting n. A prediction procedure is suggested by changing gi and gj by the contrasts <img src="http:/img/fbpe/gmb/v22n2/s_ti.gif" alt="s_ti.gif (188 bytes)"> i = <img src="http:/img/fbpe/gmb/v22n2/s_ytra.gif" alt="s_ytra.gif (986 bytes)"> i. - <img src="http:/img/fbpe/gmb/v22n2/s_ytra.gif" align="absmiddle"> .. and <img src="http:/img/fbpe/gmb/v22n2/s_ti.gif" align="absmiddle">j = <img src="http:/img/fbpe/gmb/v22n2/s_ytra.gif" align="absmiddle">.j - <img src="http:/img/fbpe/gmb/v22n2/s_ytra.gif" align="absmiddle">..; the correlation coefficient (r) was used to compare the efficiency of <img src="http:/img/fbpe/gmb/v22n2/s_gtil.gif" align="absmiddle">'s and <img src="http:/img/fbpe/gmb/v22n2/s_tiac.gif" align="absmiddle">'s for selection of lines and crosses. The analysis of variance is performed with the complete model Yij = µ + gi + gj + sij + <img src="http:/img/fbpe/gmb/v22n2/s_e_.gif" align="absmiddle">ij, and the sum of squares due to general combining ability is considered for each population separately. An alternative analysis of variance is proposed for estimation of the variance components at the interpopulation level. An analysis of ear length of maize in a partial diallel cross with n = 10 and s = 3 was used for illustration. For the 30 interpopulation crosses analyzed the coefficient of determination (R2), involving observed and estimated hybrid means, was high for the reduced (g) model [R2 (<img src="http:/img/fbpe/gmb/v22n2/s_yac.gif" align="absmiddle">ij, Yij) = 0.960] and smaller for the simplified (<img src="http:/img/fbpe/gmb/v22n2/s_ti.gif" align="absmiddle">) model [R2 (<img src="http:/img/fbpe/gmb/v22n2/s_yac.gif" align="absmiddle">ij, Yij) = 0.889]. Results indicated that the proposed procedure may furnish reliable estimates of means of hybrids not available in the partial diallel.

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.


2017 ◽  
Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽  
pp. 600-603
Author(s):  
B. Gelvonauskis ◽  
D. Gelvonauskienė

Apple cultivars were crossed according to the half-diallel and topcross mating design. Apple scab resistance of seedlings was estimated by using a 0–5 scale: 0 – no infection on leaves, 5 – more than 75% of leaf area infected. Percentage of scab resistant seedlings in crosses involving cultivars Prima varied from 35.8% to 67.6%, involving cultivars Florina and Arbat – 51.9–59.5% and 53.5–72.5%, respectively. Significant differences for resistance to scab were found among the crosses. Both general combining ability (GCA) and specific combining ability (SCA) were highly significant. The significance of GCA for scab resistance shows that genetic variability exists for this trait and selection should result in genetic progress, because the mean square for GCA was larger than that calculated for SCA. Therefore, selection of parents on its phenotype should be effective for development of resistant apple cultivars. The significant SCA estimates indicate that a large number of resistant seedlings from particular crosses should be selected.


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.


2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Edy Kurnianto ◽  
Mukh Arifin ◽  
Prasetyo Nugroho

Suatu penelitian telah dilakukan untuk mengevaluasi general combining ability (GCA) dan specific cobining ability (SCA) untuk sifat produksi dan reproduksi pada babi. Materi yang digunakan adalah catatan keturunan hasil persilangan tiga bangsa babi (Duroc, Landrace, Yorkshire) sebanyak 573 anak babi yang berasal dari 13 pejantan dan 65 induk. Formula yang digunakan untuk menganalisis parameter adalah Partial Diallel Cross Metode II dari Griffings. Parameters yang diamati pada anak adalah litter size, bobobt lahir, jumlah puting, pertambahan bobot badan (PBB) sebelum dan sesudah sapih dan bobot sapih. Hasil penelitian menunjukkan bahwa GCA Duroc lebih tinggi dibandingkan Yorksire and Landrace, yang nilai GCA untuk litter size, bobot lahir, jumlah puting, jumlah anak pada saat sapih, bobot sapih, PBB sebelum sapih, PBB setelah sapih dan bobot badan pada umur 42 hari masing-masing -0,18; -0,02; -0,52; -0,13; -0,21; -0,01; 0,01 dan 0,03. Persiilangan antara Duroc x Yorkshire menunjukkan SCA paling tinggi untuk bobot lahir (0.30), jumlah puting (3.60), bobot sapih (1.10) dan PBB sebelum sapih (0.04). Persilangan antara Yorkshire x Landrace menghasilkan SCA paling tinggi untuk litter size (2.47), jumlah anak waktu sapih (2.23), PBB sebelum sapih (0.04), PBB setelah sapih (0.06) and bobot badan pada umur 42 hari (2.30). Kesimpulan penelitian ini adalah nilai paling baik untuk GCA ditunjukkan oleh Duroc, sementara itu SCA oleh persilangan antara Yorkshire x Landrace.


2020 ◽  
Vol 8 (5) ◽  
pp. 819-829 ◽  
Author(s):  
Xin Wang ◽  
Zhenliang Zhang ◽  
Yang Xu ◽  
Pengchen Li ◽  
Xuecai Zhang ◽  
...  

1985 ◽  
Vol 15 (6) ◽  
pp. 1142-1148 ◽  
Author(s):  
Carl W. Mize ◽  
Richard C. Schultz

Many researchers set up an experiment, make measurements, do an analysis of variance, calculate the mean response for each treatment, and then try to decide if the treatment means are significantly different and why. Duncan's multiple-range test is frequently used to test the difference among treatment means. It is, however, only one of a number of techniques that can be used to examine treatment means. Some researchers are unaware of the different techniques and that the interpretation of the results of an experiment can be strongly influenced by the technique used. In fact, using an inappropriate technique can lead to making incorrect recommendations and to completely missing major treatment effects. Selection of the appropriate technique to use for a particular experiment depends upon the nature of the treatments and the objectives of the research. This paper discusses four techniques (ranking treatment means, multiple comparison procedures, fitting response models, and using contrasts to make planned comparisons) that can be used to examine treatment means and presents examples of each one.


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


1999 ◽  
Vol 22 (3) ◽  
pp. 451-456 ◽  
Author(s):  
Cleso Antônio Patto Pacheco ◽  
Cosme Damião Cruz ◽  
Manoel Xavier dos Santos

The objective of the present work was to provide a methodology to study the inheritance of adaptability and stability through the breakdown of Eberhart and Russell regression coefficients and regression deviations in effects due to the mean and additive genetic effects (gi's and gj's) as well as dominance effects (sij's) of Griffing´s methodology, when the diallel is conducted in several environments. It was concluded that the adaptability and stability parameters are determined in the same manner as are genetic effects. So an F1 cross inherits half the general combining ability (GCA) mean effect from each parent, while the effects due to specific combining ability (SCA) are subjected to the same considerations relative to sij's, i.e., they are dependent on specific combinations.


2004 ◽  
Vol 60 (4) ◽  
Author(s):  
M. Conradie ◽  
E. Smit ◽  
M. Louw ◽  
M. Prinsloo ◽  
L. Loubser ◽  
...  

Background and purpose: Physiotherapists frequently use central posterior-anterior (PA) joint mobilization techniques for assessing and managing spinal disorders. Manual examination findings provide the basis for the selection of treatment techniques. From the literature it is evident that the level of reliability varies when physiotherapists perform different mobilization techniques. Repeatability of mobilization techniques is important for better physiotherapy management. The aim of the study was to determine whether experienced physiotherapists apply equal magnitude of force during a grade I central PA mobilisation technique on the cervical spine. Another aim was to determine the variation in the magnitude of forceapplied by each individual physiotherapist. Subjects: Sample of convenience, consisting of sixteen (n=16) selected qualified physiotherapists with experience inOrthopaedic Manual Therapy.Methods: A grade I central PA was performed on the Flexiforce TM sensors positioned on C6 of the same asymptomatic model to measure the applied magnitude of force. Two separate measurements, each lasting 30-seconds, were obtained.Results: The average maximum peak force applied by the majority of physiotherapists (87.5%) was between 10.95gand 72g. The difference in the forces applied for the two measurements ranged between 0.64g and 24.4g. The BlandAltman scatterplot determined the mean of the difference between measurement one and two, calculated for the group, was zero. When comparing the two measurements, little variation was noted in the forces applied, as well as the coefficient of variation for each physiotherapist.Conclusion and Discussion: Current results demonstrated good intra-therapist and moderate to good inter-therapist repeatability. Further research is required to generalize results.


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