Expected efficiencies of mating designs for reselection of parents

1990 ◽  
Vol 20 (10) ◽  
pp. 1664-1671 ◽  
Author(s):  
R. D. Burdon ◽  
J. P. van Buijtenen

Expected efficiencies, in terms of genetic gain from reselection of parents (backwards selection), were compared for hierarchical mating, factorial, partial factorial, modified half diallel, and partial diallel crossing designs and polycrosses; this was done in parallel with a separate study of expected efficiencies for advanced-generation (forwards) selection, assuming a fixed-resources model of 100 parents and 10 000 offspring. The present study considered a single-trait case, with variable numbers of crosses per parent, varying heritability (h2) levels (h2 = 0.1, 0.2, and 0.5), and varying ratios of specific combining ability to general combining ability variance (0, 0.5, and 1). Compared with the case of forwards selection, the relative efficiencies of the different designs were generally similar. Two notable exceptions were the comparative inefficiency of small, disconnected factorial sets for backwards selection and the generally high (but not always maximal) efficiency of polycrosses for this purpose.

Plant Omics ◽  
2020 ◽  
pp. 7-14
Author(s):  
Jose Ricardo Bagateli ◽  
Carlos André Bahry ◽  
Raimunda Nonata Oliveira da Silva ◽  
Ivan Ricardo Carvalho ◽  
Giordano Gelain Conte ◽  
...  

This study aimed to estimate the general and specific combining ability of partial soybean diallel crossings. The parents were divided in two groups contrasting for the characteristics of mass of thousand seeds, maturity group, flowers’ color, lodging and growth aspect. The scheme of partial diallel followed the Griffing model, where it were included the parents and the F1 generation. There was predominance of additive genic effects for the characteristics number of seeds per pods, number of seeds per plant and plants height. For number of pods per plant, seeds per plant and mass of hundred seeds the dominance effects were expressed by the superiority of specific combining ability in the determination of these characters. The parents G3 and G7 were the ones that contributed the most to the increase in yield in function of general combining ability for the characters number of pods per plant, seeds per plant, plant yield and mass of hundred seeds. The hybrids from the crossings between G3 x G5 and G3 x G4 are more promising for the characteristics related to yield, since they present elevated heterosis effect and high specific combining ability associated to increase general combining ability presented by the parent G3.


1970 ◽  
Vol 21 ◽  
pp. 270-273
Author(s):  
O. M. Tsereniuk ◽  
O. V. Akimov ◽  
O. I. Chalyi ◽  
Yu. V. Chereuta

Aim. Poltava Meat and Welsh pigs breed reciprocal crossing combination ability study. Methods. The combination ability evaluation method, the method of incomplete diallel crossing. The traditional methods of pigs general and specific combining ability effects estimation. Results. The Rosinka family sows were characterized by positive values of general combining ability, except the prolificacy rate. The Bystra family sows by the multiple pregnancy and milk production indexes had positive values of general combining ability, but by a nest weight at a birth and weaning – negative. For the Vorskla family sows the positive indexes of general combining ability were identified for a nest weight at a birth only, for the rest indexes – the negative value of general combining ability were installed. The Rosinka family sows had the positive value of specific combining ability for all maternal productivity indxes. The Bystra family sows were characterized by positive value of specific combining ability only for a nest weight at a birth and milk production indexes. The Vorskla family sows by the all maternal productivity indexes had negative specific combining values. Conclusions. For complex reproductive ability indexes for various lines and families combinations the highest positive effect of specific combining values was obtained for Rosinka family sows combinations of Poltava meat breed with the Welsh breed boars. Keywords: pigs, Welsh breed, Poltava Meat breed, reproductive ability, combining ability.


2019 ◽  
Vol 48 (2) ◽  
pp. 231-237
Author(s):  
Tao Yang ◽  
Yawen Zeng ◽  
Juan Du ◽  
Shuming Yang ◽  
Xiaoying Pu

Genetic analysis of 4 major flavonoids in barley interspecific hybrids which were used as parents for half diallel crossingwas carried out. Compared with seven parents, the highest general combining ability of catechin content was Clipper barley, the higest general combining ability (GCA) of myricetin content were Schooner barley and Huangchangguang barley, the highest general combining ability of quercetin content were Ziguangmang barley and Kuanying barley, the highest general combining ability of kaempferol content were Ziguangmang barley and Schooner barley, the highest general combining ability of flavonoids are Schooner barley and Huangchangguang barley. The hybrid combination of a good matching were Clipper barley, Schooner barley, Ziguangmang barley and Kuanying barley, as a comprehensive general combining ability, specific combining ability, and combinations of which can be used as flavonoids in barley breeding.


2020 ◽  
Vol 18 (1) ◽  
pp. 18-25
Author(s):  
FMA Haydar

Inheritance of grain yield, heterosis and combining ability were investigated in maize populations obtained from half-diallel crossing among six inbred parental lines. General (GCA) and specific (SCA) combining ability effects were significantly different among parental lines. The grain yield was under the partial gene effect. The parents P1, P3 and P5were considered suitable according to their yield contributing attributes couple with general combining ability effects. The midparentheterosis values ranged from -27.246 (P2 xP5) to 15.209% (P1 xP2) whereas the better parent heterosis values varied between 22.375(P2x P3) to 40.363% (P2 x P5) only seven crosses had higher grain yields. Of those crosses, P1×P2, P2×P5 and P1×P3 were considered most promising hybrids yielding heterosis as 15.880%, 20.363% and 40.363 respectively over their parents. The Agriculturists 2020; 18(1) 18-25


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.


1969 ◽  
Vol 11 (4) ◽  
pp. 810-822 ◽  
Author(s):  
D. R. Knott ◽  
S. S. Sindagi

Diallel crosses were made among six varieties of hard red spring wheat that differed considerably in yield and other characteristics. The F1 hybrids were tested at two seeding rates and the F2, hybrids at one. Heterosis was not great in either generation and no cross appeared to be promising. General combining ability was much more important than specific combining ability and parental yields gave reasonable predictions of hybrid yields. Yields of hybrids at the two seeding rates were closely correlated.


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.


Author(s):  
В. В. Ващенко ◽  
О. О. Шевченко

У системі діалельних схрещувань п’яти сортів яч-меню ярого (Донецький 12, Донецький 14, Донецький 15,Прерія, Галактик) установлено особливості генети-чного контролю мінливості ознак: висота рослин,кількість зерен у колосі, маса 1000 зерен у відповід-ності зі співвідношенням варіанс специфічної комбі-наційної здатності (СКЗ) і загальної комбінаційноїздатності (ЗКЗ). Виділено й запропоновано сорти якджерела ознак висота рослин Галактик і Донецький14; кількість зерен у колосі – сорт Прерія; маса 1000зерен – сорт Донецький 15. Виділені зразки з високимі стабільним рівнем комбінаційної здатності запро-поновано використовувати в селекційній роботі. A total of diallel analysis varieties of springbarley Donetskiy 12, Donetskiy 14, Donetskiy 15,Prairie, Galactic set features genetic controlvariability characteristics: plant height, number ofgrains per ear, 1000 grain weight in accordance withthe ratio of variance of specific combining ability(SSI) and general combining ability (ZKZ).Identified and proposed as a source of variety traitsplant height and Donetsk 14, Galactic, the numberof grains per ear sort Prairie, weight of 1000 grainsDonetskiy 15. Samples of high and stable levels ofcombining ability is proposed to use in breedingwork have beeen celected.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Jeffrey N. Wilson ◽  
Michael R. Baring ◽  
Mark D. Burow ◽  
William L. Rooney ◽  
Charles E. Simpson

Peanut (Arachis hypogaeaL.) has the potential to become a major source of biodiesel, but for market viability, peanut oil yields must increase. Oil yield in peanut is influenced by many different components, including oil concentration, seed mass, and mean oil produced per seed. All of these traits can potentially be improved through selection as long as there is sufficient genetic variation. To assess the variation for these traits, a diallel mating design was used to estimate general combining ability, specific combining ability, and heritability. General combining ability estimates were significant for oil concentration, weight of 50 sound mature kernels (50 SMK), and mean milligrams oil produced per SMK (OPS). Specific combining ability was significant for oil concentration. Reciprocal effects were detected for OPS. Narrow-sense heritability estimates were very high for oil concentration and 50 SMK and low for OPS. The low OPS heritability estimate was caused by the negative correlation between oil concentration and seed size. Consequently, oil concentration and seed mass alone can be improved through early generation selection, but large segregating populations from high oil crosses will be needed to identify progeny with elevated oil concentrations that maintain acceptable seed sizes.


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.


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