Combining ability and selection for agronomic and nutritional traits in Urochloa spp. hybrids

2021 ◽  
Author(s):  
Beatriz Tomé Gouveia ◽  
Rogério Gonçalves Mateus ◽  
Sanzio Carvalho Lima Barrios ◽  
Cacilda Borges Valle ◽  
Júlio Sílvio Sousa Bueno Filho ◽  
...  
Keyword(s):  
Combining Ability ◽  
Selection For

scholarly journals GENERAL AND SPECIFIC COMBINING ABILITY IN SUNFLOWER (Helianthus annuus L.) / APTITUD COMBINATORIA GENERAL Y ESPECÍFICA EN EL GIRASOL (Helianthus annuus L.) / APTITUDE À LA COMBINATION GENERAL ET SPECIFIQUE CHEZ LE TOURNESOL (Helianthus annuus L.)

Helia ◽  
2001 ◽  
Vol 24 (34) ◽  
pp. 1-16 ◽  
Author(s):  
Domenico Laureti ◽  
Andrea Del Gatto
Keyword(s):  
Helianthus Annuus ◽  
Combining Ability ◽  
Central Italy ◽  
Specific Combining Ability ◽  
First Year ◽  
Male Sterile ◽  
Breeding Programs ◽  
East Central ◽  
Helianthus Annuus L ◽  
Selection For

SUMMARYA total of 245 test cross progenies obtained by crossing cytoplasmic male sterile (CMS) lines and restorer (RHA) lines were evaluated in replicated trials in 1995 and 1997. Experiments were carried out in two locations (Osimo, East Central Italy and Budrio, Northern Italy) in 1995, whereas in 1997 trials were conducted only in Osimo. General combining ability (GCA) and specific combining ability (SCA) of the parents was evaluated to identify genotypes suitable to be used as testers for breeding programs and to verify the performance of hybrids. The results obtained in 1995 were used to make test crosses in 1996 to be evaluated in 1997. The GCA and SCA of RHA and CMS lines were nearly always significant for all the studied traits when lines were randomly taken in 1995. When selected testers were used on the basis of the results of the first year, the SCA of new RHA lines and GCA of new CMS lines were not significant for achene yield, but they were for the other traits.The best GCA estimates for RHA were often higher than those of CMS, indicating that selection for RHA could be more useful than for CMS. As expected, GCA was always lower than SCA. CMS and RHA, with high variance among their test crosses for yield and many other traits, could be used as testers. The lack of a tester with high variance in all traits requires more than one tester in evaluating lines. The GCA of a line can change in function of the germplasm with which it is combined.

scholarly journals Diallelic analysis for lysine and oil contents in maize grains

2009 ◽  
Vol 66 (2) ◽  
pp. 204-209 ◽  
Author(s):  
Leonardo Oliveira Medici ◽  
Salete Aparecida Gaziola ◽  
Vanderlei Aparecido Varisi ◽  
José Antonio Carmezini de Paula ◽  
Renato Rodrigues Ferreira ◽  
...  
Keyword(s):  
Grain Yield ◽  
Combining Ability ◽  
Oil Content ◽  
General Combining Ability ◽  
Lysine Content ◽  
Nitrogen Levels ◽  
N Level ◽  
Complete Series ◽  
Selection For ◽  
Selection Of

Six S5 lines of maize, with differences for lysine and oil contents in grains, were used to carry out a complete series of diallelic crosses. The resulting 15 hybrids were grown in a field at two nitrogen levels (10 and 130 kg N ha-1). The general combining ability (GCA) and specific combining ability (SCA) were obtained by using the method 4, model I of Griffing for grain yield, and grain lysine and oil contents. Significant (p < 0.001) interaction was observed between GCA and N levels for grain yield, indicating the selection of different lines for each N level. This interaction was not significant for lysine content, but there were significant effects of GCA for this trait at both N levels (p < 0.1). Significant effects were not observed for GCA or SCA for oil content, however a positive correlation was observed between lysine and oil contents in the hybrids, in the lines and even in the control cultivars. The results indicate the effectiveness of selection for lysine content, irrespective of N level, in the studied non-opaque maize lines, and the possibility of achieving both high lysine and oil content in grains.

Relations of carbon isotope discrimination and other physiological traits to yield in common bean (Phaseolus vulgaris) under rainfed conditions

1994 ◽  
Vol 122 (2) ◽  
pp. 275-284 ◽  
Author(s):  
J. W. White ◽  
J. A. Castillo ◽  
J. R. Ehleringer ◽  
J. A. C. Garcia ◽  
S. P. Singh
Keyword(s):  
Phaseolus Vulgaris ◽  
Carbon Isotope ◽  
Water Deficit ◽  
Seed Yield ◽  
Combining Ability ◽  
Carbon Isotope Discrimination ◽  
Isotope Discrimination ◽  
Rainfed Conditions ◽  
Mechanisms Of Adaptation ◽  
Selection For

SUMMARYAlthough direct selection for seed yield under water deficit can result in genetic gains in the common bean (Phaseolus vulgaris L.), progress could be enhanced through selection for additional traits that are related to underlying mechanisms of adaptation to water deficit. Carbon isotope discrimination (Δ) has received considerable attention as an indicator of water use efficiency and adaptation to water deficit. To test the utility of Δ as a selection criterion, Δ and other traits were measured in F2 and F3 generations of a nine-parent diallel grown under rainfed conditions at two locations in Colombia with contrasting soil types. An irrigated trial was also conducted at one location. Significant (P 0·05) differences among parents, F2 and F3 were found for carbon isotope discrimination (Δ), leaf optical density (OD), leaf nitrogen (N) and potassium (K) concentrations, relative duration of pod-filling period (RDPF), shoot dry weight (SDW) and harvest index (HI). Effect of location and water regime and their interactions with genotype were also frequently significant. Heritability estimates, determined by regressing the F3 on the F2, ranged from 0·11±011 (S.E.) to 0·33 ±0·10 for OD, 0·22 ± 0·07 to 0·44±0·09 for N, 0·04±0·05 to 0·29±0·08 for K, 0·40 ± 0·08 to 0·43 ± 0·15 for RDPF and 0·30±0·22 to 1·00±0·24 for SDW. All values for Δ and HI did not differ significantly from zero. Correlations between seed yield and OD and RDPF were negative, whereas those with N, K, SDW, and HI were positive. For all traits, mean square values for general combining ability (GCA) were usuall significant and larger than those for specific combining ability (SCA). All significant GCA effects for Δ for ‘Rio Tibagi’, ‘San Cristobal 83’ and ‘Apetito’ were negative, while those for ‘Bayo Rio Grande’, ‘Bayo Criollo del Llano’, ‘Durango 222’ and BAT1224 were positive. Although Δappears unsuitable as an indirect criterion for selection for yield under water deficit, further study of genotypes exhibiting contrasting values of A might reveal differences in mechanisms of adaptation to water deficits, thus leading to other selection criteria or identification of valuable parental lines.

ESTIMATION OF GENERAL AND SPECIFIC COMBINING ABILITIES IN POTATO

1976 ◽  
Vol 18 (3) ◽  
pp. 463-470 ◽  
Author(s):  
G.C.C. Tai
Keyword(s):  
Solanum Tuberosum ◽  
Specific Gravity ◽  
Combining Ability ◽  
Solanum Tuberosum L ◽  
High Yield ◽  
Average Weight ◽  
Stabilizing Selection ◽  
Low Frequencies ◽  
Significant Difference ◽  
Selection For

Seven quantitative traits of the cultivated potato (Solanum tuberosum L.) were studied in a partial diallel cross experiment. Large specific combining ability effects were observed for total and marketable yields, total number of tubers, and number of marketable tubers. Large general combining ability effects were obtained for average weight per tuber, average weight per marketable tuber, and specific gravity. The SCA effect for specific gravity was also significant. It is suggested that the difference of combining ability performance noted above for the two yield components was due to a long history of directional selection for high yield and stabilizing selection for tubers within the marketable size range. There were low frequencies of both GCA and SCA effects showing significant difference from the population mean. This is interpreted as an affirmation of the narrow genetic base which exists in the present gene pool in Solanum tuberosum. Heritability estimates based on GCA effects indicated that parents can be efficiently selected for average tuber weight and specific gravity.

Sign in / Sign up

Export Citation Format

Share Document