Exploiting combining ability and maternal effects for genotypic selection of best hybrids in sweet corn and normal corn crosses

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.

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Agronomic traits and chemical composition of single hybrids of sweet corn

Horticultura Brasileira ◽

10.1590/s0102-05362011000400015 ◽

2011 ◽

Vol 29 (4) ◽

pp. 531-536 ◽

Cited By ~ 3

Author(s):

Angela Kwiatkowski ◽

Edmar Clemente ◽

Carlos Alberto Scapim

Keyword(s):

Chemical Composition ◽

Crop Yield ◽

Combining Ability ◽

Grain Quality ◽

Sweet Corn ◽

Agronomic Traits ◽

Block Design ◽

Research Station ◽

Randomized Block Design ◽

Fixed Model

In Brazil, the greengrocery market of sweet corn has been expanding along the country. In contrast, there have been few agri-industries canning sweet corn (Zea mays) because of the lack of cultivars with agronomic characteristics proper to industrial purposes. The purpose of this study was to evaluate the general combining ability (GCA) of seven inbred lines of sweet corn, and the specific combining ability (SCA) of their hybrid combinations based on their agronomic traits, and the chemical composition of the grain. In the growing season 2006/2007, twenty-one single hybrids were evaluated in the Iguatemi Research Station, Maringá County, Northwestern Paraná, in Brazil using a complete randomized block design with four replications. Data were subjected to the analysis of variance and the genotypes were clustered by the Scott-Knott test. We estimated the GCA and SCA effects using the Griffing's method IV with the fixed model for plant height (PH), height of ear (EH), dehusked ears yield (DEY), reducing (RS) and total sugars (TS), starch (ST), proteins (PTN), ether extract (EE) and fibers (FB). The inbred line L4, which was originated from the 'Doce de Cuba', had the best GCA for crop yield and grain quality and therefore should be used in the next hybrid combinations. The hybrids L4xL5 and L3xL7 were the most promising with regard to crop yield and grain quality.

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Selección de líneas para formar híbridos de maíz dulce ricos en Lisina l. Probadores.

Agronomía Mesoamericana ◽

10.15517/am.v9i2.20102 ◽

2016 ◽

Vol 9 (2) ◽

pp. 57

Author(s):

María Cristina Vega ◽

Enrique Navarro ◽

José Espinoza ◽

José Luis Guerrero ◽

Gustavo A. Burciaga

Keyword(s):

Inbred Line ◽

Sweet Corn ◽

Agronomic Traits ◽

Average Response ◽

Performance Factors ◽

Grain Color ◽

Color Uniformity ◽

Ear Height ◽

And Performance ◽

Selection Of

Twenty S5 sweet corn lines containing the opaque-2 gene that increases Iysine contents as well as the sugary-2 gene were evaluated. The lines were crossed with three testers: one unrelated inbred line, and two related synthetic varieties. Six commercial and three experimental hybrids were used during the trials. Test crosses were evaluated in two locations of Mexico during 1994 using a randomized complete block designo The experiment's goal was to compare lines' performance in combination with three testers, taking into account yield, soundness, uniformity, and corn quality. The average response of lines combined with testers was superior than that of commercial hybrids for traits such as flowering time and plant and ear height. Performance factors analyzed (ear length, grain color, uniformity, soundness, and number of marketable ears) in trial crosses were superior or equal in average to those in experimental hybrids, but this was not the case with sugar percentage. The best results were observed with the unrelated LD tester inbred line for agronomic traits and performance factors. This study made possible the selection of lines for future breeding based on the above mentioned traits, as well as the general combining ability for ear length and number of green flag leaves.

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Using scab resistant donors in apple breeding

Plant Protection Science ◽

10.17221/10566-pps ◽

2017 ◽

Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽

pp. 600-603

Author(s):

B. Gelvonauskis ◽

D. Gelvonauskienė

Keyword(s):

Combining Ability ◽

Apple Scab ◽

General Combining Ability ◽

Scab Resistance ◽

Mean Square ◽

Genetic Progress ◽

Apple Cultivars ◽

The Mean ◽

Half Diallel ◽

Selection Of

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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