scholarly journals Estimates for Genetic Variance Components in Reciprocal Recurrent Selection in Populations Derived from Maize Single-Cross Hybrids

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Matheus Costa dos Reis ◽  
José Maria Villela Pádua ◽  
Guilherme Barbosa Abreu ◽  
Fernando Lisboa Guedes ◽  
Rodrigo Vieira Balbi ◽  
...  

This study was carried out to obtain the estimates of genetic variance and covariance components related to intra- and interpopulation in the original populations (C0) and in the third cycle (C3) of reciprocal recurrent selection (RRS) which allows breeders to define the best breeding strategy. For that purpose, the half-sib progenies of intrapopulation (P11and P22) and interpopulation (P12and P21) from populations 1 and 2 derived from single-cross hybrids in the 0 and 3 cycles of the reciprocal recurrent selection program were used. The intra- and interpopulation progenies were evaluated in a10×10triple lattice design in two separate locations. The data for unhusked ear weight (ear weight without husk) and plant height were collected. All genetic variance and covariance components were estimated from the expected mean squares. The breakdown of additive variance into intrapopulation and interpopulation additive deviations (στ2) and the covariance between these and their intrapopulation additive effects (CovAτ) found predominance of the dominance effect for unhusked ear weight. Plant height for these components shows that the intrapopulation additive effect explains most of the variation. Estimates for intrapopulation and interpopulation additive genetic variances confirm that populations derived from single-cross hybrids have potential for recurrent selection programs.

1998 ◽  
Vol 21 (4) ◽  
pp. 537-544 ◽  
Author(s):  
Carlos Alberto Arrabal Arias ◽  
Cláudio Lopes de Souza Júnior

New genetic variance and covariance components related to intra- and interpopulational recurrent selection methods have been theoretically developed by Souza Jr. (Rev. Bras. Genet. 16: 91-105, 1993) to explain the failure of these methods to concomitantly develop hybrid and per se populations. Intra- and interpopulation half-sib progenies of 100 genotypes were sampled from maize (Zea mays L.) populations BR-106 and BR-105 to estimate variance and covariance components and to compare the expected responses to reciprocal (RRS), intrapopulational (HSS), and modified (MRS) recurrent selection in interpopulation hybrid, populations per se, and to determine heterosis. Four sets of 100 progenies, two intra- and two interpopulational, were evaluated in partially balanced 10 x 10 lattices arranged in split-blocks with two replications in two years (1991/92 and 1992/93) and two locations in Piracicaba, SP. Data for ear weight, plant and ear height, and ear by plant height ratio were recorded. Populations and interpopulation crosses were high yielding and showed high breeding potential for production of hybrids from inbred lines. Mid parent and the highest parent heterosis were relatively high, but lower than values reported for these populations under other environmental conditions. Additive variance estimates of populations per se and interpopulation crosses confirmed the high potential of these materials. The magnitude of the variance estimates for the deviations from intra- and interpopulation additive effects (<img src="http:/img/fbpe/gmb/v21n4/1918f1.jpg" alt="1918f1.jpg (1262 bytes)" align="middle"> for BR-106 and <img src="http:/img/fbpe/gmb/v21n4/1918f3.jpg" alt="1918f3.jpg (1259 bytes)" align="middle">for BR-105) and covariance between additive effects with these deviations (<img src="http:/img/fbpe/gmb/v21n4/1918f2.jpg" alt="1918f2.jpg (2022 bytes)" align="middle"> for BR-106 and <img src="http:/img/fbpe/gmb/v21n4/1918f4.jpg" alt="1918f4.jpg (1995 bytes)" align="middle"> for BR-105) indicated that these new components can significantly influence the effectiveness of breeding methods. Genetic component estimates for BR-105 had relatively small errors, with <img src="http:/img/fbpe/gmb/v21n4/1918f4.jpg" alt="1918f4.jpg (1995 bytes)" align="middle"> negative for all traits. Estimates of <img src="http:/img/fbpe/gmb/v21n4/1918f1.jpg" alt="1918f1.jpg (1262 bytes)" align="middle">and <img src="http:/img/fbpe/gmb/v21n4/1918f2.jpg" alt="1918f2.jpg (2022 bytes)" align="middle"> had relatively larger errors for BR-106. The MRS method was more effective than the RRS and HSS methods in producing hybrids from inbred lines. The choice of a population tester for the MRS method based on population means per se may be incorrect. The additional use, when possible, of intra- and interpopulation additive genetic variances from each population would be more appropriate.


2012 ◽  
Vol 42 (5) ◽  
pp. 770-776 ◽  
Author(s):  
Lauro José Moreira Guimarães ◽  
Glauco Vieira Miranda ◽  
Rodrigo Oliveira DeLima ◽  
Ciro Maia ◽  
Lucimar Rodrigues de Oliveira ◽  
...  

The objective of this study was to evaluate four maize testers for identification of superior inbreed lines in testcross. The four testers evaluated are cultivars with narrow or wide genetic base (single-cross hybrids and open pollinated varieties) and two kernel types (flint or dent). SynD and SynF testers are open pollinated varieties with dent and flint kernels, respectively, and FSH and DSH testers are single-cross hybrids with flint and dent kernels, respectively. SynD tester showed the biggest genetic variance among the maize inbreed lines in crosses. The effects of general combining ability (GCA) for lines and specific combining ability (SCA) for lines x testers were significant, whereas GCA effects for testers were not significant. SynD and SynF testers identified the largest number of lines with higher GCA. The DSH and FSH testers showed suitable to identify lines with high SCA. It was concluded that SynD and SynF testers are adequate to identify inbreed lines with high GCA effects, and it's possible to identify new lines with high heterotic potential in each one of the four testers.


1974 ◽  
Vol 16 (4) ◽  
pp. 861-870
Author(s):  
G. H. Liang ◽  
A. D. Dayton ◽  
T. L. Walter

Epistasis, or interaction between nonallelic genes in grain sorghum (S. bicolor (L.) Moench), was estimated by comparing means of 20 balanced sets of single- and 3-way crosses. Each balanced set consisted of three single crosses and three 3-way crosses derived from three of the six parental varieties used. Results indicated that epistasis was present in nine sets for grain yield, in 13 sets for half-bloom date, and in 11 sets for plant height and for kernel weight. Epistasis seemingly fluctuates over years and locations. On the average, 3-way hybrids yielded less grain, flowered later, and were taller than the single-cross hybrids.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Mandakini Kabi ◽  
Bhabendra Baisakh ◽  
Manasi Dash ◽  
Swapan K Tripathy ◽  
S. Sahu ◽  
...  

The study of gene action and combining ability have been conducted in 28 F1 cross combinations along with eight parents in 8x8 half-diallel scheme following Griffing’s Approach for 14 morphoeconomic traits including seed yield and oil content in sesame. The general combining ability (GCA) and specific combining ability (SCA) component of variation were significant for parents and crosses respectively for all characters except internode length for GCA indicating role of both additive and nonadditive gene action. However, higher proportion of SCA variance (?2 sca) than GCA variance (?2 gca) revealed preponderance of non-additive gene action for all characters except capsule length and capsule width under study. Further, variance due to dominance played a significant role than additive variance in all traits except capsule width and 100-seed weight. Nirmala is considered as the best general combiner owing to its higher estimate of gca effects for yield per plant, for days to maturity, plant height, branches per plant, capsules per plant, seeds per capsule, capsule length and 100-seed weight. Among cross combinations; Rama × GT-10, AT-382 × Krishna, AT-382 × Nirmala, Krishna × Nirmala, Krishna × Uma, Nirmala × Prachi and Prachi × Uma showed significantly higher sca effect for seed yield per plant in the desired direction indicating their merit for recovery of transgressive segregants for higher productivity following reciprocal recurrent selection.


2015 ◽  
Vol 15 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Lucas Rafael de Souza Camacho ◽  
Carlos Alberto Scapim ◽  
Henrique José Camargo Senhorinho ◽  
Thiago Vincenzi Conrado

The aim of this study was to evaluate the combining ability of popcorn lines and hybrids with favorable traits for baby corn production, using lines extracted from the major genotypes of the Brazilian germplasm. From nine popcorn lines, derived from the genotypes Zélia, CMS 42, CMS 43, UEM M2, Zaeli and IAC 112, 36 single-cross hybrids were obtained without reciprocals. In partial diallel crosses, 25 single-cross hybrids were obtained, derived from crosses of five lines of the Zaeli (group I) with five lines from IAC 112 (group II). We recommend using lines derived from Zaeli and CMS 42 in hybrid breeding programs for higher ear yields. The lines P9.5.1 and P9.5.5 (group I) and P8.3 and P8.5 (group II) can be recommended for recombination within each group and for the formation of two synthetic populations for recurrent selection, in order to increase ear yield.


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