Reciprocal Recurrent Selection in Swine: Carcass Traits

1984 ◽  
Vol 58 (4) ◽  
pp. 821-830
Author(s):  
B. Bereskin ◽  
H. O. Hetzer
2018 ◽  
Vol 24 (2) ◽  
pp. 55-66
Author(s):  
Rokhana Faizah ◽  
Sri Wening ◽  
Hernawan Yuli Rahmadi ◽  
Abdul Razak Purba

Inbreeding is a common method used to reproduce candidate mother plant from selected parental lines for commercial seeds in Reciprocal Recurrent Selection (RRS) oil palm breeding program. However this practice may increased homozigosity level of selected population. This study concerned the level of homozygosity of SP540T fourth generations and Dura Deli Dolok Sinumbah fifth generations (3 crosses respectively) and their correlation with inbreeding depression symptoms. Polymerase Chain Reaction-Simple Sequence Repeat (PCR-SSR) with 16 markers developed for oil palm was used to analyze 327 samples. The result shows that the levels of homozigosity of SP540T fourth selfing generation were ranged between 0.44-0.84 or 0.61 in average. While the levels of homozygosity of Dura Deli fifth selfing generations were ranged between 0.60-0.93 or 0.78 in average. The homozygosity level in Dura Deli was 1.27% higher than SP540T populations. Correlation analysis showed that the higher the level of homozygosity, the higher of the inbreeding symptoms 2 observed (R =0.95).


Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 492
Author(s):  
Meriem Riache ◽  
Pedro Revilla ◽  
Oula Maafi ◽  
Rosa Ana Malvar ◽  
Abderahmane Djemel

Drought and low nitrogen are major stresses for maize (Zea mays L.), and maize populations from the Sahara Desert are potential sources of stress tolerance. The objectives were to assess the tolerance and varietal and heterosis effects of Algerian populations under no-nitrogen fertilization and water stress. A diallel among six Algerian maize population was evaluated under drought (300 mm irrigation) vs. control (600 mm) and no-nitrogen fertilization vs. 120 kh ha−1 N fertilization. Genotypes showed significant differences and genetic effects for water- and nitrogen-stress tolerance. We propose a reciprocal recurrent selection to take advantage of additive and non-additive effects, using AOR and IGS, since they showed good performance in optimum and stress conditions, for improving yield heterosis for AOR × IGS. Negative effects are not expected on plant height, anthesis–silking interval or early vigor. These populations and BAH could be sources of inbred lines tolerant to drought and no-nitrogen fertilization. There was no relationship between origin and genetic group and stress tolerance per se or as parents of tolerant crosses. These populations and crosses could be used as base material among Algerian populations, for breeding programs focusing on tolerance to water or nitrogen stress.


2003 ◽  
Vol 26 (3) ◽  
pp. 355-364 ◽  
Author(s):  
Luciana Rossini Pinto ◽  
Maria Lucia Carneiro Vieira ◽  
Claudio Lopes de Souza Jr. ◽  
Anete Pereira de Souza

Author(s):  
Rui Alberto Gomes Junior ◽  
Alessandra Ferraiolo de Freitas ◽  
Raimundo Nonato Vieira da Cunha ◽  
Antônio José de Abreu Pina ◽  
Higo Otávio Brochado Campos ◽  
...  

Abstract The objective of this work was to estimate the genetic parameters, correlations, and selection gains for the oil production of interspecific hybrids progenies between American oil palm, of ‘Manicoré’ origin, and oil palm, of ‘La Mé’ origin. Thirty-nine progenies were evaluated from the sixth to the ninth year after planting, for the productivity of fresh fruit bunches (PROD_FFB), oil content in the bunch (OCB), and palm oil productivity (PROD_OP). The genetic parameters and gains from direct (GDS) and indirect (GIS) selection were estimated for PROD_OP. High values of heritability for the CVg/CVe ratio indicated favorable conditions for the selection. With the selection of 20% of the progenies (selection in both sexes), the following estimates were obtained: 11.15% GDS for PROD_OP, 9.1% GIS for OCB, and 8.1% GIS for PROD_FFB. The PROD_OP of the progenies was of 6,175, 6,057, and 5,995 kg ha-1 per year with GDS and GIS for OCB and PROD_FFB, respectively. The restricted selection of the LM2T male genitor offspring resulted in 5.1% estimated GSD and in a mean of 5,800 kg ha-1 per year for PROD_OP. Selection gains for PROD_OP can be achieved immediately through the selection restricted to oil palm male genitors, and, in the medium and long term, through the interspecific reciprocal recurrent selection between American oil palm and oil palm populations.


2016 ◽  
Vol 7 (1) ◽  
pp. 58
Author(s):  
Enrique Navarro ◽  
Cristina Vega ◽  
Fernando Narváez ◽  
Hugo Córdova

This study was carried out in 1993 to evaluate S2 lines from four maize tropical populations improved by reciprocal recurrent selection. These lines were evaluated under field and laboratory conditions, the latter one to determine physiology quality. The main goal was to measure genetic variability within and among populations for traits such as grain yield, vigor and germination and to select the best lines under field and laboratory conditions. The combined analysis of variance showed great genetic variability among the S2 lines within and among populations for grain yield, days to flower, plant and ear height, among others. The maximum genetic variability was observed on the lines from population 43 and pool 23 for most of the traits, although the latter showed a greater genetic variability for grain yield. Besides, it is important to mention that the above populations included the best genotypes for grain yield, germination and vigor. Taking into account the above mentionel agronomic traits, fifteen lines were selected; 2 belong to population 43* pool 20, 2 from pool 19* pool 23, 8 from population 43, and 3 from pool 23. These results confirm the genetic superiority of the lines from populations 43 and pool 23, so that these populations should be recommended for future genetic improvement by reciprocal recurrent procedures.


Author(s):  
Andreea Daniela ONA ◽  
Ioan HAȘ ◽  
Ivan ILARIE ◽  
Voichița HAȘ ◽  
Nicolae TRITEAN ◽  
...  

In the last 40 years, pre-breeding works induced, in more and more centers of maize breeding, full-sib reciprocal recurrent selection programmes to identify some heterotic pairs which can be sources for obtaining performance inbred lines. The aim is to identify the heterotic pairs with the best results according to the yield potential of maize, the breaking and falling resistance, and the grains moisture at the harvesting time. The creation programme of A and B composite population started at ARDS Turda in 1985. Inside of A composite came the next inbred lines: B73, A632, M117, TC209, T291, being from the B SSS heterotic group, and inside of B composite came the inbred lines Mo17, C103, TC 208, T248, W633, appreciated by us or being related to Lancaster Sure Crop heterotic group. The experimentation was done in two orientation comparative cultures, each one with 49 variants, in 4 repetitions; the comparative culture was a balanced quadratic grid of 7x7 type. From each culture were chosen the first six variants, which were evaluated according to the next characters: production potential, breaking and falling resistance, grains moisture at harvest. The presented results are a part from the second cycle of full-sib reciprocal recurrent selection. Test crosses and self-pollinations were made on plants from the two composites which had two cobs; on the first cob from A Composite realised the cross with the corresponding plant from the B Composite, and from the plant panicle of the B Composite was collected pollen to pollinate the chosen plant from the A Composite. At the both plants from the crossing, the second cob was self-pollinated and kept in reserve until 2010, when the test crosses was experimented and were selected the pairs with the best results according to the above characters. Using the full-sib reciprocal recurrent selection, we can successfully harnessing, simultaneously, the additive and non-additive gene effects.


2004 ◽  
Vol 34 (1) ◽  
pp. 195-208 ◽  
Author(s):  
R J Kerr ◽  
M J Dieters ◽  
B Tier ◽  
H S Dungey

Computer simulation is the only realistic method of evaluating alternative methods of breeding hybrid forest trees. Empirical tests would be very long term and expensive. This paper describes the development of a simulation program, called XSIM, which generates two different but closely related outcrossing tree species. The genetic correlation between performance in each parental species and performance in the resulting hybrid can be set, in addition to the amounts and types of variances in each parental species. The breeding strategies available for testing include conventional reciprocal recurrent selection, reciprocal recurrent selection with forward selection, recurrent selection within each pure species, and the creation of a synthetic species. XSIM allows the strategies to be compared using the same base populations, equivalent selection intensities, and comparable mating patterns. Innovative best linear unbiased prediction procedures allow all ancestral and current progeny generation data, from both parental species and the hybrid, to be analysed together. The theoretical basis for the simulation is given, and genetic and statistical models are described. In summary, XSIM allows rigorous comparisons of the strategies in terms of genetic gain per time and provides useful insight into hybrid forest tree breeding.


Genome ◽  
1989 ◽  
Vol 32 (3) ◽  
pp. 420-424 ◽  
Author(s):  
A. Gallais

The application to autotetraploids of the concepts of varietal value and of test value allows the derivation of expressions of genetic advance for the different types of varietal values (per se value, line value, single-cross or double-cross values, synthesizing ability) according to the testing system used to select the intercrossed plants. Formulae are given for series of intrapopulation schemes and for reciprocal recurrent selection. With autotetraploids, if non-inbred plants are intercrossed and when epistasis is not involved, there is a contribution of additive effects and of dominance effects for the considered testing systems. However, it is shown that, except for mass selection or S1 selection devoted to improve the per se value of the population, the contribution of dominance is very low. The formulae are exactly the same as for diploids if the contribution of dominance variance is neglected.Key words: autopolyploid, quantitative genetics, varietal ability, test value, recurrent selection.


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