scholarly journals Efectos genéticos y heterosis en poblaciones parentales y poblaciones derivadas de maíz (Zea mays L)

2016 ◽  
Vol 4 ◽  
pp. 07
Author(s):  
Enrique Navarro G. ◽  
Fernando Borrego E.

This study with the Gardner-Eberhart model (1966) involved eight maize parental populations and their related populations. The objectives were to estimate the cumulative gene effects (additive, dominance and heterotic) which could The justify support of a maize hybrid programo The grain yield inter-varietal dominance effects accounted for 55.54% of the generation means, suggesting large genetic variability within populations. Heterotic effects accounted for 12.11 %, indicating little difference in gene frequency for loci controlling grain yield. Plant height followed the same pattero as grain yield, since dominance effects were the most important. However, homozygote loci (aj) were important in explaining genetic variability for days to bloom and number of ears. For grain yield, the cross Pop. 32 x Pop. 21 maximized the heterotic effects. Population 21 exhibited a high average heterosis, so we suspect that its, combination with Popo 32 and CN(S)-C3, among others, would be a great genetic material for a Reciprocal Recurrent Selection Programo

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.


2003 ◽  
Vol 60 (2) ◽  
pp. 291-297 ◽  
Author(s):  
Luciana Rossini Pinto ◽  
Maria Lúcia Carneiro Vieira ◽  
Cláudio Lopes de Souza Jr. ◽  
Rainério Meireles da Silva

Maize (Zea mays L.) is one of the crops in which the genetic variability has been extensively studied at isoenzymatic loci. The genetic variability of the maize populations BR-105 and BR-106, and the synthetics IG-3 and IG-4, obtained after one cycle of a high-intensity reciprocal recurrent selection (RRS), was investigated at seven isoenzymatic loci. A total of twenty alleles were identified, and most of the private alleles were found in the BR-106 population. One cycle of reciprocal recurrent selection (RRS) caused reductions of 12% in the number of alleles in both populations. Changes in allele frequencies were also observed between populations and synthetics, mainly for the Est 2 locus. Populations presented similar values for the number of alleles per locus, percentage of polymorphic loci, and observed and expected heterozygosities. A decrease of the genetic variation values was observed for the synthetics as a consequence of genetic drift effects and reduction of the effective population sizes. The distribution of the genetic diversity within and between populations revealed that most of the diversity was maintained within them, i.e. BR-105 x BR-106 (G ST = 3.5%) and IG-3 x IG-4 (G ST = 4.0%). The genetic distances between populations and synthetics increased approximately 21%. An increase in the genetic divergence between the populations occurred without limiting new selection procedures.


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.


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.


2020 ◽  
Vol 5 (01) ◽  
pp. 45-49
Author(s):  
Ankit Kumar ◽  
Amit Tomar

The results revealed that parents namely, TSK-10, TSK-27, New Blue-II, Kurara and TSK-109 were found highly genetic diverse for days to 50% tasseling, days to 50% silking, days to 755 dry husk. The parents namely, TSK-109, Kurara, New Blue-II and TSK-10 were found highly genetic diverse for plant height (cm), cob height, number of cobs per plant and number of grains per cob. The parents namely, Kurara, TSK-109, TSK-10, New Blue-II and TSK-27 were found highly genetic diverse for shelling percentage, grain yield per plant, grain yield per cob and 100-grain weight.


Crop Science ◽  
2018 ◽  
Vol 58 (6) ◽  
pp. 2360-2369
Author(s):  
Adesike O. Kolawole ◽  
Abebe Menkir ◽  
Essie Blay ◽  
Kwadwo Ofori ◽  
Jennifer G. Kling

2017 ◽  
Vol 52 (11) ◽  
pp. 1033-1041
Author(s):  
Odilon Peixoto de Morais Júnior ◽  
Patrícia Guimarães Santos Melo ◽  
Orlando Peixoto de Morais ◽  
José Manoel Colombari Filho

Abstract: The objective of this work was to estimate genetic and phenotypic parameters among progenies of the CNA6 population of upland rice (Oryza sativa) for grain yield and plant height in four cycles of recurrent selection, in order to evaluate the genetic variability and the genotype × location interaction. The experimental data were obtained from yield trials of S0:2 progenies, which were carried out in the experimental design of Federer’s augmented blocks, without replications for progenies within each location. The effect of S0:2 progenies was significant in all cycles for grain yield and in the first three cycles for plant height, indicating the maintenance of the population’s genetic potential to generate transgressive progenies. The participation of the component of the progeny × location interaction in phenotypic variance was of high magnitude. The genetic variability of the CNA6 population of upland rice is maintained for grain yield and plant height during the four cycles of recurrent selection.


2021 ◽  
Vol 9 (11) ◽  
pp. 182-201
Author(s):  
F Shahrin ◽  
P Roy ◽  
M S Raihan ◽  
M M Haque ◽  
M G Rasul

Overcoming malnutrition through biofortification breeding in rice is aimed to assist nutritional food security in Bangladesh. So to select parents for nutritional improvement, estimation and exploitation of mineral nutrients reserves of rice grain and their variability assessment in different genotypes is essential. Eighty-five (85) T. aman rice genotypes collected from different coastal regions of Bangladesh were evaluated at the Advanced Plant Breeding laboratory, GPB of BSMRAU to estimate the grain nutrients content and to elucidate their genetic variability among the genotypes. Considerable significant variation (0.1% level of probability) was noted among the genotypes for studied different grain nutrient contents and yield per hill. The mean values of N, P, K, Ca, Mg, Na, Zn, Fe, Cu, Mn and grain yield/ hill were 10788.24 mg/kg, 804.85 mg/kg, 3798.58 mg/kg, 13795.29 mg/kg, 2778.87 mg/kg, 3771.17 mg/kg, 7.25 mg/kg, 5.01 mg/kg, 1.05 mg/kg, 1.90 mg/kg and 433.29 g, respectively. Box and whisker plots analysis were done to represent data graphically for better understanding. Histogram was used to present the frequency distribution of genotypes for N, P, K, Ca, Mg, Na, Zn, Fe, Cu, Mg and Grain yield/hill content in 85 diverged rice genotypes All the traits had equality in genotypic and phenotypic variances with high heritability and high genetic advance which indicated preponderance of additive gene effects for these traits. The genotype R080 (Chinigura) contained the highest content of grain P, Fe and Cu. The R030 (Mota Dhan), R040 (Dudh Kalam) and R019 (Chikon Dhan) were noted for the highest Ca, Mg and Na content, respectively. The maximum N and Zn content were observed in R029 (Dudh Kolom) and R075 (Gopal Bogh), respectively. R083 (Lal Dhan) was marked for the highest grain yield/ hill and K content. Genetic variability parameters, heat map analysis and neighbor joining clustering methods indicated these genotypes including R079 can be considered for biofortification program and used as parents for the improvement of those grain nutrients in rice breeding.


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