Genetic variability analyses considering multi-environment trials in maize breeding

Euphytica ◽  
2022 ◽  
Vol 218 (2) ◽  
Author(s):  
Igor Ferreira Coelho ◽  
Renan Garcia Malikouski ◽  
Jeniffer Santana Pinto Coelho Evangelista ◽  
Marco Antônio Peixoto ◽  
Rodrigo Silva Alves ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Maize Breeding

scholarly journals Genetic variability of maize breeding material - Zea mays L

2004 ◽  
pp. 29-38
Author(s):  
Zorica Nikolic ◽  
Marija Zlokolica ◽  
Mirjana Milosevic ◽  
Milka Vujakovic
Keyword(s):  
Genetic Variability ◽  
Total Sample ◽  
Genetic Distances ◽  
Vegetable Crops ◽  
Maize Breeding ◽  
Maize Hybrids ◽  
Suitable Material ◽  
Breeding Material ◽  
Maize Populations ◽  
Novi Sad

A study has been conducted in order to assess genetic variability in three maize populations, which are part of breeding material of Institute of Field and Vegetable Crops in Novi Sad. Variability has been analyzed for seven enzymes. PGM enzyme was monomorphic while enzymes ACP, GLU, IDH, MDH, PHI and PGD had from 2 to 5 alleles. In the total sample which consisted of 228 lines, 34 alleles were found. The greatest variability was found in Pgd1 and Pgd2. The average heterozygosities of loci per population were from 0.203 to 0.274, and polymorphism varied between 0.727 and 0.818. The genetic distances and heterozigosities among the populations marked them as suitable material for selecting parental pairs in development of maize hybrids.

scholarly journals Pre-breeding: a link between genetic resources and maize breeding

2000 ◽  
Vol 57 (3) ◽  
pp. 581-587 ◽  
Author(s):  
Luciano Lourenço Nass ◽  
Ernesto Paterniani
Keyword(s):  
Developing Countries ◽  
Genetic Variability ◽  
Genetic Resources ◽  
Efficient Utilization ◽  
Maize Breeding ◽  
Breeding Programs ◽  
Promising Alternative ◽  
The Future ◽  
Germplasm Banks

Activities related to genetic resources are characterized by high cost and long term return. Thus the conservation of genetic variability for the future and the efficient utilization of available accessions are two important goals to be attained. However, the low utilization of germplasm banks is not restricted to Brazil but to other developing countries as well. Therefore, pre-breeding is a promising alternative to link genetic resources and breeding programs. Several aspects for maize are discussed such as concept, importance, methods and results. Problems to be investigated and suggestions are also presented.

scholarly journals Isoenzymatic variation in the germplasm of Brazilian races of maize (Zea mays L.)

2000 ◽  
Vol 23 (2) ◽  
pp. 375-380 ◽  
Author(s):  
Marcos Aparecido Gimenes ◽  
Catalina Romero Lopes
Keyword(s):  
Genetic Diversity ◽  
Zea Mays ◽  
Genetic Variability ◽  
Zea Mays L ◽  
Polymorphic Locus ◽  
Maize Breeding ◽  
Breeding Programs ◽  
Expected Heterozygosity ◽  
Total Genetic Diversity ◽  
The Mean

There are more than 200 races of maize (Zea mays L.) divided into three groups (ancient commercial races, the recent commercial races, and indigenous races). Although the indigenous races have no commercial value, they have many important characteristics which can be incorporated into maize breeding programs. Most Brazilian indigenous germplasm race stocks were collected at least 40 years ago, and nothing is known of the genetic variability present in this germplasm. The genetic variability was assayed in 15 populations from four indigenous races of maize (Caingang, Entrelaçado, Lenha and Moroti) and five indigenous cultivars, using five isoenzymatic systems encoded by 14 loci. The analysis revealed a low level of variability among the samples studied. Overall, the mean number of alleles/polymorphic locus was three, 64.3% of the loci analyzed being polymorphic and the estimated heterozygosity was 0.352. The mean number of alleles/polymorphic locus per population was 1.6. A mean of 47.5% of the loci were polymorphic. The mean expected heterozygosity was 0.195, the mean genetic identity was 0.821 and the proportion of total genetic diversity partitioned among populations (Gst) was 0.156. A founder effect could explain the low variability detected.

scholarly journals Genetic Gains to Grain Yield of Maize Varieties for Small Farmers in Brazil

2020 ◽  
pp. 1-12
Author(s):  
Ana Paula Cândido Gabriel Berilli ◽  
Rafael Nunes de Almeida ◽  
Luis Eduardo Gottardo ◽  
Monique Moreira Moulin ◽  
Messias Gonzaga Pereira ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Recurrent Selection ◽  
Food Sovereignty ◽  
Block Design ◽  
Reciprocal Recurrent Selection ◽  
Maize Breeding ◽  
Genetic Gains ◽  
Maize Populations ◽  
Maize Varieties ◽  
Small Producers

The demand for expanding the genetic base in working collections of older maize breeding programs points to the need to pool efforts and reaffirm methodologies for conserving genetic variability that can still be accessed in maize populations. The objective of the work was to select full sib maize progenies and to estimate genetic gains in the first cycle of reciprocal recurrent selection for common maize intended for cultivation in a region characterized by family farm, in Brazil. We evaluated 120 full sib families of maize from crossbreeding between individuals of the Cimmyt and Piranão varieties. Competition trials were conducted at two experimental stations in the state of Espírito Santo, Brazil. A randomized block design was adopted with 2 repetitions, arranged in sets. Different selection indexes were tested in order to enhance gains in productivity and prolificacy. The selection of 40 superior families made it possible to estimate a gain of 0.77 Mg ha-1 in grain productivity for producers in the region. With these results, we discussed the importance of work to improve maize populations for small producers to motivate the conservation of the genetic variability of tropical maize germplasm. Thus, from the results obtained in this study, we show the possibility of investing in technologies aimed at small producers in order to motive the conservation of genetic resources, food sovereignty of producers and, consequently, world security, given the importance of this culture for human feed.

Role of genetic variability in the renin-angiotensin system in diabetic and nondiabetic renal disease

2001 ◽  
Vol 21 (6) ◽  
pp. 580-592 ◽  
Author(s):  
Arnold Boonstra ◽  
Dick de Zeeuw ◽  
Paul E. de Jong ◽  
Gerjan Navis
Keyword(s):  
Genetic Variability ◽  
Renal Disease ◽  
Renin Angiotensin System ◽  
Angiotensin System ◽  
Renin Angiotensin

Alpha-dystroglycanopathies: Clinical and genetic variability

2013 ◽  
Vol 44 (02) ◽  
Author(s):  
H Trippe ◽  
S Lutz ◽  
A Della Marina ◽  
U Hehr ◽  
W Kress ◽  
...  
Keyword(s):  
Genetic Variability

PROFILING OF GUAVA GENOTYPES GROWN IN VIDARBHA CONDITIONS ON THE BASIS OF MORPHOLOGICAL TRAITS

2017 ◽  
Vol 23 (1) ◽  
Author(s):  
R.A. PATIL ◽  
S.G. BHARAD ◽  
S.N. SAWANT
Keyword(s):  
Genetic Diversity ◽  
Genetic Variability ◽  
Morphological Traits ◽  
Considerable Extent ◽  
Fruit Traits ◽  
Breeding Programmes ◽  
Tree Leaf ◽  
Qualitative Characteristics ◽  
Intrapopulation Diversity

Assessment of genetic diversity in the available germplasm is the prerequisite for development of improved genotypes through planned breeding programmes. In the view of this Forty-eight genotypes of seedling origin guava along with 1 check (L-49/Sardar) collected and conserved at germplasm block, Main Garden, Department of Horticulture, Dr. P. D. A. University, Akola were evaluated for genetic variability and diversity based on the qualitative characteristics. The genotypes were evaluated for sixteen morphological traitsviz. tree, leaf, floral and fruit traits. Results Show considerable extent of variability amongst the 49 genotypes in each traits. A sizeable amount of intrapopulation diversity recorded can be used to identify diverse parents which can be utilized in hybridization programmes.

Hybrid maize breeding with doubled haploids: Comparison between selection criteria

2006 ◽  
Vol 54 (3) ◽  
pp. 343-350 ◽  
Author(s):  
C. F. H. Longin ◽  
H. F. Utz ◽  
A. E. Melchinger ◽  
J.C. Reif
Keyword(s):  
Selection Criteria ◽  
Doubled Haploids ◽  
Optimum Allocation ◽  
Finite Sample ◽  
Sample Sizes ◽  
Maize Breeding ◽  
Selection Gain ◽  
Breeding Programmes ◽  
Hybrid Maize ◽  
Breeding Resources

The optimum allocation of breeding resources is crucial for the efficiency of breeding programmes. The objectives were to (i) compare selection gain ΔGk for finite and infinite sample sizes, (ii) compare ΔGk and the probability of identifying superior hybrids (Pk), and (iii) determine the optimum allocation of the number of hybrids and test locations in hybrid maize breeding using doubled haploids. Infinite compared to finite sample sizes led to almost identical optimum allocation of test resources, but to an inflation of ΔGk. This inflation decreased as the budget and the number of finally selected hybrids increased. A reasonable Pk was reached for hybrids belonging to the q = 1% best of the population. The optimum allocations for Pk(q) and ΔGkwere similar, indicating that Pk(q) is promising for optimizing breeding programmes.

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