Isoenzymatic variability in tropical maize populations under reciprocal recurrent selection

Pinto, Luciana Rossini; Vieira, Maria Lúcia Carneiro; Souza, Cláudio Lopes de; Silva, Rainério Meireles da

doi:10.1590/s0103-90162003000200013

Cited by 4 publications

(4 citation statements)

References 26 publications

(19 reference statements)

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“…Based on the quantitative evaluation of isoenzyme diversity of the Slovak and Czech local maize populations they appertain into the range of populations originating from other areas. This is confirmed for instance by the studies of Brazilian and other tropical maize populations where average numbers of alleles per loci were lower than within our populations -1.6 and 2.0-2.4, respectively (Gimenes & Lopes 2000;Pinto et al 2003). This parameter is also generally affected (decreased) by a low number of analyzed populations (Dubreuil & Charcosset 1998).…”

Section: Resultssupporting

confidence: 89%

“…Local population improvement by recurrent selection also increases the frequency of favourable alleles and reduces overall variation. Such an effect of recurrent and reciprocally recurrent selection in maize was described at the isoenzyme and RFLP loci (Stuber et al 1982;Labate et al 1999;Pinto et al 2003). Discrepant variation between maize populations of different origin may also be a consequence of small sample size collected (Reedy et al 1995) and founder effects (Doebley et al 1983).…”

Section: Resultsmentioning

confidence: 99%

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Inter- and intra-population variation of local maize (Zea mays L.) populations from Slovakia and Czech Republic

Múdry¹,

Kraic²

2007

CZECH J GENET PLANT

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Maize (Zea mays ssp. mays) was introduced into Europe at the end of the 15 th century by the expedition of Christopher Columbus. Dissemination from Spain, associated transmission over the old continent from different parts of America, and subsequent maize exploitation during the next five centuries contributed to the establishment of native maize genetic diversity in Europe. Even though the genetic variation of American populations will probably remain higher forever in comparison with European maize, alleles specific to European populations also emerged during adaptation to the local climate and environment (Rebourg et al. 2003). Contrasting climate, soils, agronomical practices, and breeder's effort created local populations progressively cultivated in favourable European regions. Local populations were grown by the end of the forties of the 20 th century. After World War Two traditional local maize populations (landraces, obsolete cultivars) were progressively replaced by agronomically improved hybrids. At the same time there were efforts to preserve traditional populations (landraces) and collections of maize genetic resources were established in different countries. The maintenance of genetic resource collections is necessarily associated with relevant evaluation and characterization of genetic diversity. The maize germplasm belongs to the most studied. Extensive evaluations of morphological traits were complemented later by isoenzyme markers as the first type of applied molecular markers. Many laboratories have been investigating the polymorphic isoenzyme patterns in plants for more than twenty years (Brown 1979

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Section: Resultssupporting

confidence: 89%

Section: Resultsmentioning

confidence: 99%

Inter- and intra-population variation of local maize (Zea mays L.) populations from Slovakia and Czech Republic

Múdry¹,

Kraic²

2007

CZECH J GENET PLANT

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“…Liu et al (2003), using SSR markers in maize inbred lines of importance for the improvement of temperate, tropical, and subtropical regions, also identified exclusive alleles. Working with populations of tropical maize in an RRS program, Pinto et al (2003b) also found unique alleles in populations under study, being largely observed in the BR-106 population. Graphical representation of genetic divergence allows verification of the existence of significant variability among and within populations.…”

Section: Resultsmentioning

confidence: 84%

Functional molecular markers (EST-SSR) in the full-sib reciprocal recurrent selection program of maize (Zea mays L.)

Galvão¹,

Ramos²,

Santos³

et al. 2015

Genet. Mol. Res.

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ABSTRACT. This study aimed to improve grain yield in the full-sib reciprocal recurrent selection program of maize from the North Fluminense State University. In the current phase of the program, the goal is to maintain, or even increase, the genetic variability within and among populations, in order to increase heterosis of the 13th cycle of reciprocal recurrent selection. Microsatellite expressed sequence tags (EST-SSRs) were used as a tool to assist the maximization step of genetic variability, targeting the functional genome. Eighty S 1 progenies of the 13th recurrent selection cycle, 40 from each population (CIMMYT and Piranão), were analyzed using 20 EST-SSR loci. Genetic diversity, observed heterozygosity, information content of polymorphism, and inbreeding coefficient were estimated. Subsequently, analysis of genetic dissimilarity, molecular variance, and a graphical dispersion of genotypes were conducted. The number of alleles in the CIMMYT population ranged 7345 EST-SST markers in the maize breeding program ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (3): 7344-7355 (2015) from 1 to 6, while in the Piranão population the range was from 2 to 8, with a mean of 3.65 and 4.35, respectively. As evidenced by the number of alleles, the Shannon index showed greater diversity for the Piranão population (1.04) in relation to the CIMMYT population (0.89). The genic SSR markers were effective in clustering genotypes into their respective populations before selection and an increase in the variation between populations after selection was observed. The results indicate that the study populations have expressive genetic diversity, which corresponds to the functional genome, indicating that this strategy may contribute to genetic gain, especially in association with the grain yield of future hybrids.

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“…We have previously studied AK from a wide range of plant species and noted a considerable variability in its action and stability during isolation, purification and characterization. Maize is one of the major crops worldwide (Pinto et al, 2003) and in this report we have analyzed AK from maize tissues callus cell cultures and optimized the assay for the determination of AK activity from maize. Due to the nature of such a study, the experiments were carried out twice and the means of three repetitions for each assay were taken into consideration.…”

Section: Introductionmentioning

confidence: 99%

Determination of aspartate kinase activity in maize tissues

Ferreira

Vendemiatti²,

Gratão³

et al. 2005

Sci. agric. (Piracicaba, Braz.)

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Lysine, threonine, methionine and isoleucine are synthesized from aspartate in a branched pathway in higher plants. Aspartate kinase plays a key role in the control of the aspartate pathway. The enzyme is very sensitive to manipulation and storage and the hydroxamate assay normally used to determine aspartate kinase activity has to be altered according to the plant species and tissue to be analyzed. We have optimized the assay for the determination of aspartate kinase in maize plants callus cell cultures. Among all the assay parameters tested, the concentration of ATP/Mg and temperature were critical for enzyme activity. In the case of temperature, 35°C was shown to be the optimum temperature for aspartate kinase activity. Key words: aspartate pathway, maize, lysine, threonine, methionine DETERMINAÇÃO DA ATIVIDADE DE ASPARTATO QUINASE EM TECIDOS DE MILHORESUMO: Lisina, treonina, metionina e isoleucina são derivados do aspartato. Aspartato quinase tem um papel chave no controle da via metabólica do aspartato. A enzima é muito sensível à manipulação e armazenagem e o ensaio enzimático do hidroxamato que é normalmente utilizado para determinar a atividade da aspartato quinase deve ser alterado de acordo com a espécie de planta e tecido vegetal a ser analisado. Nós otimizamos o ensaio para a determinação da atividade da aspartato quinase em culturas celulares de calos de milho. Entre os vários parâmetros testados do ensaio, a concentração de ATP/Mg e temperatura foram críticos para atividade enzimática. No caso da temperatura, 35°C foi a temperatura ótima para atividade da aspartato quinase.

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Isoenzymatic variability in tropical maize populations under reciprocal recurrent selection

Cited by 4 publications

References 26 publications

Inter- and intra-population variation of local maize (Zea mays L.) populations from Slovakia and Czech Republic

Inter- and intra-population variation of local maize (Zea mays L.) populations from Slovakia and Czech Republic

Functional molecular markers (EST-SSR) in the full-sib reciprocal recurrent selection program of maize (Zea mays L.)

Determination of aspartate kinase activity in maize tissues

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