Ronald José Barth Pinto

Análise dialélica e heterose de populações de milho-pipoca

A diallel set of crosses among nine varieties of popcorn (Zea mays L.) - UNB-2, RS-20, UEM-J1, UEM-M2, CMS 42, CMS 43, Vicosa, Beija-flor and advanced generation of hybrid three-way Zelia) and their hybrid combinations was carried out to obtain capacity hability and heterosis estimates. These varieties and F1s were evaluated in two crop years (98/99 and 99/00) with three replications each year in Iguatemi, State of Parana, Brazil. The results allowed the synthesis of composts based in varieties of high combining ability for yield, like UNB-2 and CMS-42 and the varieties Zelia, RS-20 e UEM-M2 to popping expansion. The varieties Beija-flor and RS-20 were recommend to be used in a reciprocal recurrent selection program. For popping expansion there are positive and negative heterosis, indicating non unidericional dominance.

Componentes genéticos de médias e depressão por endogamia em populações de milho-pipoca

Ten popcorn populations (PR 038, PR 079, RR 046, SC 016, PR 017, BRS ANGELA, SC 002, PR 009, PR 023 and SE 013) were evaluated to estimate inbreeding depression and average genetic components. The experiment was a split plot in a randomized complete block design with three replications. The plots were the inbreeding levels (S1 and S0) and the sub-plots were the populations in two locations (Maringa and Iguatemi-PR) during the 2001/2002 grown season. Plant and ear height, grain yield and popping expansion were evaluated. It was observed lower values of inbreeding depression and predominance of additive effects for popping expansion in relation to yield. The sucess of getting high popping expansion inbred lines is higher with BRS ANGELA and SC 002 populations.

Evaluation of sunflower cultivars for central Brazil

Despite a large availability of areas suitable for sunflower cropping in Central Brazil, few adapted cultivars are available in the market. The objective of this work was to select sunflower cultivars adapted to this important production region. Experimental data from 2000 to 2004 were obtained by the National Sunflower Trials, coordinated by Embrapa Soja. The evaluated traits were grain and oil yields. Two criteria were used for selection of cultivars: i) the general mean obtained from different environments; ii) partitioning of general mean in favorable and unfavorable environments. Partitioning of the general mean allowed to detect the specific environment indicated for each cultivar. For grain yield, the cultivar Helio 251 presented general indication, Milenio and CF 17 could be indicated for favorable environments and ACA 884, ACA 885 and ACA 872 for the unfavorable ones. For oil yield, CF 13, Milenio, DK 4030, Helio 250 and ACA 872 had general indication; AG 966, GH 12, GV 26043, CF 17 and VDH 93 could be indicated for favorable environments, while VDH 488, Helio 251, ACA 884 and ACA 885 for the unfavorable conditions. In 2002, the partition of the general mean was not carried out. In this year, general mean of cultivars Exp 37, AG 962, GV 26048 and AG 967 were overweight the controls for grain yield and the cultivars AG 962, AG 967, GV 26048, AG 972, BRS 191, Guarani were overweight the controls for oil yield.

Genetic diversity of breeding popcorn lines determined by SSR markers

P1-3 and P8-1 was lowest, while P3-3 and P8-2 were genetically more similar. The cophenetic correlation showed that the Unweighted Pair-Group Method Using Arithmetic Averages (UPGMA) was reliable to discriminate the genotypes in five groups. The clusters were consistent with the estimates of genetic identity. There was a moderate coincidence degree between the groups and genealogy of lines. Higher levels of heterozygosity are expected from crosses between the group containing lines P3-3 and P7-3 with that of P1-3 and P7-4. Crosses between lines P1-3 and P8-1 are also promising.

Adaptabilidade e estabilidade de genótipos de girassol para a região subtropical do Brasil

O sucesso da cultura do girassol (Helianthus annuus L.) no Brasil esta associado a escolha adequada de cultivares com adaptacao a diferentes ambientes. Quando ha respostas diferenciadas dos genotipos testados nos diferentes ambientes, a decisao de lancamento de novas cultivares pode ser facilitada com estudos de adaptabilidade e estabilidade desses genotipos para reduzir os efeitos da interacao genotipos x ambientes. No pais, essas informacoes tornam-se mais importantes, pois a maioria das cultivares utilizadas, ou em lancamento, foram desenvolvidas em outros paises, com caracteristicas de solo e clima diferentes. Este trabalho teve como objetivo estudar a adaptabilidade e estabilidade de genotipos de girassol na regiao subtropical do Brasil, uma das regioes promissoras do pais para o seu cultivo. Os dados foram obtidos da Rede Nacional de Ensaios de Avaliacao de Genotipos de Girassol, coordenada pela Embrapa Soja, entre os anos de 1999/2000 e 2003/2004. Os caracteres avaliados foram rendimentos de graos e de oleo (kg ha-1). Os estudos de adaptabilidade e estabilidade foram realizados segundo as metodologias de PORTO et al. (2007), EBERHART & RUSSELL (1966) e ROCHA et al. (2005), as quais utilizam procedimentos biometricos distintos. Diferente do metodo de EBERHART & RUSSELL (1966), o de PORTO et al. (2007) selecionou genotipos que, apesar de terem medias gerais inferiores as testemunhas, tiveram bons desempenhos em ambientes especificos. Esse metodo foi mais rigoroso em selecionar genotipo, em relacao ao de ROCHA et al. (2005). Para rendimento de graos, o genotipo ACA 884 apresentou indicacao para ambientes em geral, EM 677008, Agrobel 930 e GV 26048 foram indicados para ambientes favoraveis, e ACA 885, para os desfavoraveis. Para rendimento de oleo, ACA 884 teve indicacao geral, GV 26048, CF 17, Agrobel 972 e Helio 358 tiveram indicacao para ambientes favoraveis, e HT 01 e ACA 885, para os desfavoraveis.

Diallel analysis of maize inbred lines for grain yield, oil and protein content

O presente trabalho teve como objetivos investigar a capacidade combinatoria e o efeito heterotico de linhagens tropicais e temperadas sobre o rendimento de graos (RG), teor de oleo (TO) e proteina (PB). Os hibridos e as linhagens foram avaliados a partir de um dialelo completo, sem reciprocos, em dois experimentos delineados em blocos casualizados com tres repeticoes. O desdobramento da soma de quadrado de genotipos em soma de quadrados para capacidade geral (CGC) e especifica (CEC) de combinacao e a subsequente constatacao de significância de CGC e de CEC evidenciaram que tanto efeitos aditivos quanto nao-aditivos estiveram envolvidos no controle genetico das caracteristicas avaliadas. Pelas estimativas dos componentes quadraticos, houve superioridade dos efeitos geneticos nao-aditivos no controle das caracteristicas. Contudo, percebe-se que para PB e TO o efeito nao-aditivo influenciou negativamente as combinacoes hibridas. O cruzamento L6x L10foi considerado promissor, pois associou positivamente RG com PB e TO.

Inheritance and potential use of grain color in the identification of genotypes resistant to pre-harvest sprouting in wheat

The inheritance of grain color and pre-harvest sprouting in wheat was studied to identify genotypes with high resistance to pre-harvest sprouting and evaluate the possible use of grain color in indirect selection of resistant lines. The genotypes of most lines were characterized with regard to the loci that control grain color. No significant correlations between grain color and pre-harvest sprouting resistance were observed, but correlations were useful when the frequency of segregating genotypes with white grain was relatively high. Of the eight F2:3 populations evaluated, only two differed significantly in grain sprouting between the white and red classes. Three genes for pre-harvest sprouting resistance seem to be present in the genotypes Frontana and Onix. Grain color should not be used as the only criterion for selecting wheat genotypes resistant to pre-harvest sprouting.

Diallel analysis and inbreeding depression of hybrid forage corn for agronomic traits and chemical quality

This study aimed to estimate the combining ability and inbreeding depression of corn hybrids for agronomic traits and forage quality. Nine corn hybrids, 36 F1 combinations from a diallel, 9 S1 populations and two checks were evaluated in two experiments in a randomized complete block design with three replications, in the 2009/2010 and 2010/2011 growing seasons. The parents Impacto, CD304 and DKB390 are recommended to form a composite to be subjected to a recurrent selection program aiming to improve forage production. Crosses between Impacto and parents DKB390, P30P34 and P30B39 are promising to increase forage quality by reducing the fiber content and also by increasing the protein content, being recommended for extracting inbred lines and interpopulation improvement. High inbreeding depression for grain yield was detected, indicating that non-additive effects contributed to the inheritance of the trait.

COMPARAÇÃO DE TESTADORES NA AVALIAÇÃO DA CAPACIDADE DE COMBINAÇÃO DE FAMÍLIAS S2 DE MILHO-PIPOCA

The large-scale production of Baculovirus to control fall armyworm, Spodoptera frugiperda, presents many limitations. The most important limiting factor is that the baculovirus, which infects fall armyworm, causes liquefaction of the integument immediately after death. This disruption of the integument difficultates the large scale production because dead insect must be frozen before being harvested. This fact implies in high lab work need, increasing the cost of the biopesticide. This problem was overcome by the discovery of a new baculovirus nucleopolyhedrovirus (NPV) isolate in Cascavel/PR, that doesn’t cause liquefaction of the integument (isolate 6NR) immediately after the insect death. This is an extremely important factor in a large-scale baculovirus production. In addition, mortality caused by isolate 6NR on 6-day-old-larvae was above 93% (SEM=0.7%), the average weight dead larva was 116.21 mg (SEM=22.9), the larval equivalent and weight equivalent/ha were 15.04 g (SEM=1.2) and 140.32 larvae (SEM=20.1), respectively.

EL ANÁLISIS BAYESIANO Y LA PRECISIÓN DE LOS VALORES DE LA HEREDABILIDAD EN ESPECIES PERENNES

The objectives of the present work were to evaluate the precision of the estimate of heritability, which was determined by standard error, considering a Bayesian approach, and to compare such estimate with the classic procedure. Data from progeny trial of 39 Eucalyptus cladocalyx families were used. Trunk basal diameter (measured at age 6) was the dependent variable analyzed. The Bayesian approach was implemented by using the Independence Chain algorithm with informative priors, which had a lower standard deviation of the heritability than both the classic method of Robertson and Jeffreys’ prior distribution (Jeffreys’ prior is in fact a class of uninformative and often improper prior distributions). The Bayesian approach is a valuable inference tool for the genetic evaluation of perennial species, because it considers the variability of the parameters by using posterior distributions.