Celso Mattes de Oliveira

Resistance of tomato strains to the moth Tuta absoluta imparted by allelochemicals and trichome density

We examined the resistance of improved tomato strains rich in 2-tridecanone (2-TD), zingiberene (ZGB) and acyl sugars (AA) to the tomato moth, Tuta absoluta. We also studied whether selection for strains with higher densities of glandular trichomes, and thus presumably strains with higher concentrations of 2-tridecanone, was effective in promoting greater resistance to the moth. The TOM-584 and TOM-679 strains were used as susceptible controls, which have normal concentrations of the three allelochemicals. The improved strain TOM-687, which has a high AA content, has a widely documented resistance and was used as a standard resistant strain. The wild strain PI134417, which is resistant by means of its high 2-TD content, was also used as a standard resistant strain. The experiment was installed in a greenhouse with a completely randomized design. The wild strain PI 134417 was confirmed as being highly resistant. TOM-622 (rich in 2-TD), ZGB-703 (rich in ZGB), and TOM-687 (rich in AA) showed significant reductions in the oviposition rate of the tomato moth, damage to the plants, injury to the leaflets, and the percentage of leaflets attacked in comparison with the control strains (TOM-584 and TOM-679). The levels of resistance to the moth for the TOM-622, ZGB-703, and TOM-687 strains were similar. In general, the genotypes with higher densities of glandular trichomes had greater resistance than the susceptible controls, with the strain BPX-367D-238-02 being particularly notable in its resistance.

Application of artificial neural networks in indirect selection: a case study on the breeding of lettuce

The efficiency of artificial neural networks (ANN) to model complex problems may enable the prediction of characteristics that are hard to measure, providing better results than the traditional indirect selection. Thus, this study aimed to investigate the potential of using artificial neural networks (ANN) for indirect selection against early flowering in lettuce, identify the influence of genotype by environment interaction in this strategy and compare your results with the traditional indirect selection. The number of days to anthesis were used as the desired output and the information of six characteristics (fresh weight of shoots, mass of marketable fresh matter of shoots, commercial dry matter of shoots, average diameter of the head, head circumference and leaf number) as input file for the training of the ANN-MLP (Perceptron Multi-Layer). The use of ANN has great potential adjustment for indirect selection for genetic improvement of lettuce against early flowering. The selection based on the predicted values by network provided estimates of gain selection largest that traditional indirect selection. The ANN trained with data from an experiment have low power extrapolation to another experiment, due to effect of interaction genotype by environment. The ANNs trained simultaneously with data from different experiments presented greater predictive power and extrapolation.

Desempenho agronômico e parâmetros genéticos em genótipos de batata-doce

O presente trabalho teve por objetivo avaliar o desempenho agronomico em genotipos de batata-doce e estimar parâmetros geneticos. O experimento foi composto por 65 variedades (clones do banco de germoplasma de batata-doce da Universidade Federal dos Vales do Jequitinhonha e Mucuri), instalado num delineamento em blocos ao acaso com tres repeticoes e 15 plantas por parcela. Foram avaliadas a produtividade de massa verde das ramas (MV), produtividade total das raizes (PT), peso medio das raizes totais (PMT), produtividade de raizes comerciais (PC), peso medio das raizes comerciais (PMC), formato das raizes (FORM) e resistencia a insetos (RI). Considerando-se os ganhos de selecao estimados para estas caracteristicas, infere-se que a selecao de clones pode levar a progressos geneticos significativos. Os caracteres PT, PMT, PC, e PMC estao positivamente correlacionados, logo, a selecao em qualquer um deles acarreta ganhos geneticos nos demais. A selecao para producao de raizes pode ser conduzida no carater PT, pois sua avaliacao e mais simples e correlaciona-se com a producao comercial, que e de maior importância. A selecao no carater MV promove aumento nas caracteristicas PMT e PMC e nao causa efeitos nas demais. Para a maioria das caracteristicas houve predominância dos efeitos ambientais sobre os geneticos. Os genotipos BD-15, BD-42 e BD-67 apresentaram melhor desempenho agronomico.

Capacidade combinatória de linhagens de tomateiro em híbridos do tipo italiano

Due to the growing importance of the saladette fresh tomato market in Brazil, our objective in this paper was to assess the combining abilities of lines potentially useful as parents in hybrids of this type. The experiment comprised 28 genotypes, 18 hybrids from a partial diallel cross obtained from crossing two groups of tomato lines: Group I (9 parents) and Group II (2 parents), 8 F1 experimental hybrids, and 2 commercial checks. Traits evaluated were total yield, mean fruit weight, fruit firmness, shape and percent of soluble solids. Additive genetic effects were generally more important than non-additive effects for all traits under evaluation. The TOM-542 and TOM-734 lines, from group I, and the TOM-720 line, from group II, presented high general combining ability (CGC) estimates for most of the traits of importance for saladette tomatoes, and were therefore considered suitable parents for hybrids of this type. Greater fruit firmness of the TOM-723 line compared to the TOM-720 line (Group II), as parental lines, was mainly attributed to the presence of the nor A allele in the former, which controls greater fruit shelf life. The F1 hybrids (TOM-542 x TOM-720), (TOM-580 x TOM-720), (TOM-734 x TOM-720), and (TOM-727 x TOM-720) showed good performance and fruit quality and thus constitute possible commercial varieties.Given the growing importance of the saladette fresh tomato market in Brazil, the objective of this paper was to assess the combining abilities of lines potentially useful as parents of hybridsin this class. The experiment consisted of28 genotypes, 18 hybrids from a partial diallel crossobtained from crossing two groups of tomato lines (Group I, with 9 parents, and Group II, with 2 parents), 8 F1 experimental hybrids, and 2 commercial checks. Traits evaluated were total yield, mean fruit mass, fruit shelf life, shape and percentsoluble solids. Additive genetic effects were generally more important than non-additive effects for all traits evaluated. The TOM-542 and TOM-734 lines, from group I, and the TOM-720 line, from group II, presented high general combining ability (GCA) estimates for most of the traits of importance for saladette tomatoes, and were therefore considered suitable parents of hybrids of this class. Higher fruit shelf life of TOM-723 as a parental line compared with TOM-720 (Group II), was mainly attributed to the presence in the former of the norA allele, which controls longer fruit shelf life. F1 hybrids (TOM-542 x TOM-720), (TOM-580 x TOM-720), (TOM-734 x TOM-720), and (TOM-727 x TOM-720) showed good performance and fruit quality and thus constitute possible commercial varieties.

Resistance of sweet potato clones to meloidogyne incognita races 1 and 3

The objective of this study was to evaluate sweet potato clones for resistance to root-knot nematode, Meloidogyne incognita races 1 and 3. For each nematode physiological race, a greenhouse experiment was set up in a randomized block experimental design with three replications and six plants per plot. Fifty-eight sweet potato clones from the UFVJM germplasm bank were evaluated, plus five commercial cultivars (Brazlândia Rosada, Brazlândia Branca, Palmas, Princesa and Coquinho), plus the cv. Santa Clara tomato (susceptible to Meloidogyne spp.). Stems were planted in 72-cell expanded polystyrene trays, filled with commercial substrate and inoculated with the pathogen thirty days after planting. Forty-five days after inoculation, the eggs were extracted, counted, and later evaluated. Resistance level classification was performed based on reproduction factor (RF) and reproduction index (RI). Among the 63 analyzed clones, a percentage of 78% were classified as resistant to M. incognita race 1.79% to race 3 and 67% showed multiple resistance to both M. incognita races.

Parâmetros genéticos e análise de trilha para o florescimento precoce e características agronômicas da alface

The objective of this study was to evaluate the genetic parameters of agronomic traits and of tolerance to early flowering of eleven cultivars of lettuce, as well as to verify the existence of an association between the characteristics. The experiment was carried out in a protected environment, in a randomized complete block design, with four replicates, and twelve plants per plot. Forty-five days after seedling transplanting, the following traits were measured: total shoot fresh mass, marketable shoot fresh mass, marketable dry shoot weight, fresh and dry weight of roots, diameter and circumference of head, plant height, number of leaves per plant, and number of days until anthesis. There was genetic variability between cultivars for all variables, except for circumference of plant and fresh weight of root. The cultivars Regina 500, Livia and Atracao were superior for number of days to flowering and also for the other characteristics. The selection against early flowering caused gain of all the characteristics, but did not affect root dry matter. Fresh matter of shoots and head diameter are indicated for indirect selection against early flowering.

Interaction of the mutant genes B, og c , hp and t in the coloring of tomato fruit

The aim of this study was to assess the effect of the mutant genes B, ogc, hp, and t on the fruit color of tomato genotypes. Two tomato lines (TOM-498 and TOM-499) with BB genotype composition (high β-carotene homozygous) were used in hybrid combinations with 7 tomato lines with different genotype compositions in loci ogc, hp, or t—Floradade, TOM-596, TOM-544, NC-8276, NC-2Y, Florida 7775, and Florida 7781. A randomized complete block design with 24 treatments and four replications was used. Both external and internal fruit color were assessed with a Minolta CR-400 colorimeter in the CIE L*, a* and b* mode. Hue and chroma readings were taken at four different points (epidermis, pericarp, placenta, and columella) of the fruit. For high β-carotene heterozygous hybrids B+/B, hue angle indicated an orange color (since these hybrids did not come to equal the genotypes of normal coloring, red), even when genes promoting lycopene synthesis (ogc, hp) were deployed as heterozygous genotypes. Fruit of high β-carotene heterozygous hybrids, without t, ogc, or hp, had chroma values similar to fruit of homozygous high β-carotene lines. The use of the ogc allele in heterozygosity led to higher chroma values in high β-carotene heterozygous genotypes in relation to the values found in high β-carotene heterozygous genotypes not bearing the ogc gene. The ogc homozygous lines had hue values that did not differ from those in normal genotypes in the epidermis and pericarp, but showed a significant shift towards red in the placenta and in the columella.