Lettuce is the most-consumed leafy vegetable in Brazil due to its ease of preparation, nutritional quality, and affordability. Despite these benefits, there are few cultivars of crisphead lettuce (Lactuca sativa) that possess agronomic potential, high carotenoid content and resistance to nematodes. Therefore, we evaluated the agronomic potential of crisphead lettuce genotypes that are resistant to the root-knot nematode. The experiment was conducted at the Vegetable Experiment Station of the Federal University of Uberlandia (UFU), Monte Carmelo Campus. The trial was set up in a randomized block design with 49 treatments (43 genotypes obtained from crosses between Uberlandia 10000 and Belissima and six commercial cultivars) and three replications. After preparing the beds and before transplanting the seedlings, 11 simple samples were taken from each of the three experimental blocks to confirm the presence of nematodes within the experimental area. The following variables were determined 48 days after transplanting: chlorophyll content, leaf temperature, plant diameter, number of leaves per plant, fresh mass and incidence of root gall. The data were submitted to analysis of variance (ANOVA) and an F-test and the means were compared by the Scott-Knott test. Genetic diversity was represented by a dendrogram that was obtained using the hierarchical method of UPGMA and the optimization method of Tocher. We found genetic divergence and agronomic potential among the evaluated genotypes. Specifically, 199#1#1-E, 199#2#1-E, 199#2#2-E, 199#3#1-E, 199#6#1-E and 75#2#2-E presented good agronomic potential, were rich in carotenoids and showed resistance to the root-knot nematode.

Vegetables with high carotenoids content can help to prevent many diseases. Lettuce is one of the most consumed vegetables all over the world that present potential for biofortification investment. However, there are few genotypes of lettuce biofortificated on the market and for direct use in plant breeding. Evaluate new lettuce genotypes that are rich in carotenoids are essential in order to know the commercial potential and their usefulness as possible parents in breeding programs. Therefore, the experiment aimed to evaluate the agronomic potential and genetic dissimilarity between lettuce genotypes with different levels of carotenoids. It was conducted in a randomized block design, with 83 treatments and two replications. During the course of the trial, were evaluated quantitative characters: leaf chlorophyll content (a, b and total), canopy diameter and number of leaves; and qualitative characters: size, color and shape of the leaves. The genetic diversity was obtained by multivariate analyzes using the sum of quantitative and qualitative data and, after that, using different grouping methods (UPGMA and Tocher). The genotypes showed genetic dissimilarity and agronomic potential for different lettuce segments and high carotenoids content. Among the evaluated characters, total chlorophyll content represented the main contribution for genetic variability. There was no coherence between the hierarchical method of UPGMA and the optimization method of Tocher when used for determinate the genetic diversity between lettuce genotypes with different levels of carotenoids.

ABSTRACT:In several species, seed longevity may be influenced by genotype and storage environment. It is scarce researches that evaluated those effects in onion seeds. From the exposed, it was aimed to evaluate the behavior from onion seeds of different genotypes stored in three conditions of relative humidity (25; 35 and 45% RH) monitored during six different storage periods. The research was executed at the Laboratório de Análise de Sementes e Recursos Genéticos from Universidade Federal de Uberlândia, Monte Carmelo Campus -MG. After harvested, the seeds of two cultivars were storaged in three conditions (SC): 25, 35 e 45% of relative humidity (RH). It was kept the same temperature (17ºC) in all storage conditions. After one year of storage, it was collected monthly seed samples of each genotype inside each storage condition for evaluation of physiological potential with vigor and germination tests. There was significant effect in germination and vigor of the seeds in the storage period and condition and in genotype versus environment, in all analysed variables. The quality of onion seeds may be influenced by genotype, storage conditions and storage period. The best condition to storage onion seeds is at 35% of RH. Seed deterioration was increased with storage period, although, short storage periods have increased germination rates.

RESUMO A ferrugem asiática da soja (FAS), causada pelo fungo Phakopsora pachyrhizi, é uma das doenças mais severas na cultura. Dentre as estratégias para seu manejo propõe-se a utilização de genótipos com resistência horizontal ou parcial, ainda restritos no mercado, mas promissores pela durabilidade da resistência. O objetivo deste trabalho foi avaliar a resistência de diferentes genótipos de soja à ferrugem asiática para futura utilização em programas de melhoramento. Na safra 2015/2016, foram avaliados 11 genótipos de soja provenientes do LAGER-UFU e a cultivar Desafio 8473 (padrão de suscetibilidade) frente à infecção artificial e natural de P. pachyrhizi no campo. Com os dados de severidade da FAS, calculou-se a área abaixo da curva de progresso da doença (AACPD). O percentual de área foliar afetada e os valores da AACPD dos genótipos avaliados oscilaram de 1,56 a 80,75 e de 380,62 a 975,62, respectivamente. Os genótipos L-210, L-166, L-268, L-203, L-279, L-224, L-216 e L-218 apresentam menores valores de AACPD, indicando resistência parcial, enquanto os genótipos L-144, L-104, L-266 e a cv. Desafio 8473 apresentaram maiores valores de AACPD, portanto, com menor resistência parcial ou suscetíveis. Ainda assim, os genótipos L-144, L-104 e L-266 apresentaram coeficientes de progresso da severidade da doença de 1,8 a 2,0 vezes menores comparativamente à cv. Desafio 8473. Conclui-se que os genótipos do Programa de Melhoramento Genético da UFU (LAGER-UFU), apresentam potencial de utilização no desenvolvimento de cultivares de soja resistentes à P. pachyrhizi.

Currently, planting onion through seedling production is predominant in the state of Rio Grande do Sul. Thus, the present work aimed to evaluate the agronomic potential of new onion genotypes as a function of the planting system for this region. Eleven genotypes were evaluated, as follows: “commercial genotypes” Bola Precoce, Mulata, Sprint, Suprema and “pre-commercial genotypes” TE 201, TE 209, TE 216, TE 230, TE 242, TE 316 and TE 329, submitted to four planting systems: seedling production, seedling production with leaf pruning before transplanting, no-tillage manually planted at the definitive site and seedling production in trays. Treatments were arranged in an 11 x 4 factorial scheme (eleven genotypes and four planting systems). Although little practiced, the no-till system for onion cultivation for the northwestern region of Rio Grande do Sul can potentially be explored. Genotypes that best adapted to this system were: Bola Precoce, Suprema, Sprint, Mulata and TE 201. Comparatively, “commercial” genotypes showed an increase of 10.81 t ha-1 in relation to “pre-commercial” genotypes in the no-till system, proving the efficiency of this system.

Lettuce is the main leafy vegetable, presenting the highest consumption and economic importance in the world. In the recent decades, concerns about vitamin A deficiency have led Brazilian researchers to develop cultivars with higher levels of carotenoids provitamin A. Therefore the experiment aimed to verify the genetic dissimilarity of biofortified lettuce genotypes, investigating the correlation between agronomic characteristics and the potential for use to increase the carotenoid content in future breeding programs. Ninety one genotypes were evaluated, with 86 lettuce strains from hybridization between cultivars Pira 72 versus Uberlândia 10000 (rich in carotenoids) followed by three successive self-fertilizations and 5 commercial cultivars (Grand Rapids; UFU MC BIOFORT1; Pira 72; Uberlândia 10000 and Robusta).During the course of the trial, were evaluated characteristics as chlorophyll content of the leaves, plant diameter, stem diameter and the number of leaves per plant were counted. Genetic diversity was represented by a dendrogram that was obtained using the hierarchical method of UPGMA and the optimization method of Tocher. There is genetic divergence between the lettuce genotypes analyzed, and the carotenoid content character contributed most significantly to the divergence between the evaluated genotypes. The UFU215#12 genotypes; UFU215#14; UFU215#2; UFU 215#1; UFU215#4; UFU199#3 and UFU199#2 have good agronomic characteristics and high levels of carotenoids, being promising to continue the biofortified lettuce breeding program, aiming to obtain new cultivars rich in carotenoids pro vitamin A.

Tabela 2. Estimativas de ganhos de seleção (GS%) obtidos para nove caracteres avaliados, pela seleção direta e indireta, para 65 genótipos de abóbora. Monte Carmelo, 2018...

The pepper crop is cultivated in all Brazilian regions, and the planting system with the arrangement of plants in the single-row prevails. Therefore, this work aimed to evaluate the agronomic performance and physiological quality of the seeds of different pepper genotypes according to the planting systems. The experiment was carried out at the Federal University of Uberlândia, in Monte Carmelo, in a randomized blocks experimental design, in a 4 x 2 factorial scheme, four genotypes (UFU-62-5M; UFU-28-1M; UFU-58-6D and UFU-5-3BD) under two planting systems (Single-row planting-SRP and Double-row planting-DRP), with four repetitions. The spacing of 0.6 m between plants and rows was used in the SRP. In the DRP, the spacing of 0.6 m between rows and 1.20 m between plants were used. Each plot was composed of six plants, the two central plants were considered for the evaluations of total production; fruit mass; fruit diameter; fruit length; electric conductivity of seeds; 1000-seeds weight; fruit production; first germination count; and chlorophyll a and b. The double-row planting had significant increases in the physiological quality of pepper seeds; thus, for seed production, this would be the best system. Because there are no differences in productivity between the systems, the double-line system would be advantageous to facilitate the harvesting and allow future mechanization.