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.

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.

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.

In Brazil, pepper cultivation gives producers more marketing opportunities in various segments, either for fresh consumption or industry. Reproductive traits are efficient methods for comparing genetic divergence in pepper, once most differences among accessions could be verified at this stage. This study aimed to evaluate the genetic divergence in the reproductive phase of pepper accessions by multivariate analysis and test the efficiency of different methods. Sixty-five genotypes from the Federal University of UberlândiaCapsicum spp. Germplasm Bank were evaluated 145 days after sowing, and morphological characterization was performed at reproductive phase. Graphical representation of genetic distances was obtained by UPGMA. Tocher optimization method was also used to group accessions. Genotypes were arranged in seventeen different groups by Tocher method. UPGMA dendrogram collaborated with Tocher method, indicating the wide genetic variability of genotypes. Tocher and UPGMA methods were partially in agreement, allowing grouping 44 of the 65 analyzed accessionsequally. Multicategorical traits have the advantage of easy observation and require less time and labor, being ideal for use in gene bank and collections that do not have high human and financial resources. Moreover, these traits are not affected by the environment. Genetic divergence detected in this paper encourages other researchers to perform the characterization of pepper collections as completely as possible, because it becomes possible to generate more reliable information of the variability and genetic divergence among accessions. Our research discloses the reproductive biodiversity of pepper in “Alto Paranaíba” and “TriânguloMineiro” regions and the importance of maintaining these genotypes.