RESUMO: Objetivou-se com o presente trabalho estudar a morfologia de sementes e plântulas, além de se obter informações sobre o tipo e tempo da germinação das sementes de limão-doce em cinco substratos (em papel mata-borrão, entre papel mata-borrão, em areia esterilizada lavada, entre areia esterilizada lavada e em rolo de papel). Sementes de C. limetta foram mensuradas suas dimensões e realizada a descrição externa. Posteriomente, semeadas entre areia e mantidas à 25 ºC para acompanhamento da germinação e descrição morfologica das plântulas resultantes. Um segundo experimento foi avaliado quanto a eficiência dos substratos: rolo de papel, sobre e entre papel, sobre e entre areia na germinação de sementes de C. limetta. Foram avaliados o índice de velocidade, o tempo médio e a frequência relativa da germinação. Além disso, foi estabelecida a data da primeira e última contagem da germinação. As médias dos tratamentos foram comparadas pelo teste de Tukey a 5% de probabilidade. As sementes de C. limetta são ovoides, levemente enrugadas e poliembrionicas. A germinação é hipógea, criptocotiledonar ou fanerocotiledonar. As plântulas apresentam eofilos coriáceos com folhas simples, formato elíptico ou próximo do elíptico, tendendo para ovado. Apresenta sistema radicular pivotante coloração de amarelo a creme com presença de raízes secundárias. O tempo médio de germinação é entre 18 e 22 dias. O substrato indicado para germinação das sementes é sobre papel.

ABSTRACT: This research studied the morphology of seeds and seedlings, in addition to obtaining information about the type and time of germination of sweet lemon seeds in five substrates (on blotting paper, between blotting paper, on washed sterilized sand, between washed sterilized sand and in paper roll). C. limetta seeds were measured, and external description was performed. Afterwards, sown in the sand and kept at 25 ºC to monitoring germination and morphological description of the resulting seedlings. A second experiment was evaluated for substrate efficiency: paper roll, on and between paper, on and between sand in the germination of C. limetta seeds. Speed index, average time and relative frequency of germination were evaluated. In addition, date of the first and last germination count was established. Treatment averages were compared using the Tukey test at 5% probability. C. limetta seeds are ovoid, slightly wrinkled and polyembryonic. Germination is hypogeal, cryptocotylar or phanerocotylar. The seedlings have leathery eophylls with simple leaves, elliptical shape or close to the elliptical, tending to ovate. It has a pivoting root system that is colored yellow to cream with the presence of secondary roots. The average germination time is between 18 and 22 days. The substrate indicated for seed germination is on paper.

ABSTRACT In plant breeding programs, the selection of potential progenies in early generations of inbreeding is an essential step. Considering that, the adoption of topcrosses helps the breeder in the selection, this study aimed to verify the potential of S2 strains for synthesis of synthetic varieties and to obtain experimental information on yield and agronomic potential of topcross hybrids. As such, 75 topcross hybrids were generated from crossing 75 S2 lines with F2 generation of the commercial hybrid. The 75 hybrids were grown in a field, along with two commercial hybrids in a randomized complete block design with 4 replicates and in 4-meter plots. Flowering, plant height, height, diameter, length and weight in the ear, and grain yield traits were examined. Analysis of variance was performed, the combining ability was estimated, and, from the means, the Scott & Knott test was conducted. So, the topcross hybrids that distinguished themselves for grain yield were those composed by lines 67, 14, 44, and 69, presenting high CGA, therefore indicating good potential for producing synthetic or base population. For the other traits of agronomic interest that were assessed in maize, a potential for selection with different focuses was found: reduction of cycle and height and increase in length and diameter of the ear.

Resumo O pessegueiro é uma fruteira de clima temperado, propagada por meio de enxertia com a cultivar copa e o porta enxerto oriundo de sementes, o que resulta em reduzida uniformidade, sendo a propagação por estaquia herbácea uma alternativa viável. Objetivou-se avaliar o desempenho de diferentes genótipos de porta-enxerto de pessegueiro propagados por estaquia herbácea. O experimento foi realizado utilizando-se de estacas padronizadas em 15 cm de comprimento, tratadas em solução de AIB, na concentração de 3.000 mg L-1 que, posteriormente, foram transplantadas para embalagens de polietileno com capacidade para 3 L. Adotou-se o delineamento experimental inteiramente casualizado, com cinco repetições, sendo cada parcela composta por três plantas. Foram testados 16 genótipos de pessegueiro oriundos do programa de melhoramento genético da UFV: 713-3; 713-6; 713-7; 713-10; 813-2; 813-3; 813-5; 813-15; 913-3; 913-6; 913-11; 913-17;C6; C7 e C8; e após 80 dias, foram avaliados os parâmetros: comprimento de haste (cm), diâmetro de haste (mm) e comprimento de entrenós (cm). Os dados foram submetidos à análise de variância, pelo teste F; e as médias, comparadas pelo teste Scott-Knott, ao nível de 5% de probabilidade, com o auxílio do programa estatístico GENES. Conclui-se que o menor desenvolvimento inicial foi obtido no genótipo 1113-11, e as maiores estacas foram obtidas nos genótipos 713-13 e 813-5.

Abstract The peach tree is a temperate fruit tree propagated by grafting with the scion cultivar and the rootstock from seeds, generating low uniformity, a viable alternative is propagation by herbaceous cuttings. The objective of this study was to evaluate the performance of different genotypes of peach rootstock propagated by herbaceous cuttings. The experiment was carried out with standardized cuttings of 15 cm in length treated with 3,000 mg L-1 of IBA solution, then were transplanted into 3 L polyethylene bags. A completely randomized design with five replications was adopted, each plot consisting of three plants. Sixteen peach genotypes from UFV breeding program were tested: 713-3, 713-6, 713-7, 713-10, 813-2, 813-3, 813-5, 813-15, 913-3, 913-6, 913-11, 913-17, C6, C7 and C8. After 80 days the following parameters were evaluated: stem length (cm), stem diameter (mm) and internode length (cm). Data were subjected to analysis of variance by the F test and averages compared by the Scott-Knott test at a 5% probability level with the GENES statistical software. It can be concluded that the lower initial development was observed in genotype 1113-11 and the highest initial development was from genotypes 713-13 and 813-5.

Resumo As plantas de Anacardium humile A. St.- Hil. (cajuzinho-do-cerrado) possuem potencial produtivo, sendo seus frutos apreciados na região do Cerrado por apresentarem sabor característico; no entanto, esta espécie ainda é explorada de forma extrativista, fazendo com que sejam necessários estudos que objetivem sua domesticação. O objetivo do presente trabalho foi estimar a área foliar de plantas de Anacardium humile. As folhas foram coletadas na coleção biológica de um campo de recursos genéticos e avaliadas quanto ao comprimento, largura e massa fresca, e foram escaneadas na resolução de 300 dpi para determinar a área foliar com auxílio do programa de análise de imagens ImageJ. Posteriormente, foi destacado um disco foliar na porção basal de cada folha com o auxílio de um vazador de 22,27 mm, no qual se obteve a massa fresca dos discos. Os dados foram submetidos à análise descritiva, e a relação entre as características, explicadas pela correlação de Pearson no programa Rbio. Os dados foram ainda submetidos a analises de regressão para explicar a relação entre a área foliar e as medidas de comprimento, largura e peso das folhas, e para ajustar o modelo matemático adequado com o software Origin. Concluiu-se que a área foliar pode ser determinada por programas de análises de imagens que a as medidas lineares se relacionam com a área foliar.

Abstract The Anacardium humile A. St.- Hil. fruit tree has productive potential, being their fruits appreciated in the Cerrado region for having characteristic flavor, however, this species is still exploited in an extractive way, being necessary studies for its domestication. The aim of this work was to estimate the leaf area of Anacardium humile. One hundred leaves were collected in the biological collection from a genetic resources field and evaluated for length, width and fresh weight, and scanned at resolution of 300 dpi to determine the leaf area with the aid of the ImageJ image analysis program. Subsequently, a leaf disc with a diameter of 22.27 mm was detached at the basal portion of each leaf, in which the fresh weight of the discs was obtained. Data were submitted to descriptive analysis and the relationship among the features explained by Pearson’s correlation with the software Rbio. The data were also subjected to regression analysis to explain the relationship between leaf area and measurements of width, length and leaf weight, and to fit the proper statistical model with the software Origin. It was concluded that leaf area can be determined by image analysis software and linear measurements are correlated to leaf area.