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Plant breeders need to understand the genetic diversity and relationships between genotypes to choose parents of segregating populations. We evaluated the genetic diversity of 35 soybean genotypes and determined their potential as parent lines in breeding programs by analyzing their agronomic traits and microsatellite markers. Phenotypic analysis was carried out in the field at Fazenda Capim Branco, a research station of the Federal University of Uberlândia. Nine microsatellite markers and seven agronomic traits in were evaluated in 35 conventional soybean genotypes. Genotypes were grouped by UPGMA and Tocher cluster analyses, and molecular analysis was used to calculate polymorphism for each microsatellite locus. Nine microsatellite markers amplified 26 alleles, ranging from two to four. Polymorphism varied ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 19 (1): gmr18105 L.B. Sousa et al. 2between 0.29 and 0.66, and averaged 0.44. The number of days to maturity was the characteristic that contributed the most to yield (29.44%). Seven potential parents (G11, G12, G16, G21, G22, G26 and G33) had average grain yields higher than 5000 kg ha -1 . UPGMA and Tocher methods identified groups from the matrix of phenotypic and molecular data. Hybrids of G11, G12, G16, G22, G26 and G33 genotypes segregated promising populations with superior genetic variability.

The increasing use of Vernonia condensata Baker highlights the importance of developing strategies to reduce the impact of exploitation on nature reserves. The aim of this study was to establish a micropropagation protocol to produce homogenous plants with high phytosanitary quality. Apical, nodal, and internodal segments of plants grown in the field were used for in vitro growth. The segments were disinfected in sodium hypochlorite solution (1.0 and 2.0%) for 15 and 30 minutes and then transferred to Petri dishes containing MS culture medium for 30 days. A completely randomized factorial experiment (3 x 2 x 2) with five replicates was designed. After this period, a completely randomized in vitro multiplication experiment was carried out with six treatments (BAP - 0.0; 0.5; 1.0; 1.5; 2.0; 2.5 mg L-1) and six replicates. The shoots obtained in the best treatment were transferred to flasks with rooting medium (MS, MS/2 or MS/4). The experiment was completely randomized with 12 replicates. Microplants were acclimatized in polyethylene terephthalate (PET) bottles filled with autoclaved topsoil. Our results showed that 40.0% of the nodal segments (immersed in 1.0% sodium hypochlorite for 30 minutes) were adequately disinfected and survived. In the in vitro multiplication experiment, the 0.5 mg L-1 concentration of BAP yielded the highest number of shoots and the best vegetative growth. With regard to the assessed characteristics, MS/4 was the best rooting medium, with 100% survival during acclimatization. This study showed that V. condensata in vitro culture might produce 32,000 seedlings in 7 months.

The objective of this work was to evaluate the resistance of transgenic papaya populations (PTPs) to Papaya ringspot virus-P (PRSV-P). 'Sunrise Solo' transgenic papaya plants were produced with the gene of the PRSV-P protein coat, and PRSV was mechanically inoculated in plants in greenhouse conditions. The presence of the CP/PRSV gene and homozygosis were evaluated by polymerase chain reaction (PCR). Selected plants and the 'Sunrise Solo' control were transplanted to the field for agronomic evaluations. The plants evaluated in greenhouse conditions showed resistance between 96.3 and 5.8%, without variation of symptoms. The PTPs 1/6, 1/7, 1/9, 1/10, 1/15, 2/38, 2/41, 2/56, 2/65, 3/27, 3/46, 3/48, 4/9, 4/27, 8/4, 8/23, 8/33, 18/3, 18/4, 18/8, 18/22, 18/27, 28/97, 28/104, and 28/110 showed no symptoms, they were ELISA negative, and most of them contained the CP and NPT II genes. PTPs 1/6 and 3/46 had the CP gene in homozygosis and in double insertion. PTPs 1/6/20, 1/6/59, 1/6/64, 1/6/90, 3/46/44, 3/46/52, and 18/27/97 had a well-formed fruit cluster, piriform fruit weighing approximately 500 grams, orange pulp, and less than 10% carpelloidy. PTPs 1/6/59 and 3/46/52 show resistance to PRSV, good agronomic characteristics, and the CP gene in homozygosis.

Este trabalho tem por objetivo estabelecer condições de crescimento mínimo, visando o desenvolvimento de um protocolo de conservação in vitro de Vernonia condensata Baker, para ser utilizada em pesquisas e inserção na saúde pública do Recôncavo da Bahia. Foram utilizados segmentos nodais de aproximadamente 1,5 cm de tamanho, provenientes de plantas de alumã previamente cultivadas in vitro. Estes explantes foram inoculados em tubos de ensaio contendo o meio de cultura MS (MS, MS/2 e MS/4), suplementado com 15 g L-1 e 30 g L-1 de sacarose, mantidos em sala de crescimento (25 ± 1 ºC) e em BOD (20 ± 1 ºC) durante 120 dias, sendo realizadas avaliações em intervalos de 30 dias, utilizando as variáveis: altura da planta, número de folhas verdes, número de folhas senescentes e número de raízes. O meio MS com adição de 15 g L-1 de sacarose proporcionou o menor desenvolvimento in vitro de plantas de V. condensata. Para a manutenção de plantas da V. condensata por um período de 120 dias com menor altura e número de folhas verdes satisfatórios, deve ser considerado o meio de cultura MS com 15 g L-1 de sacarose, associado ao ambiente de cultivo com temperatura de 25 ºC.