Abstract The efficiency of maize transformation mediated by Agrobacterium tumefaciens is influenced by various factors. The aim of this study was to test the effect of different concentrations of N6 salts (50% - half strength, and 100% - full strength) in the infection and cocultivation media on genetic transformation efficiency of the L3 tropical elite maize line. Immature embryos were transformed via A. tumefaciens harboring the binary vector pTF102 containing the genes uidA and BAR under control of the CaMV35S promoter. The efficiency of the transgenic events produced was 3% for full strength and 1.1% for half strength N6 salts. Although under a lower concentration of salts, GUS expression was stronger; under this concentration, regeneration was less efficient. Thus, the results showed that the presence of 100% N6 salts in the infection and cocultivation media favored genetic transformation of the L3 maize inbred line mediated by A. tumefaciens.

O flamboyanzinho (Caesalpinia pulcherrima, Fabaceae) é muito utilizado como cerca-viva e na arborização de ruas, parques e jardins. De florescimento exuberante, suas flores podem apresentar coloração rosa, laranja ou amarela, conforme a variedade. Como características florais são essenciais para a definição do valor comercial de espécies ornamentais, o objetivo principal do trabalho foi verificar a existência de polimorfismo entre plantas de C. pulcherrima, que produzem flores de diferentes colorações, por marcadores moleculares RAPD. Foram escolhidas aleatoriamente 30 plantas adultas, cultivadas no município de Jaboticabal, Estado de São Paulo, para a retirada de amostras foliares para a extração de DNA. Dentre essas matrizes, 20 possuem flores alaranjadas, oito, flores amarelas, e apenas duas produzem flores de coloração rosa. Dos 140 primers de RAPD avaliados, 94 foram capazes de ampliar fragmentos definidos, gerando 246 bandas, das quais se observou 100% de bandas monomórficas, indicando que nenhum dos primers utilizados detectou polimorfismo entre os tratamentos. Concluiu-se que a técnica para detecção de polimorfismo por marcadores RAPD não foi eficiente, e que existe a necessidade de se testarem marcadores moleculares mais específicos. Além disso, a característica morfológica "cor de flor" é, possivelmente, controlada por vários genes ou pela combinação deles.

The species Caesalpinia pulcherrima, which belongs to the Fabaceae family, is frequently used as a hedge or street tree in urban landscapes, parks and gardens. It flowers profusely, and the flowers, depending on the variety, may be pink, orange or yellow. As flower characteristics are essential for determining the commercial value of ornamental species, the main objective of this work was to identify polymorphisms in C. pulcherrima plants that produce flowers of different colors using RAPD molecular markers. For this study, 30 adult plants were randomly chosen on streets located in Jaboticabal city, São Paulo State, Brazil, and leaf samples were collected for DNA extraction. Among these trees, 20 have orange flowers, eight have yellow flowers and only two produce pink flowers. From the 140 tested RAPD primers, 94 primers amplified defined fragments that resulted in 246 bands, which were 100% monomorphic. Thus, a polymorphism was not detected by any of the primers tested. It was concluded that the RAPD technique is not an efficient method for detecting polymorphisms and that more specific molecular markers should be tested. Additionally, the morphological characteristic "flower color" may be controlled by several genes or by the association of them.

O objetivo deste trabalho foi identificar e caracterizar os genes cry3, vip1, vip2 e vip1/vip2 em uma coleção de 1.078 isolados de Bacillus thuringiensis potencialmente tóxicos para larvas de coleópteros. Foram utilizados pares de oligonucleotídeos iniciadores gerais obtidos a partir de regiões conservadas dos genes e do alinhamento de sequências consenso. Posteriormente, os isolados positivos foram caracterizados por meio da técnica de PCR‑RFLP, tendo-se utilizado enzimas de restrição específicas, para identificar novas subclasses de genes nos isolados. Cento e cinquenta e um isolados foram positivos para os genes avaliados, com maior frequência para o gene vip1/vip2 (139 isolados). Pela técnica de PCR‑RFLP, foram observados 14 perfis polimórficos, o que indica a presença de diferentes alelos e, consequentemente, de distintas subclasses desses genes.

The objective of this work was to identify and characterize cry3, vip1, vip2 and vip1/vip2 genes in a collection of 1,078 Bacillus thuringiensis isolates potentially toxic against Coleoptera larvae. Pairs of primers derived from conserved regions of genes and from sequence alignment consensus were used. Subsequently, positive isolates were characterized by PCR‑RFLP, using specific restriction enzymes to identify new subclasses of genes in the isolates. One hundred and fifty‑one isolates were positive for the evaluated genes, with higher frequency for the vip1/vip2 gene (139 isolates). By PCR‑RFLP, 14 polymorphic profiles were observed, indicating the presence of different alleles, and, therefore, of distinct subclasses of these genes.