No abstract

Dentre as hortaliças folhosas, a alface é uma hortaliça folhosa bastante consumida no Brasil, sendo recomendado o uso de cultivares adaptadas às diferentes condições climáticas. Com isso, este trabalho teve como objetivo selecionar genótipos de alface de folhas lisas e tolerantes ao florescimento precoce. O experimento foi implantado no município de Itabaiana, Estado de Sergipe em blocos casualizados com três repetições, sendo testados 12 genótipos, os quais foram avaliados quanto à massa fresca e seca da parte aérea, massa fresca e seca da raiz, massa de folhas comerciais e não comerciais, número de folhas comerciais e não comerciais, diâmetro da cabeça e comprimento do caule. O genótipo AFX005B-121-02, que possui folhas lisas e é tolerante ao florescimento precoce, apresentou melhor desempenho comercial e agronômico, sendo promissor para plantio nas condições do Agreste.

HIGHLIGHTS The seeds obtained from the fruit pulp industry have a physiological quality for seedling propagation. There is a high potential for reducing fruit pulp industry residues by using these seeds for propagation. Higher pixel density is observed for full seeds with an efficiency of forming normal seedlings.

Leifsonia xyli subsp. xyli, the causal agent of ratoon stunting, is an endophytic bacteria that colonize sugarcane xylem vessels. It is generally accepted that sugarcane is the only natural host of ratoon stunting. The objective of this work was to investigate the presence of bacteria in insects associated with sugarcane in an experimental area cultivated with four varieties. The plants were artificially inoculated with bacteria, the samples of insects were collected from the sugarcane crop. Specific PCR was used with DNA extracted from different insect parts (head, abdomen, or whole-body). The DNA of the bacterium was not detected in those investigated insects, confirming that the host range of the bacterium is restricted to Saccharum spp.

No abstract

One of the methods used to promote the rapid and uniform germination of vegetable seeds is the use of osmotic conditioning. The technique aims to regulate the osmotic potential of the solution, thus restricting the entry of water into the seeds without them germinating during the process. This work evaluated the germination of lettuce seeds of Grand Rapids, Everglades, and Verônica cultivars, submitted to osmotic conditioning. The seeds were immersed in polyethylene glycol solutions (PEG 6000) at potentials of 0.0; -0.6; -0.8, and -1.0 MPa, and remained in imbibition for 14, 24, and 48 h. After this period, the seeds were germinated on paper, moistened with water at 2.5 times their mass, and kept at 20ºC for seven days. The experimental design used was completely randomized, in a factorial scheme with three cultivars, four osmotic potentials, and three temperatures, with four replications of 25 seeds each. The germination percentage, the germination speed index, the mean speed of germination, and the mean germination time were evaluated. Data were subjected to analysis of residual normality by the Shapiro-Wilk test and the homogeneity of variances using the Bartlett test and submitted to analysis of variance. Data from osmotic potential and time of imbibition were submitted to polynomial regression. The treatment means were compared at 5% probability. Seeds of ‘Grand Rapids’ and ‘Everglades’ showed positive effects after osmoconditiong treatments.

I. Background: Plant phenotyping has been a bottleneck for selecting insect-resistant plants in breeding programs. Our objectives were to: use text-mining tools to investigate state of the art about Leptocybe invasa in Eucalyptus; identify associated molecular interactions involving genes as a candidate and their impact and associated metabolites pathways and determine how products are currently used to control this insect as patents. II. Methods and Results: The literature survey was explored by title, abstract, and keywords of scientific articles, a database of genes and protein sequences, and patents. Nucleotide and protein sequences were mined in public banks. In the literature, we searched for homology to known genes or predicted proteins with sequences described in Eucalyptus sp. To obtain a broad set of studies, we accessed literature data of the last 20 years conducted with combinations of search terms “Leptocybe invasa” OR “eucalyptus gall wasp” AND “control”. Patents were prospected and analyzed using Orbit Intelligence patent research software III. Conclusions: Succinct interpretation of results as well as significance of findings. Statement There are perspectives to access the genotype resistance; furthermore, it is critical managing the evaluable information as state of the art to overcome the damages of L. invasa beyond the genotype selection. The target genes found in this research can serve as a basis for further functional characterizations of Eucalyptus genes possibly related to response expression to L. invasa.

Abiotic stress caused by rigorous environmental conditions, such as drought, has negative effects on seeds. The species from arid and semiarid areas have mechanisms to maintain seed viability. In this study, the analyses of physical and physiological quality of the seeds of Erythrina velutina and their response to drought stress and RNA extraction methods were carried out. The seeds were collected from mother trees in two different provenances of natural occurrences of the species. The physical quality, viability, and vigor of the seeds were evaluated by morphometric parameters, germination, and electrical conductivity tests. The seeds were submitted to drought stress conditions for 0, 24, 48, and 72 hours on -0.8 MPa polyethylene glycol solution. To evaluate the viable RNA extraction method, the seed embryos were used for the extraction of this molecule and with an assessment of quantity and quality. The seeds from Pernambuco that were harvested in 2008 were bigger and presented lower vigor when in comparison to seeds that were harvested from Sergipe in 2012. The seeds under drought stress conditions presented null germination for all the treatments. After the drought stress, they were germinated on a paper substrate moistened with water, with better responses from the Lot Sergipe, 2012. The imbibition of seeds in the solution for 24 hours provides an increase in germination for less vigorous seeds, being indicated as a pre-germinative treatment. The RNA quality obtained by using a commercial extraction kit has better results, providing materials without contaminants when compared to the TRIzol method.