Jefferson Fernando Naves Pinto

Seleção de descritores vegetativos para caracterização de acessos de guariroba (Syagrus oleracea (Mart.) Becc.)

The present paper had the purpose of selecting morphological vegetative descriptors and to determine their relative importance in the characterization of guariroba accesses, as well as to verify the association between discarded and accepted descriptors.. Eighteen morphological descriptors, of which 8 relative to the leaf and 10 to the stipe, in 36 guariroba accessions in the State of Goias were evaluated . The discarded descriptors did not cause loss of information, as they presented significant correlations with the descriptors that were accepted. The relative contribution of the selected descriptors was similar for A7A, ENI7180, DFBF, D0, CPC and DPC, with descriptors ENI70 and ENS70 having the lowest contribution.

Genetic diversity of gabiroba based on random amplified polymorphic DNA markers and morphological characteristics.

The fragmentation of the original vegetation of the Cerrado biome, caused by the expansion of agricultural areas, mainly in central-west Brazil, calls for an assessment of the native population of this vegetation, especially of the species of interest for domestication and sustainable use. The purpose of this study was to characterize the genetic diversity of 140 gabiroba mother plants (Campomanesia spp) and their progenies from 17 locations in Goiás. The morphological characteristics of the mother plants were evaluated, and the leaflets were collected for molecular analysis using 12 random amplified polymorphic DNA primers. The seed progenies of these matrices were transplanted to the field and morphologically evaluated. Distance matrices of the morphological data of the mother plants and progenies as well as the molecular data of the mother plants were constructed, and groups were formed using the Tocher method and the unweighted pair-group method based on arithmetic averages. The polymorphism level in the matrix was 90.44%. The greatest molecular distance (0.66) was observed between mother plants from Santa Rita do Araguaia and Alexânia. By the Tocher method, 10, 13, and 17 groups were formed. The morphological evaluation of the mother plants and progenies as well as the molecular analysis of the mother plants showed genetic diversity. Significant genetic variability was detected in the progenies of the gabiroba base collection planted in Campus Jataí, Goiás.

Genetic divergence in pepper genotypes from southwest Goiás

Knowledge on the genetic diversity in genebanks is important for germplasm conservation and use in breeding programs, where it can reduce time and costs of breeding of new genotypes. The purpose of this study was to evaluate the genetic divergence among 137 genotypes of Capsicum chinense Jacq. by morphological descriptors and multivariate techniques, with a view to the identification of groups for promising crosses for breeding programs. The experiment was conducted in a greenhouse, arranged in a randomized complete block design with four replications, where each plot consisted of a pot with one plant. The 20 descriptors recommended by the International Plant Genetic Resources Institute - IPGRI were considered for the morphological characterization. By analysis of variance, significant differences between genotypes were detected for the studied descriptors. Clustering by the Tocher optimization method formed five groups, and by the hierarchical clustering method UPGMA, 11 groups. Based on larger distances intergroup, crosses are recommended among genotypes of the groups II x V, II x IV, and I x V for the Tocher method, and by UPGMA among genotypes of the groups VI x XI, II x XI, IV x XI,. The cophenetic correlation coefficient for the hierarchical clustering method UPGMA was 0.797 (p <0.01). The traits that contributed most to the total genetic diversity were number of days to flowering and plant height.

Efeito de diferentes tratamentos na superação da dormência de sementes da palmeira Syagrus oleracea Becc.

The Guariroba Palm (Syagrus oleraces Becc) is the only species known as producer of bitter palm heart, which is very appreciated in Goiânia cooking and can also be used in animal feeding and landscaping; however, it is little studied. The slow and uneven germination of seeds cause problems in the propagation of this species, thus complicating mainly the seedling production at a commercial scale. This study evaluated different treatments to reduce the dormancy state and consequently to speed up the germination period of guariroba palm seeds and looking for techniques of easy comprehension and application by small farmers. The experimental design was in completely randomized blocks with three replications in a 2 x 7 factorial arrangement; i.e, two levels for type of seeds (pulped and not pulped) an seven different methods of seed treatment. In the second stage, the interference of coleobroca in the seed germination was quantified by counting the number of attacked seeds after seedling germination. The observed results showed that treatments under low temperatures caused a significant decrease in seed germination of guariroba and that non pulped seeds reduced the time required for germination. It was also evidenced that reducing humidity to 8% does not affect the germination of guariroba seeds and that the water absorption by the seeds was influenced directly by the time of immersion in the water glass, independently of pulp presence. The studied treatments were not effective in reduccing coleobroca attack.

Escherichia coli enterohemorrágica O157: H7 em bovinos leiteiros saudáveis no Centro-Oeste do Brasil: ocorrência e caracterização molecular

Enterohemorrhagic Escherichia coli (EHEC) serotype O157:H7 represents the major Shiga toxin-producing E. coli (STEC) strain related to large outbreaks and severe diseases such as hemorrhagic colitis (HC) and the potentially lethal hemolytic uremic syndrome (HUS). The aim of this study was to report the occurrence and molecular characterization of O157:H7 isolates obtained by rectal swab from 52 healthy dairy cattle belonging to 21 farms in Mid-West of Brazil. Detection of 16SrRNA, stx1, stx2, rfbO157, fliCh7, eae, ehxA, saa, cnf1, chuA, yjaA and TSPE4.C2 genes was performed by PCR. The isolates were further characterized by serotyping. Two hundred and sixty E. coli isolates were obtained, of which 126 were characterized as STEC. Two isolates from the same cow were identified as serotype O157:H7. Both isolates presented the stx2, eae, ehxA, saa and cnf1 virulence factor genes and the chuA gene in the phylogenetic classification (virulent group D), suggesting that they were clones. The prevalence of O157:H7 was found to be 1.92% (1/52 animals), demonstrating that healthy dairy cattle from farms in the Mid-West of Brazil are an important reservoir for highly pathogenic E. coli O157:H7.

Diversidade genética de frutos de macaúba provenientes de 35 municípios de Goiás

The objective of this work was to evaluate the genetic diversity of macaúba (Acrocomia aculeata) accessions from 35 municipalities of the state of Goiás, Brazil, in order to obtain information about the genetic variability and to provide subsidies for the commercial deployment of the culture in the Midwestern region of Brazil. The bunches were harvested with ripe fruits. The following were evaluated: fruit and almond lengths and diameters; the weights of fruits and almonds; the average number of almonds, as well as the oil contents in the almond and in the dehydrated fruit. The parameters that indicated significant contributions to the variability were fruit weight, fruit width, fruit length, and oil content in the almond.