Construção de mapa genético e análise comparativa entre cruzamentos interespecíficos de Oryza glumaepatula x Oryza sativa utilizando marcadores microssatélites.

Este trabalho objetivou: 1) desenvolver um mapa genético baseado em marcadores SSR para o cruzamento interespecífico Oryza sativa (Cica 8) x Oryza glumaepatula (RS-16); 2) avaliar a conservação da ligação e ordem dos locos SSR entre dois mapas interespecíficos, os quais possuem o parental RS-16 em comum; 3) genotipar 118 famílias na geração RC2F1 obtida a partir do cruzamento interespecífico entre Oryza sativa (Cica 8) e Oryza glumaepatula (RS-16)

Selection of rice genotypes with greater seedling vigor under controlled conditions.

This study aimed to identify allele sources for seedling vigour in 65 rice genotypes, using the slantboard test in a germination chamber, and to determine the best parameter for evaluating seedling vigour. The experiment was arranged in the randomized block design with three replicate blocks. Root and primary leaf length data were collected from seedlings grown in the dark at 18 degrees C, 15 days after sowing and at 25 degrees C, ten days after sowing. The best performing genotypes for seedling vigour were included in Group 2, which contained red rice accessions. The vigour was best evaluated under controlled conditions (grown at 18 degrees C, 15 days after sowing) through measurements of roots and primary leaves.

Development of rice lines with gene introgression from the wild Oryza glumaepatula by the AB-QTL methodology.

Wild rice of the species Oryza glumaepatula is found Brazil and has been used to broaden the genetic basis of irrigated rice populations in Embrapa breeding programmes. The objective of this study was to demonstrate and discuss approaches used in the development of Oryza sativa lines containing genes transferred from Oryza glumaepatula, resulting in introgression lines with a broader genetic basis and high yield. First of all, genes were transferred from the wild species to cultivated rice by the AB-QTL methodology. Eighteen families were selected using QTL analysis and agronomical performance data. After the heterosis test, the families CNAi 9020 and CNAi 9024 were selected and submitted to microsatellite marker-assisted selection. Thirty-five lines were then selected with high plant vigour, high tiller and panicle number per plant, high grain yield of the main crop, and a strong regrowth capacity which makes the use of ratoons a feasible alternative

Caracterização molecular de linhagens de introgressão do cruzamento interespecífico Oryza sativa x O. glumaepatula por marcadores SSR fluorescentes.

Este trabalho teve como objetivo realizar a caracterização molecular de 114 linhagens de Introgressão RC2F9 derivadas do cruzamento O. sativa Cica-8 x O. glumaepatula RS-16

BRS Ourominas: nova cultivar de arroz irrigado para Mato Grosso do Sul.

bitstream/item/24863/1/COT200254.pdfDocumento on-line

Comparative linkage mapping of Oryza glumaepatulaand Oryza sativa interspecific crosses based on microsatellite and expressed sequence tag markers.

Molecular linkage maps representing the rice genome have been an important tool for breeding programs because they allow the elucidation of polygenic traits and are an efficient tool for monitoring wild introgressions in interspecific crosses. Common markers among rice genetic maps are important in defining the homology of chromosomes and the synteny between genomic target regions. We used 148 markers (expressed sequence tags, microsatellites and single nucleotide polymorphisms) to construct a molecular linkage map based on co-dominant markers for an interspecific backcross population using a wild rice ( Oryza glumaepatula) from Brazil and performed a comparative analysis with other interspecific maps. The comparative analysis revealed a Spearman correlation index of 0.86 for marker order conservation to a previous map constructed for an interspecific cross using the same wild parent. Approximately 90% of markers common to other interspecific maps kept the same order. These results indicate that it will be possible to generate a unique genetic map using the wild donor and that it may be a helpful tool for breeding programs because plants derived from different interspecific populations can be rapidly scanned using markers associated with useful wild traits

Utilização de marcadores moleculares em programas de ampliação da base genética de espécies cultivadas.

Introdução; Utilização de germoplasma em programas de melhoramento genético; Determinação da variabilidade genética em acessos do banco de germoplasma; Cruzamentos amplos; Marcadores moleculares no melhoramento de plantas; Obtenção de mapas moleculares; Mapeamento de QTLs; Análise de AB-QTLs; Seleção assistida por marcadores; Considerações finais.bitstream/CNPAF/21787/1/doc_155.pd

Deriva genética nos acessos de arroz do banco de germoplasma da Embrapa Arroz e Feijão.

O objetivo do trabalho foi verificar a porcentagem de germinação das sementes dos acessos de arroz monitorando a sua viabilidade ao longo do armazenamento para indicação de multiplicação e renovação evitando assim a ocorrência de erosão genética