Melhoramento do Panicum maximum apresentacao do projeto e do material.

bitstream/item/137547/1/PESQ-EM-ANDAMENTO-24.pdfCNPGC

Registro de 25 acessos selecionados de Panicum maximum.

bitstream/item/104715/1/Registro-de-25-acesso.pd

Recurrent phenotypic selection and recurrent selection based on combining ability in tetraploid bahiagrass

Paspalum notatum Flüggé is an apomictic grass used for forage and turf. The recent generation of a sexual synthetic tetraploid population of the species provides the uniqueadvantagetoexploitheterosisbyaccumulatingfavorableallelesthroughrecurrent selection cycles. The objective was to evaluate recurrent phenotypic selection (RPS) and recurrent selection based on combining ability (RSCA) as breeding methods. The best sexual genotypes in terms of warm-season growth from a sexual synthetic tetraploid population were selected by RPS and RSCA. The selected genotypes were polycrossed and two new sexual populations were created, which were crossed with superior apomictic genotypes. Both methods allowed obtaining families that were evaluated for summer, fall, and spring growth. Breeding values and heterosis were also calculated. Summer growth for RPS families was greater than for RSCA families (33.1 and 29.08 g plant−1, respectively); however, fall, spring, and accumulated growth were similar. The breeding value for RPS sexual parents was greater than for RSCA sexual parents for summer growth, whereas those for fall and spring growth were similar. A greater level of families with heterosis (80%) was observed for RPS than for RSCA (30%) for summer growth, whereas the levels for fallandspringgrowthweresimilar.Theseresultsindicatethatbothbreedingmethods were successful in improving tetraploid P. notatum. They increased the mean value of the progenies and produced families superior for forage yield by accumulating favorable alleles.Fil: Marcón, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Martínez, Eric Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Zilli, Alex Leonel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Rodríguez, Gustavo Rubén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; ArgentinaFil: Brugnoli, Elsa Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Acuña, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentin

Introdução, avaliação e melhoramento de plantas forrageiras tropicais no Brasil: novas propostas de Modus operandi.

Um exemplo de BAG e seus resultados; Dos BAGs aos projetos monoespecíficos; Um exemplo de projeto novo monoespecífico: o projeto Panicum no CNPGC; Proposta para a organização de uma rede de avaliação a nível nacional; Primeiras propostas de metodologia para avaliação de leguminosas.bitstream/item/104690/1/Introducao-avaliacao-e-melhoramento.pd

Identification of ovule transcripts from the Apospory-Specific Genomic Region (ASGR)-carrier chromosome

<p>Abstract</p> <p>Background</p> <p>Apomixis, asexual seed production in plants, holds great potential for agriculture as a means to fix hybrid vigor. Apospory is a form of apomixis where the embryo develops from an unreduced egg that is derived from a somatic nucellar cell, the aposporous initial, via mitosis. Understanding the molecular mechanism regulating aposporous initial specification will be a critical step toward elucidation of apomixis and also provide insight into developmental regulation and downstream signaling that results in apomixis. To discover candidate transcripts for regulating aposporous initial specification in <it>P. squamulatum</it>, we compared two transcriptomes derived from microdissected ovules at the stage of aposporous initial formation between the apomictic donor parent, <it>P. squamulatum </it>(accession PS26), and an apomictic derived backcross 8 (BC₈) line containing only the Apospory-Specific Genomic Region (ASGR)-carrier chromosome from <it>P. squamulatum</it>. Toward this end, two transcriptomes derived from ovules of an apomictic donor parent and its apomictic backcross derivative at the stage of apospory initiation, were sequenced using 454-FLX technology.</p> <p>Results</p> <p>Using 454-FLX technology, we generated 332,567 reads with an average read length of 147 base pairs (bp) for the PS26 ovule transcriptome library and 363,637 reads with an average read length of 142 bp for the BC₈ovule transcriptome library. A total of 33,977 contigs from the PS26 ovule transcriptome library and 26,576 contigs from the BC₈ovule transcriptome library were assembled using the Multifunctional Inertial Reference Assembly program. Using stringent <it>in silico </it>parameters, 61 transcripts were predicted to map to the ASGR-carrier chromosome, of which 49 transcripts were verified as ASGR-carrier chromosome specific. One of the alien expressed genes could be assigned as tightly linked to the ASGR by screening of apomictic and sexual F₁s. Only one transcript, which did not map to the ASGR, showed expression primarily in reproductive tissue.</p> <p>Conclusions</p> <p>Our results suggest that a strategy of comparative sequencing of transcriptomes between donor parent and backcross lines containing an alien chromosome of interest can be an efficient method of identifying transcripts derived from an alien chromosome in a chromosome addition line.</p

Chromosomal and embryological analyses in sexual apomictic hybrids of Panicum maximum Jacq

Summary. Cytological analyses in series of crosses between 7 sexual pistillate and 8 apomictic staminate parents of species Panicum nzaximunz (Gramineae) are reported. Although these 15 progenitors were tetraploid (2n = 32), 2 dihaploids (2n = 16), 45 hexaploids (2n = 48) and 5 octoploids (2n = 64) were observed among 333 progeny plants. The role of unreduced gametes as the originators of polyploidy is discussed in relation to the so-called &apos;elements of apomixis&apos;. The 2 dihaploids appeared to be sexual while the hexaploids and octoploids were all apomictic. At the tetraploid level sexual and apomictic hybrids segregated in a, ratio close to 1: 1. These results were then compared to those already obtained from studies on other tropical grasses and indicate a simple genetic determinism for gametophytic apomixis