Experiments were conducted to determine the outcrossing rate, the inheritance of markers and establish a basic linkage map in grasspea, <i> Lathyrus sativus </i>L. The outcrossing rate in a white-flowered line of grasspea ranged from 1.7 to 2.7% among eight combinations of gene frequency and location. The outcrossing rate in this study (2.2 ± 0.7%) suggests that individual lines of grasspea should be maintained in isolation to maintain their genetic integrity. Inheritance and linkage were determined for one morphological, 11 isozyme and 72 RAPD markers in five F₂ populations (all RAPD markers were in one F₂ population). The inheritance of flower colour was monogenic with colour dominant over white. The isozymes, ACO-1, ACO-2, AAT-1, AAT-2, EST-6, FDH, LAP-1, PGD-2, SKDH and TPI-1, were codominantly expressed with monogenic inheritance. The isozymes LAP-1 and PGD-2 segregated in a non-Mendelian ratios in the crosses PI 426891.1.3 x PI 283564c.3.2 and PI 426891.1 x PI 172930.4, respectively. The isozymeEST-3 was monogenically inherited and dominantly expressed. Most RAPD markers segregated in a 3:1 ratio. Marker UBC368_425/655 segregated in a co-dominant fashion. The RAPD markers UBC304₈₃₁, UBC304₉₆₄, UBC308₉₉₀, UBC322₁₄₃₂, UBC328₈₃₁, UBC332₁₁₁₈, UBC3321₁₅₈₁, UBC333₆₁₇, UBC349<sub>752<?sub>, UBC365₁₀₁₃ and UBC388₄₅₉ showed distorted segregation. In two F₂ populations, PI 283564c.3 x PI 426885.2 and PI 358601.5 x PI 173714.5, a linkage between AAT-2 and SKDH was reconfirmed. In the cross PI 426891.1.3 x PI 283564c.3.2, one morphological, three isozyme and 71 RAPD markers were mapped resulting in the delineation of 14 linkage groups including 69 markers (1 morphological, 3 isozyme and 65 RAPD markers). The total genome length covered by these 75 markers (69 linked and six unlinked) was about 864 cM. Considering cost, simplicity and abundance, RAPD analysis was more efficient than isozyme analysis in developing linkage map.

Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-08-17T13:43:36Z No. of bitstreams: 1 flaviarangeldesouza.pdf: 928380 bytes, checksum: cf3367ab259e0a080c36f809b17947c3 (MD5) / Rejected by Adriana Oliveira (adriana.oliveira@ufjf.edu.br), reason: on 2017-08-24T11:26:44Z (GMT) / Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-08-24T15:17:40Z No. of bitstreams: 0 / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-08-30T14:31:44Z (GMT) No. of bitstreams: 0 / Made available in DSpace on 2017-08-30T14:31:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-02-21 / O capim-elefante (Cenchrus purpureus) é uma gramínea perene utilizada na alimentação bovina, principalmente na bovinocultura de leite. Atualmente, devido a sua alta produção de biomassa, o capim-elefante tem sido utilizado como insumo energético na produção de energia térmica (combustão direta, carvão vegetal e resíduos), energia mecânica (álcool combustível e bio-óleos) e energia elétrica (pela combustão, gaseificação e queima de gases). A forma de propagação do capimelefante é preferencialmente vegetativa, através de estacas, e a espécie é conhecida por produzir sementes de baixa germinação, o que dificulta a expansão em grandes áreas. Dessa forma, torna-se necessário avançar no conhecimento a respeito da biologia reprodutiva e gerar conhecimento para auxiliar a seleção de genótipos superiores nos programas de melhoramento do capim-elefante. O objetivo deste trabalho foi estimar a taxa de cruzamento do capim-elefante a fim de entender o comportamento reprodutivo na espécie. Para este estudo, 18 indivíduos pertencentes ao Programa de Melhoramento de Capim-Elefante da Embrapa Gado de Leite foram selecionados, e sementes foram coletadas. 20 mudas descendentes de uma mesma planta foram escolhidas, tendo uma população final de 378 indivíduos. Foi inicialmente extraído o DNA de todos os indivíduos, e as regiões de interesse foram amplificadas por PCR. Testes foram realizados com dezenove marcadores microssatélites, e seis obtiveram sucesso na amplificação e na presença de bandas polimórficas. Foi gerado um dendrograma com os parentais para identificar relações de parentesco entre os indivíduos amostrados, que mostrou uma baixa similaridade, sendo a maioria dos parentais com índices menores do que 0,75. Além disso, a AMOVA revelou que 86% da variabilidade da população está presente dentro das progênies, resultado que está de acordo com espécies predominantemente alógamas. A alogamia foi confirmada com resultados da estimativa da taxa de cruzamento: a taxa multilocus, de 0,957; a taxa unilocus, de 0,900; a taxa de autofecundação, de 0,043, além de apresentar coeficiente de endogamia de -0,200 e correlação de paternidade de 0,045, demonstrando que há maior presença de heterose e que são poucos os indivíduos que são irmãos completos. Os resultados apresentados são importantes para o entendimento do tipo de cruzamento presente na espécie e auxiliarão na definição de novas estratégias nos programas de melhoramento. / The Napier grass (Cenchrus purpureum) is a perennial grass used as forage crop mainly in dairy cattle. Nowadays, the Napier grass has been used as energy feedstock, due to high biomass yield, producing thermal energy (direct combustion, charcoal and residues), mechanical energy (biofuels and bio-oils) and electrical energy (through gas combustion, gasification and burn). C. purpureum is, preferably, a vegetative propagation species, that reproduces through stems. Its seeds have low quality, making difficult its expansion in extensive areas. Thus, it is necessary to extend the knowledge about the reproductive biology and selection of superior genotypes in Napier grass breeding programs. The aim of this study was to estimate the outcrossing rate of Napier grass in order to understand the reproductive behavior of this species. For that, 378 individuals were selected and divided in 18 parental and its progenies groups. DNA was extracted from all individuals and selected microsatellite regions were amplified by PCR. A total of 19 microsatellite markers were tested and six were successful in the amplification of polymorphic DNA bands. A dendrogram was generated with parental individuals to identify the relationship among them and a low similarity (<0.75) was found. AMOVA revealed 86% of variability within progenies which correlates with species predominantly alogamic. The allogamy was confirmed through analysis of outcrossing rate: the multilocus rate (0.957), unilocus rate, (0.900), selfing rate (0.043), inbreeding coefficient (-0.200), and correlation of paternity (0.045). These results indicate that heterosis is present and few individuals share the same parental origin. These findings are important to understand the outcrossing rate in this species and may help to define new strategies in breeding programs.

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