Finding the genes that underlie variation in production and developmental traits has important economic applications. Incubation behaviour represents a loss of production in conventional breeds of chicken adapted to local conditions and was what motivated this thesis. The Mendelian traits of comb type, crest, Silkie and normal feathers, feathered leg, fibromelanosis, comb colour, skin and shank colour, feather colour and patterns are of interest because of the insight they give to genes and development and were also investigated in the thesis. We used White Leghorn and Silkie lines of chicken to detect the genetic loci controlling incubation behaviour and Mendelian traits using linkage based analysis in an F2 cross. The evidence for QTL affecting incubation status over the whole period on chromosome 5 was strong (P<0.05). After the addition of 218 new informative SNP markers across the genome including chromosome 5 the 95% confidence interval spanned a region around 45 cM having previously been 95 cM. Three other suggestive QTL for incubation status were found after the addition of SNP markers on chromosome 1, 18, 19, E22C19W28 at 70, 0, 1 and 13cM respectively. The mode of action of the incubation status QTL indicates that the White Leghorn allele was either promoting incubation behaviour or that heterozygotes have performance that exceeds the homozygotes except the QTL on chromosome 1 where the Silkie allele is promoting incubation behaviour as might be expected. A highly significant QTL (P<0.01) for early incubation behaviour (25-30 weeks) was found on chromosome 8 at 18 cM. This QTL has an additive effect with the possession of a Silkie allele increasing the likelihood of incubation behaviour. Other suggestive QTL for early incubation behaviour were found on chromosome 26 and 1 at 0 and 66cM respectively. For Mendelian traits, genome wide significant (P<0.01) genetic loci for comb type, crest type and feather type was found on chromosome 7 at 77cM, linkage group E22C19W28 at 7cM and on chromosome 3 at 169cM respectively. Significant genetic loci (P<0.01) for leg colour and skin colour were found on chromosome 20 at 56cM and 60cM respectively. In the present study, loci for all feather patterns were found on E22C19W28 even after removing animals carrying the dominant white alleles, suggesting dominant white or another allele at the locus was still influential. Comb type and incubation behaviour were investigated at the gene level. Thyroid stimulating hormone receptor (TSHR) is believed to be involved in the process of domestication and was found at the peak position of the most significant QTL on chromosome 5 for incubation behaviour. Functional exploration of Wnt genes as a candidate gene for comb type was investigated by in-situ hybridization in Silkie and White Leghorn embryos. The Wnt6 gene showed expression in the region of the presumptive comb development of embryos. In conclusion, for the first time genetic loci that explain maternal behaviour have been described. The coincidence of the incubation behaviour locus on chromosome 5 with the site of the strongest selective sweep in poultry, the TSHR, and the coincidence of QTL on chromosome 1 and 8 with thyroid hormone activity it would appear that the thyrotrophic axis may be critical to the loss of incubation behaviour and improved reproductive performance with domestication. Further analysis of these loci should be able to produce markers that can reduce the propensity for birds to incubate. Comb type marker might allow introgression of this trait to prevent comb damage in commercial hens.

Made available in DSpace on 2014-06-11T19:22:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-12-17Bitstream added on 2014-06-13T18:48:43Z : No. of bitstreams: 1 pincelli_rp_me_botfca.pdf: 933139 bytes, checksum: dc525360fa3fad2d769f79bc71a084be (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A seca é um dos principais fatores limitantes à produtividade agrícola ao redor do mundo. Com a expansão da área de plantio da cana-de-açúcar para regiões brasileiras caracterizadas por apresentarem deficiência hídrica por longos períodos durante o ano, torna-se essencial a obtenção de germoplasma de cana-de-açúcar tolerante a esse estresse. Identificar ferramentas adequadas de seleção e características quantificáveis podem facilitar o processo de melhoramento da cultura para tolerância à seca, visto que há dificuldade em identificar características únicas que possam ser utilizadas para a seleção. O objetivo do presente trabalho foi verificar a habilidade de algumas variáveis morfofisiológicas para distinguir entre tolerantes e susceptíveis quatro cultivares comerciais de cana-de-açúcar sob dois regimes hídricos. O experimento foi conduzido em vasos contendo 22 litros de substrato, em casa de vegetação localizada na Unidade de Pesquisa e Desenvolvimento da APTA Polo Centro-Oeste, Jaú,SP. O delineamento experimental foi inteiramente casualizado, em esquema fatorial 4x2x3 (cultivares x regimes hídricos x épocas de avaliação), com três repetições. Aos 84 dias após a emergência, as cultivares RB72454, RB855453, SP81-3250 e SP83-2847 foram submetidas aos tratamentos de teor de umidade (%): sem deficiência (-D) e com deficiência (+D) promovida por 50% do teor de umidade ideal e avaliadas durante três épocas: 0, 28 e 56 dias após o início dos tratamentos. As variáveis avaliadas foram: altura do colmo, número de folhas verdes, comprimento e largura da folha +3, área foliar, densidade estomática, massa foliar específica, estimativa do conteúdo de clorofila (via SPAD e via espectrofotômetro), máxima eficiência fotoquímica do fotossistema II (Fv/Fm), condutância estomática, conteúdo relativo de água, potencial hídrico foliar e massa... / Drought is one of major limiting factors to agricultural productivity around the world. With the expansion of planting area of sugarcane for Brazilian regions characterized by water stress for long periods during the year, it becomes essential to obtain germplasm of tolerant sugarcane. Identify appropriate tools for selection and quantifiable characteristics can facilitate the process of crop breeding for drought tolerance, since there is difficulty in identifying unique characteristics that can be used for selection. This study aimed to verify the ability of some morphological and physiological variables to distinguish between tolerant and susceptible four sugarcane commercial cultivars under two water regimes. The experiment was carried out in pots containing 22 liters of substrate, in a greenhouse located in the Unit of Research and Development of APTA, Jaú, SP. The experimental design was randomized in factorial 4x2x3 (genotypes x water regimes x evaluation times) with three replicates. At 84 days after emergence, cultivars RB72454, RB855453, SP81-3250 and SP83-2847 were exposed to humidity treatments: no stress (-D) and stress (+ D) promoted by 50% of the ideal humidity and evaluated for three times: 0, 28 and 56 days after the initiation of the treatments (DAT). The variables evaluated were: stalk height, green leaf number, length and width of leaf +3, leaf area, stomatal density, specific leaf mass, estimated chlorophyll content (via SPAD and via spectrophotometer), maximum photochemical efficiency of photosystem II (Fv/Fm), stomatal conductance, relative water content, leaf water potential and dry weight of shoots and roots. We found a higher height of stalk, number of green leaves, leaf area, stomatal density at adaxial and abaxial surfaces, higher maximal photochemical efficiency of photosystem II (Fv/Fm), estimation of chlorophyll content (SPAD index) and leaf water potential... (Complete abstract click electronic access below)

Orientador: Marcelo de Almeida Silva / Banca: Carlos Alexandre Costa Crusciol / Banca: Maria Ines Tiraboschi Ferro / Resumo: A seca é um dos principais fatores limitantes à produtividade agrícola ao redor do mundo. Com a expansão da área de plantio da cana-de-açúcar para regiões brasileiras caracterizadas por apresentarem deficiência hídrica por longos períodos durante o ano, torna-se essencial a obtenção de germoplasma de cana-de-açúcar tolerante a esse estresse. Identificar ferramentas adequadas de seleção e características quantificáveis podem facilitar o processo de melhoramento da cultura para tolerância à seca, visto que há dificuldade em identificar características únicas que possam ser utilizadas para a seleção. O objetivo do presente trabalho foi verificar a habilidade de algumas variáveis morfofisiológicas para distinguir entre tolerantes e susceptíveis quatro cultivares comerciais de cana-de-açúcar sob dois regimes hídricos. O experimento foi conduzido em vasos contendo 22 litros de substrato, em casa de vegetação localizada na Unidade de Pesquisa e Desenvolvimento da APTA Polo Centro-Oeste, Jaú,SP. O delineamento experimental foi inteiramente casualizado, em esquema fatorial 4x2x3 (cultivares x regimes hídricos x épocas de avaliação), com três repetições. Aos 84 dias após a emergência, as cultivares RB72454, RB855453, SP81-3250 e SP83-2847 foram submetidas aos tratamentos de teor de umidade (%): sem deficiência (-D) e com deficiência (+D) promovida por 50% do teor de umidade ideal e avaliadas durante três épocas: 0, 28 e 56 dias após o início dos tratamentos. As variáveis avaliadas foram: altura do colmo, número de folhas verdes, comprimento e largura da folha +3, área foliar, densidade estomática, massa foliar específica, estimativa do conteúdo de clorofila (via SPAD e via espectrofotômetro), máxima eficiência fotoquímica do fotossistema II (Fv/Fm), condutância estomática, conteúdo relativo de água, potencial hídrico foliar e massa... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Drought is one of major limiting factors to agricultural productivity around the world. With the expansion of planting area of sugarcane for Brazilian regions characterized by water stress for long periods during the year, it becomes essential to obtain germplasm of tolerant sugarcane. Identify appropriate tools for selection and quantifiable characteristics can facilitate the process of crop breeding for drought tolerance, since there is difficulty in identifying unique characteristics that can be used for selection. This study aimed to verify the ability of some morphological and physiological variables to distinguish between tolerant and susceptible four sugarcane commercial cultivars under two water regimes. The experiment was carried out in pots containing 22 liters of substrate, in a greenhouse located in the Unit of Research and Development of APTA, Jaú, SP. The experimental design was randomized in factorial 4x2x3 (genotypes x water regimes x evaluation times) with three replicates. At 84 days after emergence, cultivars RB72454, RB855453, SP81-3250 and SP83-2847 were exposed to humidity treatments: no stress (-D) and stress (+ D) promoted by 50% of the ideal humidity and evaluated for three times: 0, 28 and 56 days after the initiation of the treatments (DAT). The variables evaluated were: stalk height, green leaf number, length and width of leaf +3, leaf area, stomatal density, specific leaf mass, estimated chlorophyll content (via SPAD and via spectrophotometer), maximum photochemical efficiency of photosystem II (Fv/Fm), stomatal conductance, relative water content, leaf water potential and dry weight of shoots and roots. We found a higher height of stalk, number of green leaves, leaf area, stomatal density at adaxial and abaxial surfaces, higher maximal photochemical efficiency of photosystem II (Fv/Fm), estimation of chlorophyll content (SPAD index) and leaf water potential... (Complete abstract click electronic access below) / Mestre

Thesis (M. Agricultural Management (Animal Production)) -- University of Limpopo, 2022 / Modern analytical techniques such as data mining algorithms are used to create a model that accurately estimates continuous dependent variable from independent variables of a given set of data. The present study used different data mining algorithms to assess the association between body weight (BW) and morphological characteristics such as body length (BL), heart girth (HG), withers height (WH), rump height (RH), and rump length (RL) of South African non-descript indigenous goats. The research was carried out in the Lepelle-Nkumbi Local Municipality, Capricorn District in the Limpopo province of South Africa. The study used 700 non-descript indigenous goats which include 283 bucks and 417 does with age ranged from one to five years old. The morphological characteristics were taken with a tailor measuring tape and a wood ruler calibrated in centimetres (cm), while the BW was taken with a balanced animal scale calibrated in kilograms (kg). Before the goats were allowed to go for grazing, the following body measurements (BW, BL, HG, WH, RH and RL) was taken once in the morning. Data was analyzed using descriptive statistics, Pearson correlation, various data mining algorithms (Chi-square automatic interaction detector, Classification, and regression tree), analysis of variance and goodness of fit equations (Coefficient of determination (R2), adjusted coefficient of determination (Ajd.R2), root mean square error (RMSE), relative approximate error (RAE), standard deviation ratio (SD. ratio) and coefficient of variance (CV)). The result showed that, BW and HG had higher mean values in does than bucks, BL and WH had higher mean values in bucks than does, and RH and RL had equal mean values in bucks and does, according to descriptive statistics. Furthermore, our findings showed that the BW of does had positive significant correlation (P < 0.01) with BL (r = 0.65), and positive significant correlation (P < 0.05) with HG (r = 0.28), but non-significant correlation (P > 0.05) with WH (r = 0.21), RH (r = 0.23) and RL (r = 0.23). However, the result for bucks indicated that BW had positive significant correlation (P < 0.01) with BL (r = 0.65) but non-significant correlation with HG (r = 0.22), WH (r = 0.07), RH (r = 0.14) and RL (r = 0.12). The chi-square automatic interaction detector and classification and regression tree results indicated that BL in bucks and does had statistical significance (P < 0.01) on BW followed by age, HG, and villages where the animals were raised. Goodness of fit results indicated there was high R2 = 0.58, Adj. R2 = 0.58, and low SD. Ratio = 0.65, RAE = 0.02, RMSE = 5.53) and CV = 14.49 in CHAID model and low R2 = 0.51, Adj. R2 = 0.46 and high SD. Ratio = 0.70, RAE = 0.20, RMSE = 5.95 and CV = 15.49 in CART model. Analysis of variance results indicated that age had significant difference (P < 0.01) on BW and some morphological traits including BL, HG, WH and RH. Sex only revealed significant difference (P < 0.01) in RL. It was concluded that BL alone in both sexes can be used as a selection criterion when determining body weight of goats. Both CHAID and CART suggest that BL alone can be used as a predictor of body weight in goats. Goodness of fit calculations suggest that CHAID is the best model due to its high R2, Adj. R2 and low RAE and RMSE. Findings suggest that age can be used as deciding factor for the measured traits including BW, BL, HG, WH and RH in both does and bucks. Findings suggest that sex can only be used as a deciding for RL only in the current study. / National Research Foundation (NRF)

O gênero Dioscorea é o mais amplo da família Dioscoreaceae, apresentando cerca de 600 espécies distribuídas, sobretudo, nos trópicos, com grande importância na alimentação, principalmente na África Ocidental, na Sudeste Asiático, no Caríbe e em alguns países da América do Sul. No Brasil, algumas espécies de inhame (Dioscorea spp.), juntamente com a mandioca (Manihot esculenta Crantz), têm uma profunda importância na agricultura de subsistência, sendo utilizadas basicamente como fonte de carboidrato para alimentação humana. Pouco se conhece sobre a diversidade e estrutura genética dessas espécies, como evoluíram nos últimos anos, sobretudo pela escassez de avaliações moleculares. O presente estudo tem como objetivos: (i) apresentar dados sócio-econômicos e etnobotânicos relativos aos diferentes agricultores que cultivam a espécie; (ii) isolar primers de microssatélites usando uma biblioteca genômica enriquecida e testar sua amplificação entre outras espécies de Dioscorea; (iii) analisar a relação genética entre 73 variedades locais e 17 acessos comerciais de inhame coletados em cinco diferentes regiões do Brasil (Sul, Sudeste, Nordeste, Norte e Centro-oeste) usando um conjunto de 12 microssatélites. Túberas de inhame foram coletadas em 28 municípios proveniente de cinco regiões onde a espécie é comumente cultivada, bem como em mercados locais e feiras de vários estados do Brasil. Outros acessos foram obtidos dos bancos de germoplasma ex situ pertencentes a ESALQ/USP, IAC e FCA/UNESP. Uma análise descritiva de diferentes agricultores foi realizada, indicando distintos perfis entre as regiões analisadas. Um amplo espectro de nomes populares foi registrado com diferenças entre regiões. As entrevistas com os agricultores revelaram que a espécie tem perdido sua importância em algumas áreas tradicionais/locais. O isolamento de marcadores microssatélites polimórficos resultou na detecção de 14 locos de microssatélites (SSR). Destes, dez foram selecionados para caracterizar 80 acessos de D. alata. O conteúdo de informação polimórfica foi de 0,39 a 0,78 e o poder de descriminação foi de 0,15 a 0,91. Seis destes marcadores mostraram transferibilidade entre as espécies D. bulbifera, D. cayenensis-D. rotundata e D. trifida. Em um estudo de diversidade morfológica e molecular, 12 pares de microssatélites polimórficos (nove desenvolvidos neste estudo e três obtidos da literatura) foram usados para gerar perfis de DNA de cada acesso da espécie e quatro perfis morfológicos foram analisados. A caracterização morfológica mostrou considerável diversidade e nenhum agrupamento específico foi observado entre as regiões. As análises moleculares de D. alata mostraram alta diversidade intra-específica nos acessos locais de diferentes regiões do Brasil. Contudo, a estrutura populacional entre as regiões coletadas foi relativamente baixa. Somente acessos da região Centro-Oeste apresentaram um aparente agrupamento regional, resultado quase similar foi observado nos acessos do nordeste. Estes resultados mostram uma mistura de acessos em todas as regiões coletadas, na qual é consistente com a falta de correlação entre as distâncias geográficas e genéticas, sugerindo que as túberas de inhame têm se movido extensivamente pelo fluxo humano. A diversidade genética encontrada pode ser explicada pelo resultado de um contínuo intercâmbio de variedades através do território brasileiro. O desenvolvimento de marcadores moleculares SSR em D. alata e análises de genética populacional são essenciais para o avanço de pesquisas nesta espécie. A geração de informação é de grande importância para a identificação, exploração racional e conservação da variabilidade genética da espécie, tanto da forma in situ e/ou ex situ. / The genus Dioscorea is the largest in the Dioscoreaceae family, featuring approximately 600 species distributed mainly in the tropics, with high importance as food supply in West Africa, Asia southeast, the Caribbean and a few countries in South America. In Brazil, some species of yam (Dioscorea spp.) together with cassava (Manihot esculenta Crantz), have a profound importance in subsistence agriculture, being used primarily as a source of carbohydrate for human feeding. Little is known about the genetic diversity and structure of these species, and also how it evolved in recent centuries, particularly because of the scarcity of molecular evaluations. The present study is intended to: (i) present socio-economic and ethnobotanical data on the different agriculturists that cultivated the species; (ii) isolate microsatellite primers using an enriched genomic library technique and test for cross amplifications in other species of Dioscorea; (iii) analyse the genetic relationships among 73 local acessions and 17 commercial accessions of water yam collected in five different regions in Brazil (South, Southeast, Northeast, Central-West and North) using a set of 12 microsatellite. Tubers of D. alata were collected in 28 municipalities from this five regioesn where the species is commonly cultivated, as well as on local markets and fairs from several states across Brazil. Other accessions were obtained from the ex situ germplasm collections belonging to ESALQ/USP, IAC and FCA/UNESP. A descriptive analysis of different farmers was performed, indicating unequal profiles between the screened regions. A wide range of vernacular names were registered with differences between regions. The interviews eith the agriculturist revealed that the species are losing their importance in some traditional/local areas. The isolation of codominant polymorphic microsatellite markers resulted in the detection of 14 short tandem repeat (SSR) loci, and ten were selected to characterize 80 D. alata accessions. The polymorphism information content varied from 0.39 to 0.78 and the power discrimination ranged from 0.15 to 0.91. Six of the markers showed transferability between the species D. bulbifera, D. cayenensis-D. rotundata and D. trifida. In a morphological and molecular diversity study, 12 polymorphic microsatellite primers were used to generate DNA profiles for each accession of the species and four morphological traits were analyzed. The morphological characterization showed considerable diversity and no specific clustering was observed between regions. The molecular analyses of D. alata showed a high intraspecific diversity in local varieties from different regions in Brazil. However, population structuring between sampling regions was rather low. Only the accessions from the Central-Western region showed an apparent regional clustering, almoust similar were observed with northeast acessions. These results show an admixture of accessions in all sampling regions, which is further consistent with the lack of a correlation between geographic and genetic distances, suggesting that water yam tubers have moved extensively by human fluxes. The genetic diversity found can be explained by the result of a continuous exchange of varieties through the Brazilian distribution range. The development of molecular SSR markers for D. alata and genetic population analysis is essential for the ongoing research on this species. The generated information is of great importance for the identification, rational exploitation and conservation of the genetic variability of this species, in a in situ and/or ex situ way.

Soil and root microbial communities have been studied for decades, and the incorporation of high-throughput techniques and analysis has allowed the identification of endophytic/non-culturable organisms. This has helped characterize and establish the core microbiome of many model plant species which include underground and aboveground organs. Unfortunately, the information obtained from some of these model plants is not always transferable to other agronomic species. In this project, we decided to study the microbiome of the Nicotiana genus because of its importance in plant physiological and plant-microbe interactions studies. The data obtained was used as baseline information that allowed us to better understand the effect of microbial inoculums on the assembly of the microbiome of the plant. We analyzed 16s rRNA amplicons to survey the microbiome in different plant organs and rhizosphere from four different species. Bacterial strains evaluated were screened for a consistent reduction or improvement in plant growth. Four bacterial strains were tested and used as seed inoculum (Lf-Lysinobacillus fusisormis, Ms –Micrococcus sp., Bs–Bacillus sp., Bc–Bacillus cereus). Bs and Bc inoculants caused plant growth promotion, and in contrast Ms caused retarded growth, while Lf acted as a neutral or non-inducing phenotype strain. Data supported that microbial inoculum used as seed treatment caused systemic changes in the host plant microbiome. Functionality of the inoculum was studied and the response in plant growth was linked to hormonal changes (evaluated in the plant and in the bacterial strains). Gene expression analysis using a genome-scale approach revealed that genes that could possibly be involved in stress response are down-regulated for Bc and Bs treatments and up-regulated for Ms. Flexibility variability of the inoculum was also evaluated to have a better understanding of the main factors involved in the promotion or suppression of growth, and possibly its effect in following generations. In summary, the findings of this project support that the plant functional microbiome responds to exogenous stimulation from abiotic and biotic factors by adapting endogenous hormone responses.

O gênero Dioscorea é o mais amplo da família Dioscoreaceae, apresentando cerca de 600 espécies distribuídas, sobretudo, nos trópicos, com grande importância na alimentação, principalmente na África Ocidental, na Sudeste Asiático, no Caríbe e em alguns países da América do Sul. No Brasil, algumas espécies de inhame (Dioscorea spp.), juntamente com a mandioca (Manihot esculenta Crantz), têm uma profunda importância na agricultura de subsistência, sendo utilizadas basicamente como fonte de carboidrato para alimentação humana. Pouco se conhece sobre a diversidade e estrutura genética dessas espécies, como evoluíram nos últimos anos, sobretudo pela escassez de avaliações moleculares. O presente estudo tem como objetivos: (i) apresentar dados sócio-econômicos e etnobotânicos relativos aos diferentes agricultores que cultivam a espécie; (ii) isolar primers de microssatélites usando uma biblioteca genômica enriquecida e testar sua amplificação entre outras espécies de Dioscorea; (iii) analisar a relação genética entre 73 variedades locais e 17 acessos comerciais de inhame coletados em cinco diferentes regiões do Brasil (Sul, Sudeste, Nordeste, Norte e Centro-oeste) usando um conjunto de 12 microssatélites. Túberas de inhame foram coletadas em 28 municípios proveniente de cinco regiões onde a espécie é comumente cultivada, bem como em mercados locais e feiras de vários estados do Brasil. Outros acessos foram obtidos dos bancos de germoplasma ex situ pertencentes a ESALQ/USP, IAC e FCA/UNESP. Uma análise descritiva de diferentes agricultores foi realizada, indicando distintos perfis entre as regiões analisadas. Um amplo espectro de nomes populares foi registrado com diferenças entre regiões. As entrevistas com os agricultores revelaram que a espécie tem perdido sua importância em algumas áreas tradicionais/locais. O isolamento de marcadores microssatélites polimórficos resultou na detecção de 14 locos de microssatélites (SSR). Destes, dez foram selecionados para caracterizar 80 acessos de D. alata. O conteúdo de informação polimórfica foi de 0,39 a 0,78 e o poder de descriminação foi de 0,15 a 0,91. Seis destes marcadores mostraram transferibilidade entre as espécies D. bulbifera, D. cayenensis-D. rotundata e D. trifida. Em um estudo de diversidade morfológica e molecular, 12 pares de microssatélites polimórficos (nove desenvolvidos neste estudo e três obtidos da literatura) foram usados para gerar perfis de DNA de cada acesso da espécie e quatro perfis morfológicos foram analisados. A caracterização morfológica mostrou considerável diversidade e nenhum agrupamento específico foi observado entre as regiões. As análises moleculares de D. alata mostraram alta diversidade intra-específica nos acessos locais de diferentes regiões do Brasil. Contudo, a estrutura populacional entre as regiões coletadas foi relativamente baixa. Somente acessos da região Centro-Oeste apresentaram um aparente agrupamento regional, resultado quase similar foi observado nos acessos do nordeste. Estes resultados mostram uma mistura de acessos em todas as regiões coletadas, na qual é consistente com a falta de correlação entre as distâncias geográficas e genéticas, sugerindo que as túberas de inhame têm se movido extensivamente pelo fluxo humano. A diversidade genética encontrada pode ser explicada pelo resultado de um contínuo intercâmbio de variedades através do território brasileiro. O desenvolvimento de marcadores moleculares SSR em D. alata e análises de genética populacional são essenciais para o avanço de pesquisas nesta espécie. A geração de informação é de grande importância para a identificação, exploração racional e conservação da variabilidade genética da espécie, tanto da forma in situ e/ou ex situ. / The genus Dioscorea is the largest in the Dioscoreaceae family, featuring approximately 600 species distributed mainly in the tropics, with high importance as food supply in West Africa, Asia southeast, the Caribbean and a few countries in South America. In Brazil, some species of yam (Dioscorea spp.) together with cassava (Manihot esculenta Crantz), have a profound importance in subsistence agriculture, being used primarily as a source of carbohydrate for human feeding. Little is known about the genetic diversity and structure of these species, and also how it evolved in recent centuries, particularly because of the scarcity of molecular evaluations. The present study is intended to: (i) present socio-economic and ethnobotanical data on the different agriculturists that cultivated the species; (ii) isolate microsatellite primers using an enriched genomic library technique and test for cross amplifications in other species of Dioscorea; (iii) analyse the genetic relationships among 73 local acessions and 17 commercial accessions of water yam collected in five different regions in Brazil (South, Southeast, Northeast, Central-West and North) using a set of 12 microsatellite. Tubers of D. alata were collected in 28 municipalities from this five regioesn where the species is commonly cultivated, as well as on local markets and fairs from several states across Brazil. Other accessions were obtained from the ex situ germplasm collections belonging to ESALQ/USP, IAC and FCA/UNESP. A descriptive analysis of different farmers was performed, indicating unequal profiles between the screened regions. A wide range of vernacular names were registered with differences between regions. The interviews eith the agriculturist revealed that the species are losing their importance in some traditional/local areas. The isolation of codominant polymorphic microsatellite markers resulted in the detection of 14 short tandem repeat (SSR) loci, and ten were selected to characterize 80 D. alata accessions. The polymorphism information content varied from 0.39 to 0.78 and the power discrimination ranged from 0.15 to 0.91. Six of the markers showed transferability between the species D. bulbifera, D. cayenensis-D. rotundata and D. trifida. In a morphological and molecular diversity study, 12 polymorphic microsatellite primers were used to generate DNA profiles for each accession of the species and four morphological traits were analyzed. The morphological characterization showed considerable diversity and no specific clustering was observed between regions. The molecular analyses of D. alata showed a high intraspecific diversity in local varieties from different regions in Brazil. However, population structuring between sampling regions was rather low. Only the accessions from the Central-Western region showed an apparent regional clustering, almoust similar were observed with northeast acessions. These results show an admixture of accessions in all sampling regions, which is further consistent with the lack of a correlation between geographic and genetic distances, suggesting that water yam tubers have moved extensively by human fluxes. The genetic diversity found can be explained by the result of a continuous exchange of varieties through the Brazilian distribution range. The development of molecular SSR markers for D. alata and genetic population analysis is essential for the ongoing research on this species. The generated information is of great importance for the identification, rational exploitation and conservation of the genetic variability of this species, in a in situ and/or ex situ way.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The impact arising from livestock activity in grassland ecosystems reflects a long history of how this activity was carried. One alternative of lasting management for conservation of these lands is to use the capacity of resilience of natural grassland, in which important tools for recovery are control of leaf defoliation and nutrient replacement. Changes in vegetation take place throughout time and space by a broad range of factors and, for their interpretation, plant s mechanisms of capture and storage of resources must be understood. Plant functional types are one approach highlighted at large scale responses. However to make this framework operational, it depends on knowledge of species development and especially their role in biomass production or in ecological processes at the landscape level. This work s hypothesis is that communities ranked into functional groups of plants may show patterns of biomass distribution along the community that are related to environmental factors and management. The experiment was conducted in livestock farms (UEPAs) enrolled in a project linked to EMBRAPA-CPPSUL established since 2008. In such UEPAs rotational grazing and natural fertilizers were applied together in natural grassland paddocks. Four surveys were conducted for assessment of species contribution on biomass since April/2012 to September/2011. Poaceae species were ranked according to its contribution in vegetation, through their morphological traits: specific leaf area and leaf dry matter content. This approach allows defining groups of species with different features even for large-scale environmental factors . Through biomass accumulation of plant groups with similar functional traits it was possible to diagnose vegetation patterns in response to environmental and management factors. / O impacto decorrente da atividade pecuária em ecossistemas campestres reflete um longo histórico da forma como essa atividade foi exercida. Para manutenção dessas áreas, uma alternativa de manejo durável é usar a capacidade de resiliência da pastagem natural, onde são partes importantes na recuperação: o controle da desfolha e a reposição de nutrientes. Mudanças na vegetação ocorrem ao longo do tempo e do espaço por uma ampla extensão de fatores e para a sua interpretação devem ser entendidos os mecanismos de captura e estocagem de recursos efetuados pela planta. A abordagem de tipos funcionais de plantas é destacada nas respostas em ampla escala, no entanto tornar esse conhecimento um quadro mais operacional depende do conhecimento do desenvolvimento das espécies e sobre tudo sua implicação na produção ou nos processos ecológicos em nível de pastagem. A hipótese deste trabalho é que as comunidades classificadas em grupos funcionais de plantas possam demonstrar padrões de configurações de biomassa na comunidade que se relacionam a fatores ambientais e de manejo. Este estudo foi realizado em estabelecimentos rurais (UEPAs) cadastradas em projeto vinculado a EMBRAPA-CPPSUL implantado a partir do ano de 2008. Nessas UEPAs foram realizados quatro inventários para determinação da composição botânica e contribuição das espécies na massa de forragem, no período de setembro/2011 a abril/2012. O manejo do pastoreio foi o rotativo e a pastagem natural recebeu aplicação de fertilizantes naturais. Na abordagem foram classificadas as espécies de Poaceae que possuem maior participação na vegetação, através de seus atributos morfológicos TMS e AFE, possibilitando agrupar espécies com diferentes características em diferentes condições ambientais. Através do acúmulo de biomassa nas comunidades de grupos de plantas com atributos funcionais semelhantes foi possível diagnosticar padrões de vegetação em resposta aos fatores ambientais e de manejo.

Submitted by Luciana Sebin (lusebin@ufscar.br) on 2016-09-12T19:18:57Z No. of bitstreams: 1 DissMASSL.pdf: 2017110 bytes, checksum: 0268f5d954312659c26bf8cb7bd75a25 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-13T18:18:59Z (GMT) No. of bitstreams: 1 DissMASSL.pdf: 2017110 bytes, checksum: 0268f5d954312659c26bf8cb7bd75a25 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-13T18:19:08Z (GMT) No. of bitstreams: 1 DissMASSL.pdf: 2017110 bytes, checksum: 0268f5d954312659c26bf8cb7bd75a25 (MD5) / Made available in DSpace on 2016-09-13T18:19:17Z (GMT). No. of bitstreams: 1 DissMASSL.pdf: 2017110 bytes, checksum: 0268f5d954312659c26bf8cb7bd75a25 (MD5) Previous issue date: 2015-09-18 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Azedinha (Rumex acetosa L.) has pleased the consumer for its sour taste. Considered an unconventional vegetable, their redemption becomes important to allow notable gains from the nutritional, social, cultural, economic and environmental point of view. The objective was to characterize morphologically copies of azedinha obtained from seeds, determine their sensory characteristics and acceptance, as well as analyze some physicochemical parameters, and determine the absorptions of macro and micronutrients and biometric parameters during 60 days after transplanting (DAT). The experiment was conducted at the Centro de Ciências Agrárias, belonging to the Universidade Federal São Carlos - UFSCar in the city of Araras - SP. Biometric parameters were evaluated (length of the leaf, relative leaf area, fresh and dry weight of shoots) and the macro and micronutrients absorption march from plants collected at 15, 20, 25, 30, 35, 40, 50 and 60 DAT. They evaluated the length, width and length / width ratio of leaf blade; petiole length and width close to the blade; diameter of the stump; the shoot length; length of ochreas; shape of the leaf blade; kind of apex; base form; type of veining and type of margin of the leaf blade; type of ochreas; characterization of the stem; length and diameter (neck) of the root. It also determined the levels of ascorbic acid, phenolic compounds and chlorophyll parameter. For sensory analysis was used the Quantitative Descriptive Analysis (QDA). Sensory analysis of acceptance was conducted with 52 judges, in relation to vii appearance, aroma, flavor, texture and overall impression, as well as purchase intent. The biometric parameters increased over time after transplantation and most markedly after the recommended times for harvest (20 and 35 DAT). The maximum levels of macro and micronutrients accumulated in the shoot, in descending order were as follows: K > N > Mg > P and Fe > Mn > Zn > Cu. The morphological descriptors with greater discriminatory power for azedinha were the types of margin and venation of the leaf blade, the characterization of the stem, the presence of ochrea and shape of the leaf blade, ranging from sagittate the hastate. It also infers that the best harvest time is between 20 and 35 DAT. The average content of ascorbic acid was 10,25 mg 100g-1 sample, total phenolic 291,46 mg of gallic acid 100 g-1 dry weight and chlorophyll parameter was 36,6 SPAD units. As for the quantitative descriptive analysis, the leaves of azedinha framed up closer to dark green; most have arrow or spear shape; smooth; with sharp aroma of grape skin; more acid flavor, such as green blackberries; there was no residual bitterness; they were folding; wrinkle free; soft to chew and thin. Regarding the acceptability test, the notes to the variable color, flavor, texture and overall acceptability were high and most judges would buy this vegetable. / A azedinha (Rumex acetosa L.) tem agradado o consumidor por seu sabor ácido. Considerada hortaliça não convencional, seu resgate se torna importante ao possibilitar ganhos notáveis do ponto de vista nutricional, social, cultural, econômico e ambiental. Objetivou-se caracterizar morfologicamente exemplares de azedinha obtidos de sementes, determinar seus atributos sensoriais e aceitação, bem como analisar alguns parâmetros físico-químicos, e determinar a marcha de absorção de macro e micronutrientes e os parâmetros biométricos durante 60 dias após transplante (DAT). O experimento foi conduzido no Centro de Ciências Agrárias, pertencente à Universidade Federal de São Carlos - UFSCar, no município de Araras – SP. Avaliaram-se os parâmetros biométricos (comprimento da lâmina foliar, área foliar relativa, massas fresca e seca da parte aérea) e a marcha de absorção de macro e micronutrientes de plantas coletadas aos 15, 20, 25, 30, 35, 40, 50 e 60 DAT. Foram avaliados o comprimento, a largura e a relação comprimento/largura das lâminas foliares; comprimento e largura do pecíolo próximo à lâmina; diâmetro da touceira; comprimento da parte aérea; comprimento das ócreas; forma da lâmina foliar; tipo de ápice; forma da base; tipo de nervação e tipo de margem da lâmina foliar; tipo de ócrea; caracterização do caule; comprimento e diâmetro (colo) da raiz. Foram determinados também os teores de ácido ascórbico, fenólicos totais e o parâmetro clorofila. Para a análise sensorial foi utilizada a Análise Descritiva Quantitativa (ADQ). A análise sensorial de v aceitação foi realizada com 52 julgadores, em relação à aparência, aroma, sabor, textura e impressão global, além da intenção de compra. Os parâmetros biométricos aumentaram ao longo do tempo após o transplante e, mais acentuadamente, após o intervalo estimado, pela literatura, para a colheita (20 a 35 DAT). Os teores máximos dos macro e micronutrientes acumulados na parte aérea, em ordem decrescente foram respectivamente: K > N > Mg > P e Fe > Mn > Zn > Cu. Os descritores morfológicos com maior poder discriminatório para a azedinha foram os tipos de margem e nervação da lâmina foliar, a caracterização do caule, a presença de ócrea e a forma da lâmina foliar, que vai de sagitada a hastada. Infere-se também que, para mudas obtidas de sementes, a melhor época de colheita é entre 20 e 35 DAT. O teor médio de ácido ascórbico foi 10,25 mg 100g-1 de amostra, de fenólicos totais foi equivalente a 291,46 mg de ácido gálico 100g-1 de massa seca e o parâmetro clorofila foi de 36,6 unidades SPAD. Quanto à análise descritiva quantitativa, as folhas de azedinha enquadraram-se mais próximas à cor verde escura; a maioria possui formato de seta ou lança; lisas; com acentuado aroma de casca de uva; sabor mais ácido, como o da amora verde; não havia amargo residual; eram dobráveis; sem rugas; macias ao mastigar e finas. Em relação ao teste de aceitabilidade, as notas para as variáveis aparência, sabor, textura e aceitação global foram altas e a maioria dos julgadores comprariam essa hortaliça.

Thesis (Ph.D. (Plant Production)) -- University of Limpopo, 2021 / Cassava (Manihot esculenta Crantz) is a widely cultivated crop in many tropical countries in Africa, Latin America, and Asia. Cassava is a staple food security crop for over one billion people worldwide. It is a multi‑purpose and well adapted to different agricultural production systems. Although cassava is adaptable to marginal soils with low fertility, and to irregular rainfall conditions, as it allows a relatively stable productivity and flexibility for harvesting process, the challenges posed by global climate change (both temperature and drought severity increasing) have caused negative impacts on this crop‘s productivity. Given the increasing demand for higher productivity to improve food security and alleviate poverty in the dry prone regions of Africa, there is a concurrent increasing demand to expand production into marginal ecologies and improve its adaptation in such ecologies. Breeding efforts have resulted in the development of high-yielding varieties, but due to late bulking and long time taken before crop is ready for harvest, the improved varieties were not easily adopted by farmers. The complex nature of yield and other productivity traits, coupled with the biology of cassava, make it more challenging to improve the crop. However, biotechnology has revolutionised breeding with the development of advanced molecular tools that have facilitated breeding-by-design approaches leading to effective manipulation of genes for complex traits. The potential and impact of the new tools are now providing a stronger basis to adopt molecular breeding to genetically improve the crop for key traits. The main objectives of the research were to: (i) Develop a mapping population and identify traits driving the physiological basis of drought tolerance in F1 cassava genotypes; (ii) Identify traits linked with early bulking in the F1 population; (iii) Identify quantitative trait loci (QTLs) for drought tolerance and early bulking in F1 cassava genotypes; and (iv) Estimate the genetic improvement for drought tolerance in the F1 population. Two genotypes (TMS98/0505 and TMS98/0581) with contrasting desirable traits such as high yield in marginal environment, good disease resistance, vigour, and flowering potentials were used in the development of the mapping population used in this study. Results indicate that there was a positive correlation between yield, yield-related traits .and morphological/physiological traits. Principal component analysis identified the scar level, height of stem with leaf, fresh root yield, dry root yield, root number and dry-matter content as traits driving drought tolerance in marginal environment. This study also identified early-bulking cassava varieties in the F1 population and traits associated with early bulking. Fresh root yield was significantly associated with morphological and productivity traits while principal component analysis identified important traits such as root weight, root number, plant biomass, fresh root yield, plant height, , and stem diameter. Composite interval mapping identified 27QTLs and 30 QTLs in the first and second year, respectively, associated with the traits phenotyped in dry savannah ecology of Nigeria, while 16 and 12 QTLs associated with early bulking at 7 MAP were identified in the first and second year. Identification of these loci will aid breeding for drought tolerance and early root bulking in cassava. There was a better performance among traits such as biomass, root number, dry-matter content, number of scars, number of leaves, and length of stem with leaf in the second population (population C) than in the first population (population B). Twenty superior genotypes were selected from population C, which will be incorporated in the breeding programmes for further evaluation and germplasm enhancement. KEY WORDS: Composite interval mapping, Fresh root yield, Manihot esculenta, morphological traits, Population C, physiological traits. / National Root Crops Research Institute (NRCRI) Umudike