This study investigates geographic patterns of genetic variation in aspen spring phenology to understanding how tree population adapts to climatically risk environments. These finding suggest rules to guide seed transfer between regions. I use a classical common garden experiment to reveal genetic differences among populations from western Canada and Minnesota, and present a novel method to seamlessly map the heatsum required for remotely sensed green-up. Both approaches reveal two major geographic patterns: northern and high elevation aspen populations break bud earlier than sources from the boreal plains, and late budbreak is strongly associated with the driest winter and spring environments. This suggests selection pressures for late budbreak due to both frost and drought risks in early spring, and we therefore caution against transfer of seed to drought regions of the boreal plains. Although such transfers have been shown to increase plantation productivity in short-term tests, non-local planting material may be susceptible to exceptional spring droughts. / Forest Biology and Management

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Made available in DSpace on 2015-03-26T13:39:30Z (GMT). No. of bitstreams: 1 texto completo.pdf: 282103 bytes, checksum: 52b693b90beeb2ac7e51c64a3e575c4f (MD5) Previous issue date: 2008-12-16 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The peach (Prunus persica) specie is a temperate fruit plant. It can be also grown in mild winter areas through use of genotypes developed for mild winter climate. This specie show dormancy in buds and seeds. The chilling is the principal form for breaking the buds and seed dormancy. Generally plants with low chilling requirement to break dormancy of buds produced seeds with similar tendency in relation to chilling requirement to germinate. The dormancy from these two organs appeared have interrelation, although this relation is not totally well understood. Based on the probable link existed between them, the selection with base on the chilling requirement of seeds to get plants with similar chilling requirement, experiment were studied. Therefore, it is necessary to understand the control processes of seed dormancy for that it will be possible. This work constitute three studies: i) the response of twenty two families of peach tree in F2 generation in the mild winter region were observed. The families were obtained from the combination of nineteen genotypes (varieties and selections) showed low and medium chilling requirement. The characteristics evaluated were vegetative budbreak percentage, tree height and main stem diameter; ii) the general combining ability (GCA) and specific combining ability (SCA) between two groups of progenitors was evaluated from the progenies at F2 generation using partial diallel analysis. In this analysis two varieties (Premier and Rubro-sol) were used as male parents and five varieties (Biuti, Cristal, Doçura, Real and Relíquia) were used as female parents. The vegetative budbreak percentage, plant height and main stem diameter were evaluated. iii) to evaluate the influence of the genotype of the embryo in the seeds dormancy of peach tree, the experiment was realized with seeds obtained from open pollinated peach plant Campinas 1 (low chilling requirement) and crossed with Miraflores (high chilling requirement). The seeds were stratified and the stratification time for germination was compared between the seeds. Eight of twenty two families studied in relation of the adaptation for subtropical condition showed superiority in relation of vegetative budbreak, indicated high adaptability for the area of production. The two variables that it indicate vigor (diameter and tree height) did not showed significant correlation with budbreak percentage, but there was significant correlation (0.8231**) when compared it. The diallel analysis showed significant for the variance of general combining ability and specific combining ability for all the variables studied, indicating the involvement of additive and non-additive genetic effect in the control of these characteristics. In the female parent, the Rubro-Sol variety presented high GCA for budbreak percentage, while Premier variety presented high GCA for tree height and stem diameter. Within the female parents the Biuti variety showed high GCA for all the characteristics evaluated. The best specific combination was Rubro-sol x Biuti crossing which showed high genetic gain for all of the characteristics evaluated. The peach seed tree showed dormancy due to the effect of the genotype of the embryo. / O pessegueiro (Prunus persica) é uma espécie de clima temperado que pode ser cultivada em áreas com climas apresentando inverno ameno através da utilização de genótipos adaptados. Esta espécie apresenta dormência em gemas e sementes, sendo que a exposição a um período sob baixas temperaturas é a principal forma para a superação da dormência nesses dois órgãos. Geralmente, plantas que apresentam baixa necessidade de frio para a superação da dormência de gemas produzem sementes com mesmo comportamento relacionado à necessidade de frio para germinarem. A dormência existente nesses dois órgãos parece estar relacionada, embora esta relação ainda não esteja totalmente esclarecida. Por meio de provável ligação existente entre ambas, tem sido realizadas tentativas de praticar pré-seleção de indivíduos com baixa necessidade de frio para gemas baseados nos requerimentos da semente. No entanto, é necessário melhor entendimento do controle do processo de dormência da semente para que isso seja possível com confiabilidade. Este trabalho constituiu-se de três estudos: i) foi observado o comportamento de vinte e duas famílias de pessegueiro na geração F2 em região de inverno ameno. As famílias foram obtidas das combinações entre dezenove genótipos (cultivares e seleções) apresentando entre baixa a média necessidade de frio. As características avaliadas foram a taxa de brotação, altura de plantas e diâmetro do tronco; ii) a capacidade combinatória geral (CGC) e específica (CEC) entre dois grupos de progenitores foi obtida a partir de descendentes na geração F2, no delineamento dialelo parcial. Dois cultivares ( Premier e Rubro-sol ) foram utilizados como progenitores masculinos e cinco ( Biuti , Cristal , Doçura , Real e Relíquia ) como progenitores femininos. As características avaliadas foram taxa de brotação, altura de plantas e diâmetro do tronco; iii) a influência do genótipo do embrião sobre a dormência de sementes de pessegueiro foi estudada, obtendo-se para tanto, sementes resultantes da autopolinização natural do pessegueiro Campinas 1 (de baixa necessidade de frio), e do cruzamento deste com Miraflores (de alta necessidade de frio). As sementes foram estratificadas e o tempo necessário para a germinação entre ambos foi comparado. Oito das vinte e duas famílias estudadas quanto à adaptação as condições subtropicais apresentaram superioridade em relação à brotação de gemas vegetativas, indicando maior adaptação ao local de cultivo. As duas variáveis indicadoras de vigor das plantas (diâmetro do tronco e altura) não apresentaram correlação significativa com a taxa de brotação, porém comparando-se as mesmas houve alta e significativa correlação (0.8231**). Na análise dialélica observou-se significância para as variâncias de capacidade geral e específica para todas as variáveis estudadas, indicando que efeitos gênicos aditivos e não-aditivos estão envolvidos no controle das características avaliadas. No grupo de genitores masculinos, o cultivar Rubro-sol apresentou maior CGC para a taxa de brotação, enquanto que para o cultivar Premier a maior CGC foi para altura de planta e diâmetro do tronco. No grupo de genitores femininos, o cultivar Biuti apresentou maior CGC para todas as características avaliadas. A melhor combinação específica foi entre Rubro-sol x Biuti , promovendo ganhos em todas as características avaliadas. Sementes de Campinas 1 apresentaram germinação rápida e uniforme, enquanto sementes do híbrido Campinas 1 Miraflores apresentaram germinação lenta. A necessidade de frio para a superação da endodormência era influenciada pelo genótipo do embrião. Esse resultado indica que a necessidade de frio para a superação da dormência em sementes poderá ser empregado na seleção precoce de plantas com baixa necessidade de frio.

Climate change poses a significant threat to bioenergy production, impacting plant’s phenology and physiological performance. Investigating the adaptation of bioenergy crops like Populus is crucial for sustaining production. Populus, known for its genetic variation and ease of study, offers insights into tree responses to climate change. My research, part of the Advancing Populus Pathways in the Southeast (APPS) project, focuses on various Populus genotypes across multiple growing seasons, exploring phenology under different management strategies. Planting Populus across two sites, namely Monroe and Pontotoc, allows for the examination of genotype responses to climate change factors, particularly in terms of phenology and productivity. Factors like parentage provenance and temperature fluctuations influence budburst timing. Additionally, management practices, such as coppicing, significantly affect budburst, with coppiced trees showing delayed timing (five to ten days) compared to non-coppiced ones. Cold spell damage during budbreak reveals vulnerability, with northern provenances exhibiting greater resilience. Understanding such events is vital for tailored management. Cold spells not only impact initial budbreak but also alter leaf phenology and canopy dynamics, affecting overall productivity. Genotypes exhibit varied responses to rising temperatures and CO2 levels, influenced by their parentage. Trees with northern provenance, for instance, display higher photosynthetic capacity, but may face thermal stress under certain temperature increases. Conversely, southern genotypes demonstrate moderate photosynthetic capacity, but showcase better adaptation to heat, offering potential for breeding resilient varieties. Leaf traits serve as proxies for biomass production and water use efficiency prediction, aiding in genotype screening. Mechanisms like self-shading and leaf movability influence responses to environmental changes. For instance, self-shading helps regulate leaf temperature, thereby enhancing photosynthetic performance, albeit with some trade-offs. Elevated CO2 levels enhance water use efficiency, but determining whole-tree water use efficiency requires integration of various methods. While leaf-level measurements correlate with whole-tree water use efficiency, an integrated approach, combining leaf-level gas exchange and isotopic measurements, shows promise. In conclusion, understanding Populus responses to climate change is crucial for sustainable bioenergy production in the southeastern United States. Insights into phenology, productivity, and adaptation mechanisms offer avenues for management and breeding strategies, ensuring resilience amidst shifting climates.

Philosophiae Doctor - PhD / The domesticated apple (Malus x domestica Borkh.) has been distributed into diverse climatic conditions worldwide for commercial production of fruit. Apple trees need exposure to cold temperatures, referred to as chill unit (CU) accumulation during winter, in order for budbreak to occur promptly and uniformly after winter. In warmer production areas the application of dormancy breaking chemicals has enabled successful production of high chilling requiring apple cultivars in suboptimal environmental conditions. In the Western Cape region of South Africa it is common orchard practice to apply dormancy breaking chemicals after winter in order to stimulate vegetative growth. If this is not done prolonged dormancy symptoms (PDS) are experienced which include extended rest, less synchronised breaking of buds and reduced branching. An increasing awareness of both global warming and the negative effects associated with the use of chemical sprays (for both pest and disease resistance and growth regulation) has resulted in the need to breed cultivars better adapted to current and future environmental conditions. The breeding of new cultivars using conventional breeding methods is a time consuming process, especially in perennial tree species with a long juvenile phase such as apple. The implementation of marker-assistedbreeding (MAB) and selection (MAS) will enable the selection of favourable genotypes at a very early seedling stage. Although markers linked to genes involved in disease resistance for a variety of known apple pathogens have been identified and are already in use in breeding programs, the genetic determinants of dormancy related characteristics residing within the bud itself iii (endodormancy) are poorly understood. This hampers the genetic improvement of such characters. Although this study focused on time of initial vegetative budbreak IVB, there are various other characteristics that can be associated with dormancy, such as position and number of budbreak and budbreak duration.

>Magister Scientiae - MSc / The Rosaceae family contains major temperate crops such as the domesticated apple(Malus x domestica Borkh.), peach (Prunus persica L. Batsch) and European pear (Pyrus communis L.). However, despite its evident economic importance, it is generally poorly studied in genomic terms, relative to the other major crop groups. Microsatellite and Diversity Array Technology (DArT) genetic markers have been exploited in this work and are essential tools in genetic map construction and marker-assisted selection (MAS) of high quality apples and other rosaceous crops. Microsatellites are advantageous in that they are co-dominant, highly polymorphic, abundant, transferable and reliably reproducible; hence their use in this study. In order for budbreak to take place in a timely and homogenous fashion, apple trees need a period of exposure to low temperatures.Within orchards the application of chemicals that induce budbreak in unsuitable environments is required to produce apples from cultivars that require high chilling levels. However, this and other practices using chemicals in orchards tend to pollute the environment. One of the solutions to this problem is to breed low chill apples such as ‘Anna’ cultivar, which was used as one of the parents in this study.This work was aimed at understanding the underlying genetic factors that determine chilling requirements for the time of initial vegetative budbreak trait in the apple cross ‘Anna’ x ‘Austin’. This was achieved through linkage map construction using SSR and DArT molecular markers followed by QTL analysis. This thesis has therefore exploited the large number of Expressed Sequence Tags (ESTs) and genome sequence data for the apple, using Tandem Repeats Finder, to design a total of 98 new SSR primers pairs. The other 369 SSR markers used in this work were from published work. JoinMap! 4.1 software was used to create an integrated genetic map with 17 linkage groups, for the domesticated apple cultivar, ‘Austin’ x ‘Anna’ mapping population with 80 individuals.The result of this process was a genetic map 1 212cM in length, and a total of 429 markers (314 DArT and 115 SSR), at an average density of a marker every 4 cM. This map was used identify the Quantitative Trait Loci (QTLs) determining chilling requirements for time of vegetative budbreak (IVB). In this process, putative IVB QTLs were identified in the ‘Anna’ x ‘Austin’ mapping population using the rMQM analysis function of MapQTL! 6.0, for both adult and seedling data collected over 3 growing seasons from 1996 to 1998. These QTLs were detected on linkage groups 2, 9 and 14,and explained 0.3 to 12.8 % of the observed phenotypic variation for the adult population,and 5.3 - 21 % for the seedling population. Seedling (LG 14) and adult (LGs 5, 7, 10) specific QTLs were also detected for the ‘Anna’ x ‘Austin’ cross. These QTLs will provide the basis for marker validation on related mapping populations in the apple breeding programme, and for the future identification of candidate genes controlling the process of budbreak.

Made available in DSpace on 2014-08-20T14:22:04Z (GMT). No. of bitstreams: 1 tese_moacir_silva_rocha.pdf: 11149179 bytes, checksum: e3b2cd08e4d3981b82037c3e46190f2d (MD5) Previous issue date: 2006-03-02 / The peach crop in Brazil is spread from Rio Grande do Sul to Minas Gerais states. It has adapted to different environmental conditions, being cultivated in temperate and sub-tropical zones, since it develops in areas with latitudes between 30º S and 45º N. In Rio Grande do Sul, the regions that are outstanding on peach production are: Pelotas; Porto Alegre; and Serra Gaúcha. In the Serra Gaúcha besides peaches for fresh market, are also grown vine grapes and apples. In Porto Alegre, There are peach and plum productions supplying the local market. In Pelotas, most of the peaches produced are for the local industry. However, the canning peaches produced in Pelotas, has worsen the quality and lowered productivity in the last years due to the very variable winter temperature, low chilling hours and severe draught during summer and fall seasons. A way that may contribute for production regularity and to overcome damaging abiotic factors is the right choice of the rootstock. The objectives for this study were: a) to evaluate the agronomical behavior of cultivar Chimarrita on the rootstocks Aldrighi, Capdeboscq, GF305, Okinawa and Tsukuba 1; b) to evaluate the agronomical and phonological behavior of peach trees cultivar Granada on the rootstocks cvs. Aldrighi, Capdeboscq, and Okinawa, originated from both, seeds and air layering. It were observed that the trees of cultivar Chimarrita: on either rootstocks Capdeboscq or Okinawa had greater size and vigor; on Okinawa had higher fruit production, whereas on Capdeboscq had larger fruits, and delayed leaf fall, and had later bloom; the trees cultivar Granada independent of the rootstock cultivar had earlier fruit ripening as that on the same rootstock cultivars, originated from seeds (seedlings). Regarding to cultivar Granada, the trees on Capdeboscq seedling were of larger size, whereas those on Okinawa produced more fruits in the first bearing season. In general, the Granada trees on rootstocks originated from air layering had earlier harvesting, independent of the rootstock cultivar. / O pessegueiro é uma espécie cultivada desde o Rio Grande do Sul até o Estado sul da Bahia, adaptando-se às diferentes condições ambientais, sendo cultivada em zonas temperadas e subtropicais. Esta cultura se desenvolve em regiões com latitudes entre 32º S e 45º N. Dentre as regiões produtoras do Estado do Rio Grande do Sul têm-se destacado as regiões de Pelotas, Porto Alegre e da Serra gaúcha. Na região da Serra Gaúcha cultiva-se a videira principalmente para a industrialização de vinhos e derivados: a macieira destinada para o mercado interno e exportação e o pêssego mesa. Na grande Porto Alegre, a produção de pêssego de mesa e ameixa é destinada aos mercados locais. Na região de Pelotas, a mais de cinqüenta anos, a cultura do pessegueiro tem se direcionado à produção de pêssegos para atender a indústria regional. Pela falta de regularidade da temperatura e de chuvas nos últimos anos, principalmente no período que antecede a floração, entre o final do outono e início inverno, tem-se observado floração e brotação desuni forme, baixa qualidade das frutas e a baixa produtividade de pêssego na Região de Pelotas. Os programas de melhoramento genético do pessegueiro tem-se concentrado no desenvolvimento de variedades copa e deixado à questão do porta-enxerto a segundo plano. A escolha dos porta-enxerto pode contribuir para a regularidade da produção e para superação de fatores abióticos. Desta forma, o presente trabalho teve como objetivos: a) avaliar o desenvolvimento vegetativo, peso médio das frutas, eficiência produtiva, sólidos solúveis totais (SST), firmeza de polpa e coloração das frutas da cultivar Chimarrita enxertada nos porta-enxerto Aldrighi , Capdeboscq , GF305 , Okinawa e Tsukuba 1 ; b) avaliar a época da queda das folhas, época de brotação, período de floração, frutificação efetiva e período de colheita de pêssego da cultivar Chimarrita enxertada em cinco diferentes porta-enxerto; c) avaliar o desenvolvimento vegetativo da cultivar Granada enxertada em três diferentes porta-enxerto ( Adrighi , Capdeboscq e Okinawa ) obtidos por alporquia e por sementes; e d) avaliar a época de queda das folhas, início de brotação, período de floração, densidade floral, frutificação efetiva, início da colheita, intervalo de maturação e período de colheita das frutas da cultivar Granada enxertadas em três porta-enxerto obtidos por sementes e alporquia. Os resultados obtidos nos quatro experimentos permitem concluir que: a) o porta-enxerto Capdeboscq e Okinawa induziram maior desenvolvimento vegetativo na cultivar Chimarrita. O porta-enxerto Okinawa induziu maior rendimento produtivo na cultivar Chiamarrita, enquanto que Capdeboscq apresentou frutas de maior tamanho. (O porta-enxerto GF305 induziu o menor desenvolvimento vegetativo e mais baixa produtividade na cultivar e o porta-enxerto Tsukuba 1 proporcionou frutas de melhor coloração em Chimarrita nas condições em que foi instalado experimento b) Os porta-enxerto Capdeboscq e Okinawa prolongaram a permanência de folhas e o início de brotação mais tardia na cultivar Chimarrita. O porta-enxerto Okinawa retardou a plena floração e obteve a maior eficiência produtiva da cultivar Chimarrita no ano de 2005, enquanto que os porta-enxerto Aldrighi , GF305 e Okinawa anteciparam o iníncio da colheita das frutas da cultivar Chimarrita; c) O porta-enxerto Capdeboscq obtido de semente proporcionou maior crescimento vegetativo na cultivar Granada, enquanto que o Okinawa teve a maior produtividade no primeiro ano de colheita de pêssegos. Os porta-enxerto Capdeboscq e Okinawa apresentaram a melhor resposta no retardamento da queda das folhas; d) Os porta-enxerto obtidos por alporquia antecipou a colheita, com exceção de Aldrigui quando comparado aos obtidos de sementes. portaenxerto obtidos por alporquia mostrou melhor resposta na relação entre a floral e a frutificação efetiva em relação aos porta-enxerto de sementes.