2 resultados para breeding programs

em Repositório Institucional da Universidade Tecnológica Federal do Paraná (RIUT)


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To design strategies for the conservation and use of genetic resources of tree species such as jaboticaba tree, it is essential to make the characterization. In southwestern Paraná region, there are several forest fragments containing native jaboticaba tree (Plinia cauliflora), whose materials have broad potential for commercial orchards or breeding programs. As is the potential genetic diversity of a population to produce different genotypes, it would be able to start in such a characterization one of these fragments. The aim was to characterize fruits of jaboticaba tree (P. caulifora) of forest fragment kept in Clevelândia - PR for the presence of phenotypic variability, seeking to identify those superiors named for future selection as farming or male parent, as well as estimate genetic divergence between them, as a complementary tool for this purpose. Also, verify the regeneration and spatial distribution of the species. For the study was defined portion of a hectare (10.000 m²), with all individuals identified, mapped, with local coordinate system, and measured height and diameter. Fruits were characterized by sensory and biochemical characteristics in two years, 70 genotypes at 2013 and 56 at 2014, and of these 33 genotypes in both years. As a pre-selection criteria was adopted the choice of 20% of the genotypes that showed the highest frequency of superiority in the evaluated characteristics of the fruit. Genetic divergence among 33 genotypes per year was analyzed. The distribution pattern and spatial association was evaluated by Ripley's K function. It was classified for the first time the following ontogenetic stages of jaboticaba tree, by plant height, seedling (from 0.01 to 0.99 m), juvenile (1.0 to 4.99 m), immature (> 5.0 m, non-reproductive), adult (reproductive). It was also have been describe for the first time the naturally occurring juxtaposed seedlings, indicating polyembryony. The number of regenerating identified in the population (seedlings: n = 2163; juveniles: n = 330; immature: n = 59) was much larger than the number of adults (n = 132). The species showed reverse J-shaped size structure standard, with high concentration of regenerating. The regeneration distribution occurs in aggregate pattern and there is seedling-adult dependence, due seed dispersal and seedling emergence closest to mothers. The jaboticaba tree regeneration is sufficient to maintain the species for long term in this population, which should serve as reference to regeneration success for other studies of this important fruiting species from Ombrofile Mixed Forests. Has been pre-selected the jaboticaba trees 7, 42, 43, 47, 54, 91, 97, 104, 105, 118, 134, 153, 154, 157, 163, 169, 177, 186, 212, J7-01 and J7- 02, and 16 and 194 the ones that can now be selected by the superior characteristics of both cycles. It was recommended to carry out hybridization between genotypes 79 and 119, and 96 to 148. The quality of fruit analyzed showed potential for use as a dual purpose serving both in natura market or processing.

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The identification of genotypes for drought tolerance has a great importance in breeding programs. The aim of this study was to characterize genotypes of beans in response to drought tolerance in different reproductive stages through physiologic, agronomic and molecular analysis. The experiment was conducted in greenhouse, using a randomized block design with four replicates; 10 cultivars: ANFC 9, ANFP 110, BRS Esplendor, BRSMG Realce, IPR Siriri, IPR Tangará, IPR Tuiuiu, IPR Uirapuru, IAC Imperador and IAC Milênio under two conditions of irrigation: plants irrigated during their entire life cycle, and plants under irrigation suppression in the reproductive stage (R7) until 16% of field capacity, when the irrigation was restored. In the last four days of stress, the gas exchanges were analyzed, and in the last day of stress was analyzed the percentage of closed stomata in the abaxial surface of the leaves, collected in different times of the day (9h, 12h, 15h and 18h). Additionally, plant samples were collected for the following analysis: fresh and dry mass of leaves, stems and legumes, and proline content in leaves and roots. The plants were harvested at the physiological maturity and the yield components and grain yield were determined. In addition, in order to identify polymorphisms in the sequences of promoters and genes related to drought, seven pairs of primers were tested on the group of genotypes. The drought susceptibility indexes (ISS) ranged from 0.65 to 1.10 in the group of genotypes, which the lowest values observed were for IAC Imperador (0.65) and BRS Esplendor (0.87), indicating the ability of these two genotypes to maintain grain yield under water stress condition. All genotypes showed reduction in yield components under water stress. IAC Imperador (43.4%) and BRS Esplendor (60.6%) had the lowest reductions in productivity and kept about 50% of the stomata closed during all the different times evaluated at last day of irrigation suppression. IAC Imperador showed greater water use efficiency and CO2 assimilation rate under drought stress. IPR Tuiuiú, IPR Tangará and IAC Imperador had the highest proline concentrations in the roots. Under water stress condition, there was a strong positive correlation (0.696) between the percentage of stomata closed with the number of grains per plant (0.696) and the fresh mass of leaves (0.731), the maximum percentage of stomata closed 73.71% in water stress. The accumulation of proline in the root was the character that most contributed to the divergence between the genotypes under water deficit, but not always the genotypes that have accumulated more proline were the most tolerant. The polymorphisms in DNA of coding and promoting sequences of transcription factors studied in this experiment did not discriminate tolerant genotypes from the sensitive ones to water stress.