THE RELATIVE IMPORTANCE OF THE CHARACTERS IN THE STUDY OF THE GENETIC DIVERSITY OF COMMON BEAN

INTRODUCTION The genetic diversity present in local and improved bean cultivars allows exploring an existing variability already adapted to the specific climatic conditions, contributing a lot to breeding programs. Morphoagronomic characteristics are considered of great importance, since they allow the direct evaluation of agronomic interest characters. The analyze of the relative importance of the characters makes it possible to discard characteristics that contribute less to the discrimination of the evaluated materials, reducing costs and labor in the next experiments, being that the minor importance characteristics may be those that show less variability or that are represented by other one (Cruz, Regazzi e Carneiro, 2012). The present work had the objective of accessing the genetic variability of common bean cultivars and identify the characteristics of greater relative importance. MATERIAL AND METHODS Thirty-nine bean cultivars were used for the characterization, 20 belonging to the carioca commercial group and 19 to the black commercial group (tests were performed independently for each commercial group). All cultivars come from breeding programs of public or private institutions from Brazil. The trials were established in four environments in the state of Paraná- BR, two in the 2014/2015 rainy season, in Ponta Grossa and Guarapuava, and two in the dry season of 2015, in Ponta Grossa and Santa Tereza do Oeste. The experimental design was a randomized complete block with three replicates and plots consisting of four rows of 4 meters spaced 0.5 m, with a population of 12 plants per linear meter, considering the two central lines as a useful plot. The quantitative descriptors evaluated are on Table 1. The evaluations for the descriptors were carried out in a sample of ten plants of each experimental plot (except PROD), and for the statistical analysis the average of each plot was used. The relative importance of the quantitative variables studied was analyzed by the Singh method (Singh, 1981) using the Genes computational program (Cruz, 2013)

ADAPTABILITY AND STABILITY OF COMMON BEAN CULTIVARS WITH CARIOCA GRAIN TYPE USED IN BRAZIL

INTRODUCTION In Brazil beans are of great economic and social importance, as it is cultivated by small and large producers in all Brazilian regions. Diversified production systems and sowing times are used, therefore, the crop is subject to the most diverse environmental conditions. The presence of the interaction genotypes x environments hinders the work of the breeders, as it results in the variable behavior of the genotypes on the different environments, making selection difficult, especially for quantitative characteristics (CARGNIN et al., 2006). Several studies have reported that G x E interactions can be reduced using either specific cultivars in particular environments or cultivars with wide adaptability and stability (RAMALHO et al., 2012). Thus, the aim of this study was to evaluate the influence of G x E interaction on grain yield of common bean cultivars with carioca grain type. MATERIAL AND METHODS Twenty common bean cultivars belonging to the carioca commercial group were used. All cultivars come from breeding programs of public or private institutions from Brazil, and indicated for cultivation in the state of Paraná. The trials were established in four environments in the state of Paraná- BR, two in the 2014/2015 rainy season, in Ponta Grossa and Guarapuava, and two in the dry season of 2015, in Ponta Grossa and Santa Tereza do Oeste. The experimental design was a randomized complete block design with three replicates and plots consisting of four rows of 4 meters spaced 0.5 m, with a population of 12 plants per linear meter, considering the two central lines as a useful plot. The grain yield was obtained by weighing grams of the two central rows of the plot, adjusted to 13% of humidity and extrapolated to kg/ha. The results were submitted to analysis of individual variance of each environment and the test of homogeneity of error variance, followed by analysis of joint variance, considering the effects of genotype and environment as fixed. For the study of adaptability and stability, the methodology proposed by EBERHART & RUSSELL (1966) was used. All analyzes were processed in the Genes software (CRUZ, 2013)

PHOSPHORUS CONTENT IN SEEDS OF COMMON BEAN GROWN IN DIFFERENT PHOSPHORUS LEVELS

INTRODUCTION Seed phosphorus (P) is a fundamental energy source that acts on germination and seedling development. In addition to the inorganic P (Pi), the seed also accumulates as phytate salts and other forms of phosphate compounds denominated organic P (Po). Although necessary for the seed development, an excess of Po may interfere with the accumulation of calcium, iron and zinc nutrients, which are easily complexed with P and become unavailable for human diet and animal feed (RABOY, 2009). The availability of P in the soil or nutrient solution may influence the storage forms of this mineral in the seed. Therefore, the study aimed to evaluate the partition of the absorbed P in common bean genotypes grown in different levels of P in hydroponic solution. MATERIAL AND METHODS The experiment was carried out in the greenhouse at Agronomic Institute of Paraná (IAPAR), Londrina, Paraná, Brazil, in September to December 2015. The experimental design was a randomized block with six replicates and treatments arranged in a factorial design with two genotypes (BRS Estilo and IPR Tangará) and five P levels (2, 4, 6, 8 e 10 mg L-1). The seedlings with uniform shoot and roots were transplanted into polyethylene pots with capacity 3.35 L containing nutrient solution Hoagland and Arnon (1950), modified by Pavan and Bingham (1982). The redox potential (pH) and electrical conductivity (EC) of the nutritive solution were monitored daily. The solution was aerated continuously and when the electric conductivity reached 0.14 dS cm-2 the nutrient solution was exchanged. To determine total P content the seeds were ground in Perten 3100 mill and submitted to nitroperchloric digestion according to the methodology of Miyazawa et al. (1999). Pi content was extracted according to the method proposed by Raboy and Dickson (1984) and it was quantified by the method described by Chen et al. (1956). Po content was obtained by subtracting the Pi from the total P. The phytate content was determined according to the methodology of Oomah et al. (2008). The data have been subjected to analysis of variance and test Tukey (p ≤ 0.05) for mean comparison. The statistical analyzes were performed using the Sisvar version 5.3 software (FERREIRA, 2010)

DROUGHT TOLERANCE OF COMMON BEAN GENOTYPES CHARACTERIZED BY PHYSIOLOGICAL AND BIOCHEMICAL MARKERS

INTRODUCTION Common bean (Phaseolus vulgaris L.) is considered the main legume for human consumption, being an important source of proteins, carbohydrates and minerals. However, most of its farming occurs under drought conditions, with water deficit being one of the main limiting factors for production, which can reduce it by up to 80% (ROSALES et al., 2012). The effects of drought on the common bean depend on the frequency, duration and intensity of the stress and the phenological stage of the crop, which can affect the photosynthetic efficiency, stomatal conductance, transpiration rate and solute accumulation. Quantifying these components related to drought tolerance is extremely important to define strategies for their use in breeding programs. Therefore, the present study aimed to evaluate two common bean genotypes for tolerance to drought through biochemical and physiological characteristics. MATERIAL AND METHODS The experiment was conducted in greenhouse, at Agronomic Institute of Paraná State, the experimental design was randomized blocks with six replications and two tolerant cultivars were evaluated, IAPAR 81 and BAT 477. The plants were grown in pots with substrate under 80% of the pot capacity until the phenological stage R5, when the drought began in plots subjected to stress, in which was adopted the water treatment of 30% of the pot capacity for 19 days. Liquid photosynthesis, stomatal conductance, transpiration and carboxylation efficiency of the plant were measured in the morning on sunny days, on the last day of stress, using the portable system Photosynthesis LI-6400XT (LI-COR Biosciences, Lincoln, NE, EUA). For the biochemical analyzes (GPX, APX, protein and proline) it was collected, also in the last day of stress, a leaflet of each plant, arranged in bulk and diluted in proportion 1:5 in four different buffer solutions according to the analyzes. Data were submitted to analysis of variance and Tukey test at 5% of probability by the computer program R (http://www.r-project.org) using the ExpDes and MVar.pt packages