Raphael Lemes Hamawaki

Development of Brazilian Soybean Cultivars Well Adapted to Cerrado and Rust-Tolerant

The major diseases limiting soybean growth and yield must be either controlled or mitigated. Among these, soybean rust is the most harmful; in addition, Phakopsora pachyrhizi populations less susceptible to both IDM and IQe fungicides were observed. Therefore, this invention aimed at developing a new soybean cultivar rust resistant and highly productive. Generations were advanced by single seed descent method on the Capim Branco farm, Federal University of Uberlândia. Value for Cultivation and Use were carried out during a 3-year period (2010/13) in several locations, and Distinctness, Uniformity and Stability experiments for a 2-year period (2011/13) on the Capim Branco farm. Hence, we developed the novel soybean cultivar designated UFUS 7415. UFUS 7415 has shown high contents of oil (20%) and protein (40%), and high yield potential (4.300 kg ha-1) even in environments with Asian rust.

Soybean Breeding Aiming at increasing Productivity and Root-Knot Nematode Resistance

In Brazil, the root-knot nematode (Pratylenchus brachyurus) has gained importance, whatever because of the damage caused to soybean crops or because of its broad dispersion and incidences in producing areas. Therefore, this invention aimed at developing a new cultivar resistant to the major soybean diseases as well as to the root-knot nematode. As a result, we developed a soybean cultivar designated UFUS 8301. Generations were advanced by the single seed descent method. Value for Cultivation and Use assays were carried out during a 3-year period (2010/13). Distinctness, uniformity, and stability experiments were carried out during a 2-year period (2011/13). We used the reproduction factor (RF) statistics to assess damage and reproductive potentials of P. Brachyurus; analysis of variance tested differences between means. We accepted the null hypothesis there was no difference between UFUS 8301 and the parameter of resistance Crotalaria spectabilis. UFUS 8301 was found distinct from any other cultivar, homogeneous to the descriptors that had identified it and stable through generations. UFUS 8301 presented 19% oil and 39% protein on the seeds, and yield (3687.5 kg ha -1 ) above Brazilian national average.

Path analysis and traits correlation in soybean

1 Universidade Federal de Uberlândia, Instituto de Ciências Agrárias, Uberlândia, MG, Brazil. 2 Universidade Federal de Uberlândia, Instituto de Genética e Bioquímica, Uberlândia, MG, Brazil. 3 Southern Illinois University, Department of Plant, Soil, and Agricultural Systems, College of Agricultural Sciences, Carbondale, IL, USA. 4 Instituto Master de Ensino Presidente Antônio Carlos, Araguari, MG, Brazil. *Author for correspondence: siqueiragaia@yahoo.com.br.

Agronomic performance and genetic diversity among lines and soybean cultivars

Knowledge of genetic diversity is of great importance to the contribution of plant breeding, as it helps plant breeders to better selecting parents for establishment of segregating populations. This knowledge is especially important to crops that presents a narrow genetic base as soybean. The objective of this work was to assess agronomic performance and genetic diversity of lines and soybean cultivars, in order to find those ones with potential to be used as parents in breeding programs. Experiment was carried out during 2015/2016 season in the Federal University of Uberlândia farm known as Capim Branco. A randomized complete block designed was applied in order to assess twentythree morpho-agronomic features on twenty-four soybean genotypes. Significant genetic variability for all agronomic traits was found. Genotypes UFU B7, UFU B14, UFU B16, Msoy 6101 and UFUS 7910 were set as early maturity soybean, with life cycle duration ranging from 107.3 to 111 days. Genotypes UFU B1, UFU B3, UFU B8 and UFU B16 presented productivity values higher than national average of 2.870 kg ha. Genotypes were clustered by UPGMA, Tocher and canonical variables methods. Both UPGMA and Tocher methods formed four groups. NDF was the major contributor to genetic diversity. Hybridizations between UFU B3, UFU B8, UFU B16 genotypes with UFU B1 genotype might be promising for establishment of segregating populations shown superior genetic variability. Under these circumstances, it was concluded that agronomic features assessed were useful on detection of parents with potential to UFUs soybean breeding program.

Dissimilarity measures and hierarchical methods for the study of genetic diversity on soybean

In analysis of the genetic diversity on soybean can be used agronomic, morphological and molecular traits, which are subjected to multivariate biometrical analysis. There are different multivariate methodologies available such as Euclidean distance, Mahalanobis distance and different hierarchical methods. However, studies that may assist in the choice of such methods are lacking. The aim of this paper was to evaluate the clustering standards of soybean genotypes using Euclidean and Mahalanobis distances, following different hierarchical methods. The experiment was conducted in “Capim Branco” farm which belongs to the Federal University of Uberlândia and were used a complete randomized block design composed of 15 soybean genotypes (nine breeding lines and six cultivars) and four replications. The agronomic traits evaluated were: number of days to flowering and to maturity, height of the plant at flowering and at maturity, height of the insertion of the first pod, number of nodes on the main stalk in flowering and at maturity, number of grains per pod, total number of pods, severity of Asian rust, number of pustules and yield. The data were submitted to multivariate analysis in GENES program. The Mahalanobis distance or the Euclidean distance obtained by agronomic traits allows the determination of soybean genetic diversity. The use of the Euclidean distance in hierarchical methods allows a greater group differentiation. The UPGMA method and the nearest neighbor method shows a greater accuracy using the Mahalanobis distance and Euclidean distance.

Genetic divergence in soybeans based on phenotypic traits and microsatellite markers

Background The success of a breeding program depends on the existence of genetic variability [1]. Therefore, breeders have recommended to the formation of the population-based study, the interbreeding between superior cultivars and divergent, resulting in hybrid combinations of higher heterotic effect, so that in segregating generations it has a greater chance of obtaining transgressive genotypes [2]. Microsatellite markers or Simple Sequence Repeat (SSR) have been widely used to estimate genetic diversity in soybean due to their high degree of polymorphism, codominant inheritance, PCR-based detection, allelic diversity and the knowledge of the location of the marker in the genome the species [3]. In this report we present results of agronomic traits and microsatellite markers to evaluate the genetic diversity of 35 soybean genotypes to determine their potential as parents for breeding programs.

UFUS Guarani: new soybean cultivar for the state Minas Gerais

Day by day alternatives in genetic improvement are being been sought to ensure higher crop productivity. UFUS Guarani developed by the Federal University of Uberlandia is resistant to natural dehiscence and to the diseases: Sudden death syndrome (SDS), frogeye leaf spot, downy mildew, bacterial pustule, stem canker and stem necrosis; the potential yield is 3494 kg ha-1, the grain oil content is 18% and protein content 38%.