Abstract in English:Abstract Abscisic acid (ABA) is known to impact many areas of plant growth and development and is also assumed to facilitate plant stress regulation. ABA is also involved in the rapid suberization of wounds and is the essential dormancy release regulator. The direct application of DNA markers to plant populations enables the use of mapping to help determine the regulation of a quantitatively inherited trait isolated in a population. QTLs represent a chromosomal region that is linked to a marker gene and that significantly affects the quantitative trait under review. In the present study, we investigated the ABA content after harvest and after sprouting in a diploid population. The most noticeable QTLs related to ABA were found on chromosomes I and IV, and these QTLs fully explained 6.5% and 7% of the entire phenotypic variance, respectively. The acquired information advances our understanding of the inheritance of traits applicable for variety development.
Abstract in English:Abstract Mitigating reductions in vigor in onion seed production has been a great challenge to breeding programs. Therefore, we compared the effects of inbreeding depression among populations obtained from self-fertilization and crossbreeding with two and three plants. We evaluated eleven populations and three breeding methods (two and three-plant crossbreeding, and self-fertilization of one plant) and measured the characteristics related to seed yield (plant appearance, stem vigor, number of umbels, flowering uniformity, fruit setting, and resistance to Alternaria) from 2014 to 2015. Thirteen RAPD molecular markers were used to determine the genetic divergence among populations derived from different breeding methods. We found that inbreeding depression affects plant vigor in early generations that have greater heterozygosity. Three-plant crossbreeding results in greater seed yield in populations with low levels of inbreeding. The populations obtained from self-fertilization and two- and three-plant crossbreeding were genetically similar, demonstrating the efficiency of obtaining inbred lines without genetic divergence.
Abstract in English:Abstract The selection of sexual genitors in Urochloa decumbens breeding is dependent upon the performance of their progeny simultaneously for several traits. Thus, our objectives were to (i) compare the efficiency of indices to select genitors of U. decumbens, (ii) evaluate the genetic gains obtained through selection intensities, and (iii) evaluate the multivariate pattern of progenies through principal components analysis (PCA). For this purpose, 1415 hybrids from 75 progenies of full siblings were evaluated at Embrapa Beef Cattle (Brazil) using seven cuts for dry matter production, regrowth, protein, fiber, lignin, and percentage digestibility. Statistical analyses were performed using mixed models and PCA. The direct selection for dry matter production provided a 37.51% genetic gain. Agronomic traits using indices provided greater gains. Genitors selected using PCA Biplot were similar to selections using indices. Indices and PCA were proven to be an excellent tool to select multi-traits in U. decumbens.
Abstract in English:Abstract There is a worldwide concern about a possible narrowing of the genetic base of most crops, as e.g. that of rice (Oryza sativa L.), as a result of the modern breeding practices. Thus, the purpose of this study was to investigate this phenomenon in the germplasm of elite paddy rice in southern Brazil, including frequently used accessions in crosses. The panel consisted of 91 accessions. Data of morphological traits, SNP markers and mineral content of husked and polished grain were analyzed by hierarchical clustering and principal component analysis. The SNP markers and hierarchical clustering proved most appropriate to assess the genetic variability. A narrowing of the genetic base of rice was confirmed, although a certain level of genetic variability was still found in the germplasm of elite paddy rice in south Brazilian rice, particularly for grain mineral content.
Abstract in English:Abstract: The objective of this study was to compare the selection of plants bred by different pedigree methods using selection among, among and within and only within families. The haploid induction rate of 14 S0:1 and seven S2:3 families, all crossed with the single-cross hybrid GNZ9501, was evaluated. An experimental area of the Department of Biology of the Federal University of Lavras (UFLA), in Lavras, Minas Gerais, in the growing seasons 2012/2013 and 2014/2015, was used for the experiments. In each growing season, one experiment per was carried out, arranged in a complete randomized design, with one and two replications, respectively. Haploid induction was most effective in the families 2 and 6 in both growing seasons. Selection among and within families resulted in higher genetic gains for haploid induction. The results indicated a high genetic variability for haploid induction rate in plants within families.
Abstract in English:Abstract: The aim of this study was to ascertain the association between the REML/BLUP and GGE Biplot methodologies for selection of superior genotypes in regard to adaptability and yield stability for various regions of the Middle North region of Brazil. Sixteen soybean genotypes were evaluated in eight environments during the 2015/2016 and 2016/2017 crop seasons, analyzing the following traits: number of days to maturity, plant height, one hundred seed weight, and grain yield. In this study, the REML/BLUP and the GGE Biplot methods are highly correlated in terms of genotype ranking for selection and recommendation purposes. The genotypes BRASBT13-0528, M8372 IPRO, and BRASBT13-0621 most approximate a hypothetical ideal genotype.
Abstract in English:Abstract Determining the copy number is important because it can greatly influence the expression level and genetic stability of transgenes. This study aimed to establish a methodology that can estimate the transgene copy number in tobacco (Nicotiana tabacum) using the Auxin independent1 (Axi1) gene as an endogenous control. Tobacco c.v. Petit Havana plants were transformed via Agrobacterium tumefaciens with a pMCG1005 vector that contained Bar as a selective gene. Oligonucleotide efficiency was determined and a qPCR using the 2-ΔCt and 2-ΔΔCt methods was performed. Bar was the target gene and Axi1 was the endogenous control in five transgenic tobacco events. The results showed that the Axi1 gene was donated by the maternal parent N. sylvestris when interspecific hybridization occurred between N. sylvestris and N. tomentosiformis. The copy number results agreed with the segregation ratios for the Bar gene in T1 plants, which confirmed that Axi1 is a single copy gene that can be used as an endogenous control.
Abstract in English:Abstract The success of bean (Phaseolus vulgaris L.) crops in Brazil is due to the development of new cultivars. The aim of the present study was to critically analyze the fifty years of a bean breeding program at the Universidade Federal de Lavras (UFLA) and estimate the genetic progress (GP) achieved for grain yield. The estimated genetic progress for grain yield was 0.35% per year, which is associated with visible improvement in plant architecture, resistance to some pathogens, and better carioca bean grain quality. The program was found to be efficient, generating 119 theses and 43 dissertations during the period under study. In addition, hundreds of articles have been published, especially studies aimed at improving the efficiency of genetic breeding programs. Over the past few years, partnerships with other public institutions in performing Value for Cultivation and Use tests have resulted in 12 recommended cultivars.
Abstract in English:Abstract The objective was to evaluate the adaptability and yield stability of different peach rootstock genotypes in subtropical climate in an experiment in Chapecó, Santa Catarina, Brazil. Twenty-one rootstocks under the scion cultivar 'BRS Libra' and one genotype from self-rooted nursery trees were evaluated. The 22 genotypes were evaluated as fruit set and fruit yield in the growing seasons 2014/15, 2015/16, 2016/17 and 2017/18. Adaptability and stability were measured by the GGE biplot method. In the four years of evaluation, plants from self-rooted nursery trees had higher fruit set, yield as well as greater stability. On the other hand, the instability of plants grown on rootstocks from species other than the scion cultivar was greater. It can be concluded that under the tested conditions, the self-rooted genotype of 'BRS Libra' is a potential alternative for peach growers.
Abstract in English:Abstract In the present study, the correlation and presence of genetic interactions were studied in the F3 and F5 generations of two groundnut (Arachis hypogaea L.) crosses. Most of the characters studied were positively skewed and were governed by multiple genes, indicating quantitative inheritance. Variance, skewness, and kurtosis indicate that homozygosity has increased over the generations in both crosses. Cross-B was found to be better than cross-A in providing high-yielding segregants displaying parental diversity. Pod yield per plant and other associated characters, such as plant height, are controlled by complementary action of multiple genes. A shift in correlation coefficients was recorded between the generations, which can be attributed to the difference in gene complementation of linkage blocks and is an indication of the unstable nature of the breeding population. Overall, five lines with superior pod yield were identified, which could be used for varietal development.
Abstract in English:Abstract Wheat breeding in Brazil began in 1919. A cross between the varieties Fronteira and Mentana gave rise to Frontana, the most popular ever released, being recommended for more than 40 years. Frontana played an important role as a source of resistance to leaf and stripe rust as well as resistance to pre-harvest sprouting. Possessing an early maturity cycle, it contributed to change the predominant varietal pattern at that time. The resistance gene Lr34 was first described in Frontana. The gene confers durable adult plant resistance to leaf rust and other biotrophic fungi. Because of its durability, stability across environments, haplotype diversity and wide geographical distribution, Lr34 is probably the most important single resistance gene in wheat. We evaluated 453 wheat varieties that have been released or recommended for cultivation in Brazil from 1922 to 2016 using KASPar markers to detect those varieties carrying the diagnostic mutations corresponding to the presence of the Lr34 resistance allele.
Abstract in English:Abstract The cassava cultivars BRS 417, BRS 418 and BRS 419 are the first specifically developed for flour and starch production in the Cerrado biome of Central Brazil. They are promising for higher yields, lower production costs (mechanical planting) and the increase of genetic variability in cassava crops.
Abstract in English:Abstract Cultivar RB036091 is an early-maturing sugarcane with a long period of industrial suitability; in the Central South region of Brazil, harvest is recommended between April and August, and the cultivar is indicated for planting on moderate to highly fertile soils. It is widely adaptable and has a high sugar yield and stability of agricultural yield.
Abstract in English:Abstract The new cassava variety ‘BRS Novo Horizonte’ was developed and released in Bahia, Brazil for industrial use, particularly for starch production. The fresh and dry root yields were 39% and 44% higher, respectively, than those of local varieties. The root quality traits allowed the extraction of high-quality starch. The variety is also adapted for mechanized cropping systems.
Abstract in English:Abstract BRS A501 CL is the first upland rice cultivar with tolerance to the broad-spectrum herbicide Kifix®. It has a medium-length cycle, high stability of whole grain yield at processing, good disease tolerance and a high grain yield.
Abstract in English:Abstract Tributun is a cultivar of Coffea canephora derived from breeding clones discovered by farmers. It was evaluated at 150 m asl in northern Espírito Santo for yield, plant vigor and pest and disease resistance. The cultivar with six genotypes produces a mean yield of 90.87 bags ha-1 year-1.
Abstract in English:Abstract RB985476 has a high tillering capacity, excellent canopy cover, high longevity, high agro-industrial yield, medium to low fiber content and high germination capacity after mechanical harvesting. RB985476 is resistant to smut, brown and orange rusts and recommended for harvest in the middle growing season in the south-central region of Brazil.
Abstract in English:Abstract The Oat Breeding Program of the Federal University of Rio Grande do Sul (UFRGS) release in 2019 a new cultivar URS MONARCA developed from the single cross UFRGS 06 6083-3 / UFRGS 00 6183-2. URS MONARCA presents high grain yield, high grain quality, wide adaptation, short plant height and excellent milling yield.