Research Article

Table of Contents | Genet. Mol. Res. 2022 (4)

Displaying 1 - 7 of 7
Research Article

Sclerotinia stem rot is a common soybean disease caused by the fungus Sclerotinia sclerotiorum, resulting in economic losses in Brazil and worldwide. The development of resistant cultivars is a good option for the management of this disease; however, it has been difficult, largely due to the variability found in the fungus. We assayed for the genetic resistance (vertical and horizontal) of soybean cultivars inoculated with various isolates of S. sclerotiorum. Twenty soybean cultivars were selected and tested; 10 were relatively resistant and 10 relatively susceptible to the pathogen. The cultivars were inoculated with mycelium from four fungal isolates: Mauá da Serra, Ingaí, and Nazareno, collected from soybean production areas and UFLA 24, an isolate normally used by the Lavras University Laboratory of Plant Resistance to Diseases team, for assays with the detached-leaf method. The experiment was conducted in a completely randomized design. Detached-leaves at V2 trefoil were placed on an agar disk containing the mycelium and each leaflet was considered a replicate. After 72 hours, the leaflets were evaluated using a scoring scale ranging from 0 (no symptoms) to 5 (susceptible). Statistical analyses were performed using the diallel method (Griffing IV model), which provided information on the vertical and horizontal resistance of the cultivars, as well as the aggressiveness of the isolates. The soybean cultivars BRS Baliza RR, M-SOY 8001, Emgopa 316 and M-SOY 8329 showed horizontal resistance; BRS Favorita RR, Emgopa 315, MG/BR 46 (Conquista), 7166RSF IPRO, BRS Silvânia RR and BRS Milena presented specific resistance to most isolates The UFLA 24 and Ingaí fungal isolates were the most aggressive, indicating that these isolates should be preferred for evaluating the level of resistance of soybean genotypes.

Genet. Mol. Res. 2022
DOI: 10.4238/gmr19074
Research Article

The Solanaceae family comprises about 100 genera and 2,500 species, with a cosmopolitan distribution and greatest diversity in the Neotropical region. In Brazil, 36 genera and 506 species have been identified, including 236 endemic species. The family has a high diversity of species of economic importance as a source of food, medicinal extracts, and for ornamental use. The species are sources of bioactive secondary metabolites, with diverse applications. We made ae structural and functional characterization and developed three-dimensional models of putrescine N-methyltransferase (PMT) proteins, a key enzyme of secondary metabolism, involved in biosynthesis of nicotine, tropane alkaloids, and calistegines. We examined 48 PMT sequences from Solanaceae species available in public databases. A hydrophilic characteristic of PMT was found for all species, and the isoelectric point demonstrated a somewhat acidic character (5.4 - 6.6). We identified four functional domains in the PMT sequences. Cluster analysis by Neighbor-Joining was consistent with recent taxonomic classifications of the species.

Genet. Mol. Res. 2022
DOI: 10.4238/gmr19076
Research Article
Authors:

Cassava Periclinal chimera plants could be synthesized by a very easy grafting method. Thanks to this technique we can produce vigorous plants during a very short period. This can be achieved by grafting two types that have high combining ability. The most striking feature is that we can obtain enormous roots up to five times the common ones. It is suggested this vigor is due to gene action of overdominance and there is DNA movement from epidermis (one cell layer tissue) to internal tissues. Previous results are explained in view of this present one.

Genet. Mol. Res. 2022
DOI: 10.4238/gmr19079
Research Article

The challenge presented by the SARS-CoV-2 pathogen has changed the global perception about virus diseases. In Wuhan, China the first case of the disease called COVID-19 (Coronavirus Disease 2019) was reported in December 2019 and quickly reached 215 countries. The pathogenic SARS-CoV-2 virus has an RNA genome composed of a positive-sense single-strand, harboring 14 ORFs that encode 50 proteins composed of typical structural proteins. The spike protein, a surface glycoprotein, is essential for the invasion of the causal agent of COVID-19 into the host system. Several variants have specific mutations in protein S that affect transmission processes, diagnosis, and available therapies. Entry of SARS-CoV-2 into the host cell promotes immunological dysregulation with increased expression of interferon type 1 and an exaggerated proinflammatory cytokine event called "cytokine storm". This event is often associated with deleterious outcomes such as acute respiratory distress syndrome. In addition, substantial immunological memory can be generated after initial SARS-CoV-2 infection, involving four major cell types, such as anti-spike protein memory B cells (RBD IgG, IgM), T cells (CD4+ and CD8+) and other molecules, such as antibodies. It is important to collect genetic and immunological information related to the SARS-CoV-2 virus to provide a global vision and high quality knowledge about the biology and this disease in order to develop effective control measures and treatments.

Genet. Mol. Res. 2022
DOI: 10.4238/gmr19003
Research Article

Pigeonpea is a multipurpose species and can be used for grain, forage production, and as a soil improver. In Brazil, the scarcity of productive cultivars adapted to various growing conditions contribute to the underutilization of this legume crop. The genotype × environment (G×E) interaction is one of the main challenges to the development and recommendation of cultivars. Estimates of adaptability and stability parameters make it possible to predict the behavior and effects of the G×E interaction to reduce possible inconsistencies in cultivar recommendation. From this perspective, we assessed the adaptability and stability parameters for grain yield of 21 pigeonpea lines developed in the breeding program of this pulse at Embrapa Semiárido, Petrolina, PE, Brazil, and the variety ‘guandu Petrolina’ (control), in order to recommend new cultivars for general use. The genotypes were evaluated in eight environments, with experiments conducted in five irrigated and three rainfed environments using a randomized complete block design with three replications. Grain yield was corrected by covariance based on the average plant stand. The Eberhart and Russel, AMMI, and GGE Biplot methods were used in this study. The coefficient of variation for the experiments was 12.41%, with data transformed to square root. The effects of genotypes, the environments, and the genotype-by-environment interaction were highly significant (p < 0.01). The mean grain yield of the genotypes was 1,516 kg ha-1. Lines 87, 100, and 158 simultaneously showed wide adaptability and good predictability according to the three methods, with mean yields of 1,530, 1,701, and 1,812 kg ha-1, respectively, and reaching yields of up to 2,725, 2,928, and 2,955 kg ha-1 in some environments. These lines are indicated for recommendation as new pigeonpea cultivars for the semi-arid region of Brazil.

Genet. Mol. Res. 2022
DOI: 10.4238/gmr19066
Research Article

The Amazon harbors numerous bitter cassava genotypes, of which only a few have been studied agronomically. We evaluated the genotype x environment interaction (GxE) displayed by seven traditional varieties found in the Brazilian municipalities of Lábrea-AM, 07°14’83.5”S, 64°44’70”W, (Cobiçada, Minerva, and Flecha-Amarela) and Manaus-AM, 02º59’00”S, 60º01'00”W, (Mana, Trairinha, Nanica, and Jurará), to determine the landraces best adapted to both sites. A randomized block design, with seven treatments and four replications with eight plants per plot, was adopted at each site. We evaluated commercial root number, length, diameter, length/diameter ratio, mass, dry matter, peel thickness, pulp coloring, plant height, stem diameter, and aerial part mass. GxE interaction analysis revealed GxE interaction for plant height and root diameter and number, and yield. Jurará was the most adapted variety at both sites for the main agronomical characteristics. It showed 43.7 and 26.5 t ha-1 root yield; 39.8 and 43.7 t ha-1 aerial mass; 10.8 and 4.8 roots per plant and 331.7 and 316.6 cm plant height, respectively in Lábrea and Manaus, respectively. Therefore, Lábrea and Manaus are suitable sites for making studies of GxE interaction. Jurará can be recommended for the Amazon region as well and should be tested in other tropical and subtropical regions.

Genet. Mol. Res. 2022
DOI: 10.4238/gmr19049
Research Article

Complex chromosomal rearrangements are extremely rare in humans. Most apparently balanced complex chromosomal rearrangements are de novo; they usually are detected in phenotypically normal subjects. Nevertheless, in some cases they are found in patients with multiple congenital abnormalities and neurodevelopmental disorders, which may be due to cryptic genomic imbalance. We report on a case of complex chromosomal rearrangement in a patient with an abnormal phenotype and neurodevelopmental delay. The conventional karyotyping of a child showed an apparently balanced three-way translocation t(4;7;5)(q31;p21;q31)dn. FISH and chromosomal microarray revealed that the rearrangement was far more complex than originally diagnosed, with more breakpoints involving chromosomes and four cryptic microdeletions on chromosomes 4 and 5. One copy number variant indicated microdeletion 5q31.3 syndrome associated with deletion/mutation of the gene PURA. A combination of several different approaches, including GTG, FISH and chromosomal microarrays, was sufficient to determine an unexpected level of complexity and to resolve the nature of the complex chromosomal rearrangement.

Genet. Mol. Res. 2022
DOI: 10.4238/gmr19065