Genetics and Molecular Research : GMR

Castor bean (Ricinus communis L.) is a tropical plant of great commercial interest and a potential source of biodiesel. The development of genetically improved cultivars with high amounts of oil in the seeds and low ricin toxicity is crucial to increase the productivity of this crop. The use of TRAP (target region amplification polymorphism) markers to develop elite lineages and study genetic divergence is fundamental to advance the genetic improvement of this species. The goal of this study was to evaluate the genetic divergence among 40 elite lineages of R...

The forecast of a growing energy demand in the coming years has aroused particular interest in biomass for energy cogeneration, to diversify the energy matrix by using clean and renewable sources. To meet the new demands of the sugarcane industry, this study evaluated the agronomic performance and estimated genetic parameters for yield traits in sugar- and energy cane families derived from planned crosses. The cane families were assessed in the northwest of the State of Paraná, county of Paranavaí, in a randomized complete block design, with three replications...

The present study was conducted to investigate the genetic control and to estimate the general and specific combining abilities of popcorn for agronomic attributes and attributes related to resistance to northern leaf blight (NLB). The 56 hybrids (F1 and reciprocals), together with the eight parent lines and six controls, were evaluated in two harvests, in a randomized-block design with four replications. Dominance components were more expressive than the additive components for grain yield and expression of resistance, and hybridization was the most suitable option for obtaining resistant and productive genotypes...

The microorganisms are the best source of extracellular enzymes since they allow an economical technology with low-resource consumption compared to animals and plants. The amylases are among the most important enzymes being the genus Bacillus one of the most investigated due to its ability to produce this enzyme. The objective of this study was to isolate and analyze the genetic diversity among bacteria of the genus Bacillus sp producer of amylase originated from the soil. To this end, soil samples were collected and submitted to the condition of extreme temperature...

Selection indices commonly utilize economic weights, which become arbitrary genetic gains. In popcorn, this is even more evident due to the negative correlation between the main characteristics of economic importance - grain yield and popping expansion. As an option in the use of classical biometrics as a selection index, the optimal procedure restricted maximum likelihood/best linear unbiased predictor (REML/BLUP) allows the simultaneous estimation of genetic parameters and the prediction of genotypic values...

This study uses ISSR molecular markers to characterize the demographic pattern, and spatial genetic structure (SGS) at different life stages of development (cohorts) in a natural population of Copernicia prunifera in the Rio Grande do Norte State, Brazil. All individuals were sampled and georeferenced in a 0.55-ha plot. The demographic analyses showed a clustered pattern in the first-distance classes and a random or segregated pattern at higher distance classes for all cohorts. Among the three studied life stages, juveniles showed the greatest value for Nei's genetic diversity index (HE = 0...

Melanopsin is the photopigment of intrinsically photosensitive retinal ganglion cells that mediate non-visual responses to light. The aim of this study was to describe and analyze melanopsin gene expression in the rabbit retina at different ages and compare its expression with the prototypic gene of retinal ganglion cells (Thy-1 gene). Expression levels of OPN4, Thy-1, and GADPH genes were measured by real-time PCR at 3, 4, 8, 11, 12, 17, 19, 20, 23, 27, 32, and 47 postnatal days. We also regrouped the days before and after day 12 of life (pre-photic and post-photic stage, respectively)...

The expansion of agriculture, coupled with the need for sustainable cropping, is one of the greatest challenges of the scientific community working on the generation of new cultivars adapted to abiotic stress conditions. The aim of this study was to evaluate the variability of popcorn lines as to responsiveness and efficiency in phosphorus use, as a first step towards the implementation of a breeding program interested in the practice of sustainable agriculture. Twenty-five popcorn lines were evaluated in two locations with different phosphorus levels in the soil, using a randomized block design...

Iron (Fe) is an essential microelement for all living organisms playing important roles in several metabolic reactions. Rice (Oryza sativa L.) is commonly cultivated in paddy fields, where Fe goes through a reduction reaction from Fe3+ to Fe2+ . Since Fe2+ is more soluble, it can reach toxic levels inside plant cells, constituting an important target for studies. Here we aimed to verify morphological changes of different rice genotypes focusing on deciphering the underlying molecular network induced upon Fe excess treatments with special emphasis on the role of four WRKY transcription factors...

Mocó cotton belong to the same species as the cultivated species, Gossypium hirsutum, and cultivated forms were mainly landraces but also developed as cultivars, bearing good fiber quality and drought tolerant when cropped as a perennial species. The northeast Brazil crop system based on this cotton type is finished, with a few small area planted in the three main States, where it was previously cultivated (Ceará, Paraíba, and Rio Grande do Norte), but in others, maintenance is accomplished by single dooryard plants...

Polycystic ovary syndrome is the classic example of loss of functional cyclicity and anomalous feedback. In this case, the excessive extra-glandular production and conversion of androgens to estrogens are the pathophysiological basis of the chronic anovulation. The literature describes an experimental model of the polymicrocystic ovary in obese diabetic mice with insulin resistance. The fact that these animals exhibit obesity, insulin resistance, and infertility demonstrates their skill as an experimental model for polycystic ovary...

The analysis of meiotic behavior has been widely used in the study of plants as they provide relevant information about the viability of a species. Meiosis boasts a host of highly conserved events and changes in genes that control these events will give rise to irregularities that can alter the normal course of meiosis and may lead to complete sterility of the plant. The recombination of genes that occur in meiosis is an important event to generate variability and has been important in studies for genetic improvement and to create viable hybrids...

Aldolase is a key enzyme involved in glycolysis, gluconeogenesis, and the pentose phosphate pathway. To establish the expression patterns of all three aldolase isozyme genes in different tissues and during early embryogenesis in lower vertebrates, as well as to explore the functional differences between these three isozymes, the grass carp was selected as a model owing to its relatively high glucose-metabolizing capability. Based on the cDNA sequences of the aldolase A, B, and C genes, the expression patterns of these three isozymes were analyzed in different tissues and during early embryogenesis using quantitative real-time polymerase chain reaction (qRT-PCR)...

Plant parasitic nematodes infect a wide range of hosts representing the largest source of biotic stress experienced by plants. Meloidogyne genus comprises the most important parasitic nematodes, also known as root-knot nematodes. These parasitic organisms obtain nutrients to support their development through complex interactions with their hosts. The translationally-controlled tumor protein (TCTP) is widely expressed in eukaryotic organisms, and is related to a great diversity of biological processes such as calcium binding, cell proliferation and growth, pluripotency, regulation of apoptosis, microtubules stabilization, and histamine release...

Although PCR-based techniques have become an essential tool in the field of molecular and genetic research, the amplification of repetitive DNA sequences is limited. This is due to the truncated nature of the amplified sequences, which are also prone to errors during DNA polymerase-based amplification. The complex structure of repetitive DNA can form hairpin loops, which promote dissociation of the polymerase from the template, impairing complete amplification, and leading to the formation of incomplete fragments that serve as megaprimers...

For the selection of coffee plants that have favorable characteristics, it is necessary to evaluate variables related to production. Knowledge of the genetic divergence of arabica coffee is of extreme importance, as this knowledge can be associated with plant breeding programs in order to combine genetic divergence with good productive performance. The objective of this study was to evaluate the genetic divergence among 16 genotypes of Coffea arabica with the purpose of identifying the most dissimilar genotypes for the establishment of breeding programs and adaptation to the Brazilian cerrado...

The objective of this study was to analyze the diversity and discrimination of high-performance Brazilian rice cultivars using microsatellite markers. Twenty-nine rice cultivars belonging to EMBRAPA Arroz e Feijão germplasm bank in Brazil were genotyped by 24 SSR markers to establish their structure and genetic discrimination. It was demonstrated that the analyzed germplasm of rice presents an expressive and significant genetic diversity with low heterogeneity among the cultivars. All 29 cultivars were differentiated genetically, and were organized into two groups related to their upland and irrigated cultivation systems...

Plant interspecific periclinal chimeras are a mosaic formed by tissues from two species. They are manipulated here as an efficient plant breeding tool for cassava root yields. In this study, plants synthesized from two chimeras, designated as chimera 2 and chimera 4, were characterized morphologically and cytologically to unravel the origin of their tissue layers (L2 and L3). Root yield of the two chimeras was also evaluated. Chimera 2 that was developed from graft union between Manihot fortalezensis (F) as scion and M...

Sugarcane (Saccharum sp, Poaceae) is native to Southeast Asia, and due to growing demand as raw material, its cultivation recently expanded to new frontiers. The genetic diversity analysis is essential for targeting strategies in the formation and maintenance of a germplasm. This study aimed to assess the genetic diversity of 26 accessions of sugarcane from the Active Germplasm Bank of Embrapa Coastal Tablelands, using inter-simple sequence repeat (ISSR) molecular markers. Sixteen primers were used, resulting in 87 fragments with 91...

The magnitude of ovulation rate (OR) after hormonal induction in sheep should be considered when prolific genotypes are used. We investigated for the first time the effect of the Vacaria allele and its combined effect with the Booroola prolificacy mutation on OR after hormonal treatment during breeding and anoestrous season. A hundred forty-nine Ile de France crossbred ewes, raised in natural pastures in South Brazil, were used to evaluate the OR after treatment with progestagen (MAP) followed or not by equine chorionic gonadotrophin (eCG) treatment (MAP + eCG)...