Molecular markers are important tools in the characterization of plant genetic diversity and can provide support for conservation strategies for endangered populations. The different molecular ...techniques involve the evaluation of many individuals; therefore, it is crucial to have fast, efficient, and inexpensive methods for DNA extraction. Given the importance of the Aroeira (Myracrodruon urundeuva Fr. All.) it is pertinent to optimize a protocol that allows the obtainment of intact and pure DNA, aiming to assist conservation strategies for this species that is threatened with extinction. Thus, this study aimed to compare five DNA extraction methods: Dellaporta et al. (1983), Doyle and Doyle (1987) modified, Ferreira and Grattapaglia (1995), Romano and Brasileiro (2015), and Khanuja et al. (1999) and optimize the most efficient protocol for M. urundeuva. The modified DNA extraction protocol proposed by Doyle and Doyle (1987), using 100 mg of leaf tissue and 6 µl of β-mercaptoethanol was the protocol that presented the sharpest bands after DNA electrophoresis and after the reactions of amplification employing Polymerase Chain Reaction (PCR). Therefore, it is suggested to use the protocol described by Doyle and Doyle (1987) modified for the extraction of DNA from young M. urundeuva leaves to carry out techniques involving molecular markers.
ABSTRACT Some germplasm collections have a high number of accessions, which makes it difficult to explore the genetic variability present in the germplasm bank due to the redundancy and the ...difficulty of detailed analysis of all conserved accessions. Therefore, our study aimed to analyze the genetic diversity of 153 lima bean (Phaseolus lunatus) accessions for the purpose of constructing a core collection. Eleven SSRs were used for this purpose. The 153 lima bean accessions can be represented by low redundancy using a minimum of 34 accessions, thus representing 22 % of the size of the entire germplasm bank. The core collection had a higher Shannon diversity index and expected heterozygosity (1.906 and 0.811, respectively) than those presented by the entire germplasm bank (1.605 and 0.713, respectively), indicating a higher polymorphism of the representative cultivars in relation to the entire collection. The accessions selected for the core collection may be used in future studies of genome association as well as in genetic crosses in breeding programs aimed at developing improved cultivars with high genetic diversity which can meet current and future market needs.
The increase in importations of elite garlic (
Allium sativum
L.) in Brazil to meet the local demand in many cities may affect the cultivation of garlic landraces in small family farming systems by ...driving to the reduction of the harvested area and genetic diversity. The landraces are fundamental sources of genetic variability and adapted germplasm that could be potentially be implemented in breeding programs. The objective of this study was to evaluate the changes in the patterns of genetic diversity in landraces cultivated in family farming systems after three decades of competitiveness with imported garlic. Three landraces of garlic currently cultivated on family farms in the Picos municipality and immediate regions (7° 04′ 55.5″ S 41° 28′ 04.2″ W) and a landrace collected in the same region in the 1970s, before the increase of imports of garlic in Brazil, were selected for this study. Additionally, six garlic accessions from the Garlic Germplasm Bank from ESALQ/USP (Sao Paulo—Brazil) were selected to parallel the genetic diversity present in landraces with other varieties collected in Brazil, completing a set of ten accessions. A randomized block design was used to evaluate nine agro-morphological traits and rank the landraces according to the economically important agronomic traits. The potential changes in genetic diversity patterns and population structure in these populations were also evaluated at a molecular level using eight microsatellite markers. The agro-morphological evaluation indicates that there is genetic diversity in the garlic populations, and it is structured between Picos landraces and ESALQ/USP accessions. There is also evidence of genetic structure between the landraces and populations of the ESALQ/USP accessions (K = 3) based on a Bayesian clustering approach. The moderate genetic differentiation (FST = 0.09) accessed by the microsatellite markers may be associated with the existence of these two different gene pools: Picos landraces and ESALQ/USP accessions. The results indicate that the reduction in harvested areas in the past decades did not affect most morphological characteristics in the landraces, but there was a reduction in the quality of the bulbs. The garlic landraces cultivated nowadays in Picos municipality present a higher number of cloves per bulb, an undesirable characteristic that may affect its commercial value. However, we demonstrate that even with such reduction in harvested areas due to the lack of competitiveness of landraces, there was no reduction in the molecular genetic diversity in these landraces accessed by the microsatellite markers. These are promising results since there is genetic diversity to implement these landraces in genetic breeding programs.
Cajui (Anacardium spp.) is a native fruit tree (small cashew) of the Brazilian Cerrado and possesses the potential for commercialization. However, cajui exploitation occurs exclusively through ...extractivism in the absence of conservation strategies. The lack of conservation strategies may lead to a decrease in genetic diversity of Anacardium. In this work, the genetic diversity and population structure of three natural populations in Sete Cidades National Park (PNSC; PI, Brazil) were assessed using ISSR analysis of 56 cajui accessions and two A. occidentale accessions (outgroup) from Pacajus (CE, Brazil). A total of 112 markers were obtained, 93 (83.04%) of which were polymorphic. The diversity indices of these populations indicated moderate levels of genetic diversity. According to AMOVA, 96.17% of the genetic variability lay within populations, with low genetic differentiation among populations (ΦST = 0.03828). Furthermore, STRUCTURE analysis indicated the existence of four connected genetic groups. The findings show that the individuals from the three collection sites did not represent different subpopulations, likely due to the high gene flow (Nm = 6.7) favored by the floral biology of Anacardium, pollinators and small-animal seed dispersers. This research identifies genetically divergent individuals (C-03, C-05, C-22, C-26, C-34 and C-39), which should be considered priority individuals for conservation and can inform conservation programs for Anacardium spp.
The mangabeira is a native fruit tree from Brazil with fruits that present significant potential for exploitation. This species is experiencing genetic erosion, which increases the importance of ...elucidating the genetic diversity that exists in mangabeira populations to support conservation programs. Thus, this study aimed to evaluate the diversity and genetic structure of mangabeira populations from the Germplasm Bank of Embrapa Meio-Norte using inter simple sequence repeat (ISSR) markers. A total of 29 accessions from Brazil were characterized, including one from Sergipe, one from Bahia, three from the Distrito Federal, 11 from Piauí and 13 from Paraíba. The 11 ISSR primers provided 166 loci, among which 120 were polymorphic. The analysis of molecular variance (AMOVA) indicated that 69.66% of the observed genetic variability occurred within populations and that the populations showed high genetic differentiation. The results obtained from the STRUCTURE analysis indicated the existence of two genetic groups. The Nei and Shannon indices of genetic diversity varied from 0.15 to 0.24 and from 0.22 to 0.34, respectively. The coefficient of similarity ranged from 0.57 to 0.94, with a mean of 0.76. The mean was used as the cut-off point in the dendrogram, and seven groups were identified. In conclusion, this study demonstrates the presence of low or moderate genetic diversity within the studied mangabeira populations and high genetic differentiation between the populations. The results indicate a need to increase the number of mangabeira population samples from different collection sites as a strategy to achieve more significant results for the conservation and genetic improvement of this species.
“Sucupira branca” is a plant found in the Brazilian Cerrado and is adapted to low fertility soils, and its fruit extract has anti-inflammatory, healing, antiulcerogenic, antimicrobial, cercaricidal, ...leishmanicidal and antioxidant activities. Furthermore, it provides protection against oxidative stress, is a natural biocontrol agent of Aedes aegypti, has very resistant wood, is a melliferous plant and has been used in reforestation programs. The development of conservation strategies is important for maintaining diversity in natural populations of “sucupira branca” since these populations are in the process of genetic erosion. Molecular biology techniques, which are important for characterizing the genetic diversity of plants to develop conservation strategies, require sufficient high-quality genomic deoxyribonucleic acid (DNA). This study aimed to compare five methods to extract DNA from “sucupira branca”. The quality and concentration of DNA were revealed by agarose gel electrophoresis, and only the protocols of Dellaporta, Wood and Hicks et al. (1983) and Khanuja et al. (1999) did not result in satisfactory quantities of DNA. When PCR (Polymerase Chain Reaction) was performed with three inter-simple sequence repeat (ISSR) primers, DNA was successfully amplified from extractions performed with the protocols proposed by Doyle and Doyle (1987), Romano and Brasileiro (1998) and Ferreira and Grattapaglia (1995), which are less expensive than commercial purification kits. These protocols resulted in DNA of sufficient quality and quantity after the amplification reactions were performed.
Divergência genética em germoplasma de alho Viana, João Paulo Gomes; Pires, Carolline de Jesús; Pinheiro, José Baldin ...
Ciência rural,
02/2016, Letnik:
46, Številka:
2
Journal Article
Recenzirano
Odprti dostop
RESUMO: O alho é uma das hortaliças mais importantes no mercado brasileiro e mundial. No Piauí, mais especificamente na microrregião de Picos, o alho semi-nobre foi cultivado em larga escala e supria ...a demanda de vários municípios do estado. Devido à entrada do alho nobre no mercado brasileiro, houve redução na produção de alho semi-nobre que pode ter levado à perda de diversidade genética. O objetivo deste trabalho foi estudar a diversidade genética em doze variedades de alho, sendo quatro de origem piauiense e oito da Coleção de Germoplasma de Alho da Escola Superior de Agricultura "Luiz de Queiroz" - Universidade de São Paulo (ESALQ/USP). Para isso, caracterizou-se o germoplasma com base nos descritores propostos pelo International Plant Genetic Resources Institute (IPGRI), atualmente Bioversity International, e realizou-se a genotipagem das variedades a partir de oito locos SSR. Os resultados obtidos com a análise morfológica corroboraram as análises moleculares, evidenciando complementaridade dessas dimensões de análise no estudo da diversidade genética em alho. Assim, conclui-se que existe divergência genética entre as variedades de alho estudadas em função da procedência do germoplasma e sugere-se que o material oriundo da ESALQ/USP trata-se de um germoplasma distinto do cultivado no Piauí. A divergência genética existente entre as variedades de alho no Piauí indica a possibilidade de seleção de genótipos superiores que aumentem a competitividade do alho piauiense frente ao alho importado.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
RESUMO Casearia grandiflora (Salicaceae) é uma espécie típica do cerrado piauiense, o conhecimento da diversidade genética dessa espécie é de grande importância para estabelecimento de práticas e ...estratégias de conservação biológica. O presente estudo teve como objetivo caracterizar a diversidade de C. grandiflora em duas áreas de cerrado do Piauí. Foram analisados 15 descritores de natureza quantitativa, através da medição do caule, folha, fruto e semente, seguida de posterior análise multivariada (componentes principais e agrupamento). Tanto a análise de componentes principais quanto os métodos de agrupamento apresentaram semelhanças na associação das plantas, o que contribuiu para o conhecimento dos padrões de variação fenotípica e divergência da espécie, sendo que a maior variação da diversidade genética foi encontrada dentro das populações. Os resultados fornecem informações importantes, visto que na literatura descrições sobre caracterização morfológica e diversidade genética dessa espécie ainda são limitadas.
Genetic Map of Cotton with Molecular Markers Sousa, Camila Campêlo de; Figueirêdo, Lívio Carvalho de; Arrais, Maria das Graças Medina ...
American journal of plant sciences,
02/2015, Letnik:
6, Številka:
2
Journal Article
Odprti dostop
Cotton (Gossypium spp.) is the most important natural fiber in the world, and its seeds are also used as a food source. Breeding cotton for traits of interest, such as production and processing of ...fibers, will ensure that this natural product is as competitive as renewable synthetic fibers derived from petroleum. Thus, the mapping of the cotton genome for traits of interest may be the basis for its subsequent use in breeding programs. This work consists of a literature review, with the aim of bringing together works from different research groups working with the mapping of the cotton genome with molecular markers.
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