Variations in heterochromatin content reveal important polymorphisms for studies of genetic improvement in garlic (Allium sativum L.)

Allium sativum L. is an herb of the Alliaceae family with a specific taste and aroma and medicinal and nutraceutical properties that are widely marketed in several countries. Brazil is one of the largest importers of garlic in the world, despite of its production is restricted and limited to internal consumption. Thus, explore the genetic diversity of commercial garlic conserved at germplasm banks is essential to generate additional genetic information about its economically important crop. A suitable tool for this purpose is the cytogenetic characterisation of these accessions. This study aimed to characterise the cytogenetic diversity among seven accessions of garlic from a Germplasm Bank in Brazil. The karyotypes were obtained by conventional staining and with chromomycin A3 (CMA) and 4,6-diamidino-2-phenylindole (DAPI) fluorochromes. All accessions analysed showed chromosome number 2n = 16, karyotype formula 6M+2SM, symmetrical karyotypes, reticulate interphase nuclei, and chromosomes with uniform chromatin condensation from prophase to metaphase. The fluorochromes staining showed differences in the amount and distribution of heterochromatin along the chromosomes and between accessions studied. Based on the distribution pattern of these small polymorphisms, it was possible to separate the seven accessions into three groups. It was also possible to differentiate some of the accessions individually. One of the results obtained showed a heteromorphic distension of the nucleolar organiser region observed on the chromosome pairs 6 or 7 with peculiar characteristics. It was suggested for example, that the heteromorphic block of heterochromatin (CMA+++/DAPI-) on chromosome 6 of the “Branco Mineiro Piauí” accession can be used as a marker to identify this genotype or may be associated with some character of economic interest.

Cryopreservation of Arachis Hypogaea L. Varieties, from the INIAP-Ecuador Germplasm Bank

The peanut (Arachis hypogaea L.) is recognized as one of the most important legume crops globally for its use in human food; it is widely distributed and cultivated in tropical and subtropical regions. The purpose of this study was to evaluate the cryopreservation of five peanut varieties conserved in the INIAP Germplasm Bank, testing cryopreservation methods, evaluating the germination percentage of whole seeds and embryonic shoots. Subsequently, two quantitative variables, shoot length and root, were evaluated. The average germination percentage of varieties and treatments was higher when embryonic axes were isolated with 99.31% than 86.06% seeds. The best germination percentage of the five varieties for seeds and embryonic shoots was obtained by the Peruvian variety with 88.13% and 92.50%. The best treatments by variety for the germination of whole seeds and embryonic axes were obtained by the treatment (desiccation and NL) for whole seeds (GS2) with 95.42% and embryonic axes with 92.83%. Ageing and cryopreservation treatments positively affected germination and seedling vigor in whole seeds and embryonic axes. The two quantitative variables, shoot and root length showed variability between the five varieties; significant differences were observed between the four treatments evaluated for whole seeds and embryonic axes. The three treatments for whole seeds (GS1, GS2 GS3) and the non-cryopreserved control treatment (GSC), as well as the treatments for embryonic axes (GEA1, GEA2 GEA3) and the non-cryopreserved control treatment (GEAC), obtained good survival. They germinate whole seeds and embryonic axes with sprout development (aerial part) and root formation. With the most effective treatments for whole seeds (GS2) and embryonic axes (GEA2), the cryopreservation of the national peanut collection of the INIAP Germplasm Bank could be started.

Flowering capacity and botanical seed production of sweet potato genotypes

ABSTRACT The identification of genotypes with greater capacity for flowering and seed production is crucial for greater efficiency in the genetic improvement of the sweet potato crop. Thus, the objective of this work was to evaluate the flowering capacity and the production of botanical seeds in sweet potato genotypes. The work was carried out in the municipality of Lavras, located in the southern region of Minas Gerais, Brazil. Twenty-two sweet potato genotypes belonging to the germplasm bank of the Federal University of Lavras (UFLA) were evaluated. The characteristics evaluated were the flowering period (days), the number of viable seeds, the total weight of viable seeds, the weight of 1000 seeds and the percentage of germination. The obtained data were analyzed by means of descriptive statistics, study of correlations and analysis of main components. The sweet potato genotypes evaluated showed a high capacity for flowering and production of botanical seeds. Flowering usually starts 125 days after planting and extends on average for 72 days. Considering future recombination to promote flowering capacity, seed production and greater germination, genotypes BD-05, BD-26 and BD-44 should be prioritized.

Seasonal variation in the essential oil from Varronia curassavica Jacq. accessions

Varronia curassavica has anti-inflammatory properties because of the terpenes, α-humulene and β-caryophyllene, present in the essential oil. The objective of this study was to evaluate the influence of seasonality on the essential oil of V. curassavica accessions. Leaves from six accessions were collected from the Germplasm Bank of the Federal University of Minas Gerais over 12 months. Correlations between the essential oil content and meteorological factors were determined. Gas chromatography analysis coupled with mass spectrometry was conducted to determine the chemical composition of the essential oil. The content and chemical composition of the oil varied throughout the year. Relative humidity was correlated with accessions ICA-VC2 (-0.64) and ICA-VC4 (0.68). β-bourbonene, β-elemene, spathulenol, germacrene, caryophyllene oxide, α-humulene, and β-caryophyllene occurred in all accessions. Accession ICA-VC3 exhibited lower variation (22.17%), higher average (0.97%) essential oil, and maintained an average abundance of α-humulene greater than 2.6%, which is the amount necessary for phytotherapeutics.

Chemical characterization of an Ipecac active germplasm bank – a Brazilian endangered medicinal species

The active germplasm bank (AGB) of Carapichea ipecacuanha (Brot.) L. Andersson at Embrapa Eastern Amazon, in the city of Belém, PA, was the first of its kind to be opened in Brazil for this endangered medicinal species and holds important accessions for agricultural and reproductive research, including the production of active principles. This study aimed to chemically characterize 42 accessions from that AGB by simultaneously quantifying cephaeline and emetine contents in roots using high-performance liquid chromatography with a diode-array detector (HPLC-DAD). Cephaeline concentrations ranged from ‘undetected’ to 1.76%, whereas emetine concentrations were found between 0.64% and 2.49%. The overall emetine/cephaeline ratio varied from 0.43 to 3.52. The differences among mean concentrations of alkaloids observed by comparing the Scott-Knott test at 5% probability suggest the chemical variation among the samples assessed. Therefore, it is concluded such chemical differences may favor the selection of genetic material for commercial purposes based on the production of emetine and/or cephaeline, likewise may contribute to breeding programs.

Genetic parameters and selection of biofortified lettuce genotypes based on selection indices

ABSTRACT Obtaining biofortified vegetables with an emphasis on lettuce is a tool to improve the nutritional status of the population. Selection indices can maximize the simultaneous selection of good agronomic traits and high carotenoid levels. The objective of this study was to estimate the genetic parameters and efficiency of different indices in selecting genotypes of biofortified lettuce with high concentrations of carotenoids and favorable agronomic traits. Statistical analyses were performed on 91 genotypes belonging to the vegetable germplasm bank of the Federal University of Uberlândia, Brazil. The variables analyzed were the chlorophyll index of the leaves, plant diameter, stem diameter, and number of leaves per plant. The values found for narrow sense heritability (h²) ranged from 89.63% (stem diameter) to 96.05% (chlorophyll), showing a high magnitude. The Smith-Hazel index, sum of ranks by the Mulamba & Mock index, direct and indirect selection, and Williams base index were used to predict the selection gains. A total of 17 individuals were selected using the selection methodologies. The Smith-Hazel, Williams, and Mulamba & Mock indices were efficient in showing good direct gains for the evaluated traits. Thirteen genotypes were selected for all indices presenting suitable agronomic traits, which show promise for advancing generations within the breeding program to obtain biofortified lettuce strains.

Opportunities and Challenges to Improve a Public Research Program in Plant Breeding and Enhance Underutilized Plant Genetic Resources in the Tropics

The American tropics are hotspots of wild and domesticated plant biodiversity, which is still underutilized by breeding programs despite being conserved at regional gene banks. The improvement of those programs depends on long-term public funds and the maintenance of specialized staff. Unfortunately, financial ups and downs complicate staff connectivity and their research impact. Between 2000 and 2010, Agrosavia (Corporación Colombiana de Investigación Agropecuaria) dramatically decreased its public financial support. In 2017, we surveyed all 52 researchers from Agrosavia involved in plant breeding and plant genetic resource programs to examine the effect of decimating funds in the last ten years. We hypothesized that the staff dedicated to plant breeding still suffer a strong fragmentation and low connectivity. As we expected, the social network among researchers is weak. The top ten central leaders are predominantly males with an M.Sc. degree but have significant experience in the area. The staff has experience in 31 tropical crops, and 17 are on the list of underutilized species. Moreover, although 26 of these crops are in the national germplasm bank, this has not been the primary source for their breeding programs. We proposed five principles to improve connectivity among teams and research impact: (1) The promotion of internal discussion about gender gaps and generation shifts to design indicators to monitor and decrease this disparity over time. (2) The construction of long-term initiatives and synergies with the Colombian government to support the local production of food security crops independent of market trends. (3) Better collaboration between the National Plant Germplasm Bank and plant breeding researchers. (4) A concerted priority list of species (especially those neglected or underutilized) and external institutions to better focus the collaborative efforts in research using public funds. (5) Better spaces for the design of projects among researchers and training programs in new technologies. These principles could also apply in other tropical countries with public plant breeding research programs facing similar challenges.

Selection Strategy For The Beverage Sensory Characterization In A Large Arabica Coffee Germplasm Bank

This study proposes a selection strategy to be applied to a large number of coffee accessions, which can be useful when exploring many genotypes in breeding programs for beverage quality. Over three consecutive years, 270 Arabica coffee accessions from the Germplasm Bank of Minas Gerais, Brazil, were sensorially characterized. At the end of this period, the 20 genotypes with the greatest potential for specialty coffee production were selected, which were subjected to a second sensory characterization. Additionally, we determined the genetic correlations between the attributes that make up the final beverage score. We did not identify an attribute that was more important than the others in the organoleptic performance of the studied accessions. Through the proposed method, we identified genetic variation in our original population and selected five accessions with beverage quality considered excellent according to the SCA classification. These accessions were planted in field conditions of highly specialized farms to study their interaction with the cultivation environment and to promote the increase in production of such coffees. Additionally, the five selected accessions are being used in crosses with elite cultivars create new segregating populations. We conclude that estimation of the heritable variation of each accession, the use over the years of common check cultivars with known performance, and extremely care of experimental precision in the entire processes warrant fair comparisons.