Population Structure and Genetic Diversity of Sweet Cassava Accessions from the Midwestern, Southeastern and Southern Regions of Brazil

Abstract The objective of this work was to screen sweet cassava accessions collected in smallholding areas in the Midwestern, Southeastern and Southern regions of Brazil, using 15 SSR molecular markers, to determine population structure and genetic diversity. Polymorphism was detected in every loci analyzed, with mean of 6.33 alleles per locus, and mean polymorphism information content (PIC) of 0.6057, pointing out that the primers were highly informative. The observed heterozygosity ranged from 0.0709 (SSRY 101) to 0.9398 (GA 12), with a mean of 0.6511, and mean genetic diversity of 0.6578, ranging from 0.3592 (GA 136) to 0.8116 (SSRY 21). The most dissimilar combinations observed were BGM526PR-BGM596MS, BGM526PR-BGM622MS and BGM526PR-BGM629MS. The traditional cassava cultivars assessed were divided into four distinct groups: two with cultivars from the South, one from the Southeast and one from the Midwestern region of Brazil. The variances among and within groups determined by the analysis of molecular variance were 44 and 56%, respectively. The PhiPT parameter (analogue to Fst) of 0.44 indicates high differentiation among groups. Broad genetic diversity was found among the traditional sweet cassava cultivars assessed, and the most divergent groups were formed by cultivars from the South and the Midwestern regions of Brazil.

Analysis of the genetic relationships and diversity among 11 populations of Xanthoceras sorbifolia using phenotypic and microsatellite marker data

Background: Assessments of genetic diversity are essential for germplasm characterization and exploitation. Molecular markers are valuable tools for exploring genetic variation and identifying germplasm. They play key roles in a Xanthoceras sorbifolia breeding program. Results: We analyzed the genetic diversity of populations of this species using 23 simple sequence repeat (SSR) loci and data on kernel oil content. The 11 populations included in the study were distributed across a large geographic range in China. The kernel oil content differed significantly among populations. The SSR marker analysis detected high genetic diversity among the populations. All SSRs were polymorphic, and we identified 80 alleles across the populations. The number of alleles at each locus ranged from two to six, averaging 3.48 per primer pair. The polymorphism information content values ranged from 0.35 to 0.70, averaging 0.51. Expected heterozygosity, observed heterozygosity, and Shannon's information index calculations detected large genetic variations among populations of different provenance. The high average number of alleles per locus and the allelic diversity observed in the set of genotypes analyzed indicated that the genetic base of this species was relatively wide. The statistically significant positive correlation between genetic and geographic distances suggested adaptations to local conditions. Conclusions: Microsatellite markers can be used to efficiently distinguish X. sorbifolia populations and assess their genetic diversity. The information we have provided will contribute to the conservation and management of this important plant genetic resource.

Morphological characterization and analysis of genetic variability among pepper accessions / Caracterização morfológica e análise da variabilidade genética entre acessos de pimenta

ABSTRACT: The peppers of the genus Capsicumhave economic potential and elevated genetic variability. The objective of the study was to characterize morpho-agronomically and estimate the genetic divergence among pepper accessions of the active germplasm bank of Capsicumof the Instituto Federal do Espírito Santo, Campus Alegre. Thirty accessions were characterized based on ten morphological descriptors being the experimental design completely randomized, with six repetitions. Genetic diversity among the accessions was estimated by the Tocher grouping method as a measurement of dissimilarity and formed eight groups. The Singh method, used to estimate the relative contribution of each character in the expression of genetic divergence, indicated that the diameter of the produce (20.19%) and the height of the plant (19.46%) were the ones to contribute most to the total divergence (39.65%) among the accessions of pepper being studied. The study evidenced the existence of high genetic variability among the accessions of C. annuumcollected in the south region of the state of Espírito Santo. No correlation was detected between the genetic distance and location of collections.

RESUMO: As pimentas do gênero Capsicumpossuem potencial econômico e elevada variabilidade genética. Objetivou-se realizar a caracterização morfoagronômica e estimar a divergência genética entre acessos de pimenta do banco ativo de germoplasma de Capsicumdo Instituto Federal do Espírito Santo, Campus de Alegre. Foram caracterizados trinta acessos com base em dez descritores morfológicos, sendo o delineamento experimental inteiramente casualizado, com seis repetições. A divergência genética entre os acessos foi estimada pelo método de agrupamento de Tocher, como medida de dissimilaridade, formando-se oito grupos. O método de Singh, utilizado para estimar a contribuição relativa de cada caráter na expressão da divergência genética, indicou que o diâmetro do fruto (20,19%) e a altura da planta (19,46%) foram os que mais contribuíram para a divergência total (39,65%) entre os acessos de pimenta avaliados. O estudo realizado evidencia a existência de alta variabilidade genética entre os acessos de C. annuumcoletados no Sul do Estado do Espírito Santo. Não foi detectada correlação entre a distância genética e os locais de coleta.

Sugars, organic acids, and phenolic compounds of ancient grape cultivars (Vitis vinifera L.) from Igdir province of Eastern Turkey

BACKGROUND: The Eurasian grapevine (Vitis vinifera L.) is the most widely cultivated and economically important horticultural crop in the world. As a one of the origin area, Anatolia played an important role in the diversification and spread of the cultivated form V. vinifera ssp. vinifera cultivars and also the wild form V. vinifera ssp. sylvestris ecotypes. Although several biodiversity studies have been conducted with local cultivars in different regions of Anatolia, no information has been reported so far on the biochemical (organic acids, sugars, phenolic acids, vitamin C) and antioxidant diversity of local historical table V. vinifera cultivars grown in Igdir province. In this work, we studied these traits in nine local table grape cultivars viz. 'Beyaz Kismis' (synonym name of Sultanina or Thompson seedless), 'Askeri', 'El Hakki', 'Kirmizi Kismis', 'Inek Emcegi', 'Hacabas', 'Kerim Gandi', 'Yazen Dayi', and 'Miskali' spread in the Igdir province of Eastern part of Turkey. RESULTS: Variability of all studied parameters is strongly influenced by cultivars (P < 0.01). Among the cultivars investigated, 'Miskali' showed the highest citric acid content (0.959 g/l) while 'Kirmizi Kismis' produced predominant contents in tartaric acid (12.71 g/l). The highest glucose (16.47 g/100 g) and fructose (15.55 g/100 g) contents were provided with 'Beyaz Kismis'. 'Kirmizi Kismis' cultivar had also the highest quercetin (0.55 mg/l), o-coumaric acid (1.90 mg/l), and caffeic acid (2.73 mg/l) content. The highest ferulic acid (0.94 mg/l), and syringic acid (2.00 mg/l) contents were observed with 'Beyaz Kismis' cultivar. The highest antioxidant capacity was obtained as 9.09 μmol TE g-1 from 'Inek Emcegi' in TEAC (Trolox equivalent Antioxidant Capacity) assay. 'Hacabas' cultivar had the highest vitamin C content of 35.74 mg/100 g. CONCLUSIONS: Present results illustrated that the historical table grape cultivars grown in Igdir province of Eastern part of Turkey contained diverse and valuable sugars, organic acids, phenolic acids, Vitamin C values and demonstrated important antioxidant capacity for human health benefits. Further preservation and use of this gene pool will be helpful to avoid genetic erosion and to promote continued agriculture in the region.