scholarly journals The Genetic Diversity and Structure of Tomato Landraces from the Campania Region (Southern Italy) Uncovers a Distinct Population Identity

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 564
Author(s):  
Martina Caramante ◽  
Youssef Rouphael ◽  
Giandomenico Corrado

Italy is one of the main producers and processors of tomato and it is considered a secondary center of diversity. In some areas, such as the Campania region (Southern Italy), a range of traditional tomato landraces is still cultivated. The distinction of this heritage germplasm is often based only on folk taxonomy and a more comprehensive definition and understanding of its genetic identity is needed. In this work, we compared a set of 15 local landraces (representative of traditional fruit types) to 15 widely used contemporary varieties, using 14 fluorescent Simple Sequence Repeat (SSR) markers. Each of the accessions possessed a unique molecular profile and overall landraces had a genetic diversity comparable to that of the contemporary varieties. The genetic diversity, multivariate, and population structure analysis separated all the genotypes according to the pre-defined groups, indicating a very reduced admixture and the presence of a differentiated (regional) population of landraces. Our work provides solid evidence for implementing conservation actions and paves the way for the creation of a premium regional brand that goes beyond the individual landrace names of the Campania region known throughout the world.

2019 ◽  
Vol 11 (15) ◽  
pp. 4112 ◽  
Author(s):  
Rosanna Manco ◽  
Boris Basile ◽  
Claudio Capuozzo ◽  
Pasquale Scognamiglio ◽  
Marcello Forlani ◽  
...  

The European plum (Prunus domestica L.) is a worldwide distributed tree species. Italy has an ample number of traditional varieties, but many are neglected and at risk of extinction. This germplasm is still cultivated in rural areas in spite of the EU-28 crisis of the stone fruit sector. Traditional European plum varieties remain poorly characterized, strongly limiting their promotion in local markets, use for farm diversification, and exploitation for local gastronomic products. In this study, we carried out an investigation of the morphological and genetic diversity present in an ex-situ collection of 29 traditional varieties of P. domestica of the Campania region (Southern Italy). The combination of five continuous and five categorical fruit traits allowed us to phenotypically distinguish all the varieties. Similarly, the Simple Sequence Repeats (SSRs) employed (five genomic and five deriving from Expressed Sequence Tags) identified a unique molecular profile for each variety. Moreover, the data indicated that the phenotypic and molecular investigations provided different clustering, suggesting that the two analyses sampled different sources of diversity. The number and the distribution of the scored phenotypes as well as the indices of genetic diversity imply the presence of a wide-ranging variation, which may sustain the development of high-value, niche market products. Our work provided evidence that the implementation of measures for a combination of ex-situ and on-farm conservation of traditional European plum varieties should be preferred to avoid the loss of an ample diversity.


2021 ◽  
Author(s):  
Varun Hiremath ◽  
Kanwar Pal Singh ◽  
Neelu Jain ◽  
Kishan Swaroop ◽  
Pradeep Kumar Jain ◽  
...  

Abstract Genetic diversity and structure analysis using molecular markers is necessary for efficient utilization and sustainable management of gladiolus germplasm. Genetic analysis of gladiolus germplasm using SSR markers is largely missing due to scarce genomic information. In the present investigation, we report 66.66% cross transferability of Gladiolus palustris SSRs whereas 48% of Iris EST-SSRs were cross transferable across the gladiolus genotypes used in the study. A total of 17 highly polymorphic SSRs revealed a total 58 polymorphic loci ranging from two to six in each locus with an average of 3.41 alleles per marker. PIC values ranged from 0.11 to 0.71 with an average value of 0.48. Four SSRs were selectively neutral based on Ewens-Watterson test. Analysis of genetic structure of 84 gladiolus genotypes divided whole germplasm into two subpopulations. 35 genotypes were assigned to subpopulation 1 whereas 37 to subpopulation 2 and rest of the genotypes recorded as admixture. Analysis of molecular variance indicated maximum variance (53.59%) among individuals within subpopulations whereas 36.55% of variation observed among individuals within total population. Least variation (9.86%) was noticed between two subpopulations. Moderate (FST = 0.10) genetic differentiation of two subpopulations was observed. Grouping pattern of population structure was consistent with UPGMA dendrogram based on simple matching dissimilarity coefficient (ranged from 01.6 to 0.89) and PCoA. Genetic relationships assessed among the genotypes of respective clusters assist the breeders in selecting desirable parents for crossing. SSR markers from present study can be utilized for cultivar identification, conservation and sustainable utilization of gladiolus genotypes for crop improvement.


Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1282
Author(s):  
Yu Wang ◽  
Zhongyi Jiao ◽  
Jiwei Zheng ◽  
Jie Zhou ◽  
Baosong Wang ◽  
...  

Chosenia arbutifolia (Pall.) A. Skv. is a unique and endangered species belonging to the Salicaceae family. It has great potential for ornamental and industrial use. However, human interference has led to a decrease in and fragmentation of its natural populations in the past two decades. To effectively evaluate, utilize, and conserve available resources, the genetic diversity and population structure of C. arbutifolia were analyzed in this study. A total of 142 individuals from ten provenances were sampled and sequenced. Moderate diversity was detected among these, with a mean expected heterozygosity and Shannon’s Wiener index of 0.3505 and 0.5258, respectively. The inbreeding coefficient was negative, indicating a significant excess of heterozygotes. The fixation index varied from 0.0068 to 0.3063, showing a varied genetic differentiation between populations. Analysis of molecular variance demonstrated that differentiation accounted for 82.23% of the total variation among individuals, while the remaining 17.77% variation was between populations. Furthermore, the results of population structure analysis indicated that the 142 individuals originated from three primitive groups. To provide genetic information and help design conservation and management strategies, landscape genomics analysis was performed by investigating loci associated with environmental variables. Eighteen SNP markers were associated with altitude and annual average temperature, of which five were ascribed with specific functions. In conclusion, the current study furthers the understanding of C. arbutifolia genetic architecture and provides insights for germplasm protection.


2014 ◽  
Vol 12 (2) ◽  
pp. 248-254 ◽  
Author(s):  
Kai Wang ◽  
Fulin Qiu ◽  
Madonna Angelita Dela Paz ◽  
Jieyun Zhuang ◽  
Fangming Xie

The characterization of genetic diversity and structure for improved cultivated varieties/elite lines is tremendously important to assist breeders in parental selection for inbred and hybrid breeding and heterotic group construction. In this study, a total of 737 improved indica varieties/lines developed recently and/or widely used by present indica breeding programmes worldwide were genotyped with a 384-single-nucleotide polymorphism assay. Model-based population structure analysis revealed the presence of two major groups with six subgroups (SGs), wherein no clear correlation was found between the groups/SGs and breeding programmes or geographical origin of the accessions. Over half of the accessions (51.8%) appeared to have less than 0.6 memberships assigned to any one of the six model-based groups, highlighting the wide range of gene flow within improved indica varieties/lines and the genetic integration of valuable alleles shared by ancestries among improved high-yielding varieties/lines through germplasm exchanges. Distance-based clustering revealed that Latin-American cultivated indica lines have tended to form their own ecological cline, which could serve as a potential heterotic ecotype for hybrid rice breeding, although they are still closely related to Asian indica lines. African cultivated indica lines, on the other hand, have not yet formed their own ecological cline. It was also observed that the most well-known hybrid rice parents, Zhenshan97B and Minghui63, were unexpectedly clustered in the same SG with a relatively narrow genetic distance, which suggests that a significant genetic distance between parents is not a prerequisite for all elite hybrid rice lines with high heterosis.


2018 ◽  
Vol 44 (3) ◽  
pp. 407-413
Author(s):  
Wen-Xiu Tang ◽  
Wan-Juan Dai ◽  
Xing-Hua Hu ◽  
Shi-Xun Huang

The genetic diversity and structure of 4 wild population and 2 ex situ conserved population of Hopea chinensis (Merr.) Hand.-Mazz were analyzed and compared by ISSR marker method. Fifty eight bands were amplified from total genomic DNA with 10 primers in which there were 51 polymorphic, the percentage of polymorphic bands of populations ranged from 53.45 to 79.31, with an average value of 69.82, indicating the presence of high genetic diversity. However, the percentage of polymorphic band, Nei’s diversity index (He) and Shannon information index (I) of wild populations (86.21, 0.3636 and 0.5232, respectively) were higher than those of ex situ conservated populations (77.59, 0.3153 and 0.4597, respectively), which meant that ex situ conservations of Hopea chinensis had a narrow genetic diversity. Population structure analysis revealed that genetic variation of Hopea chinensis was 0.0373, so the genetic differentiation was 3.73% among populations, and 96.27% in populations. Furthermore, the strong gene flow (Nm = 12.8896) would be the main reason of limited population differentiation. It concluded that ex situ population had not yet fully covered the entire genetic diversity of Hopea chinensis.  


2021 ◽  
Vol 70 (1) ◽  
pp. 217-225
Author(s):  
Diego Torres-Dini ◽  
Leonardo Delgado-Cerrone ◽  
Lorena Luna ◽  
Fernando Resquin ◽  
Ananda Virginia Aguiar ◽  
...  

Abstract The improvement of Eucalyptus clones plays a crucial role in modern silviculture. This study used a set of 17 microsatellite loci to analyze the genetic diversity and structure of 107 elite clones (80 E. grandis and 27 E. globulus). All clones were cultivated in Uruguay and were sourced from three different providers. Using the fingerprinting technique, an exclusive molecular profile was assigned for each clone, and the genotyping reaction showed differences between the two species. The cumulative probability of identifying two random individuals that share the same genotype (PI) with all 17 loci, was estimated as low for E. grandis (1.18×10-15) and E. globulus (4.03×10-14). The combined PIsibs was (1.05×10-5) and (2.17×10-5) for E. grandis and E. globulus, respectively. A total of 180 alleles were detected for E. grandis and 100 for E. globulus. We found a high mean number of alleles per locus (10 for E. grandis and 6 for E. globulus), and the results for mean polymorphic information content (PIC ) were (0.648) and (0.548), respectively. The observed heterozygosity (Ho ) ranged from 0.216 to 0.838 (mean = 0.509) for E. grandis and 0 to 1 (mean = 0.566) for E. globulus. Two core sets of seven EST-SSR loci were identified for each species. These markers revealed unambiguous fragment amplification, providing a minimum number of SSRs for effective clonal identification. The genetic structure analysis suggests that the germplasm of the E. grandis population is structured in four clusters, while the E. globulus population consists of two clusters.


2020 ◽  
Author(s):  
HaiXia Zhan ◽  
ZhongPing Hao ◽  
Rui Tang ◽  
LiNi Zhu ◽  
JingJiang Zhou ◽  
...  

Abstract Background: Strongyllodes variegatus (Fairmaire) is a major insect pest of oilseed rape in China. Despite its economic importance, the contribution of its population genetics in the development of suitable protection control strategy for oilseed rape crops is poorlys tudied. Using the sequences mitochondrial DNA cytochrome c oxidase subunit I (COI ) and cytochrome b (Cytb ) as genetic markers, we analyzed population genetic diversity and structure of 437 individuals collected from 15 S. variegates populations located in different oilseed rape production areas in China. In addition, we estimated the demographic history using neutrality test and mismatch distribution analysis. Results: The high level of genetic diversity was detected among the COI and Cytb sequences of S. variegates . The population structure analysis strongly suggested three distinct genetic and geographical regions in China with limited gene flow. The Mantel test showed that the genetic distance was greatly influenced by the geographical distance. The demographic analyses showed that S. variegates experienced population fluctuation during the Pleistocene Epoch, which was likely to be related to the climatic changes. Conclusion: Overall, these results demonstrate that the strong population genetic structure of S. variegates in China may is attributed to the isolation through the geographical distance among populations, their weak flight capacity and subsequently adaptation to the regional ecological conditions.


Author(s):  
Nichelle M. VanTassel ◽  
Todd J. Morris ◽  
Christopher G. Wilson ◽  
David T Zanatta

We compared the genetic diversity and structure between wild and captive-propagated freshwater mussels at risk in Canada, Lampsilis fasciola (Wavy-rayed Lampmussel, WRL) and Ptychobranchus fasciolaris (Kidneyshell, KS), using microsatellite generated genotypes. No significant differences were detected between wild and propagated WRL (from 12 mothers) or KS (from 7 mothers) based on genetic diversity metrics using Kruskal-Wallis tests. Effective population size (Ne) was estimated and there was considerable overlap in the estimated Ne between wild and captive populations of both species. Pairwise FST and Dest values among wild WRL, hatchery-raised WRL juveniles, and across different time periods (2008 to 2018) were generally low (FST = 0.007-0.043, Dest = 0.005-0.282). Pairwise FST and Dest for KS were not significant and low (0.012, 0.017). When comparing captive-reared offspring with the wild population, STRUCTURE analysis revealed strong support for a single genetic population. With at least 7 females contributing to brood stock, genetic diversity was maintained. Further research is needed to assess the male contribution to each glochidial brood, and the variability of genetic diversity in individual glochidial broods.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adré Minnaar-Ontong ◽  
Abe S. Gerrano ◽  
Maryke T. Labuschagne

AbstractWith its drought tolerant and protein-rich properties, Bambara groundnut [Vigna subterranea (L.) Verdc.], an indigenous African legume crop can contribute immensely to food security. This miracle crop is used as food and for the enhancement of soil fertility in South Africa. Knowledge on the genetic diversity and structure among the Bambara groundnut landraces can pave the way for the effective use and cultivation of this crop in southern Africa, especially South Africa. The aim of this study was to assess the genetic diversity and structure among Bambara groundnut landraces collected across South Africa and compared to a limited number of accessions from southern Africa using SSR markers. Seventy-eight Bambara groundnut accessions were genotyped using 19 Bambara specific SSR markers. SSR loci explored in this study, were all polymorphic. A total of 127 alleles were detected with a mean of 6.7 alleles per locus. Allele diversity and frequency among genotypes varied from 0.21 to 0.85 with an average of 0.62 per locus. Genetic variation as described by the analysis of molecular variance indicated higher genetic diversity (92%) within landraces than between (8%) different landraces. Population structure analysis showed that three subpopulations existed, and most of the South African accessions were restricted to one subpopulation, indicating that Bambara landraces has the ability to form unique haplotypes in different environments. Information harnessed in this study is helpful for further use in breeding programs for crop improvement.


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