scholarly journals Preservation of the genetic diversity of a local common carp in the agricultural heritage rice–fish system

2018 ◽  
Vol 115 (3) ◽  
pp. E546-E554 ◽  
Author(s):  
Weizheng Ren ◽  
Liangliang Hu ◽  
Liang Guo ◽  
Jian Zhang ◽  
Lu Tang ◽  
...  

We examined how traditional farmers preserve the genetic diversity of a local common carp (Cyprinus carpio), which is locally referred to as “paddy field carp” (PF-carp), in a “globally important agricultural heritage system” (GIAHS), i.e., the 1,200-y-old rice–fish coculture system in Zhejiang Province, China. Our molecular and morphological analysis showed that the PF-carp has changed into a distinct local population with higher genetic diversity and diverse color types. Within this GIAHS region, PF-carps exist as a continuous metapopulation, although three genetic groups could be identified by microsatellite markers. Thousands of small farmer households interdependently obtained fry and parental carps for their own rice–fish production, resulting in a high gene flow and large numbers of parent carps distributing in a mosaic pattern in the region. Landscape genetic analysis indicated that farmers’ connectivity was one of the major factors that shaped this genetic pattern. Population viability analysis further revealed that the numbers of these interconnected small farmer households and their connection intensity affect the carps’ inherent genetic diversity. The practice of mixed culturing of carps with diverse color types helped to preserve a wide range of genetic resources in the paddy field. This widespread traditional practice increases fish yield and resource use, which, in return, encourages famers to continue their practice of selecting and conserving diverse color types of PF-carp. Our results suggested that traditional farmers secure the genetic diversity of PF-carp and its viability over generations in this region through interdependently incubating and mixed-culturing practices within the rice−fish system.

2020 ◽  
Author(s):  
Nhut Salem

Abstract An experiment was carried out in Vietnam on an integrated rice-fish polyculture system with three species: common carp (Cyprinus carpio), Nile tilapia (Oreochromis niloticus) and silver barb (Barbonymus gonionotus). Agricultural by-products were used as supplementary feed at a rate of 2-3% total body weight of fish per day. The total fish yield (823 kg ha-1) and fish production (988 kg ha-1 yr-1) at 2 fish m-2 were significantly higher (p<0.05) than at 1 fish m-2 (453 kg ha-1 and 544 kg ha-1 yr-1, respectively). The cost : benefit ratio (1.80) and the cost : profit ratio (1.75) for farm household income at 1 fish m-2 were lower than at 2 fish m-2 (2.08 and 2.02, respectively). This system should be adopted by aquaculture extension programmes to improve rural farmers' income when the market prices for common carp, tilapia and silver barb are sufficiently high to obtain a benefit at the end of the culture cycle.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Medelin Ocejo ◽  
Beatriz Oporto ◽  
José Luis Lavín ◽  
Ana Hurtado

AbstractCampylobacter, a leading cause of gastroenteritis in humans, asymptomatically colonises the intestinal tract of a wide range of animals.Although antimicrobial treatment is restricted to severe cases, the increase of antimicrobial resistance (AMR) is a concern. Considering the significant contribution of ruminants as reservoirs of resistant Campylobacter, Illumina whole-genome sequencing was used to characterise the mechanisms of AMR in Campylobacter jejuni and Campylobacter coli recovered from beef cattle, dairy cattle, and sheep in northern Spain. Genome analysis showed extensive genetic diversity that clearly separated both species. Resistance genotypes were identified by screening assembled sequences with BLASTn and ABRicate, and additional sequence alignments were performed to search for frameshift mutations and gene modifications. A high correlation was observed between phenotypic resistance to a given antimicrobial and the presence of the corresponding known resistance genes. Detailed sequence analysis allowed us to detect the recently described mosaic tet(O/M/O) gene in one C. coli, describe possible new alleles of blaOXA-61-like genes, and decipher the genetic context of aminoglycoside resistance genes, as well as the plasmid/chromosomal location of the different AMR genes and their implication for resistance spread. Updated resistance gene databases and detailed analysis of the matched open reading frames are needed to avoid errors when using WGS-based analysis pipelines for AMR detection in the absence of phenotypic data.


Agriculture ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 680
Author(s):  
Thuy T. P. Mai ◽  
Craig M. Hardner ◽  
Mobashwer M. Alam ◽  
Robert J. Henry ◽  
Bruce L. Topp

Macadamia is a recently domesticated Australian native nut crop, and a large proportion of its wild germplasm is unexploited. Aiming to explore the existing diversity, 247 wild accessions from four species and inter-specific hybrids were phenotyped. A wide range of variation was found in growth and nut traits. Broad-sense heritability of traits were moderate (0.43–0.64), which suggested that both genetic and environmental factors are equally important for the variability of the traits. Correlations among the growth traits were significantly positive (0.49–0.76). There were significant positive correlations among the nut traits except for kernel recovery. The association between kernel recovery and shell thickness was highly significant and negative. Principal component analysis of the traits separated representative species groups. Accessions from Macadamia integrifolia Maiden and Betche, M. tetraphylla L.A.S. Johnson, and admixtures were clustered into one group and those of M. ternifolia F. Muell were separated into another group. In both M. integrifolia and M. tetraphylla groups, variation within site was greater than across sites, which suggested that the conservation strategies should concentrate on increased sampling within sites to capture wide genetic diversity. This study provides a background on the utilisation of wild germplasm as a genetic resource to be used in breeding programs and the direction for gene pool conservation.


2012 ◽  
Vol 92 (6) ◽  
pp. 1121-1133 ◽  
Author(s):  
S. C. Debnath ◽  
Y. L. Siow ◽  
J. Petkau ◽  
D. An ◽  
N. V. Bykova

Debnath, S. C., Siow, Y. L., Petkau, J., An, D. and Bykova, N. V. 2012. Molecular markers and antioxidant activity in berry crops: Genetic diversity analysis. Can. J. Plant Sci. 92: 1121–1133. An improved understanding of important roles of dietary fruits in maintaining human health has led to a dramatic increase of global berry crop production. Berry fruits contain relatively high levels of vitamin C, cellulose and pectin, and produce anthocyanins, which have important therapeutic values, including antitumor, antiulcer, antioxidant and anti-inflammatory activities. There is a need to develop reliable methods to identify berry germplasm and assess genetic diversity/relatedness for dietary properties in berry genotypes for practical breeding purposes through genotype selection in a breeding program for cultivar development, and proprietary-rights protection. The introduction of molecular biology techniques, such as DNA-based markers, allows direct comparison of different genetic materials independent of environmental influences. Significant progress has been made in diversity analysis of wild cranberry, lowbush blueberry, lingonberry and cloudberry germplasm, and in strawberry and raspberry cultivars and advanced breeding lines developed in Canada. Inter simple sequence repeat (ISSR) markers detected an adequate degree of polymorphism to differentiate among berry genotypes, making this technology valuable for cultivar identification and for the more efficient choice of parents in the current berry improvement programs. Although multiple factors affect antioxidant activity, a wide range of genetic diversity has been reported in wild and cultivated berry crops. Diversity analysis based on molecular markers did not agree with those from antioxidant activity. The paper also discusses the issues that still need to be addressed to utilize the full potential of molecular techniques including expressed sequence tag-polymerase chain reaction (EST-PCR) analysis to develop improved environment-friendly berry cultivars suited to the changing needs of growers and consumers.


Istoriya ◽  
2021 ◽  
Vol 12 (7 (105)) ◽  
pp. 0
Author(s):  
Alexandre Tchoudinov

The article is devoted to the problem of cross-cultural interaction between the French and the Arabs during the Egyptian expedition of Napoleon Bonaparte 1798—1801. Using a comparative analysis of a wide range of French sources and Arab chronicles, the author comes to the conclusion that Bonaparte&apos;s attempt at an inter-civilizational dialogue with the Muslim population of Egypt ended in complete failure. Based on the stereotypical ideas about the Orient, common in the French literature of the Enlightenment, Napoleon tried to play in Egypt the same role that, according to the French philosophers, the Prophet Muhammad allegedly played in his time, namely, to take advantage of the “credulity” and “superstition” of the local population to subordinate it to his power. However, the Egyptians were very skeptical concerning Bonaparte&apos;s claims about the French army&apos;s commitment to Islam and his attempts to present himself as the Mahdi, the prophet of the last times. The daily practices of the occupiers, which openly contradicted the culture of Islam, completely alienated the Muslims from the French, which resulted not only in their mutual misunderstanding, but also in real hatred for each other.


2009 ◽  
Vol 1 (3) ◽  
pp. 624-634 ◽  
Author(s):  
S. K. Saikia ◽  
D. N. Das

Periphyton is being used traditionally as rich aquatic feed for fishes throughout the countries like Cambodia, West Africa, Srilanka, India and Bangladesh. In waterlogged rice environment, it can be judiciously utilized as feed source introducing periphytophagous fish. Studies supported rice straw as suitable substrate for periphyton growth. The study of gut content of Common carp (Cyprinus carpio L.) from a periphyton-based rice-fish culture system in Apatani Plateau of Arunachal Pradesh, India showed maximum of 60 genera of microflora and fauna with periphytic in nature. The farmers from this rice-fish culture practice are gaining an average fish production of 500kg ha-1 180 day-1 without employing any supplementary feed. Better selection and determination of appropriate stocking density of periphytophagous fish in waterlogged rice-fields might extend the rice-fish culture towards a sustainable and self-substrating periphyton based aquaculture (SSPBA) practice. Keywords: Periphyton; Sustainable agriculture; Rice-fish; Self-substrating; Common carp; Apatani plateau. © 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v1i3.2114              J. Sci. Res. 1 (3), 624-634 (2009) 


2018 ◽  
Vol 16 (4) ◽  
pp. 352-358 ◽  
Author(s):  
Junichi Kashiwagi ◽  
Koji Hamada ◽  
Yutaka Jitsuyama

AbstractDirect sowing of rice in a flooded paddy field is a beneficial cultivation practice for water use and labour efficiency, compared to the transplanted cultivation. However, a drastic reduction in seedling emergence under flooded paddy fields is a serious constraint especially when the seeds fell at deeper soil layers. Suitable rice germplasm for the direct sowing in flooded paddy fields could ensure the success of this cultivation practice. Instead of laborious field-based screening systems, a pot-based screening method was adopted for simplicity and efficient evaluation of seedling emergence of a subset of world rice germplasm (n = 75) at different sowing depths. As a result, two rice genotypes, ‘Vary Futsi’ (landrace from Madagascar, non-glutinous, subspecies Indica) and ‘Dahonggu’ (landrace from China, non-glutinous, subspecies Indica), with consistently better seedling emergence were identified from a wide range of rice germplasm. These genotypes could serve as excellent parents for the breeding program in developing new rice cultivars with the improved seedling emergence in flooded paddy fields. There were no significant differences in the seedling emergence rate in flooded paddy conditions among the groups from various agro-geographical regions.


2021 ◽  
Vol 12 ◽  
Author(s):  
◽  
Aline Fugeray-Scarbel ◽  
Catherine Bastien ◽  
Mathilde Dupont-Nivet ◽  
Stéphane Lemarié

The present study is a transversal analysis of the interest in genomic selection for plant and animal species. It focuses on the arguments that may convince breeders to switch to genomic selection. The arguments are classified into three different “bricks.” The first brick considers the addition of genotyping to improve the accuracy of the prediction of breeding values. The second consists of saving costs and/or shortening the breeding cycle by replacing all or a portion of the phenotyping effort with genotyping. The third concerns population management to improve the choice of parents to either optimize crossbreeding or maintain genetic diversity. We analyse the relevance of these different bricks for a wide range of animal and plant species and sought to explain the differences between species according to their biological specificities and the organization of breeding programs.


Author(s):  
R. H. Sammour ◽  
M. A. Karam ◽  
Y. S. Morsi ◽  
R. M. Ali

Abstract The present study aimed to assess population structure and phylogenetic relationships of nine subspecies of Brassica rapa L. represented with thirty-five accessions cover a wide range of species distribution area using isozyme analysis in order to select more diverse accessions as supplementary resources that can be utilized for improvement of B. napus. Enzyme analysis resulted in detecting 14 putative polymorphic loci with 27 alleles. Mean allele frequency 0.04 (rare alleles) was observed in Cat4A and Cat4B in sub species Oleifera accession CR 2204/79 and in subspecies trilocularis accessions CR 2215/88 and CR 2244/88. The highest genetic diversity measures were observed in subspecies dichotoma, accession CR 1585/96 (the highest average of observed (H0) and expected heterozygosity (He), and number of alleles per locus (Ae)). These observations make this accession valuable genetic resource to be included in breeding programs for the improvement of oilseed B. napus. The average fixation index (F) is significantly higher than zero for the analysis accessions indicating a significant deficiency of heteozygosity. The divergence among subspecies indicated very great genetic differentiation (FST = 0.8972) which means that about 90% of genetic diversity is distributed among subspecies, while 10% of the diversity is distributed within subspecies. This coincides with low value of gene flow (Nm = 0.0287). B. rapa ssp. oleifera (turnip rape) and B. rapa ssp. trilocularis (sarson) were grouped under one cluster which coincides with the morphological classification.


2020 ◽  
Author(s):  
Miran Kim ◽  
Dong Choi ◽  
Myung Park

Abstract Cyanobacteria are ubiquitous in marine environments and play an important role as primary producers. Some cyanobacteria, the so called cyanobionts (cyanobacterial symbionts), have a symbiotic relationship with unicellular organisms. Among these relationships, in particular, the nature (e.g., genetic diversity, host or cyanobiont specificity, and cyanobionts seasonality) of the cyanobionts-dinoflagellate host consortia remain poorly understood. In this study, 16S rDNA of cyanobionts in a total of 138 single host cells isolated over four seasons in temperate waters were sequenced using the MiSeq platform. Genetic analysis of cyanobionts from the dinoflagellate host Ornithocercus revealed that three genetic types of Synechococcales cyanobionts occurred at a wide range of water temperatures (11–24°C) and their distribution seems to be closely associated with the variation in salinity. Furthermore, this study showed the presence of some degree of host (or cyanobiont) specificity in cyanobionts (or host) among Ornithocercus species as well as among other dinophysoid species (i.e. Amphisolenia, Citharistes, and Histioneis). In addition to Synechococcales cyanobionts, this study identified some OTU sequences affiliated with the Vampirovibrionales and Chroococcidiopsidales in some Ornithocercus cells, suggesting that Ornithocercus species seem to be an additional new habitat for those bacterial groups.


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