scholarly journals Genetic diversity of Carica papaya as revealed by AFLP markers

Genome ◽  
2002 ◽  
Vol 45 (3) ◽  
pp. 503-512 ◽  
Author(s):  
M S Kim ◽  
P H Moore ◽  
F Zee ◽  
M MM Fitch ◽  
D L Steiger ◽  
...  

Genetic relationships among Carica papaya cultivars, breeding lines, unimproved germplasm, and related species were established using amplified fragment length polymorphism (AFLP) markers. Seventy-one papaya accessions and related species were analyzed with nine EcoRI–MseI primer combinations. A total of 186 informative AFLP markers was generated and analyzed. Cluster analysis suggested limited genetic variation in papaya, with an average genetic similarity among 63 papaya accessions of 0.880. Genetic diversity among cultivars derived from the same or similar gene pools was smaller, such as Hawaiian Solo hermaphrodite cultivars and Australian dioecious cultivars with genetic similarity at 0.921 and 0.912, respectively. The results indicated that self-pollinated hermaphrodite cultivars were as variable as open-pollinated dioecious cultivars. Genetic diversity between C. papaya and six other Carica species was also evaluated. Carica papaya shared the least genetic similarity with these species, with an average genetic similarity of 0.432; the average genetic similarity among the six other species was 0.729. The results from AFLP markers provided detailed estimates of the genetic variation within and among papaya cultivars, and supported the notion that C. papaya diverged from the rest of Carica species early in the evolution of this genus.Key words: DNA fingerprinting, germplasm, genetic relationship, molecular phylogeny, polymorphism.

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 998A-998 ◽  
Author(s):  
Jinggui Fang ◽  
Panchanoor S. Devanand ◽  
Chih Cheng T. Chao ◽  
Philip A. Roberts ◽  
Jeff D. Ehlers

Cowpea (2n=2x=22) is a high protein, short-cycle, and essential legume food crop of the tropics, especially in the low input agricultural areas of sub-Saharan Africa, Asia, and South America. Lack of genetic diversity within breeding programs can limit long-term gains from selection. The cowpea gene pool is thought to be narrow and the genetic diversity within breeding programs could be even less diverse. Genetic relationships among 87 cowpea accessions, including 60 advanced breeding lines from six breeding programs in Africa and the United States, and 27 accessions from Africa, Asia, and South America were examined using amplified fragment length polymorphism (AFLP) markers with six near-infrared fluorescence labeled EcoR I + 3/Mse I + 3 primer sets. A total of 382 bands were scored among the accessions with 207 polymorphic bands (54.2%). Overall, the 87 cowpea accessions have narrow genetic basis and they shared minimum 86% genetic similarities. The data also show that the advanced breeding lines of different programs have higher genetic affinities with lines from the same program but not with lines from other programs. The results suggest that there is a need to incorporate additional germplasm of different genetic background into these breeding lines and to ensure the long-term genetic gains of the programs.


2011 ◽  
Vol 76 (4) ◽  
pp. 321-331 ◽  
Author(s):  
Magdalena Szczepaniak ◽  
Elżbieta Cieślak

Fragmented distribution, the breeding system and effects of genetic drift in small-size populations occurring at edge of the species range play an important role in shaping genetic diversity of such a species. <em>Melica transsilvanica</em> is a plant rare in the flora of Poland, where it reaches the northern limit of its continuous range. Amplified Fragment Length Polymorphism (AFLP) DNA profiling method was applied to measure genetic diversity among and within populations of <em>M. transsilvanica</em>. Additionally, genetic relationships between M. transsilvanica and Melica ciliata, two closely related species, were explored. A total of 68 plants from 7 populations of <em>M. transsilvanica</em> and 24 plants from 2 populations of <em>M. ciliata</em>, collected in Poland and outside it, were analyzed. Using 294 AFLP fragments from 3 primer combinations, accessions were grouped into two major clusters associating with <em>M. ciliata</em> and <em>M. transsilvanica</em>, respectively. Further, two subclusters, corresponding to the samples collected from the Pieniny Mts and from the Kraków - Częstochowa Upland were clearly distinguished within the <em>M. transsilvanica</em> group. The hierarchical AMOVA exhibited significant genetic distinction between these geographic regions (60.89%, p &lt; 0.001). The obtained results showed that the most genetic diversity resided between the populations of <em>M. transsilvanica</em> (86.03%) while considerably lower genetic variation was found within the populations (13.97%), which is consistent with the results reported for self-plants. The low level of AFLP genetic variation of <em>M. transsilvanica</em> can be caused by the geographic isolation of populations, which preserves the dominant self-mating breeding system of the species. Individual populations of <em>M. transsilvanica</em> are characterized by isolated gene pools differing by a small number of loci.


Rice ◽  
2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Ai-ling Hour ◽  
Wei-hsun Hsieh ◽  
Su-huang Chang ◽  
Yong-pei Wu ◽  
Han-shiuan Chin ◽  
...  

Abstract Background Rice, the most important crop in Asia, has been cultivated in Taiwan for more than 5000 years. The landraces preserved by indigenous peoples and brought by immigrants from China hundreds of years ago exhibit large variation in morphology, implying that they comprise rich genetic resources. Breeding goals according to the preferences of farmers, consumers and government policies also alter gene pools and genetic diversity of improved varieties. To unveil how genetic diversity is affected by natural, farmers’, and breeders’ selections is crucial for germplasm conservation and crop improvement. Results A diversity panel of 148 rice accessions, including 47 cultivars and 59 landraces from Taiwan and 42 accessions from other countries, were genotyped by using 75 molecular markers that revealed an average of 12.7 alleles per locus with mean polymorphism information content of 0.72. These accessions could be grouped into five subpopulations corresponding to wild rice, japonica landraces, indica landraces, indica cultivars, and japonica cultivars. The genetic diversity within subpopulations was: wild rices > landraces > cultivars; and indica rice > japonica rice. Despite having less variation among cultivars, japonica landraces had greater genetic variation than indica landraces because the majority of Taiwanese japonica landraces preserved by indigenous peoples were classified as tropical japonica. Two major clusters of indica landraces were formed by phylogenetic analysis, in accordance with immigration from two origins. Genetic erosion had occurred in later japonica varieties due to a narrow selection of germplasm being incorporated into breeding programs for premium grain quality. Genetic differentiation between early and late cultivars was significant in japonica (FST = 0.3751) but not in indica (FST = 0.0045), indicating effects of different breeding goals on modern germplasm. Indigenous landraces with unique intermediate and admixed genetic backgrounds were untapped, representing valuable resources for rice breeding. Conclusions The genetic diversity of improved rice varieties has been substantially shaped by breeding goals, leading to differentiation between indica and japonica cultivars. Taiwanese landraces with different origins possess various and unique genetic backgrounds. Taiwanese rice germplasm provides diverse genetic variation for association mapping to unveil useful genes and is a precious genetic reservoir for rice improvement.


Author(s):  
Thien Minh Nguyen ◽  
Tien Thi My Pham

The agronomic values of this population have been evaluated in the field experiments based on their phenotypic performance of agronomic traits, but the genetic variability of this population needs to be evaluated via techniques based on genetic material - DNA. In this study, the genetic variability in the investigated population of 71 hybrids and their parents was evaluated by RAPD technique, using eight selected arbitrarily primers; Genetic parameters and dendrogram expressing the genetic relationships among the investigated population were analyzed by GenALEx 6.1, Popgene 1.31 and NTSYSpc 2.1 softwares. Eight primers were used to generate the amplify products on each individual in the investigated population. From 74 genotypes, a total of 109 fragments were generated, among which, there were 89 polymorphic bands representing 81.65% with an average of 11 polymorphic bands/primer. Genetic similarity coefficient among the investigated population, based on DICE coefficient, ranged from 0.560 (LH05/0822 and PB260) to 0.991 (LH05/0781 and LH05/0841) with an average of 0,796, meaning that the genetic distance among ranged from 0.009 to 0.440 with an average of 0.231. The Shannon index and mean heterozygosity values were 0.328 and 0,176, respectively. This indicated that the progenies of the two investigated crosses possessed a relatively high range of genetic variability. The analysis of molecular variance (AMOVA) showed that genetic variation within population represented 62%, while genetic variation among two different crosses contributes 38% to the total genetic variability. Dendrogram based on DICE’s genetic similarity using UPGMA method showed that the hybrids divide into two major genetic groups (0.75), but the crosses were scattered independently of the hybrid.


2020 ◽  
Vol 24 (5) ◽  
pp. 474-480
Author(s):  
I. I. Suprun ◽  
S. A. Plugatar ◽  
I. V. Stepanov ◽  
T. S. Naumenko

In connection with the development of breeding and the creation of new plant varieties, the problem of their genotyping and identification is becoming increasingly important, therefore the use of molecular methods to identify genetic originality and assess plant genetic diversity appears to be relevant. As part of the work performed, informative ISSR and IRAP DNA markers promising for the study of genetic diversity of the Rosa L. genus were sought and applied to analysis of genetic relationships among 26 accessions of the genus Rosa L. from the gene pool collection of Nikita Botanical Gardens. They included 18 cultivated varieties and 8 accessions of wild species. The species sample included representatives of two subgenera, Rosa and Platyrhodon. The subgenus Platyrhodon was represented by one accession of the species R. roxburghii Tratt. Cultivated roses were represented by varieties of garden groups hybrid tea, floribunda, and grandiflora. The tested markers included 32 ISSRs and 13 IRAPs. Five ISSR markers (UBC 824, ASSR29, 3A21, UBC 864, and UBC 843) and three IRAPs (TDK 2R, Сass1, and Сass2) were chosen as the most promising. They were used for genotyping the studied sample of genotypes. In general, they appeared to be suitable for further use in studying the genetic diversity of the genus Rosa L. The numbers of polymorphic fragments ranged from 12 to 31, averaging 19.25 fragments per marker. For markers UBC 864 and UBC 843, unique fingerprints were identified in each accession studied. The genetic relationships of the studied species and varieties of roses analyzed by the UPGMA, PCoA, and Bayesian methods performed on the basis of IRAP and ISSR genotyping are consistent with their taxonomic positions. The genotype of the species R. roxburghii of the subgenus Platyrhodon was determined genetically as the most distant. According to clustering methods, the representative of the species R. bengalensis did not stand out from the group of cultivated varieties. When assessing the level of genetic similarity among the cultivated varieties of garden roses, the most genetically isolated varieties were ‘Flamingo’, ‘Queen Elizabeth’, and ‘Kordes Sondermeldung’; for most of the other varieties, groups of the greatest genetic similarity were identified. This assessment reflects general trends in phylogenetic relationships, both among the studied species of the genus and among cultivated varieties.


2004 ◽  
Vol 129 (5) ◽  
pp. 690-697 ◽  
Author(s):  
Pachanoor S. Devanand ◽  
Jianjun Chen ◽  
Richard J. Henny ◽  
Chih-Cheng T. Chao

Philodendrons (Philodendron Schott) are among the most popular tropical ornamental foliage plants used for interior decoration. However, limited information is available on the genetic relationships among popular Philodendron species and cultivars. This study analyzed genetic similarity of 43 cultivars across 15 species using amplified fragment length polymorphism (AFLP) markers with near infrared fluorescence labeled primers. Forty-eight EcoR I + 2/Mse I + 3 primer set combinations were screened, from which six primer sets were selected and used in this investigation. Each selected primer set generated 96 to 130 scorable fragments. A total of 664 AFLP fragments were detected, of which 424 (64%) were polymorphic. All cultivars were clearly differentiated by their AFLP fingerprints, and the relationships were analyzed using the unweighted pair-group method of arithmetic average cluster analysis (UPGMA) and principal coordinated analysis (PCA). The 43 cultivars were divided into five clusters. Cluster I comprises eight cultivars with arborescent growth style. Cluster II has only one cultivar, `Goeldii'. There are 16 cultivars in cluster III, and most of them are self-heading interspecific hybrids originated from R.H. McColley's breeding program in Apopka, Fla. Cluster IV contains 13 cultivars that exhibit semi-vining growth style. Cluster V has five cultivars that are true vining in morphology, and they have lowest genetic similarity with philodendrons in other clusters. Cultivated philodendrons are generally genetically diverse except the self-heading hybrids in cluster III that were mainly developed using self-heading and semi-vining species as parents. Seven hybrid cultivars have Jaccard's similarity coefficients of 0.88 or higher, suggesting that future hybrid development needs to select parents with diverse genetic backgrounds.


2004 ◽  
Vol 123 (5) ◽  
pp. 460-466 ◽  
Author(s):  
J. Muminovic ◽  
A. E. Melchinger ◽  
T. Lubberstedt

2021 ◽  
Vol 34 ◽  
pp. 3
Author(s):  
Yılmaz Çiftci ◽  
Oğuzhan Eroğlu ◽  
Şirin Firidin ◽  
Hacı Savaş ◽  
Yusuf Bektaş

In this study, the genetic relationships of 804 tarek (Alburnus tarichi) samples from a total of 18 populations, including the potamodromus and resident individuals from Lake Van basin in eastern Turkey, were studied by using nine microsatellite loci. A total of 93 alleles was detected, and the average number of alleles per locus was 10.3 ± 3.39. The mean estimated observed and expected heterozygosity were 0.340 ± 0.016 and 0.362 ± 0.015, respectively, which indicated a low level of polymorphism. After Bonferroni correction (P < 0.0027), the multi-locus test applied to each population revealed that 12 out of 18 populations were in Hardy-Weinberg equilibrium (HWE) (P = 0.0120–0.9981). Analysis of molecular variance (AMOVA) showed more than 76% genetic variability within individuals and 19% among populations, which was significantly higher than zero (FST = 0.19), and furthermore, a low level of genetic variation was observed among individuals within populations (4.84%: FIS = 0.06). Bayesian clustering analysis indicated that the total genetic variation grouped into 3 clusters. Additionally, the significance test results revealed that 11 of the 18 populations are threatened with extinction due to recent bottleneck events.We conclude that the tarek populations from the Lake Van basin can be classified into distinct genetic groups, based on microsatellite information. In addition, our results provide essential information for the development of a management plan that conserves the tarek's genetic diversity and achieves a sustainable fishery.


Plant Disease ◽  
2021 ◽  
Author(s):  
Anfei Fang ◽  
Zhuangyuan Fu ◽  
Zexiong Wang ◽  
Yuhang Fu ◽  
Yubao Qin ◽  
...  

Rice false smut caused by Ustilaginoidea virens is currently one of the most devastating fungal diseases of rice panicles worldwide. In this study, two novel molecular markers derived from SNP-rich genomic DNA fragments and a previously reported molecular marker were used for analyzing the genetic diversity and population structure of 167 U. virens isolates collected from nine areas in Sichuan-Chongqing region, China. A total of 62 haplotypes were identified, and a few haplotypes with high frequency were found and distributed in two to three areas, suggesting gene flow among different geographical populations. All isolates were divided into six genetic groups. The groups Ⅰ and Ⅵ were the largest including 61 and 48 isolates, respectively. The pairwise FST values showed significant genetic differentiation among all compared geographical populations. AMOVA showed that intergroup genetic variation accounted for 40.17% of the total genetic variation, while 59.83% of genetic variation came from intragroup. The UPGMA dendrogram and population structure revealed that the genetic composition of isolates collected from ST (Santai), NC (Nanchong), YC (Yongchuan), and WS (Wansheng) dominated by the same genetic subgroup was different from those collected from other areas. In addition, genetic recombination was found in a few isolates. These findings will help to improve the strategies for rice false smut management and resistance breeding, such as evaluating breeding lines with different isolates or haplotypes at different elevations and landforms.


2003 ◽  
Vol 1 (1) ◽  
pp. 11-18 ◽  
Author(s):  
M. O. Humphreys

AbstractUK agriculture is undergoing significant change with reduced subsidies for food production, increasing consumer demands for food safety and traceability, and environmental concerns including climate and demographic change. The International Treaty on Plant Genetic Resources for Food and Agriculture adopted by the United Nations Food and Agriculture Organisation supports the use of genetic resources for research and breeding. Mining genetic resources for useful genetic variation is perceived as a major benefit of genebanks. However, utilization by breeders may be constrained by poor characterization of genetic resources, a widening gap between improved and unimproved material, and the disruption of well- adapted genotypes during introgression. Breeders working with grasses and forage legumes for sustainable agriculture are fortunate in the wealth of genetic variation available both within the primary species of interest and among related species. New DNA technologies allow more targeted approaches to the use of these genetic resources. Possibilities for gene transfer between related species using conventional techniques expand the available gene pools while potential use of genetic transformation extend these even further.


Sign in / Sign up

Export Citation Format

Share Document