SSR Markers Research Articles

Discriminating the capabilities and efficiencies of RAPD, ISSR and SSR markers in the assessement of the genetic variation in cultivated Tunisian olives

Discriminating the capabilities and efficiencies of RAPD, ISSR and SSR markers in the assessement of the genetic variation in cultivated Tunisian olives

Polyembryony and morpho-genetic characterisation of zygotic seedlings through microsatellite markers in ten polyembryonic citrus rootstocks

Morpho-genetic characterisation of zygotic and nucellar seedlings of 10 citrus rootstocks was carried out to know the degree of polyembryony. 'Volkameriana' rootstock had maximum fruit and seed weight. Polyembryony, number of embryos per seed and clutch size was highest in 'Katazamir'. However, the seeds of 'Schaoub' took minimum days to germinate while 'Cleopatra' took maximum days. Significant positive correlation was observed between percent polyembryony and average number of embryos per seed, seed weight and number of seeds per fruit. Twenty SSR primers were utilised for detection of zygotic seedling from all rootstocks. None of the individual primers used in this study were able to consistently identify zygotic seedlings in all rootstocks tested. The maximum (26.7%) zygotic seedlings were identified in 'Katazamir' and minimum (5.0%) in 'X-639' rootstocks. There was not a significant correlation between seedling height and zygotic and nucellar seedlings, identified with SSR markers. Therefore, seedling height cannot be taken as a criteria to identify the nucellar and zygotic seedlings.

Monitoring and Genotyping of Wild Grapevine (Vitis vinifera L. subsp. sylvestris) in Slovenia.

Vitis vinifera L. subsp. sylvestris (sylvestris) is the only native wild grapevine in Eurasia (Europe and western Asia) and is the existing ancestor of the grapevine varieties (for wine and table grape production) belonging to the subsp. sativa. In Slovenia, the prevailing opinion has been that there are no Slovenian sylvestris habitats. This study describes sylvestris in Slovenia for the first time and aims to present an overview of the locations of the wild grapevine in the country. In this project, a sample set of 89 accessions were examined using 24 SSR and 2 SSR markers plus APT3 markers to determine flower sex. The accessions were found in forests on the left bank of the Sava River in Slovenia, on the border between alluvial soils and limestone and dolomite soils, five different sites, some of which are described for the first time. The proportion of female to male accessions differed between sites. At two sites, female plants dominated; at others, the ratio was balanced. The plants' genetic diversity and structure were compared with autochthonous and unique varieties of subsp. sativa from old vineyards in Slovenia and with rootstocks escaped from nature from abandoned vineyards. Sylvestris was clearly distinguishable from vinifera and the rootstocks. Based on genetic analyses, it was confirmed that Slovenian sylvestris is closest to the Balkan and German sylvestris groups. Meanwhile, a safety duplication of the wild grapevine accessions has been established at the University Centre of Viticulture and Enology Meranovo, Faculty of Agriculture and Life Sciences at the University of Maribor.

Self-(in)compatibility in Tunisian apple accessions [Malus domestica. Borkh]: S-genotypes identification and pollen tube growth analysis.

Self-incompatibility studies have revealed a potential use of Tunisian apple resources for crop improvement and modern breeding programs and a likely correlation between the pollen tube growth and flowering period. Apples [Malus domestica. Borkh] exhibit an S-RNase-based gametophytic self-incompatibility (GSI) system. Four primer combinations were used to S-genotype eighteen Tunisian local apple accessions and twelve introduced accessions that served as references. Within the Tunisian local accessions, S2, S3, S7, and S28 S-alleles were the most frequent and were assigned to 14 S-genotypes; among them, S7S28, S3S7, S2S5, and S2S3 were the most abundant. PCA plot showed that population structuring was affected by the S-alleles frequencies and revealed a modern origin of the Tunisian varieties rather than being ancient ones. Nonetheless, the results obtained with 17 SSR markers showed a separate grouping of local Tunisian accessions that calls into question the hypothesis discussed. Pollination experiments showed that the pollen started to germinate within 24h of pollination but 48h after pollination in the "El Fessi" accession. The first pollen tubes arrived in the styles within 36h of pollination in two early flowering accessions known as "Arbi" and "Bokri", and after 72h of pollination in late flowering "El Fessi" and 48h after pollination in remaining accessions. The first pollen tube arrests were observed in accessions "Arbi" and "Bokri" within 84h of pollination, within 108h of pollination in "El Fessi" and within 108h of pollination in remaining accessions. In the apple accession called "Boutabgaya," the pollen tubes reached the base of the style within 120h of pollination without being aborted. Nevertheless, the self-compatible nature of "Boutabgaya" needs more studies to be confirmed. However, our results revealed the malfunction of the female component of the GSI in this accession. To conclude, this work paved the path for further studies to enhance the insight (i) into the relation between the flowering period and the pollen tube growth, (ii) self-compatible nature of "Boutabgaya", and (iii) the origin of the Tunisian apple.

Identification of the CesA7 Gene Encodes Brittleness Mutation Derived from IR64 Variety and Breeding for Ruminant Feeding

Rice straw presents challenges as livestock feed due to its low digestibility and the presence of chemical residues. One potential solution is to focus on breeding brittle varieties that possess disease-resistance traits. In this study, AZ1803, a brittle mutant line isolated from the IR64 mutant pool, was chosen for gene identification and breeding. The AZ1803 mutant was crossed to the TNG67 variety to generate a mapping population and to the CS11 variety for fine mapping and breeding. The gene was mapped on chr. 10 between RM467 and RM171 SSR markers and was narrowed down to RM271 and RM5392 with 600 kb proximately interval. The AZ1803 and IR64 sequencing results revealed a substitution mutant in the Exon 9th of the OsCesA7 gene, resulting in an amino acid mutation at the end of the transmembrane domain 5th of the CESA7, responsible for cellulose synthesis for the secondary cell wall. The cellulose content of AZ1803 was reduced by 25% compared with the IR64. A new brittle and disease-resistant variety was bred by using developed markers in marker-assisted selection. In addition, bending tests and bacterial blight inoculation were applied. The bacterial lesion length of the bred variety is 64% lower than that of AZ1803. The rice straw of the new variety can be used for livestock feeding, which increases farmer income and reduces pesticide residues and air pollution from straw burning.

Genetic Enhancement of Blast and Bacterial Leaf Blight Resistance in Rice Variety CO 51 through Marker-Assisted Selection

The increased use of chemicals in rice farming poses significant issues regarding the emergence of pesticide/fungicide resistance and environmental sustainability concerns. This study was aimed at the genetic improvement of blast, bacterial leaf blight (BB) and gall midge resistance in a popular rice variety CO 51 which already harbours a blast resistance gene Pi54. Efforts were made to pyramid an additional blast resistance gene Pi9 along with two BB resistance genes (xa13 and Xa21) and two gall midge resistance genes (Gm1 and Gm4) into an elite rice variety CO 51 to enhance the resistance level to biotic stresses. The superior lines were selected using functional markers conferring resistance to blast (NBS4 and Pi54MAS linked to Pi9 and Pi54 genes, respectively) and BB [(xa13Prom (xa13) and pTA248 (Xa21)] and SSR markers linked to Gm1 (RM1328) and Gm4 (RM22550) for phenotypic screening and agronomic evaluation. The genotyping and phenotyping of F6 and BC2F6 progenies of CO 51 X 562-4, for agronomic traits and resistance to BB and blast, identified ten superior progenies in F6 and five superior progenies in BC2F6. The breeding lines harbouring both xa13+Xa21 exhibited high levels of resistance to BB (score ≤ 1 cm) and Pi9+Pi54 exhibited strong resistance to blast (score ≤ 2). Identified lines can be evaluated further for varietal improvement or utilised as genetic stocks in breeding programs.

The Genetic Diversity of Natural Ilex chinensis Sims (Aquifoliaceae) Populations as Revealed by SSR Markers

Ilex chinensis Sims. is an evergreen tree species native to China and mainly distributed in the region south of the Qinling Mountains and the Huai River. This species has important ornamental, medicinal, ecological, and economic values, and plays a positive role in improving the environment and people’s lives. To reveal the genetic diversity and genetic structure of 401 individuals from 14 populations in the major distribution area of I. chinensis, 11 pairs of SSR primers were selected for PCR amplification. The products were then subjected to capillary electrophoresis, and the genetic diversity of Ilex individuals was analyzed using relevant software. The results showed that the genetic diversity of I. chinensis was at a moderate-to-high level. A total of 54 alleles were detected at 11 SSR loci in the 14 Ilex populations, with an average of 4.831 alleles per locus. AMOVA analysis indicated that the genetic variation of I. chinensis populations mainly originated within populations. A STRUCTURE analysis divided the 401 I. chinensis individuals into four different genetic clusters. The unweighted pair group methods using arithmetic averages (UPGMA) clustering based on Nei’s genetic distance revealed that the population from Xinping of Yuxi, Yunnan Province (XP), and the population from Longan of Qianxinan, Guizhou Province (LoA) were located in the outermost layer of the phylogenetic tree, indicating the furthest genetic relationship between these two population and other populations. The remaining populations could be roughly divided into two groups. Principal coordinate analysis (PCoA) demonstrated that the 401 individuals were clearly divided into three groups, which was consistent with the results of the STRUCTURE analysis and UPGMA clustering. This study identified the hotspots of genetic diversity of I. chinensis, as well as units for the conservation of individuals. It also revealed the patterns of genetic variation and population distribution of I. chinensis in different regions, providing a molecular basis for the geographical zoning and formulation of breeding programs for I. chinensis, as well as germplasm resource management.

Molecular and Morphological Profiling of Rice Cultivars Using Hypervariable Microsatellite Markers and DUS Descriptors

Identification and protection of varieties is one of the most important tasks in the plant breeding programme. As the number of new varieties increasing year by year, there is a need to protect and maintain the purity of the varieties. DNA fingerprinting studies allows us to identify the plant varieties with high precision as it is not influenced by environment and other factors. In this context, the present study has been taken up for morphological and molecular profiling of 20 rice genotypes using 39 DUS descriptors and SSR markers. The field experiment was conducted during the year Kharif 2021 and Kharif 2022 at Agricultural Research Station, Bapatla and molecular profiling studies were conducted at RARS, Lam, Guntur. Significant variations were observed for 16 morphological traits at different growth stages, which are relatively more informative in the identification and characterization of rice genotypes. A total of 45 polymorphic SSR markers were used to screen 20 rice genotypes, which produced 336 alleles. The number of alleles produced by these markers ranged from 3 (RM1048) to 15 (RM124) with an average number of alleles of 7.46 per marker. The PIC values of these markers ranged from 0.54 (RM1048) to 0.92 (RM124) with an average PIC value of 0.75. SSR based molecular profiles were developed using 12 highly polymorphic SSR markers viz., RM495, RM6933, RM489, RM6006, RM3351, RM510, RM418, RM3215, RM105, RM6364, RM144 and RM2972 for discrimination of each genotype as well as easy identification.

Monitoring and Genetic Characterization of Historical Grapevine Varieties (V. vinifera ssp.) from Styria in Slovenia

The aim of this research work was to find historical varieties that existed in this area before phylloxera and to identify them on the basis of historical written sources and genetic analyses. At the beginning of the 19th century, around 300 grape varieties were cultivated in Styria. Between 2020 and 2022, old vineyards were monitored at 115 locations in Styria (between the Mura and Sava rivers) in Slovenia. The directly collected samples (340 grapevine accessions) were determined by molecular analysis with 24 SSR markers. A total of 66 different genotypes were detected. After comparison with the available databases, 29 historical varieties and 37 unknown historical genotypes were identified. Several parameters were calculated to evaluate the usefulness of the selected loci in this work, and a dendrogram representing the genetic similarities between the origins was created using the neighbor-joining method to investigate possible ancestry relationships in the sample set. The most common historical varieties were ‘Belina’ (‘Heunisch weiss’), ‘Vrbovec’ (‘Tantovina Eihenblaetrige’), ‘Ranfol’ (‘Ranfol beli’), and ‘Pelesovna’ (‘Vulpea’). Varieties from the current variety list were also frequently found, such as ‘Frankinja’ (‘Blaufraenkisch’) and ‘Žametovka’ (‘Kavčina črna’). In a few locations, one of the most important red varieties from the beginning of the 20th century was also found in this area (alongside ‘Frankinja’ and ‘Žametovka’), i.e., ‘Vranek’ (‘Zimmettraube balu’). At that time, this variety was planted in multi-variety vineyards and was preserved, but its importance in single-variety vineyards quickly declined due to female flower. In addition, genetic analyses have shown that 37 unknown historical genotypes have been found in this area. These genotypes need to be described ampelographically and technologically evaluated in the future. Most of the vegetative offsprings of these genotypes have already been transferred to the Meranova gene bank, where they can be accurately described ampelographically under the same pedoclimatic conditions.

Genotyping of Croatian Olive Germplasm with Consensus SSR Markers

Leaf samples of 226 cultivated olive trees were collected from traditionally managed olive orchards and genotyped with eleven consensual SSR markers. The proportion of shared allele distance was used for the estimation of distances between olive genotypes. Cluster analyses were performed using a Fitch–Margoliash least-squares algorithm. The number of different genetic subgroups of olive genotypes (K) was investigated using STRUCTURE analysis. The standardization of allele lengths was performed to enable the comparison SSR profiles of Croatian olive genotypes with olive profiles obtained with the same SSR primers in OleaDB and WOGB databases. Overall, 73 SSR profiles of known Croatian varieties and 53 profiles of unknown olive genotypes were differentiated. Synonyms were detected in 18 varieties, and we found intra-varietal differences in 15 varieties. Three genetic subgroups of olive genotypes were determined. Following allele length standardization achieved using nine referral samples, the genetic profiles of 126 cultivated olive genotypes were compared to OleaDB and WOGB databases, out of which 92 genotypes were found to be unique to Croatian olive germplasm. The results revealed the wide genetic diversity of olive germplasm beyond the known, registered varieties. The FAZ_oliveDB database containing the profiles of 126 Croatian olive genotypes was created and made available for public use.

Protein quality enhancement in temperate corn through introgression of o2o2 using marker assisted backcross and shuttle breeding

Abstract Quality protein maize (QPM) has protein quality of opaque 2 (>0.074% tryptopan) with endosperm modifiers which turn its kernels vitreous that is similar to normal maize. Use of QPM as a cereal can significantly improve daily intake of lysine and tryptophan for humans and livestock. However QPM cultivars have lower yields due to trait compensation. Therefore, a breeding programme was carried out to convert parental lines of Shalimar maize hybrid 5 (SMH-5) viz. IML-187 and BML-6 into QPM versions. Marker polymorphism was worked out in donors and recipients. IML-187 was crossed with DQL-2029-1 and BML-6 was crossed with DQL-779-2-9. The first and second backcross generations involving IML-187 as recurrent parent were marked as BC1F1 (A) and BC2F1 (A) respectively, whereas those involving BML-6 were designated as BC1F1 (B) and BC2F1 (B) respectively. The BC2F2 lines derived from two generation of backcrossing coupled with SSR marker and phenotypic background and foreground selection were advanced to BC2F3. Approximately 80–90% of RPG similarity was observed in BC2F2 lines. Eight lines namely IML-187 × DQL-2029-1- BC2F3:06, 07 and 23: BML-6 × DQl-779-2-9: 02,04,09,20 and 13 were identified from BC2F3 to have tryptophan higher than 0.075% and <25% opaqueness. These lines were used for trait fixing and crosses were made to produce QPM version of SMH-5. Six improved versions of SMH-5 were selected for higher grain yield and tryptophan content and are to be employed in further testing and varietal release in Northern Hill Zone (NHZ) in India.

Development of polymorphic simple sequences repeats markers from whole gene resequencing data comparison of 68 Oncorhynchus mykiss

Rainbow trout (Oncorhynchus mykiss) is a significant cold-water fish farmed in China. Currently, most molecular marker-assisted breeding applications in rainbow trout rely on SSR markers. Although many rainbow trout SSR markers have been developed, methods for mining many polymorphic SSR markers from the genome and identifying them efficiently and rapidly are still lacking. For this reason, this study used in silico simulation method to rapidly develop a large number of polymorphic SSR markers quickly. A total of 354,613 SSR loci with two to six nucleotide repeat motifs were mined from 32 chromosomes of the rainbow trout reference genome using GMATA. The chromosome sequences of the reference genome were then aligned to the whole genome sequencing data (10×) of 68 rainbow trout samples. In silico genotyping was performed using the HipSTR programme to compare and count the variation in the number of repeats of the motifs of the SSR loci in the samples. The loci with high deletion rates and monomorphism were discarded, while those with more than one non-reference allele were kept. The final set of polymorphic SSR loci screened was 78,828. Finally, 4,821 SSR loci were selected with more than 3 alleles and no deletion in all rainbow trout samples and were physically mapped. The average polymorphic information content of these loci was 0.692, indicating high levels of polymorphism. These SSRs were utilized to analyse the genetic diversity and population structure of the 68 rainbow trout samples. The results showed that these 68 samples were divided into two groups. These newly discovered polymorphic SSR markers will provide valuable information for evaluating the construction of rainbow trout family lines for genetic diversity and improvement.

Lectotypification and comments on the taxonomic status of Taraxacum pobedimovae Schischk. (Asteraceae: Crepidinae)

Taraxacum pobedimovae Schischk. was previously considered a synonym of T. hybernum Steven. The type of the former species consists of several plants mounted on a single specimen, which were found to belong to two different taxa: typical T. hybernum and the species previously referred to as the pinkish-achened form of T. hybernum. The lectotype of T. pobedimovae corresponding to the pinkish-achened form is designated. Taraxacum pobedimovae differs from T. hybernum by pinkish (not brown) achenes which are longer and with narrower spinules in comparison with those of the latter species. In addition, T. pobedimovae usually has larger and more numerous leaves with prominently purple veins, longer scapes, and larger capitula, as well as a larger and more branched root. The differences between these two species were confirmed by RAPD, ISSR, and SSR markers as well. The length of the achene beak, previously reported as the diagnostic character, is not useful to distinguish T. pobedimovae from T. hybernum.

Production and verification of novel Osmanthus hybrids

Osmanthus fragrans Lour. is prized for its fragrant, cool-season blooms, smooth leaves, and compact tree form; however, the species is limited in production and use to USDA Hardiness Zones 7 and higher. Increasing the total amount of genetic variability available for evaluation, selection, and breeding is foundational to the development of novel Osmanthus cultivars with increased cold-hardiness and improved ornamental characteristics such as high rooting rates, faster growth, fragrant flowers, and an evergreen or semi-evergreen habit. Hybridization among Osmanthus species should generate novel phenotypes and allow trait introgression among populations and breeding lines. The objectives of this study were to produce, verify, and evaluate Osmanthus hybrids by making controlled and open-pollinated crosses among Osmanthus species, using SSR markers to determine parentage of cross progeny, and comparing flowering, leaf shape, and form of hybrids offspring with parents. Fifty-eight of 66 progenies (88%) were assigned paternity at the 95% confidence level or above and 47 progenies (71%) were assigned paternity at the 99% confidence level. Novel Osmanthus hybrids were produced including O. armatus × O. fortunei, O. armatus × O. heterophyllus, and O. armatus × O. fragrans. Open-pollinated families increased in height an average of 204% and 159% per year in the first and second growing seasons, respectively. Male flower type was significantly associated with progeny flower type (χ2 = 17.5, p < 0.0001) while leaf margin was not associated with cross family (χ2 = 0.83, p = 0.84). Evaluation of more Osmanthus accessions and subsequent hybridizations will be necessary to introgress favorable genes and generate the variation necessary to expand the genus into new markets.

Germplasm evaluation and identification of the population source of hard clam (Mercenaria mercenaria) in China using SSR and COI markers

In aquaculture, good germplasm resources are nearly decisive for its development. The hard clam (Mercenaria mercenaria), a significant marine aquaculture bivalve in China, has flourished quickly since being introduced from North America in 1997. However, for numerous reasons, it has suffered from germplasm deterioration and uncertain origins. To address these issues, seven microsatellite DNA loci (SSRs) and mtCOI were employed to evaluate germplasm and trace the origins of various Chinese populations. The results of these two molecular genetic markers revealed weak genetic differentiation among all Chinese populations, with high genetic diversity observed across most individuals, except for a few outliers. This suggests an alarming situation regarding germplasm resources in China. Based on results of traceability analysis, the most likely areas of origin for the Chinese populations are Chesapeake Bay and the southern region of Cape Hatteras. This study provides a crucial theoretical foundation for the cultivation, conservation, and subsequent introduction of hard clam populations in China, thereby ensuring the sustainable growth of the hard clam breeding sector.

Morphological and Genetic Characterization of Maize Landraces Adapted to Marginal Hills in North-West Italy.

The growing interest in maize landraces over the past two decades has led to the need to characterize the Italian maize germplasm. In Italy, hundreds of maize landraces have been developed, but only a few of them have been genetically characterized, and even fewer are currently employed in agriculture or for breeding purposes. In the present study, 13 maize landraces of the west Emilia-Romagna region were morphologically and genetically characterized. These accessions were sampled in 1954 from three provinces, Modena, Parma, and Piacenza, during the characterization project of Italian maize landraces. The morphological characterization of these 13 accessions was performed according to the UPOV protocol CPVO/TP2/3, examining 34 phenotypic traits. A total of 820 individuals were genotyped with 10 SSR markers. The genetic characterization revealed 74 different alleles, a FST mean value of 0.13, and a Nm mean of 1.73 over all loci. Moreover, AMOVA analysis disclosed a low degree of differentiation among accessions, with only 13% of genetic variability found between populations, supporting PCoA analysis results, where the first two coordinates explained only 16% of variability. Structure analysis, supported by PCoA, showed that only four accessions were clearly distinguished for both K = 4 and 6. Italian landraces can be useful resources to be employed in maize breeding programs for the development of new varieties, adapted to different environmental conditions, in order to increase crop resilience and expand the maize cultivation area.

Ecology, genetic diversity, and population structure among commercial varieties and local landraces of Capsicum spp. grown in northeastern states of India.

Northeastern states of India are known for unique landraces of Capsicum spp. with geographical indications. However, little information is available about these valuable landraces of chillies. Surveys and collections were carried out in niche areas to find out their ecology and diversity through morphological traits and molecular analysis using microsatellite markers. Our result characterized the ecology of niche areas as cool (11.0°C-20.7°C) and humid (>60% relative humidity) climates for dalle-chilli (Capsicum annuum L.); mild-warm (12.2°C-28.6°C) and humid for king-chilli (C. chinense Jacq.); and cool to warm (11.3°C-33.1°C) and humid for bird's eye chilli (C. frutescens L.) during the crop period. The canonical correspondence analysis has shown the significant impact of temperature on the agro-morphological traits and distribution of the landraces in their niche areas. A wide variability was observed for different quantitative traits and yield attributing characters (fruit length, diameter, weight, and yield), showing high heritability (97.0%-99.0%), and genetic advance as a percentage of the mean (119.8%-434.0%). A total of 47 SSR markers used for the molecular analysis generated 230 alleles, ranging from 2 (HPMSE-7) to 10 (HPMSE-5), with an average of 4.89 alleles per locus. The average polymorphism information content was also high (0.61) and ranged from 0.20 (HPMSE-7) to 0.85 (CAMS-91). The observed average heterozygosity was lower than the expected value. Analysis of molecular variance has shown significant variation within (69%) and between (31%) of the populations of Capsicum spp. Based on Nei's genetic distance, bird's eye chilli and king-chilli were found to be closer to each other, whereas dalle-chilli, a tretraploid species, was closer to hot pepper (C. annuum). However, the flower size of dalle-chilli was large and found closer to king-chilli in color and differs from C. chinense due to the presence of calyx teeth. For quality traits, landraces king-chilli, dalle-chilli, and bird's eye chilli have shown 2.8, 2.0, and 1.4 times higher average capsaicin and 0.46, 0.25, and 0.22 times higher average oleoresin content over the hot pepper, respectively. The knowledge of ecology and diversity can be used in identifying new areas for production, selection of elite lines, conservation, and crop improvement.

Genetic Characterization of European Plum (Prunus domestica L.) Accessions from Norway Using ECPGR-Selected SSR Markers

In order to ensure the long-term sustainability of the conservation process of Norwegian plum germplasm, as well as to enhance the possibility of its utilization, a central plum heritage cultivar collection was established in 2020. In this study, 40 plum accessions maintained at the Ullensvang plum heritage cultivar collection were genetically characterized using a set of nine microsatellite markers recently approved by the ECPGR Prunus working group. The obtained molecular data were used to investigate the genetic identity, diversity, and structure among the analyzed accessions. No redundancies were detected among the plum accessions, which is in stark contrast to the previous molecular study on plum samples collected through an on-farm inventory of Southern Norway. Furthermore, the obtained data indicate that the Ullensvang collection contains a significant genetic diversity of Norwegian plum germplasm, previously held in decentralized sites. With that in mind, this collection can certainly be considered for the role of the National Clonal Plum Germplasm Repository. The nine microsatellite markers, recommended by ECPGR, revealed a genetic structure not entirely tied to previously proposed pomological groups, possibly indicating a history of hybridization among members of the various groups.

Genetic diversity analysis of banana using SSR markers

Banana, a crucial fruit crop thriving in tropical and sub-tropical regions, facing a notable challenge of elevated sterility across various cultivated banana genotypes. This sterility issue hampers the cultivation of diverse banana varieties. Therefore, a focused endeavour is crucial to thoroughly investigate the richness of diversity within both wild and cultivated banana genotypes, aiming to preserve it for future utilization. In the present study, 21 Musa genotypes were collected from different places of North-Eastern Region, and conserved in the field gene bank at Department of Horticulture, College of Agriculture, Lembucherra, Tripura during 2015-2022. Molecular characterization and DNA fingerprinting of these banana accessions were performed by employing 16 banana SSR markers. The number of alleles per locus ranged from 15 to 24 with an average 20.375. The expected heterozygosity (He) ranged from 0.564-0.967 with a mean of 0.852, and the polymorphic information content (PIC) varies from 0.638–0.945 (mean = 0.859). Genetic diversity analysis showed dissimilar groups, indicating possibility of involvement of different accuminata and balbisiana types in evaluation of banana in NE region. The outcome of the current study will be useful for des igning banana crops against different stresses

Development of microsatellite markers for the American species Vachellia aroma (Fabac

Background and aims: There are currently no microsatellite markers available for any American species of Vachellia, and particularly, for V. aroma. Then the aims of this study were to develop SSR markers specific for V. aroma, for the first time, and test its amplification in a close related species. M&M: For the development of the SSR in V. aroma, total genomic DNA was extracted and it was sequenced in a one-fourth run on a Roche 454 GS FLX+ platform. The study area included two Argentinean populations: San José and Robles, Santiago del Estero province. Results: We detected 422 sequences containing SSR loci. A set of 39 primer pairs presented amplified products in V. aroma and V. caven, but 12 revealed clear, replicable and polymorphic loci in V. aroma. Conclusions: The results of this work indicate that a new set of SSR markers was developed for V. aroma and their transferability to V. caven was assessed. The analysis of variability, showed that these 12 polymorphic markers are highly informative, and a powerful tool to investigate population genetics parameters in V. aroma and related species.