Simple Sequence Repeat Markers Research Articles

Evaluation of Stagonospora Nodorum Blotch Severity and Parastagonospora nodorum Population Structure and Genetic Diversity Across Multiple Locations and Wheat Varieties in Virginia.

Parastagonospora nodorum is a necrotrophic pathogen that causes Stagonospora nodorum blotch (SNB) in wheat. Wheat varieties grown in Virginia vary in susceptibility to SNB, and the severity of SNB varies across locations and years. However, the impacts of wheat genetic backgrounds and environments on SNB severity and the structure of P. nodorum populations in the region have not been well studied. Thus, a population genetic study was conducted utilizing P. nodorum isolates collected from different wheat varieties and locations in Virginia. A total of 320 isolates were collected at seven locations over 2 years from five wheat varieties. Isolates were genotyped using multilocus simple sequence repeat markers, and necrotrophic effector (NE) and mating type genes were amplified using gene-specific primers. Wheat varieties varied in susceptibility to SNB, but site-specific environmental conditions were the primary drivers of disease severity. Fungal populations were genetically diverse, but no genetic subdivision was observed among locations or varieties. The ratio of the two mating type idiomorphs was not significantly different from 1:1, consistent with the P. nodorum population undergoing sexual reproduction. Three major NE genes were detected within the P. nodorum population, but not with equal frequency. However, NE gene profiles were similar for groups of isolates originating from different varieties, suggesting that wheat genetic backgrounds do not differentially select for NEs. There was no evidence of population structure among P. nodorum populations in Virginia and, thus, no support for wheat genetic backgrounds shaping these populations. Finally, although varieties only exhibited moderate resistance to SNB, current levels of resistance are likely to be durable over time and remain a useful tool for integrated management of SNB in the region. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Phenotypic and genetic diversity of doubled haploid bread wheat population and molecular validation for spike characteristics, end-use quality, and biofortification capacity.

Increasing grain quality and nutritional value along with yield in bread wheat is one of the leading breeding goals. Selection of genotypes with desired traits using traditional breeding selection methods is very time-consuming and often not possible due to the interaction of environmental factors. By identifying DNA markers that can be used to identify genotypes with desired alleles, high-quality and bio-fortified bread wheat production can be achieved in a short time and cost-effectively. In the present study, 134 doubled haploid (DH) wheat lines and their four parents were phenotypically evaluated for yield components (spike characteristics), quality parameters, and grain Fe and Zn concentrations in two successive growing seasons. At the same time, ten genic simple sequence repeats (SSR) markers linked to genes related to the traits examined were validated and subsequently used for molecular characterization of trait-specific candidate genotypes. Significant genotypic variations were determined for all studied traits and many genotypes with desired phenotypic values were detected. The evaluation performed with 10 SSR markers revealed significant polymorphism between genotypes. The polymorphic information content (PIC) values of 10 markers ranged from 0.00 to 0.87. Six out of 10 SSRs could be more effective in representing the genotypic differentiation of the DH population as they demonstrated the highest genetic diversity. Both Unweighted Pair Group Method with Arithmetic Mean (UPGMA) clustering and STRUCTURE analyses divided 138 wheat genotypes into five (K = 5) main groups. These analyzes were indicative of genetic variation due to hybridization and segregation in the DH population and the differentiation of the genotypes from their parents. Single marker regression analysis showed that both Xbarc61 and Xbarc146 had significant relationships with grain Fe and Zn concentrations, while Xbarc61 related to spike characteristics and Xbarc146 related to quality traits, separately. Other than these, Xgwm282 was associated with spike harvest index, SDS sedimentation value and Fe grain concentration, while Gwm445 was associated with spikelet number, grain number per spike and grain Fe concentration. These markers were validated for the studied DH population during the present study and they could be effectively used for marker-assisted selection to improve grain yield, quality, and bio-fortification capacity of bread wheat.

Creation and characteristics of tetraploid and mixoploid centipedegrass

AbstractPloidy manipulation has been used in many crop improvement programs to develop plant species with wider adaptability and desirable traits. The objectives of this study were to create stable tetraploid centipedegrass (Eremochloa ophiuroides [Munro] Hack.) lines and evaluate them for beneficial traits. To generate polyploid lines, “TifBlair” (2n = 2x = 18) seeds were exposed to gamma radiation and callus was generated using tissue culture, exposed to glyphosate and regenerated into plantlets. After 5 years of continuous propagation, two lines, Hongliang Wang (HW)16 and HW123, were found to be tetraploid, and one line, HW61, was found to be a mixoploid using flow cytometry and chromosome counts. Nuclear DNA contents for diploid and tetraploid lines ranged from 1.97 to 2.10 and 4.14 to 4.30 pg 2C−1, respectively. Ten centipedegrass lines were genotyped using seven simple sequence repeat markers and clustered by origin (derived from TifBlair or the University of Georgia breeding program). Six lines were evaluated for morphological and physiological traits under greenhouse conditions. Trait evaluation showed that tetraploid lines had larger stomata and leaf width and reduced stomatal density. For all other traits evaluated under greenhouse conditions, although significant differences were observed between lines, no consistent differences separated diploid and tetraploid lines. Between the tetraploid lines, HW16 had higher evapotranspiration, percentage green cover, and relative water content than HW123, whereas HW123 had a higher average clipping yield and root width than HW16. In conclusion, irradiation and tissue culture are valuable techniques for the generation of stable polyploid lines, and an increased ploidy level led to larger vegetative structures in centipedegrass.

Phenotypic and molecular evaluation of Arachis hypogaea L. against foliar fungal diseases

Groundnut improvement tasks are generally engrossed to breed foliar fungal disease-resistant varieties. Early and late leaf spot diseases of groundnuts cause significant loss in yield and quality of groundnut seeds. Simple Sequence Repeat (SSR) markers represent high polymorphic amplification, while Inter-simple sequence (ISSR) is being used widely for diversity assessment due to their large size and reproducible results. The current investigation was carried out with 96 groundnut genotypes for morpho-physiological characterization, disease indexing for early and late leaf spot diseases under field conditions and by employing SSR and ISSR markers for diversity assessment. In correlation analysis, kernel weight was found positively and highly significantly correlated with harvest index and pod weight (r ​= ​0.906) at 1% level of significance. While, pod weight is negatively correlated with early leaf spot at 30 days (r ​= ​-0.401) and at 45 days (r ​= ​-0.410), late leaf spot at 70 days (r ​= ​-0.342) and at 85 days (r ​= ​-0.309) at 1% significant level. With the use of SSR markers, a total 16 alleles were recognized with a mean of 3.20 alleles per locus. The gene multiplicity differed from 0.6074 to 0.6491 for the markers Seq5D05 and PM137 respectively with an average of 0.6289. A total 18 alleles were produced by ISSR markers with an average of 3.6 alleles per locus. In our study, the gene diversity varied from 0.5877 to 0.6625 for the markers ISSR3 and ISSR21 respectively with an average of 0.6164. Diverse group of groundnut germplasm has been identified on the basis of SSR and ISSR markers along with morphological characterization.

Construction of Longan (Dimocarpus longan Lour.) Simple Sequence Repeat Fingerprints and Application in Distinctness, Uniformity and Stability Testing

Simple sequence repeat (SSR) markers are highly polymorphism, good reproducibility, abundant number and co-dominant inheritance, and were considered to be one of the preferred molecular markers for DNA fingerprints in distinctness, uniformity and stability (DUS) testing. In this study, 10 representative Dimocarpus longan Lour (longan) varieties with significant differences were selected from 63 longan varieties according to the morphological characteristics. Based on PCR amplifications of the 10 selected varieties, 24 SSR primers pairs were screened from total 300 SSR primers pairs, to establish SSR fingerprints for all 63 longan varieties. The results showed that a total of 127 alleles were detected in 63 longan varieties, with an average of 5.29 alleles for each pair of primers. The Shannon’s index of the 24 pairs of SSR markers ranged from 0.64 to 1.58, with an average of 1.20. The polymorphism information content of each locus ranged from 0.32 to 0.72, with an average of 0.58. Clustering analysis indicated that most of the varieties with close genetic relationships tended to fall in the same cluster, and only a few in different clusters or sub-clusters. The 63 longan varieties were completely identified by the optimal combination of 6 pairs of SSR primers (LY161, LY252, LY137, LY130, LY25 and LY34). Overall, DNA fingerprints of the 63 longan varieties were constructed based on these 24 pairs of SSR primers. This study may provide a technical support for variety identification and similar variety screening in DUS detection in longan.

Evaluation of temporary immersion bioreactors for in vitro micropropagation of banana (Musa spp.) and genetic fidelity assessment using flow cytometry and simple-sequence repeat markers

Evaluation of temporary immersion bioreactors for in vitro micropropagation of banana (Musa spp.) and genetic fidelity assessment using flow cytometry and simple-sequence repeat markers

Origin and genetic variability of populations of the invasive plant Rumex alpinus L. in the Giant (Krkonoše) Mountains.

Monk's rhubarb, Rumex alpinus L. (R. alpinus), is a perennial plant native to the mountains of Central and Southern Europe. Currently, the distribution of R. alpinus has been partly affected by its utilization as a vegetable and a medicinal herb. In the mountains of the Czech Republic, it is considered an invasive plant, probably introduced into the Krkonoše Mountains by colonists from the Alps. This study's main aim was to verify whether R. alpinus was introduced into the Krkonoše Mountains by alpine colonists or whether it was anthropogenically introduced from the Carpathians. Furthermore, the genetic structure of native and introduced populations of R. alpinus was determined. For the evaluation of genetic structure, 417 samples of R. alpinus were collected from the Alps, Carpathians, Balkan, Pyrenees, and Czech Mountains. In total, 12 simple sequence repeat (SSR) markers were applied. The results of AMOVA showed a high 60% variation within populations, 27% variation among groups, and 13% among the population within groups. The overall unbiased gene diversity was high (^ĥ = 0.55). The higher level of genetic differentiation among populations (FST = 0.35; p < .01) indicated restricted gene flow between populations. Compared to native populations, limited genetic variability was observed in the nonnative populations. It was concluded that local adaptation, low gene exchange, and genetic drift affected the genetic diversity of nonnative R. alpinus. The results support a genetic link between Alpine and Czech genotypes of R. alpinus, while the Carpathians genotypes corresponded to the Balkan genotype.

Morphophysiological Diversity and Haplotype Analysis of Saltol QTL Region in Diverse Rice Landraces for Salinity Tolerance

Rice is sensitive to salinity stress at both the seedling and reproductive stages. The present study used 145 rice genotypes comprising of 100 landraces and 45 advanced breeding lines collected from different regions of India. These genotypes were evaluated in hydroponics under control [electrical conductivity (ECe) ∼1.2 dS/m] and saline (ECe ∼10.0 dS/m) environments along with susceptible (IR29) and tolerant (FL478) checks. The stress susceptibility index for eight morphophysiological traits was estimated. Analysis of variance showed significant differences among the genotypes for all the parameters studied in control, stress and relative stress conditions. We identified 3 landraces (Kuttimanja, Tulasimog and IET-13713I) as tolerant and 14 lines as moderately tolerant to salt stress. Strong correlations in the morphological (root and shoot lengths) and physiological traits (shoot Na+, Ca2+ and Mg2+ contents, and Na+/K+ ratio) were observed under all the conditions. The hierarchical cluster analysis grouped the genotypes into five clusters, among which cluster II comprised salt-tolerant lines. Haplotyping of Saltol region using 11 simple sequence repeat markers on 17 saline tolerant and moderately tolerant lines was conducted. Markers AP3206F, RM10793 and RM3412b, located close to SKC1 gene (11.23‒12.55 Mb), displayed diverse allelic variations and they were not related to the FL478 type. In this region, tolerant lines like Kuttimanja, IET-13713I and Tulasimog have new alleles. As a result, these lines may be suitable candidates for novel genomic regions governing rice salinity tolerance. Salt-tolerance ability of Kuttimanja, Tulasimog and IET-13713I was validated in two years in three salinity stress environments. These promising lines can be used in breeding programs to broaden the genetic base of salinity tolerance in rice, and it may help to dissect key genomic regions responsible for salinity tolerance.

Genetic Diversity and Population Structure in Türkiye Bread Wheat Genotypes Revealed by Simple Sequence Repeats (SSR) Markers.

Wheat genotypes should be improved through available germplasm genetic diversity to ensure food security. This study investigated the molecular diversity and population structure of a set of Türkiye bread wheat genotypes using 120 microsatellite markers. Based on the results, 651 polymorphic alleles were evaluated to determine genetic diversity and population structure. The number of alleles ranged from 2 to 19, with an average of 5.44 alleles per locus. Polymorphic information content (PIC) ranged from 0.031 to 0.915 with a mean of 0.43. In addition, the gene diversity index ranged from 0.03 to 0.92 with an average of 0.46. The expected heterozygosity ranged from 0.00 to 0.359 with a mean of 0.124. The unbiased expected heterozygosity ranged from 0.00 to 0.319 with an average of 0.112. The mean values of the number of effective alleles (Ne), genetic diversity of Nei (H) and Shannon's information index (I) were estimated at 1.190, 1.049 and 0.168, respectively. The highest genetic diversity (GD) was estimated between genotypes G1 and G27. In the UPGMA dendrogram, the 63 genotypes were grouped into three clusters. The three main coordinates were able to explain 12.64, 6.38 and 4.90% of genetic diversity, respectively. AMOVA revealed diversity within populations at 78% and between populations at 22%. The current populations were found to be highly structured. Model-based cluster analyses classified the 63 genotypes studied into three subpopulations. The values of F-statistic (Fst) for the identified subpopulations were 0.253, 0.330 and 0.244, respectively. In addition, the expected values of heterozygosity (He) for these sub-populations were recorded as 0.45, 0.46 and 0.44, respectively. Therefore, SSR markers can be useful not only in genetic diversity and association analysis of wheat but also in its germplasm for various agronomic traits or mechanisms of tolerance to environmental stresses.

Genetic Diversity of Durum Wheat (Triticum turgidum L. ssp. durum, Desf) Germplasm as Revealed by Morphological and SSR Markers.

Ethiopia is considered a center of origin and diversity for durum wheat and is endowed with many diverse landraces. This research aimed to estimate the extent and pattern of genetic diversity in Ethiopian durum wheat germplasm. Thus, 104 durum wheat genotypes representing thirteen populations, three regions, and four altitudinal classes were investigated for their genetic diversity, using 10 grain quality- and grain yield-related phenotypic traits and 14 simple sequence repeat (SSR) makers. The analysis of the phenotypic traits revealed a high mean Shannon diversity index (H' = 0.78) among the genotypes and indicated a high level of phenotypic variation. The principal component analysis (PCA) classified the genotypes into three groups. The SSR markers showed a high mean value of polymorphic information content (PIC = 0.50) and gene diversity (h = 0.56), and a moderate number of alleles per locus (Na = 4). Analysis of molecular variance (AMOVA) revealed a high level of variation within populations, regions, and altitudinal classes, accounting for 88%, 97%, and 97% of the total variation, respectively. Pairwise genetic differentiation and Nei's genetic distance analyses identified that the cultivars are distinct from the landrace populations. The distance-based (Discriminant Analysis of Principal Component (DAPC) and Minimum Spanning Network (MSN)) and model-based population stratification (STRUCTURE) methods of clustering grouped the genotypes into two clusters. Both the phenotypic data-based PCA and the molecular data-based DAPC and MSN analyses defined distinct groupings of cultivars and landraces. The phenotypic and molecular diversity analyses highlighted the high genetic variation in the Ethiopian durum wheat gene pool. The investigated SSRs showed significant associations with one or more target phenotypic traits. The markers identify landraces with high grain yield and quality traits. This study highlights the usefulness of Ethiopian landraces for cultivar development, contributing to food security in the region and beyond.

Molecular Marker and Test Cross Information Aid Selective Advancement of F4 Generation of CB174R/Azucena: An inter Sub-specific Cross in Rice for Restorer Development

The present investigation was aimed to develop restorer lines for three-line hybrid rice using indica/tropical japonica derivatives to exploit the inter sub-specific heterosis. From 75 F4 families of CB174R/Azucena, two plants were randomly selected and screened using simple sequence repeat markers DRRM-RF 3 -10 for Rf3 gene and RM6100 for Rf4 gene. One hundred and five plants possessing either or both of the genes were test crossed with CMS line COMS 23A. In 67 hybrids evaluated, the mean pollen fertility ranged from 97.3% (CB174R/Azucena 177-4-9) to 13.7% (CB174R/Azucena 13-2-4). The frequency of restorers was high (49.25%) followed by partial restorers (29.85%) and partial maintainers (20.90%). The selection efficiency for DRRM- RF3-10 and RM6100 markers were 75.75% and 54.54% respectively. Segregation for fertility restorer genes and pollen fertility among individual plants within a family was witnessed from molecular and phenotypic data. Based on phenotypic and marker information, it was concluded to advance 53.3% of plants to F5 generation to isolate stable restorer lines that can be exploited in future to produce highly heterotic three-line hybrids in rice.

Evaluation of the Genetic Structure of Some Accessions Belonging to Onobrychis spp. Using Microsatellite DNA Markers

Turkey is in a very convenient position for animal husbandry in terms of both natural resources and ecological conditions. Forage crops, which has a very important place in agricultural activities, is the insurance of plant and animal production. Sainfoin is a perennial forage legume species that grown in the northern temperate regions of the world from the Mediterranean region and the Caucasus, and to Central Asia. In this study the genetic diversity of 100 genotypes representing 44 accessions from 18 different Onobrychis species (O. arenaria subsp. arenaria, O. inermis, O. petraea, O. cyri, O. iberica, O. altissima, O. vassilczenkoi, O. conferta subsp. argentea, O. alba subsp. laconica, O. biebersteinii, O. grandis, O. kachetica, O. kemulariae, O. oxyodonta, O. megataphros, O. pallasii, Onobrychis spp., and O. viciifolia) were evaluated using 8 simple sequence repeat (microsatellite) markers. Based on the results, OVK036, OVK094, OVK125, OVM033, OVK161, OVK046, OVM061, and OVK174 loci were polymorphic. The observed number of alleles per SSR locus ranged from 6 to 21 alleles (mean of 11.625). Maximum allele frequency ranged from 0.51 to 0.93 with a mean value of 0.73. The PIC value ranged from 0.124 to 0.244. The mean polymorphism information content of loci was 0.188. Genetic diversity coefficients according to the UPGMA ranged from 0.000 to 0.9375. Cluster analysis divided the 100 sainfoin genotypes into two main groups (Cluster-I and Cluster-II). All diploid genotypes (except for 1 diploid genotype) used in the study formed a separate group within Cluster-I. The results revealed that SSR markers used in this study are useful for molecular characterization and assessing genetic diversity of sainfoin accessions. The obtained SSR alleles and genetic variability in a studied certain loci provided significant information about the genetic structure of sainfoin accessions that could be used as parental lines in sainfoin breeding programs.

The popular Algerian barley landraces Saïda and Tichedrett are autochthonous – evidence from RAPD, SSR and agrophenological markers

Abstract The characterisation of traditional barley varieties from North Africa is promising with respect to detect traits linked with resilience to drought. Nine Algerian barley varieties comprising the economically relevant local landraces Saïda183 and Tichedrett were genotyped by random amplifying polymorphic DNA (RAPD) and by Simple Sequence Repeat (SSR) markers to get insight into their phylogenetic relationship and to compare the efficiency of the two approaches. The SSR markers were chosen such that all chromosomes of barley were represented by at least one marker. In addition, a principal component analysis (PCA) of morpho-agronomical traits was conducted. We found that the phylogeny based on the RAPD markers reflected the geographical distribution of the tested varieties, while the phylogeny based on the SSR markers reflected the pedigree. Among the RAPD markers, the maximal polymorphism information content was obtained for BY14 with a value of 0.82, for the SSR markers, Bmg13 was most informative with a value of 0.60. The similarity matrix used to the construct the phylogenetic tree, inferred a close relationship (Jaccard Index 0.8 based on RAPD markers) between the accessions Fouara and Oued-Athmania occurring in close vicinity. The SSR markers group the autochthonous varieties Saïda183 and Tichedrett together with a Jaccard Index of 0.8. The close phylogenetic relationship between Saïda183 and Tichedrett is also supported by the PCA of morphological and agronomic traits. Our data underpin the diversity of Algerian barley varieties and lend support to the autochthonous origin of these two Algerian landraces.

Development of SSR molecular markers and genetic diversity analysis of Clematis acerifolia from Taihang Mountains.

Investigating the genetic diversity and population structure is important in conserving narrowly distributed plants. In this study, 90 Clematis acerifolia (C. acerifolia) plants belonging to nine populations were collected from the Taihang Mountains in Beijing, Hebei, and Henan. Twenty-nine simple sequence repeats (SSR) markers developed based on RAD-seq data were used to analyze the genetic diversity and population structure of C. acerifolia. The mean PIC value for all markers was 0.2910, indicating all SSR markers showed a moderate degree of polymorphism. The expected heterozygosity of the whole populations was 0.3483, indicating the genetic diversity of both C. acerifolia var. elobata and C. acerifolia were low. The expected heterozygosity of C. acerifolia var. elobata (He = 0.2800) was higher than that of C. acerifolia (He = 0.2614). Genetic structure analysis and principal coordinate analysis demonstrated that C. acerifolia and C. acerifolia var. elobata showed great genetic differences. Molecular variance analysis (AMOVA) demonstrated that within-population genetic variation (68.31%) was the main contributor to the variation of the C. acerifolia populations. Conclusively, C. acerifolia var. elobata had higher genetic diversity than C. acerifolia, and there are significant genetic differences between C. acerifolia and C. acerifolia var. elobata, and small genetic variations within the C. acerifolia populations. Our results provide a scientific and rational basis for the conservation of C. acerifolia and provide a reference for the conservation of other cliff plants.

Evaluation of the growth, yield traits and the genetic diversity of some Brassica napus genotypes under Egyptian conditions

BackgroundCanola (Brassica napus L.) is considered an alternate oilseed plant. Therefore, this study aimed to evaluate some growth parameters, yield, chemical parameters and genetic diversity among thirteen canola genotypes including a collection of Chinese, German, French, and local genotypes under Egyptian conditions.ResultTrapper genotype recorded the highest values of plant height (47.12 and 89.75 cm) and dry weight/plant (8.54 and 28.19 dry weight/plant) at 60 and 90 days from sowing, respectively. Data from the field experiments showed that significant differences were recorded among tested genotypes for all yield and its component parameters (i.e., plant height (cm), branches/no. plant, siliquas and seed weight (g/plant) and seed oil %. The genetic diversity and the relationships among the thirteen canola genotypes were evaluated utilizing sequence-related amplified polymorphism (SRAP) and simple-sequence repeats (SSRs) markers. The allelic frequency of the different SRAP and SSR markers tested has differed among the thirteen canola genotypes. The SRAP and SSR analyses showed 659 out of 742 and 15 out of 45 markers, respectively, were detected as polymorphic markers (88.8% and 33.33%) among the tested wheat cultivars In addition, the polymorphism information content (PIC), marker index (MI) and resolving power (RP) parameters were computed to assess the effectiveness of the markers. The results indicated the occurrence of a considerable genetic variation between Chinese, European and Egyptian genotypes.ConclusionThese markers are of considerable value and can be utilized to screen large canola populations. The results of the comparison between the two molecular markers showed that the most effective marker that showed the genetic diversity between canola genotypes was SRAP (88.8%) polymorphism. It could be concluded that the tested canola genotypes could be cultivated under the Egyptian condition with high performance especially Trapper, Agamax and Topas genotypes. Therefore, it could be suggested that these three genotypes seem to be promising for oil gap reduction and need further evaluation for the expansion under new reclaimed regions.

Morphological, Biochemical and Genetic Variation of Rice (Oryza sativa L.) Genotypes to Vegetative Stage Salinity Stress

Salinity is one of the most serious issues in rice cultivation and production. Salt stress significantly reduced seedling growth performance of rice. This research was conducted to study the effects of vegetative stage salinity stress on morphological, biochemical, molecular and genetic variation of 12 rice genotypes as well as 2 check varieties, MR297 (susceptible) and Pokkali (tolerant). The experiment was arranged in a split-plot design with 3 replications. Normal freshwater at 0 dS m-1 (L1), saline water at 6 dS m-1 (L2) and saline water at 12 dS m-1 (L3) were the main plot and rice genotypes were the sub-plot. In general, morphological and biochemical traits of all genotypes showed an overall reduction of about 47.41% in L3 as compared to L1 except for the tolerant check, Pokkali. The genetics and correlation analysis indicated that plant height, leaf size and standard evaluation system (SES) score might be used as a selection criterion in developing salt tolerant rice. The multivariate analysis revealed that a Malaysian landraces, Jarom Mas was clustered together with Pokkali as tolerant genotype. Screening using tightly linked Simple Sequence Repeat (SSR) markers (RM1287, RM10748, RM493) of salinity tolerant QTL, Saltol indicated that this QTL was absence in Jarom Mas. This finding might indicate the presence of other QTL associated with salinity tolerance in Jarom Mas. Further study on identifying the speculated QTL may be conducted to confirm this postulation.

Small cardamom genome: development and utilization of microsatellite markers from a draft genome sequence of Elettaria cardamomum Maton.

Small cardamom (Elettaria cardamomum Maton), the queen of spices, is the third most expensive spice in the world after saffron and vanilla, valued highly for its aroma and taste. This perennial herbaceous plant is a native of coastal parts of Southern India and displays a significant amount of morphological diversity. Its genetic potential has not been exploited due to lack of genomic resources limiting our understanding of the genome and important metabolic pathways which give it the economic advantage in the spice industry. Here, we report upon the de novo assembled, draft whole genome sequence of cardamom variety, Njallani Green Gold. We used a hybrid assembly strategy using the reads from the Oxford Nanopore, Illumina and 10x Genomics GemCode sequencing chemistries. The assembled genome length was 1.06 Gb (gigabases) which is close to the estimated genome size of cardamom. More than 75% of the genome was captured in 8000 scaffolds with a N50 of 0.15 Mb. The genome appears to have a high repeat content and 68055 gene models were predicted. The genome is close to Musa species and displays an expansion and contraction in different gene families. The draft assembly was used for in silico mining of simple sequence repeats (SSRs). A total of 2,50,571 SSRs were identified of which 2,18,270 were perfect SSRs and 32,301 were compound SSRs. Among the perfect SSRs, trinucleotides were most abundant (1,25,329) and hexanucleotide repeats appear least (2,380). From the 2,50,571 SSRs mined, 2,27,808 primer pairs were designed based on flanking sequence information. Wet lab validation was performed for 246 SSR loci and based on their amplification profiles, 60 SSR markers were used for diversity analysis of a set of 60 diverse cardamom accessions. The average number of alleles detected per locus were 14.57 with a minimum of 4 and maximum of 30 alleles. Population structure analysis revealed the presence of high degree of admixtures which could primarily be due to cross-pollination prevalent in this species. The SSR markers identified would help in the development of gene or trait-linked markers which can be subsequently used for marker-assisted breeding for crop improvement in cardamom. The information on utilization of the SSR loci for generation of markers has been developed into a public database, 'cardamomSSRdb' that is freely available for use by the cardamom community.

Phenotypic and molecular characterization of new interspecific Japanese plum × apricot hybrids (plumcots)

Japanese plum is a very important temperate tree fruit, ranking in the second position among the stone fruits, after peaches. In this species, there are very few self-compatible varieties and a lack of resistance to sharka disease (plum pox virus, PPV). In this context, interspecific crosses between Japanese plums and self-compatible, sharka-resistant apricot (Prunus armeniaca L.) cultivars have been performed in recent years to obtain resistant and self-compatible plumcots. The plumcot provides a new fruit typology combining the horticultural and market characteristics of these two Prunus species. In this work, new interspecific plumcots have been obtained and characterized. An initial screening of more than 600 seedlings was carried out for interspecific hybrid verification using Simple Sequence Repeat (SSR) markers. In addition, floral compatibility by S-allele genotyping and phenotypic characterization and PPV resistance evaluations in controlled conditions were performed in the interspecific genotypes. The results show some interspecific hybrids with the desired characteristics of self-compatibility alleles and sharka tolerance together with new fruit typologies with an attractive skin and flesh color and different valued organoleptic characteristics.

Phased grapevine genome sequence of an Rpv12 carrier for biotechnological exploration of resistance to Plasmopara viticola.

The downy mildew disease caused by the oomycete Plasmopara viticola is a serious threat for grapevine and can cause enormous yield losses in viticulture. The quantitative trait locus Rpv12, mediating resistance against P. viticola, was originally found in Asian Vitis amurensis. This locus and its genes were analyzed here in detail. A haplotype-separated genome sequence of the diploid Rpv12-carrier Gf.99-03 was created and annotated. The defense response against P. viticola was investigated in an infection time-course RNA-seq experiment, revealing approximately 600 upregulated Vitis genes during host-pathogen interaction. The Rpv12 regions of the resistance and the sensitivity encoding Gf.99-03 haplotype were structurally and functionally compared with each other. Two different clusters of resistance-related genes were identified within the Rpv12 locus. One cluster carries a set of four differentially expressed genes with three ACCELERATED CELL DEATH 6-like genes. The other cluster carries a set of six resistance gene analogs related to qualitative pathogen resistance. The Rpv12 locus and its candidate genes for P. viticola resistance provide a precious genetic resource for P. viticola resistance breeding. Newly developed co-segregating simple sequence repeat markers in close proximity to the R-genes enable its improved applicability in marker-assisted grapevine breeding.

Genetic diversity analysis of Wamena Arabica Coffee (Coffea arabica L.) based on SSR markers

Wamena is notable for producing and exporting high-quality coffee. However, a molecular method based on its polymorphism and not affected by external factors is required since morphological observations alone are frequently insufficient for identifying the coffee. The objective of this study is to identify Wamena Arabica coffee in the Jayawijaya District using simple sequence repeats (SSRs) molecular markers. This research involved several stages, including DNA isolation and purification, PCR SSR amplification with 5 primers, polymorphism, and heterozygosity level analysis. The results analysis proved that 30 alleles of 32 coffee genotypes were successfully amplified, with fragment sizes ranging from 176 to 553bp. The Car M052 locus (0.29%) had the least polymorphism with only two alleles, while the CarM101 locus (0.82%) had the most with 12 alleles, that high and low polymorphism indicated a measure of PIC scores. Heterozygosity analysis showed that the coffee samples were highly heterozygous. And based on the results of the bootstrap analysis, the phenogram shows that the coffee samples are divided into six clusters, with a cophenetic correlation coefficient (r) of 0.948 (excellent fit). This study proved that all SSR loci succeeded in amplifying 30 alleles and could be identified molecularly based on the genetic variation of the Wamena Arabica coffee genotypes in Papua. It seems highly possible that there is a mix of traits through gene flow and exchange between coffee genotypes, and the heterozygosity in the Arabica population on plantations. As a result, it is very important further analysis to confirm the findings.