SSR Molecular Markers Research Articles

Identification and genetic diversity analysis of specific walnut F1 progeny based on SSR molecular markers: taking heart-shaped walnuts and Jinghong 1 as examples

To gain a deeper understanding of the genetic diversity and authenticity of natural pollinated F1 progeny populations of specific walnuts (heart-shaped walnuts and Jinghong 1), as well as the genetic relationship between F1 offspring and their maternal parent. 32 heart-shaped walnut F1 offspring, 45 Jinghong 1 F1 offspring, and their maternal parent were selected as materials, and 14 pairs of SSR markers were used for genetic diversity and parent-child relationship analysis. The results showed that Jr05, Jr11, Jr29, Jr44, Jr45, Jr52, Jr53, Jr55, and Jr56 could be used as SSR markers for the identification of hybrid offspring in heart-shaped walnuts. Jr35, Jr40, Jr45, Jr50, Jr52, and Jr53 could be used as SSR markers for the identification of hybrid offspring of Jinghong 1. XX21 had the closer genetic relationship with heart-shaped walnuts, and HR20 had the closer genetic relationship with Jinghong 1. Besides, the classification results of F1 offspring based on UPGMA clustering and STRUCTURE were different. This study not only laid the foundation for parental identification of specific walnut F1 progeny, but also provided theoretical reference for fixing hybrid advantages, germplasm innovation, and new variety breeding.

Identification of rice samples with rice blast resistance genes Pi-2 and Pi-b

Since rice blast is a disease that causes significant damage to rice all over the world, the intensive development of disease-resistant genotypes is of great urgency. The use of molecular biology technologies, new biotechnological approaches and molecular genetic methods allows creating disease-resistant varieties while reducing the time of their development, which plays an important role in growing competitive products. The current paper has highlighted the results of estimating rice samples developed at the FSBSI “ARC “Donskoy” for blast resistance. The objects of the study were new samples developed in the laboratory of rice breeding and seed production. In 2022–2023, there were screened one hundred eighty-seven rice samples. They were identified on a presence of the blast resistance gene Pi-2. One hundred fifteen samples were estimated for the blast resistance gene Pi-b. Genomic DNA was isolated from young rice leaves. After estimating the quantity and quality of the isolated DNA there was conducted a polymerase chain reaction for the target genes Pi-2 and Pi-b. In order to identify the alleles of the desired genes there were used specific intragenic molecular SSR markers of dominant (for Pi-2) and codominant (for Pi-b) types. Electrophoresis of the obtained amplicons was performed on 2 % agarose gels during an hour. The results of the analysis were recorded in ultraviolet light and processed in ImageLab 5.1 software. As a result of the conducted study, there were identified new rice breeding samples that carry blast resistance genes Pi-2 and Pi-b. These samples are recommended for use in the further breeding process for blast resistance.

Characterization of the wheat-tetraploid Thinopyrum elongatum 7E(7D) substitution line with Fusarium head blight resistance

BackgroundFusarium head blight (FHB), a devastating disease of wheat production, is predominantly elicited by Fusarium graminearum (Fg). The tetraploid Thinopyrum elongatum is a tertiary gene resource of common wheat that possesses high affinity and displays high resistance traits against multiple biotic and abiotic stress. We aim to employ and utilize the novel FHB resistance resources from the wild germplasm of common wheat for breeding.ResultsDurum wheat-tetraploid Th. elongatum amphiploid 8801 was hybridized with common wheat cultivars SM482 and SM51, and the F5 generation was generated. We conducted cytogenetically in situ hybridization (ISH) technologies to select and confirm a genetically stable 7E(7D) substitution line K17-1069-5, which showed FHB expansion resistance in both field and greenhouse infection experiments and displayed no significant disadvantage in agronomic traits compared to their common wheat parents in the field. The F2 segregation populations (K17-1069-5 × SM830) showed that the 7E chromosome conferred dominant FHB resistance with dosage effect. We developed 19 SSR molecular markers specific to chromosome 7E, which could be conducted for genetic mapping and large breeding populations marker-assisted selection (MAS) during selection procedures in the future. We isolated a novel Fhb7 allele from the tetraploid Th. elongatum chromosome 7E (Chr7E) using homology-based cloning, which was designated as TTE7E-Fhb7.ConclusionsIn summary, our study developed a novel wheat-tetraploid Thinopyrum elongatum 7E(7D) K17-1069-5 substitution line which contains stable FHB resistance.

Exploring Sampling Strategies and Genetic Diversity Analysis of Red Beet Germplasm Resources Using SSR Markers

By using 14 SSR primer pairs, we here analyzed and compared the amplification results of 534 DNA samples from six red sugar beet germplasm resources under three treatments. These data were used to explore the sampling strategy for the aforementioned resources. Based on the sampling strategy results, 21 SSR primer pairs were used to evaluate the genetic diversity of 47 red sugar beet germplasm resources. The six population genetic parameters used for exploring the sampling strategy unveiled that individual plants within the population had a relatively large genetic distance. The genetic parameters Ne, I, and Nei’s of the randomly mixed sampling samples increased rapidly between 10 and 30 plants before decreasing. Therefore, when SSR technology was used to analyze the genetic diversity of the red sugar beet germplasm resources, the optimal sampling gradient for each population was the adoption of a random single-plant mixed sampling sample of no less than 10 plants and no more than 30 plants. The 21 SSR primer pairs were used to detect genetic diversity in 30 random mixed samples of 47 resources. The average polymorphic information content (PIC) was 0.5738, the average number of observed alleles (Na) was 4.1905, the average number of effective alleles (Ne) was 2.8962, the average Shannon’s information index (I) was 1.1299, the average expected heterozygosity (Nei’s) was 0.6127, and the average expected heterozygosity (He) was 0.6127. The genetic distance of the 47 germplasm resources ranged from 0.0225 to 0.551 (average: 0.316). According to the population structure analysis, the most suitable K value was six, which indicated the presence of six populations. Based on the clustering analysis results, the 47 germplasm resources were segregated into six groups, with obvious clustering and some germplasm resources noted for having groups with close genetic relationships. We here established a more accurate and scientific sampling strategy for analyzing the genetic diversity of red sugar beet germplasm resources by using SSR molecular markers. The findings provide a reference for collecting and preserving red sugar beet germplasms and protecting their genetic diversity.

Phylogeography of a herbal Pinellia ternata reveals repeated range expansions and inter/postglacial recolonization routes on the fragmented distribution pattern in China.

Most plant phylogeographic studies in China have focused on the importance of genetic divergence and where should the shelter be located. Little attention has been paid to range expansion and recolonization routes in this region. In this study, two cpDNA fragments (psbK-psbI and trnL-F), two pairs of nuclear gene sequences (ITS and ETS), and nine pairs of SSR molecular markers were used, combined with Bayesian Skyline Plot method, gene barrier analysis, and species distribution models to explore the phylogeographical pattern, potential expansion routes and population dynamic history of Pinellia ternata from 22 population. The results showed that phylogeograhical pattern and genetic structure for P. ternata are effected by environmental heterogeneity and climate fluctuation, and it can be divided into two groups (Southwest group, Central and Eastern group) and thus there are at least two glacial refugia in China. Three expanding routes within groups were explored to contribute to the phylogeogrephic pattern of P. ternata based on the geographical distribution and network analysis of haplotypes. In a word, our study reveals repeated range expansions and inter/postglacial recolonization routes on the fragmented distribution pattern in China and resolves the refugia distributing in China and has also certain reference value for the protection of the medicinal plant P. ternata.

Fruiting Characteristics and Molecular-Assisted Identification of Korla Fragrant Pear Bud Mutation Materials

Korla fragrant pear is a high-quality local pear variety native to Xinjiang, China. Currently, the low fruit-setting rate and low calyx shedding rate problems in Korla fragrant pears have been highlighted, which seriously affect the fruit yield and quality. It is of great significance to research the fruiting characteristics and molecular-assisted identification of Korla fragrant pear bud mutation materials for enriching the germplasm resources of Korla fragrant pear. In this research, a natural pollination group (YB) of Korla fragrant pear bud mutation materials and a natural pollination group (CK) of Korla fragrant pears were established. On the fruiting characteristics, the fruit-setting rate and calyx-removal rate of the two groups were investigated. In terms of fruit quality, the fruit shape index, fruit specific gravity, soluble solids content, sugar:acid ratio, soluble sugar content, and other indicators were measured. For the anatomical structure of the calyx tube, the detachment cells were observed. The formation time of the two groups of detached cells was compared. In the GBS simplified genome sequencing, a phylogenetic tree was constructed based on the obtained SNP sites. A principal component analysis, population genetic structure analysis, and genetic diversity index analysis were carried out. In the aspect of SSR molecular marker identification, the SSR types were counted. Polyacrylamide gel electrophoresis was performed. The results demonstrate the following: (1) the fruit-setting rate (30.87%) and calyx-removal rate (68.11%) in the YB group were significantly higher than those in the CK group (19.37%) and the calyx-removal rate (55.18%). (2) There was no significant difference in fruit quality indexes, such as average fruit weight (127.10–130.00 g) and soluble sugar content (9.47–9.56%) between the two groups. (3) Abscission-layer cells were observed at 2, 4, 6, 8, and 10 h after calyx tube discoloration in the YB group and at 48, 72, and 96 h after calyx tube discoloration in the CK group. (4) The genetic background of the YB group and the CK group was similar at the GBS level, but there were differences at the DNA level. This research finally shows that Korla fragrant pear bud mutation material is a good germplasm resource. This germplasm resource can promote the structural optimization of Korla fragrant pear varieties and the healthy development of the industry.

Molecular Traceability Approach to Assess the Geographical Origin of Commercial Extra Virgin Olive Oil.

Extra virgin olive oil (EVOO) is a precious and healthy ingredient of Mediterranean cuisine. Due to its high nutritional value, the interest of consumers in the composition of EVOO is constantly increasing, making it a product particularly exposed to fraud. Therefore, there is a need to properly valorize high-quality EVOO and protect it from fraudulent manipulations to safeguard consumer choices. In our study, we used a straightforward and easy method to assess the molecular traceability of 28 commercial EVOO samples based on the use of SSR molecular markers. A lack of correspondence between the declared origin of the samples and the actual origin of the detected varieties was observed, suggesting possible adulteration. This result was supported by the identification of private alleles based on a large collection of national and international olive varieties and the search for them in the molecular profile of the analyzed samples. We demonstrated that the proposed method is a rapid and straightforward approach for identifying the composition of an oil sample and verifying the correspondence between the origin of olives declared on the label and that of the actual detected varieties, allowing the detection of possible adulterations.

Pipeline for identification of genome-wide microsatellite markers and its application in assessing the genetic diversity and structure of the tropical sea cucumber Holothuria leucospilota

Microsatellite DNA (SSR) is extensively used as molecular markers in diverse fields, including molecular ecology, conservation biology, and molecular breeding. Nevertheless, the efficient and easy acquisition of high-quality SSR molecular markers for economically cultured marine animals remains a challenge. Holothuria leucospilota is an economically and ecologically important tropical sea cucumber. Recently, artificial breeding and cultivation of this species have been reported. However, there is still a lack of highly polymorphic SSR molecular markers for geographical population differentiation and genetic breeding. This study aims to develop and utilize SSR markers from genomic data to assess the genetic variation and population structure of H. leucospilota in the South China Sea. A comprehensive pipeline was created, integrating microsatellite discovery, primer design, and assessment into a single platform. Through this, 15 highly polymorphic microsatellite loci were identified and validated. The results revealed high genetic diversity and low genetic differentiation among H. leucospilota populations. Larval dispersal and ocean currents in the South China Sea were identified as the primary factors influencing genetic connectivity between populations. In addition, the artificial culture and releasing of H. leucospilota have influenced the genetic structure of their wild populations in the South China Sea. This study provides a pipeline for identifying SSR markers within genome data, and applies it to assess the genetic diversity and structure of H. leucospilota. The outcomes of this research are expected to be beneficial and applicable to the future aquaculture of tropical sea cucumbers.

SSR Molecular Marker Application in Selection of Hybrid Rice Lines with Salinity Tolerant Gene of Back Crossing Generation

SSR Molecular Marker Application in Selection of Hybrid Rice Lines with Salinity Tolerant Gene of Back Crossing Generation

Long-Term Successional Subculture Dynamics and Their Effects on the Proliferation Efficiency, Embryogenic Potential, and Genetic Stability of Embryogenic Tissues in Larix principis-rupprechtii Mayr

Larix principis-rupprechtii Mayr, a coniferous species indigenous to Northern China, possesses significant ecological and economic value. Somatic embryogenesis offers a pathway with significant potential for large-scale propagation, long-term germplasm conservation, and genetic transformation in L. principis-rupprechtii Mayr. However, it remains unclear whether significant variations occur in embryogenic tissues during long-term successive subculturing, which could impact the productivity of somatic embryos. This is a pivotal concern that lacks comprehensive understanding. In this study, three embryogenic cell lines were used to explore the dynamics and relationships among proliferation rate, pre-treatment proliferation rate, and embryogenic capabilities across a series of 32 subculturing cycles. Proliferation rate, pre-treatment proliferation rate, and somatic embryo maturation rate showed no significant correlation with subculturing cycles. However, there was a positive correlation between subculturing cycles and pre-treatment proliferation rate and a negative correlation with somatic embryo maturation rate in the BFU1 cell line. In addition, we utilized ten SSR molecular markers to investigate the genetic stability in embryogenic tissues during long-term subculturing. No genomic variations were detected in any of the three embryogenic cell lines, which suggests that the observed phenotypic dynamics during subculturing may not be primarily driven by genomic alterations. This study provides novel insights into the dynamics of the long-term culture of embryogenic tissues, laying a foundation for the optimization and application of somatic embryogenesis techniques in L. principis-rupprechtii Mayr and potentially other coniferous species.

Molecular Characterization of Mango (Mangifera indica L.) Cultivars Using SSR Markers

Nowadays, molecular characterization is essential for studying the varietal diversity of species. In addition, SSR molecular markers are widely used to identify and distinguish the genetic relationship of mango cultivars. The study aim is to determine the variability structuring level of 18 mango cultivars in Burkina Faso. Thus, genomic DNA was extracted in 2022 from young leaves at the molecular biology unit of the Biosciences laboratory at Joseph KI-ZERBO University (Burkina Faso). Analysis of the results showed a polymorphic percentage average of 21.49% per marker. Genetic distance showed that the similarity coefficient range is 0.0002 to 1.09. The greatest genetic distance (1.09) was calculated for the pairs (VSB, Valencia) and (VSB, Miamilate). On the other hand, the lowest genetic distance (0.0002) was calculated between Alphonso and Francis, Keitt and Sensation, and Mangot vert and Glazier. Examination of the dendrogram shows that the cultivars can be classified into two major groups of nine cultivars each. The first group includes Miamilate, Valencia, Lippens, Zill, Keitt, Sensation, Kent, Brooks, and Bewerly cultivars. The second group includes the cultivars Mangot vert, Glazier, Amélie, Dixon, Springfield, Francis, Alphonso, VSB and Mangot sabre. These results showed that cultivars are genetically very diverse. Therefore, our findings could be used for genetic diversity analysis and the marker-assisted breeding of mango germplasm.

Development of SSR Markers for and Fingerprinting of Walnut Genetic Resources

Walnut is one of four major nuts in the world. China has abundant walnut germplasm resources, but there are still shortcomings in the identification of germplasm resources. This study used different walnut varieties as materials and developed 14 high-quality SSR molecular markers from 60 pairs of primers based on genome re-sequencing results. This study analyzed the genetic diversity of Chinese walnut genetic resources using 14 selected SSR markers. A total of 64 alleles were detected in 47 walnut resources, with an average of 4.571 alleles per locus. The variation range of polymorphism information content was 0.096~0.711, with an average value of 0.422. Cluster analysis, population genetic structure, and principal coordinate analysis divided 47 walnut resources into ordinary walnuts, Juglans hopeiensis, and Liaoyi 1. In addition, core SSR markers (Jr45, Jr40, Jr29, Jr35, and Jr11) were selected from 14 SSR markers, which were sufficient to distinguish 47 walnut resources. At the same time, 47 unique molecular fingerprints of walnuts were constructed using these core SSR markers. This study provides strong scientific support for rapid and efficient identification, germplasm innovation, and a variety of property protection of walnut germplasm.

Developing EST-SSR Markers for Identifying and Evaluating Asparagus Germplasm Resources Based on Transcriptome Sequences

Radix asparagi is the dried root tuber of the Liliaceae plant Asparagus cochinchinensis (Lour.) Merr., which is a major Chinese medicinal herb with high medicinal and edible value in China. The planting area of A. cochinchinensis is extensive, and there is blind introduction in various regions, leading to confusion the origin of Radix asparagi and impure germplasm. This study conducted morphological and karyotype analyses on cultivated Asparagus resources from seven main production areas in China and developed SSR molecular markers suitable for the identification of Asparagus germplasm resources based on the transcriptome sequencing results. The morphological results indicate that in addition to A. cochinchinensis (Lour.) Merr., recorded in the Pharmacopoeia of the People’s Republic of China, there are also A. taliensis Wang et Tang and A. lycopodineus (Baker) Wang et Tang cultivated in China. All the tested Asparagus resources were diploid and had 20 chromosomes. A total of 8841 single genes containing SSR loci were identified using transcriptome sequencing of Neijiang Asparagus, including 761 SSR loci with trinucleotide repeat units. One hundred pairs of SSR primers were randomly designed from the trinucleotide repeat loci for PCR and polymorphism verification, and ten pairs were selected for identification of Asparagus germplasm resources. The genetic diversity results of ten pairs of primers in seven Asparagus-producing regions were consistent with the morphological identification. This study provides technical support for the comprehensive evaluation and utilization of Asparagus germplasm resources.

Genetic diversity analysis and fingerprinting of 175 Chimonanthus praecox germplasm based on SSR molecular marker

The elucidation of resources pertaining to the Chimonanthus praecox varieties and the establishment of a fingerprint serve as crucial underpinnings for advancing scientific inquiry and industrial progress in relation to C. praecox. Employing the SSR molecular marker technology, an exploration of the genetic diversity of 175 C. praecox varieties (lines) in the Yanling region was conducted, and an analysis of the genetic diversity among these varieties was carried out using the UPDM clustering method in NTSYSpc 2.1 software. We analyzed the genetic structure of 175 germplasm using Structure v2.3.3 software based on a Bayesian model. General linear model (GLM) association was utilized to analyze traits and markers. The genetic diversity analysis revealed a mean number of alleles (Na) of 6.857, a mean expected heterozygosity (He) of 0.496 3, a mean observed heterozygosity (Ho) of 0.503 7, a mean genetic diversity index of Nei՚s of 0.494 9, and a mean Shannon information index of 0.995 8. These results suggest that the C. praecox population in Yanling exhibits a rich genetic diversity. Additionally, the population structure and the UPDM clustering were examined. In the GLM model, a total of fifteen marker loci exhibited significant (P < 0.05) association with eight phenotypic traits, with the explained phenotypic variation ranging from 14.90% to 36.03%. The construction of fingerprints for C. praecox varieties (lines) was accomplished by utilizing eleven primer pairs with the highest polymorphic information content, resulting in the analysis of 175 SSR markers. The present study offers a thorough examination of the genetic diversity and SSR molecular markers of C. praecox in Yanling, and establishes a fundamental germplasm repository of C. praecox, thereby furnishing theoretical underpinnings for the selection and cultivation of novel and superior C. praecox varieties, varietal identification, and resource preservation and exploitation.

Assessing the congruence of molecular diversity using SSR molecular markers with key phenological traits among Persian walnut (Juglans regia L.) genotypes

Assessing the congruence of molecular diversity using SSR molecular markers with key phenological traits among Persian walnut (Juglans regia L.) genotypes

Molecular Characterization of Local Walnut (Juglans regia) Genotypes in the North-East Parnon Mountain Region of Greece.

Walnut is one of the most important nuts regarding their production and consumption. The available but uncharacterized genetic resources of walnut are important for the development and breeding of local varieties. Greece holds an important number of genetically uncharacterized walnut landraces, especially within the area of Parnon, which is considered to play a significant role as an in situ gene bank, due to its unique location traits. However, the genetic characterization and further use of these resources has been insufficient, due to the absence of genetic studies. In this study, we implemented SSR molecular markers, both to genetically characterize the walnut tree genetic diversity of the Parnon area and to identify its unique genetic structure, which will form the starting material for subsequent breeding programs. Overall, high levels of genetic variation were found among the individual walnut accessions that were collected in the Parnon mountain region.

Physiological Analysis and Genetic Mapping of Short Hypocotyl Trait in Brassica napus L.

Hypocotyl length is a botanical trait that affects the cold tolerance of Brassica napus L. (B. napus). In this study, we constructed an F2 segregating population using the cold-resistant short hypocotyl variety '16VHNTS158' and the cold-sensitive long hypocotyl variety 'Tianyou 2288' as the parents, and BSA-seq was employed to identify candidate genes for hypocotyl length in B. napus. The results of parental differences showed that the average hypocotyl lengths of '16VHNTS158' and 'Tianyou 2288' were 0.41 cm and 0.77 cm at the 5~6 leaf stage, respectively, after different low-temperature treatments, and '16VHNTS158' exhibited lower relative ion leakage rates compared to 'Tianyou 2288'. The contents of indole acetic acid (IAA), gibberellin (GA), and brassinosteroid (BR) in hypocotyls of '16VHNTS158' and 'Tianyou 2288' increased with decreasing temperatures, but the IAA and GA contents were significantly higher than those of 'Tianyou 2288', and the BR content was lower than that of 'Tianyou 2288'. The genetic analysis results indicate that the genetic model for hypocotyl length follows the 2MG-A model. By using SSR molecular markers, a QTL locus associated with hypocotyl length was identified on chromosome C04. The additive effect value of this locus was 0.025, and it accounted for 2.5% of the phenotypic variation. BSA-Seq further localized the major effect QTL locus on chromosome C04, associating it with 41 genomic regions. The total length of this region was 1.06 Mb. Within this region, a total of 20 non-synonymous mutation genes were identified between the parents, and 26 non-synonymous mutation genes were found within the pooled samples. In the reference genome of B. napus, this region was annotated with 24 candidate genes. These annotated genes are predominantly enriched in four pathways: DNA replication, nucleotide excision repair, plant hormone signal transduction, and mismatch repair. The findings of this study provide a theoretical basis for cloning genes related to hypocotyl length in winter rapeseed and their utilization in breeding.

Evaluation of Sesame (Sesamum indicum L.) Lines Under Salt Stress for Yield Using SSR Markers

Salinity has undesirable effects on sesame yield. In order to reduce salt's harmful effects, sesame tolerance needs to be increased. Twenty-three lines of sesame were irrigated with saline water (70 and 90 mM NaCl) and evaluated based on seed yield over two seasons (2019–2020). Genotypes were evaluated in a randomized complete block design (RCBD) with three replications. Ten SSR molecular markers were used to evaluate these lines for salt tolerance. Genotypes showed significant differences (p &amp;lt;0.05) and recorded a wide range of seed yields under optimum and salinity conditions. Four lines (C1.5, C2.2, C8.4, and C9.15) achieved the highest average performance for seed yield compared to other lines under salinity conditions. Ten SSR markers revealed 15 alleles, ranging from 1 to 4 alleles. The polymorphism information content (PIC) ranged from 0.00 to 0.44. The range of expected heterozygosity (He) was 0.00 to 0.444. The UPGMA dendrogram analysis divided all sesame genotypes into two main clusters. In addition, SSR 3 and SSR 6 markers elucidated the possibility of using them in breeding programs for enhancing salt tolerances in sesame cultivars. These lines may be used as a salt-tolerant source in future breeding to create new sesame cultivars.

Screening and genotyping of groundnut (Arachis hypogea L.) inbred lines and landraces in the North Central Nigeria

The study evaluated 33 accessions of groundnut in the field, consisting of 23 landraces from Nasarawa communities in Nigeria and 10 inbred lines. Assessment entailed the determination of plant survivorship, yield related parameters and pathological indices while genetic diversity study was undertaken using SSR and RAPD molecular markers. Data analysis was done on the Minitab 17.0 software. Significant variability was noted in all traits except in pod sizes, seed sizes and % infected seeds. About 33.3% of the accessions had a survival rate of ≥ 70.0% where 9/10 Inbred lines were found with overall yield (kg/ha) ranging from 4.0 ± 1.6 in Akwashiki-Doma to 516.8 ± 46.9 kg/ha in Samnut 24 × ICGV–91328. Five accessions (15.5%) had pathological indices of zero indicating no traces of any disease of any type and they included one landrace called Agric-Dazhogwa and four Inbred lines: Samnut 25 × ICGV–91317, Samnut 26 × ICGV–19324, Samnut 26 × ICGV–91328 and Samnut 26 × ICGV–91319. Coefficients of yield determination R2 by survivorship and pathological index were 50.6% and 15%, respectively. A fit model was established (Yield in kg/ha = –146 − 7.94 × Pi + 5.88 × S). Susceptibility to diseases depends on the type of variety (χ2(32) = 127.67, P = 0.00). Yield was significantly affected by BNR@30 (F = 5.47, P = 0.025, P &lt; 0.05) and DSV@60*RUST@60 interaction effect (F = 4.39, P = 0.044, P &lt; 0.05). The similarity coefficient ranged from 28.57 to 100 in plant morphology. Four varieties had no amplified bands with SSR primers whereas amplified bands were present only in four landraces accessions using the RAPD primer. The dendrogram generated by molecular data gave three groups where genetic similarity ranged from 41.4 to 100.0. The Inbred lines were noted for their high survivorship, good yield and disease resistance. Samnut 24 × ICGV–91328, an inbred line, had the highest yield but was susceptible to diseases. Among the landraces, Agric-Musha, Bomboyi-Dugu and Agric-Dazhogwa were selected for high survivorship and disease resistance. The selected inbred lines and landraces are valuable genetic resources that may harbour useful traits for breeding and they should be presented to the growers based on their unique agronomic values. The highest yielding inbred lines should be improved for resistance to late leaf spot diseases while the outstanding landraces should be improved for yield.

Fine-Scale analysis of both wild and cultivated horned galls provides insight into their quality differentiation

BackgroundGalla chinensis is a traditional Chinese medicine (TCM) produced due to the interaction between the Fordinae aphids and the Rhus plant species. Horned galls with high tannin content are the most widely cultivated gall type, and Wufeng county of Hubei province in China is the center of cultivation. However, long-term artificial cultivation and domestication of horned galls to meet the increasing production demand have led to quality degradation. Understanding the reasons underlying quality degradation is urgent for horned gall production and application. The present study used a combination of metabolic, genetic, and ecological analyses to investigate the quality and genetic differentiation of the horned galls under long-term domestication as well as the potential relationships between them.ResultsAnalysis of gallic acid content and other three phenotypic traits (fresh weight, gall size, and wall thickness) revealed quality differentiation of horned galls collected from five locations in Wufeng, in which the cultivated samples from Wang Jiaping (WJP) showed the highest degradation. Genetic differentiation between the cultivated and wild Rhus chinensis trees in WJP, and between WJP and the other populations was detected based on SSR molecular markers, however, no significant difference in genetic structure was seen for the aphid populations. Among the various ecological factors examined, temperature was identified as the primary one affecting the quality of horned galls.ConclusionsBoth genetic and ecological factors caused quality differentiation of horned galls. The collection of diverse germplasm of host trees and aphids will help reduce the quality degradation of horned galls in Wufeng.