Search Results (3)

The genus Chaenomeles, part of the subfamily Maloideae within the Rosaceae family, comprises five recognized species and has long been valued for its ornamental qualities. However, the use of Chaenomeles japonica as a fruit crop is relatively recent, with its introduction into targeted breeding activities only occurring in the 1950s. Due to this, genetic information on the genus remains limited, and the application of molecular markers in crop breeding and further development have been narrow, relying primarily on non-specific marker applications in germplasm analysis. One potential solution is the transfer of molecular markers between genera, specifically from the related Maloideae genera. This study aimed to test the transferability of SSR markers developed for Malus to Chaenomeles, and to analyze the structure of available Chaenomeles germplasm. By including 74 Chaenomeles genotypes, 95 SSR markers originally developed for Malus were tested, with 25 proving effective for characterizing Chaenomeles germplasm. These adapted SSR markers successfully differentiated among Chaenomeles species, including Chaenomeles japonica, Chaenomeles speciosa, Chaenomeles cathayensis, and hybrids like Chaenomeles × superba and Chaenomeles × californica. The markers demonstrated high stability and repeatability, indicating their suitability for large-scale genetic research, species composition assessment, and breeding material evaluation. Given the limited studies on SSR markers in Chaenomeles, this research lays the foundation for further exploration, potentially expanding into the genetic diversity assessment and trait screening for breeding. As genetic research on Chaenomeles is still in its early stages, the development of additional markers will be crucial for advancing this crop. Full article

The taxonomic placements of Chaenomeles Lindl. (Rosaceae) and their intrageneric species have long been controversial. This research aims to explore the palynomorphological characters of all Chaenomeles extant species in detail and to compare the results with phylogenetic relationships and the taxonomic classification scheme. The pollen morphology of 30 individuals of six taxa of Chaenomeles was investigated using both light microscopy and scanning electron microscopy. The pollens were measured, observed and statistically analyzed for 12 quantitative features and 2 qualitative ones. The study revealed that the Chaenomeles pollens are monad, tri-colporate, medium in size (P = 32.78–42.74 μm, E = 30.42–36.31 μm) and prolatespheroidal to subprolate in shape (P/E = 0.98–1.35). Based on exine ornamentation observed under SEM, two sexine sculpture types (type I—striate with microperforations, type II—striate with macroperforations) and two subtypes (twisted-striate, reticulate-striate) were recognized in the genus. Statistical analysis identified some pollen characteristics with diagnostic importance, including pollen shape, colpus dimension, length or direction of striae and diameter of perforation. These characteristics may have diagnostic and taxonomic value for the genus Chaenomeles and the family Rosaceae. An artificial key to studied species, based on pollen micromorphological attributes, is also provided. The obtained result was basically consistent with that of molecular studies published earlier. This study, for the first time, provides palynological evidence for the hybrid origin hypothesis of C. sinensis and supports the placement of this species in the monotypic genus Pseudocydonia. Full article

In recent years, Japanese quince (Chaenomeles japonica) plantations in Latvia have increased. Interest in breeding Japanese quince is also known in other European countries and Russia. The occurrence and harmfulness of fungal diseases have become increasingly significant. However, there is a lack of overall information in the literature about the diversity of fungi afflicting C. japonica. In our study, we aimed to determine the diversity of fungi associated with C. japonica in Latvia, with the possibility of identifying the fungi that are most characteristically associated with certain parts of the plant. Our research was conducted from 2017 to 2019 in eight Japanese quince plantations in Latvia. Samples of plant parts with disease symptoms were collected. Pure cultures of fungi were obtained and identified using ITS region sequencing. We determined the relative density of identified genera of fungi, which were grouped using hierarchical cluster analysis depending on the plant part from which they were found. Various disease-like symptoms were observed and described. A total of 538 isolates of fungi were obtained that belong to 36 genera and represent different ecological niches. Fusarium, Alternaria, Botrytis, and Sarocladium were the genera most frequently found during our study. The number of identified cases of fungal genera differed depending on the part of the plant from which the fungi were obtained. However, it is not possible to relate a specific genus of fungus to only one certain part of a plant. Further research is needed to clarify the pathogenicity of detected fungi and the composition of species in the detected genera of fungi. Full article