Population Analysis of Diospyros lotus in the Northwestern Caucasus Based on Leaf Morphology and Multilocus DNA Markers.

Diospyros lotus is the one of the most frost-tolerant species in the Diospyros genera, used as a rootstock for colder regions. Natural populations of D. lotus have a fragmented character of distribution in the Northwestern Caucasus, one of the coldest regions of Diospyros cultivation. To predict the behavior of D. lotus populations in an extreme environment, it is necessary to investigate the intraspecific genetic diversity and phenotypic variability of populations in the colder regions. In this study, we analyzed five geographically distant populations of D. lotus according to 33 morphological leaf traits, and the most informative traits were established, namely, leaf length, leaf width, leaf index (leaf to length ratio) and the length of the fourth veins. Additionally, we evaluated the intraspecific genetic diversity of D. lotus using ISSR and SCoT markers and proposed a new parameter for the evaluation of genetic polymorphism among populations, in order to eliminate the effect of sample number. This new parameter is the relative genetic polymorphism, which is the ratio of polymorphism to the number of samples. Based on morphological and genetic data, the northernmost population from Shkhafit was phenotypically and genetically distant from the other populations. The correspondence between several morphological traits (leaf width, leaf length and first to fifth right vein angles) and several marker bands (SCoT5, SCoT7, SCoT30: 800-1500 bp; ISSR13, ISSR14, ISSR880: 500-1000 bp) were observed for the Shkhafit population. Unique SCoT and ISSR fragments can be used as markers for breeding purposes. The results provide a better understanding of adaptive mechanisms in D. lotus in extreme environments and will be important for the further expansion of the cultivation area for persimmon in colder regions.

Transferability of ISSR, SCoT and SSR Markers for Chrysanthemum × Morifolium Ramat and Genetic Relationships Among Commercial Russian Cultivars.

Characterization of genetic diversity in germplasm collections requires an efficient set of molecular markers. We assessed the efficiency of 36 new SCoT markers, 10 new ISSR markers, and 5 microsatellites for the characterization of genetic diversity in chrysanthemum core collection of 95 accessions (Russian and foreign cultivars). Seven new SCoT (SCoT12, 20, 21, 23, 29, 31, 34) and six new ISSR markers ((GA)8T, (CT)8G, (CTTCA)3, (GGAGA)3, (TC)8C, (CT)8TG) were efficient for the genetic diversity analysis in Chrysanthemum × morifolium collection. After STRUCTURE analysis, most Russian cultivars showed 20-50% of genetic admixtures of the foreign cultivars. Neighbor joining analysis based on the combination of SSR, ISSR, and SCoT data showed the best accordance with phenotype and origin compared to the separate analysis by each marker type. The position of the accessions within the phylogenetic tree corresponded with the origin and with some important traits, namely, plant height, stem and peduncle thickness, inflorescence type, composite flower and floret types, flower color, and disc color. In addition, several SCoT markers were suitable to separate the groups distinctly by the phenotypical traits such as plant height (SCoT29, SCoT34), thickness of the stem and peduncle (SCoT31, SCoT34), and leaf size and the floret type (SCoT31). These results provide new findings for the selection of markers associated with important traits in Chrysanthemum for trait-oriented breeding and germplasm characterization.

Genetic Diversity in Diospyros Germplasm in the Western Caucasus Based on SSR and ISSR Polymorphism.

Persimmon germplasm in the Western Caucasus represent one of the most northerly collections. In our study, 51 commercial cultivars of D. kaki, 3 accessions of D. virginiana and 57 D. lotus accessions from six geographically distant populations were investigated using 19 microsatellite and 10 inter simple sequence repeat (ISSR) markers. After STRUCTURE analysis, the single accessions of Diospyros were allocated to three genetic clusters. Genetic admixtures in the important genotypes of D. kaki were revealed, whereas D. lotus accessions showed no admixture with other genetic clusters. The correspondence of genetic data and phenotypical traits was estimated in the D. kaki collection. The most frost tolerant genotypes of the collection, such as "Mountain Rogers", "Nikitskaya Bordovaya", "Rossiyanka", "MVG Omarova", "Meader", "Costata", "BBG", and "Jiro", showed a high percentage of genetic admixtures and were grouped close to D. virginiana. Some of these genotypes are known to be interspecific hybrids with D. virginiana. A low level of genetic diversity between the distant D. lotus populations was revealed and it can be speculated that D. lotus was introduced to the Western Caucasus from a single germplasm source. These results are an important basis for the implementation of conservation measures, developing breeding strategies, and improving breeding efficiency.