Assessing the Genetic Diversity of Chrysanthemum Cultivars with Microsatellites

Abstract

<jats:p>The morphological characteristics of chrysanthemum (<jats:italic>Chrysanthemum</jats:italic> ×<jats:italic>morifolium</jats:italic>) are rich in variation. However, as a result of the aneuploid polyploidy of the chrysanthemum genome and the lack of proper tools, the genomic information of this crop is limited. Development of microsatellite markers has been an increasing trend in crop genetic studies because of the applicability of these markers in breeding programs. In this study, we reported the development of a simple sequence repeat in chrysanthemums using a magnetic beads enrichment method. An enriched genomic library with AC and GT microsatellite motifs was constructed, and 53 positive clones were detected by a colony polymerase chain reaction (PCR) technique. Of these clones, 35 showed high-quality sequences, and 35 primer pairs were designed accordingly. Twenty-six (74.29%) of the 35 primer pairs revealed polymorphisms on a set of 40 chrysanthemum cultivars. There were 172 alleles amplified over 26 loci with an average of 6.615 alleles per locus. The mean values of gene diversity corrected for the sample size and the inbreeding coefficient were 0.609 and 0.119 over 26 loci, respectively, which indicated that the majority of the microsatellite loci is highly informative. Cluster analysis based on 26 polymorphic loci demonstrated that the selected cultivars were clustered according to geographical origin. This study shows the isolation efficiency of the magnetic beads technique; the abundance of microsatellites in chrysanthemum; and the potential application for the cultivar classification, the studies on genetic diversity, and molecular breeding of chrysanthemums, which is beneficial to promoting the conservation and sustainable use of this crop.</jats:p>

Application of Genomic SSR Locus Polymorphisms on the Identification and Classification of Chrysanthemum Cultivars in China

“…A total of 20 polymorphic SSR loci from chrysanthemums that had been previously verified using 40 cultivars with known genetic relationships [14] , and showed high polymorphisms were selected as loci in the present study. The PCR reaction system was based on Li et al [32] with several important modifications.…”

“…Japan, USA, UK and China are four important countries that have focused on the study of chrysanthemum classification, and accordingly, several classification systems for chrysanthemums have been proposed [1] , [11] , [12] , [13] , [14] . Both the Japanese and American classification criteria involve flower diameter and the flower head type.…”

“…Especially, cultivars possess similar morphological features can be distinguished by molecular markers very well. In recent years, random amplified polymorphic DNA (RAPD), amplified fragment length polymorphism (AFLP), inter-simple sequence repeats (ISSR), simple sequence repeats (SSR) and sequence-related amplified polymorphism (SRAP) markers have been used to identify sports or classify cultivars in chrysanthemum [14] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] . Among these markers, SSR markers have gained considerable popularity due to their many desirable attributes, including hypervariability, a multiallelic nature, codominant inheritance, reproducibility, relative abundance, extensive genomic coverage (including organellar genomes), chromosome-specific location, amenability to automation, and high-throughput genotyping [28] .…”

Host-plant resistance to western flower thrips in Arabidopsis

“…With the ascend of the -omics era in plant breeding, questions on host-plant resistance to thrips might be directly addressed to the variation in crops of interest. Pepper has already been resequenced (Qin, Yu et al 2014), and it may take only a few more years before also polyploid cut-flowers like Chrysanthemum have their genome sequenced (Zhang, Wang et al 2013). However, Arabidopsis will remain an essential species in functionally characterizing resistance genes to thrips.…”

Karyotype diversity analysis and nuclear genome size estimation for Pennisetum Rich. (Poaceae) ornamental grasses reveal genetic relationship and chromosomal evolution

“…Its high chromosome numbers (45) may result in such a significant difference, because the loading value of chromosome number was the highest in the first principle component in PCA, and thus affected the clustering procedure to a large extent. Another possible reason is that because the performances of morphological characteristics are the result of the expression of certain functional genes under the internal and external environment, the structural differences of the chromosomes or DNA are not always exposed (Zhang et al, 2013a).…”