Assessment of Genetic Diversity and Relationships Among Caladium Cultivars and Species Using Molecular Markers

Abstract

<jats:p>Caladium (<jats:italic>Caladium</jats:italic> ×<jats:italic>hortulanum</jats:italic> Birdsey) is an important aroid widely used in the ornamental plant industry. Concerns have been raised about possible loss of genetic diversity due to a drastic decline in the number of cultivars in the last century. This study assessed genetic diversity and relationships among caladium cultivars and species accessions. Forty-five major cultivars and 14 species accessions were analyzed based on 297 DNA fragments produced by the target-region amplification polymorphism marker system. A low level of diversity (44.4% polymorphism) was exhibited in cultivars, while a high level of diversity (96.8% polymorphism) was present among seven accessions of <jats:italic>Caladium bicolor</jats:italic> (Aiton) Vent., <jats:italic>Caladium marmoratum</jats:italic> Mathieu, <jats:italic>Caladium picturatum</jats:italic> C. Koch, and <jats:italic>Caladium schomburgkii</jats:italic> Schott. A small percentage (7.6%) of DNA fragments was present in cultivars but absent in the seven species accessions, while a high percentage (32.2%) of DNA fragments was present in the seven species accessions but absent in cultivars. Cultivars shared a higher level of similarity at the molecular level with an average Jaccard coefficient at 0.802, formed a large group in cluster analysis, and concentrated in the scatter plot from a principal-coordinate analysis. Two accessions of <jats:italic>C. bicolor</jats:italic> and <jats:italic>C. schomburgkii</jats:italic> were very similar to cultivars with Jaccard similarity coefficients from 0.531 to 0.771, while the rest of the species accessions had small similarity coefficients with cultivars (0.060 to 0.386). <jats:italic>Caladium steudnirifolium</jats:italic> Engler and <jats:italic>Caladium lindenii</jats:italic> (André) Madison were very dissimilar to <jats:italic>C. bicolor</jats:italic>, <jats:italic>C. marmoratum</jats:italic>, <jats:italic>C. picturatum</jats:italic>, and <jats:italic>C. schomburgkii</jats:italic>, with Jaccard similarity coefficients from 0.149 to 0.237 (<jats:italic>C. steudnirifolium</jats:italic>) and from 0.060 to 0.118 (<jats:italic>C. lindenii</jats:italic>). There is a limited amount of molecular diversity in caladium cultivars, but the great repertoire of unique genes in species accessions could be used to enhance the diversity in future cultivars and reduce potential genetic vulnerability.</jats:p>

Evaluation of Ornamental Tropical Plants for Resistance to White Mold Caused by Sclerotinia sclerotiorum

“…A significant difference in disease severity was observed between the two caladium cultivars in controlled environments, suggesting that there may be varying levels of resistance to S. sclerotiorum within cultivars of caladium. The pedigrees of many cultivars of Caladium ·hortulanum are unknown, but most are believed to originate from C. bicolor, C. picturatum, C. marmoratum, or C. schomburgkii (Deng et al, 2007). Future studies could be conducted to identify resistance in other caladium cultivars or species.…”

“…Caladium originates from tropical regions of Central and South America (Germplasm Resources Information Network, 2017). Breeding of hybrid garden caladium has occurred for over 150 years (Deng et al, 2007). Elephant ear, also known as taro, originates from Southeast Asia and is believed to be one of the oldest domesticated crops (Quero-Garcia et al, 2010).…”

Genetic Diversity and Relationships among 177 Public Sunflower Inbred Lines Assessed by TRAP Markers

“…Previous studies have demonstrated that TRAP markers are suitable for assessing genetic diversity in different crops and plants (Hu et al, 2005; Alwala et al, 2006; Deng et al, 2007; Hu et al, 2007). Results in this study also suggested that TRAP markers can be used for genetic diversity studies in sunflower.…”

“…The TRAP marker technique utilizes a fixed primer designed against a known sequence in combination with two arbitrary primers to generate polymorphic markers (Hu and Vick, 2003). Since it is easy to perform and allows for relatively high throughput, the TRAP technique has been successfully applied to the studies of sunflower genome mapping (Hu, 2006) as well as germplasm diversity and population genetics in other plant species, including spinach ( Spinacia oleracea L.) (Hu et al, 2007), lettuce ( Lactuca sativa L.) (Simko and Hu, 2008), sugarcane (Alwala et al, 2006), and a Caladium germplasm collection (Deng et al, 2007).…”

Genetic Diversity and Relationship of Mulberry Genotypes Revealed by RAPD and ISSR Markers

“…Jaccard's similarity coefficient for ISSR data also indicated a moderate level of similarity coefficient between C-2016 and M. multicaulis (0.53), Shrim-5 (0.54), and Kenmochi (0.55). A higher similarity coefficient indicates genetic closeness of the genotypes (Deng, Goktepe, and Harbaugh 2007). Therefore, the identified mulberry genotypes with low similarity coefficients can be utilized in controlled crossing programs.…”