Polymorphism analysis in identification of genetic variation and relationships among Stylosanthes species

Abstract

A total of 148 accessions representing six important species of the genus Stylosanthes, including S. guianensis, S. hamata, S. scabra, S. seabrana, S. macrocephala, and S. capitata, were used to evaluate genetic variation and relationships using sequence-related amplified polymorphism markers. The results showed that the 18 selected primer pairs generated 138 distinct fragments. The fragment sizes ranged from 150 to 2000 bp. Genetic similarity coefficients among the 148 accessions ranged from 0.51 to 0.99, with an average of 0.79. The effective allele number (ne) generated by the 18 primer pairs averaged 1.3552 and ranged from 1.2069 to 1.6080; Nei's gene diversity (He) ranged from 0.1304 to 0.3207, with an average of 0.2070; and Shannon's information index (I) averaged 0.3213 and ranged from 0.2233 to 0.4582. The unweighted pair-group method with arithmetic averages at the 0.69 similarity level separated the 148 accessions into two distinct groups. One group belonged to S. guianensis, and the other group belonged to the non-S. guianensis type. This study verified that Stylosanthes have rich genetic variation, which is an excellent basis for Stylosanthes breeding for new cultivars. This study demonstrates that the SRAP technique is a reliable tool for differentiating Stylosanthes accessions and for discerning genetic relationship among them.

Patterns of genetic diversity and potential ecological niches of Stylosanthes species from northeastern Argentina

“…In the present work, both populations and species showed private bands, indicating a strong genetic identity. Moreover, the population grouping according to their species, and the split of both species in different coordinate's axis in the PCoA, demonstrate the genetic delimitation between these two taxa as was previously reported (Huang et al., 2017; Kazan et al., 1993a). Within each species, populations were grouped according to their geographic proximity, with few exceptions, such as TC and CC populations of S. guianensis , which are distanced by only 18 km yet were separated in the PCoA.…”

“…The genetic variation detected in the present study was higher than that by random amplified polymorphic DNA (RAPD) in four cultivars and two populations (Kazan et al., 1993b). Contrarily, it was lower than that detected by amplified fragment length polymorphism (AFLP; Jiang et al., 2005), by sequence‐related amplified polymorphism (SRAP; Huang et al., 2017), and by simple sequence repeat (SSR; Santos‐Garcia, Karia, et al., 2012). These last three studies analyzed from 42 to 150 accessions (populations and cultivars from germplasm banks) and used up to five individuals per accession.…”

“…This is in concordance with reports for S. scabra populations using the same type of molecular markers (Costa et al., 2018). Several studies were conducted on S. guianensis using different markers (Huang et al., 2017; Jiang, Ma, Zhou, & Zhang, 2005; Kazan, Manners, & Cameron, 1993b; Santos‐Garcia, Karia, et al., 2012). The genetic variation detected in the present study was higher than that by random amplified polymorphic DNA (RAPD) in four cultivars and two populations (Kazan et al., 1993b).…”

“…In Argentina, eight Stylosanthes species grow naturally (Burkart, 1943; Vanni, 2017), and at least three of them are forage species: S. guianensis (Aubl) Sw., S. hippocampoides Mohlenbr., and S. scabra Vogel (Maass & Sawkins, 2004; Santos Garcia, Karia, et al., 2012; Huang, Liu, & Changjun, 2017). The distribution of the first two species covers the northeastern region of Argentina (NEA) (Vanni, 2017).…”

Dehydration response in Stylosanthes scabra: Transcriptional, biochemical, and physiological modulations

“…The Caatinga's plants include species of the genus Stylosanthes (Fabaceae). Factors such as rich genetic variability and the ability to survive under extreme conditions make species of this clade an excellent source of genes for breeding programs (Huang et al, 2017), especially targeting legumes. Furthermore, their ability to restore fertility and improve physical soil properties is worth mentioning due to their already reported association with rhizobia (nitrogen‐fixing bacteria) and their potential to provide permanent vegetation cover (de Barcellos et al, 2008).…”