Genetic diversity of Lagerstroemia (Lythraceae) species assessed by simple sequence repeat markers

Abstract

ABSTRACT. Lagerstroemia (crape myrtle) are famous ornamental plants with large pyramidal racemes, long flower duration, and diverse colors. However, little is known about the genetic structure and diversity of germplasm in Lagerstroemia. We genotyped 81 L. indica cultivars, five other species of Lagerstroemia, and 10 interspecific hybrids using 30 simple sequence repeat markers; 275 alleles were generated with a mean of nine alleles per locus. The mean polymorphism information content value, a measure of gene diversity, was 0.63, with a range from 0.25 to 0.86. The mean observed heterozygosity (0.51) tended to be lower than the mean expected heterozygosity (0.67). The mean F-statistics (F ST , F IS , and F IT ) were 0.05, 0.20, and 0.24, respectively, indicating a high level of genetic variation among cultivars. Clustering analysis based on genetic distance divided the 96 genotypes into three distinct groups, which corresponded with their genetic backgrounds and geographic regions. L. indica cultivars and the other five L. species were grouped into different sub-clusters. Chinese and North American cultivars were divided into different clusters. These data about the genetic relationship among cultivars demonstrated the potential value of L. indica cultivars and other Lagerstroemia species for widening the genetic basis of breeding programs for this ornamental flower.

The first genetic linkage map of crape myrtle (Lagerstroemia) based on amplification fragment length polymorphisms and simple sequence repeats markers

“…, He et al. ). However, the limiting factor to the broader use of SSRs is the cost of development and narrow range of primer specificity.…”

“…, He et al. ). These primers were prescreened on two parents and eight randomly selected progeny to identify polymorphisms.…”

“…, He et al. ), which would permit their application as molecular markers in crape myrtle genome mapping.…”

Screening of molecular markers linked to dwarf trait in crape myrtle by bulked segregant analysis

“…A total of 41 SSR primers demonstrated to be highly polymorphic in crape myrtle were tested He et al, 2012). All primers were synthesized by Sangon Biotech (Shanghai) Co., Ltd. (Shanghai, China) ( Table 1).…”

“…Among all DNA markers, amplified fragment length polymorphism (AFLP) is effective when little knowledge is available regarding the genome sequence (Waugh et al, 1997). Additionally, simple sequence repeats (SSRs) are abundant, co-dominant, and highly polymorphic in Lagerstroemia species and cultivars (Cai et al, 2011;He et al, 2012), and can be used as molecular markers for gene mapping in Lagerstroemia.…”