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Capsicum frutescens (C. frutescens) has rich germplasm resources, but there have been no reports on its genetic diversity analysis alone using simplified genome sequencing technology (GBS). To provide a basis for the breeding of new pepper varieties and the later development of C. frutescens SNP molecular markers, this study used GBS technology to sequence 65 collected pepper germplasm resources. A total of 1,399,391 SNP sites were obtained by GBS simplified genome sequencing, and there were 1,465,897 SNP variant sites. Through population genetic structure analysis, the population structure and phylogenetic tree of 65 C. frutescens germplasms were constructed. The GBS method is also suitable for the genetic relationship analysis of C. frutescens, and it also shows that there is an obvious separation of materials from different origins, and there is also a certain degree of genetic exchange. Most of C. frutescens varieties from Fujian Province and its surrounding areas are clustered together; C. frutescens varieties from western China are also clustered together. We selected T62 and T60 with a genetic distance of 0.2796 and a spiciness level of nine as the female and male parent combinations, respectively, and bred a new high-yield C. frutescens combination, 'Mingjiao 308'. C. frutescens varieties from the same geographical origin are usually clustered together. These germplasms may contain the ancestry of multiple varieties. This result can also provide basic data for the later construction of an SNP fingerprint database. [ABSTRACT FROM AUTHOR]

Capsicum annuum L. is extensively cultivated in subtropical and temperate regions globally, respectively, when grown in a medium with 8 holding significant economic importance. Despite the availability of genome sequences and editing tools, gene editing in peppers is limited by the lack of a stable regeneration and transformation method. This study assessed regeneration and transformation protocols in seven chili pepper varieties, including CM334, Zunla-1, Zhongjiao6 (ZJ6), 0818, 0819, 297, and 348, in order to enhance genetic improvement efforts. Several explants, media compositions, and hormonal combinations were systematically evaluated to optimize the in vitro regeneration process across different chili pepper varieties. The optimal concentrations for shoot formation, shoot elongation, and rooting in regeneration experiments were determined as 5 mg/L of 6-Benzylaminopurine (BAP) with 5 mg/L of silver nitrate (AgNO3), 0.5 mg/L of Gibberellic acid (GA3), and 1 mg/L of Indole-3-butyric acid (IBA), respectively. The highest regeneration rate of 41% was observed from CM334 cotyledon explants. Transformation optimization established 300 mg/L of cefotaxime for bacterial control, with a 72-h co-cultivation period at OD600 = 0.1. This study optimizes the protocols for chili pepper regeneration and transformation, thereby contributing to genetic improvement efforts. [ABSTRACT FROM AUTHOR]