Genetic male sterility breeding in heat tolerant bell pepper: Introgression of ms10 gene from hot pepper through marker-assisted backcrossing

The main goal of this research was to introgressed the genetic male sterility (GMS) gene ms10 from hot pepper (Capsicum annuum var. annuum) to heat tolerant bell pepper (C. annuum var. grossum) inbreds and to pyramid it with the non-pungent (pun1) gene. The gene positive plant selection was assisted by the SSR marker linked to ms10 gene located on chromosome I and the SCAR marker indicating the non-pungent pun1 gene presence. First, we backcrossed and screened BC1F1 and BC2F1 plants having heterozygous (Ms10ms10) genotype for GMS specific marker AVRDC-PP12. Secondly, the background recovery rate of the recurrent parent phenome (RPP) in both the backcrossed progeny was estimated by measuring the shift in means for fruit traits. Simultaneously, targeted gene positive (Ms10ms10) non-pungent (pun1) heterozygous plant(s) were identified in BC2F1 generation using BF7 and BF 9-SCAR marker. The best gene positive individual plant from each population was backcrossed with their respective recurrent parent and selfed for validation of ms10 gene. Finally, we obtained six gene positive (ms10) GMS lines designated as MSSM-1, MSSM-2, MSSM-3, MSSM-9, MSSM-17, and MSSM-21 from this work. To the best of our knowledge, this is the first time that GMS ms10 gene has been successfully transferred from hot pepper to heat tolerant bell pepper through marker-assisted backcross breeding scheme coupled with stringent phenotypic selection. The developed GMS lines will provide great economic value for nonpungent hybrid bell pepper seed production in the near future.