Advances in Breeding Strategies of Bell Pepper (Capsicum annuum L. var. grossum Sendt.)

Abstract

Bell pepper belongs to the Solanaceae family and is in high demand as a vegetable in India, Middle East, USA, Europe and Southeast Asian countries. It has gained the attention of progressive farmers, consumers and international market traders because of its rich nutritional profile and ever-increasing export potential (USD 4.9 billion in 2017). Thirty-eight Capsicum taxa are currently documented in the USDA Genetic Resources Information Network (GRIN), including the five under commercial cultivation. In the sixteenth century, bell pepper was introduced to the Asian continent. Currently, China, India, Pakistan, Bangladesh and Indonesia shares over 70% of the world’s bell pepper production. The World Vegetable Center in Taiwan holds the world’s largest Capsicum collection of 8165 accessions, and covers 11% of global diversity. Besides traditionally-important traits like earliness and higher yield, bell pepper breeding is now challenged by the emergence of new pests and diseases. New varieties are needed with desirable fruit color, pungency, shape and nutritional quality, along with resistance to phytophthora, anthracnose, bacteria, viruses, powdery mildews, root-knot nematodes, heat, cold, drought and salinity tolerance; all of these characteristics represent major breeding goals along with higher yields. Conventional breeding methods like introduction, pure line selection, pedigree selection, mutational and heterosis breeding, and backcross breeding are now being assisted by new breeding approaches like rootstock breeding along with modern genomic tools to break down existing barriers, and to speed up traditional breeding programs. Development and implementation of hybrid cultivars are key aspects of bell pepper production, for which the genetic male sterilitysystem is being exploited commercially in both the public and private sectors. However, in comparison of chili pepper, utilization of the cytoplasmic male sterility (CMS) system in bell pepper is restricted, owing to high instability of male sterility expression at low temperature, and poor fertility restoration (Rf) ability. This chapter describes recent advances in genetic improvement of bell pepper by using various cultivated and wild species as sources of important traits.