Mandarin (Citrus reticulata blanco) breeding

Abstract

Mandarins including clementines, tangerines, satsumas, willowleaf, tangors and tangelos are the second largest cultivated group of citrus after sweet oranges and provide about 25% of world citrus production. Classical breeding has limited potential in citrus crop improvement and is handicapped mainly by nucellar embryony, long juvenility and self-incompatibility.Molecular biology tools have revealed mandarins as one of the primary citrus species and the ancestor of secondary species. A better understanding of genomics, valuable bioinformatics databases and recent advances in molecular breeding have shortened the breeding cycle and accelerated the breeder’s productivity towards improvement in economicallyimportant traits. This chapter elucidates the economic significance, botanical classification and leading cultivars, global distribution of varieties, floral biology and functional genomics, germplasm biodiversity and conservation, origin and genetic backgrounds of polyembryony, haploids and polyploids and their significance in structural genomics, mutation breeding, seedlessness, scope of conventional and somatic hybridization, applications of molecular markers, bioinformatics databases and transgenics. Enhancing international collaboration, accelerated germplasm conservation and exchange programs, integration of classical breeding and themolecular biology tools discussed could enhance the pace of development of high-yielding cultivars with better resistance against changing climatic conditions, emerging biotic and abiotic stresses and help to ensure food security.