Molecular breeding to improve guava (Psidium guajava L.): Current status and future prospective

• The main objectives of guava breeding are aimed at improving both plant and fruit characteristics.
• Genetic advances and tools like MAS could be highly useful and offer significant help.
• Genetic work must still be pursed to locate these quality traits.

Guava (Psidium guajava L.) is often referred to as the apple of the tropics. It is a native of tropical America and has been naturalized in India. Being very hardy, it gives an assured crop even with very little care. The main objectives of guava breeding are aimed at improving both plant and fruit characteristics such as to develop high yielding, high quality dwarf varieties with fruits of uniform shape, good size, attractive skin and pulp colour, fewer seeds and or soft seeds, resistant to wilt, long storage life, suitable for table and processing purposes and to evolve wilt resistant and dwarfing rootstocks. Conventional breeding has helped to a limited extent and it is high time that biotechnological tools are explored and exploited either alone or in combination with conventional breeding to improve the crop productivity and to address challenge of improving fruit quality, and tolerance to a biotic and biotic stresses. Success of molecular breeding however, depends largely on available genomic resources which could be exploited for marker aided selection (MAS) and for genetic transformation of non food traits. Guava genomic resources are however scarce and inhibit researchers from exploiting biotechnology tools for the development of improved guava varieties. An effort has been made in this paper to collate and critically analyse the status of genomic advances in guava and their potential application for improving quality and productivity of this important fruit crop.