Guava (Psidium guajava L; Myrtaceae) popularly known as “apple of tropics” is an important fruit crop of India. It is largely a self-pollinated crop, but crosspollination also does occur. This results in a large variability in the seedling population. Among cultivars, substantial variation exists in terms of growth pattern, yielding behavior, fruit characters (peel, shape etc.) and physio-chemical composition, aroma, pulp to seed ratio, seed characters. Assessment of variability can be achieved through morphological characters, chemical composition and by biotechnological tools. Variability assessment morpho-agronomically can be done through descriptors by UPOV (1987), NBPGR (2002) and AICRP (CISH) Lucknow (2011). Broader variability in any crop offers good scope for breeding and improvement. | Biodiversity in psidium species and its exploitation for genetic improvement (2020) 9(3): 1025-1032 International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 9 Number 3 (2020) Journal homepage: Review Article Biodiversity in Psidium species and its Exploitation for Genetic Improvement Natasha Gurung1* and S. K. Sarkar2 1 ICAR-IARI Regional Station Kalimpong, West Bengal-734301, India 2 Department of Fruits and Orchard Management, Faculty of Horticulture, Bidhan Chandr Krishi Viswavidyalaya, Mohanpur, Nadia, India *Corresponding author ABSTRACT Guava (Psidium guajava L; Myrtaceae) popularly known as “apple of tropics” is an important fruit crop of India. It is largely a self-pollinated crop, but cross- pollination also does occur. This results in a large variability in the seedling Keywords population. Among cultivars, substantial variation exists in terms of growth Guava, Variability, pattern, yielding behavior, fruit characters (peel, shape etc.) and physio-chemical Psidium species, composition, aroma, pulp to seed ratio, seed characters. Assessment of variability Breeding Methods, can be achieved through morphological characters, chemical composition and by Varieties/Hybrids. biotechnological tools. Variability assessment morpho-agronomically can be done through descriptors by UPOV (1987), NBPGR (2002) and AICRP (CISH) Article Info Lucknow (2011). Broader variability in any crop offers good scope for breeding Accepted: and improvement. About 160 cultivars are available in India, among which 05 February 2020 „Allahabad Safeda‟ and „Sardar‟ varieties are widely cultivated. Crop Available Online: Improvemnet work attempted in India resulted in release of several superior 10 March 2020 selections/hybrids. Interspecific hybrids resistant to guava wilt were developed at .