268 CryoLetters 31 (3), 268-278 (2010) © CryoLetters, businessoffice@cryoletters.org AN IMPROVED POLLEN COLLECTION AND CRYOPRESERVATION METHOD FOR HIGHLY RECALCITRANT TROPICAL FRUIT SPECIES OF MANGO (Mangifera indica L.) AND LITCHI (Litchi chinensis Sonn.) Rekha Chaudhury 1 *, S.K. Malik 1 and S. Rajan 2 1 Tissue Culture and Cryopreservation Unit, National Bureau of Plant Genetic Resources, Pusa Campus, New Delhi-110012, India (email: rekha@ nbpgr.ernet.in) 2 Central Institute for Subtropical Horticulture, Rehmankhera, Lucknow, Uttar Pradesh, India *Corresponding author email: rekha@ nbpgr.ernet.in Abstract An improved method for pollen collection from freshly dehiscing anthers of mango (Mangifera indica L.) and litchi (Litchi chinensis Sonn.) using the organic solvent cyclohexane has been devised. Using this method pollen quantity sufficient for large scale pollinations could be collected and stored for future use. Transport of pollen in viable conditions over long distances, from site of collection (field genebank) to cryolab was successfully devised for both these fruit species. Cryopreservation was successfully applied to achieve long-term pollen storage over periods of up to four years. Pollen vi ability was tested using in vitro germination, the fluorochromatic reaction (FCR) method and by fruit set following field pollination. On retesting, four year cryostored pollen of different mango and litchi varieties showed high percentage viability as good as fresh control pollens. Pollens of more than 180 cultivars of mango and 19 cultivars of litchi have been stored in the cryogenebank using the technology developed, thus facilitating breeding programmes over the long-term. Keywords: mango, litchi, cryopreservation, pollen, viability, cyclohexane INTRODUCTION Mango (Mangifera indica L.; family Anacardiaceae) is one of the most important fruit crops of India with its origin traced to the Indian subcontinent, especially Assam and North- Eastern regions (14). It is an open pollinated crop and more than a thousand types are available in India with extensive genetic diversity (17). For breeding new varieties with specific qualities using improved genetic material, the existing natural variability offers a vast genetic resource of desirable genes. Mango hybridization programmes have been undertaken by some Indian research organizations over the last two decades to exploit this available