Diversity in genusmangiferaL. and varietal variation and improvement in mango (mangifera indicaL.): A review

Abstract

Mango (mangifera indica L.) originated as allopolyploid most probably amphidiploid with 40 somatic (2n) chromosomes of small size (0.2–2.0μm). Cytology revealed regular meiosis with regular pairing of chromosomes and their disjunction in 20 bivalents. Origin of mango to Indo-Burma (Myanmar) region is unquestionably established and the origin of the genus mangifera L. has been established in the region of Myanmar-Siam-Indochina or Malay Archipelago as its primary center and Sunda Islands (Java, Sumatra, Bornco)- the Philippines and Celebes-Banda-Timor group as the secondary centre. m. odorata, m. zeylanica, m. caloneura, m. Sylvatica, m. foetida and m. caesia have the same number of chromosomes and thus show a possibility of occurring cross ability among them. m. indica L. and its closely related species have enormous variability, which is considered valuable for mango improvement. Characterization of these species morphologically and by molecular markers has been attempted and their relatedness has been indicated. Genetic relationship among m. indica, m. odorata, m. caesia and m. foetida has been indicated by AFLP analysis. mangifera species are valuable for mango improvement, as they are resistant to certain biotic and abiotic stresses. Mango has rich germplasm, which comprises of 1682 cultivars in the world and 108 other accessions including farmers’ varieties in India. Efforts made in the improvement of mango have resulted in many improved varieties. Some varieties selected from open-pollinated natural seedlings and also as clones of commercial cultivars have potential of commercial use as table, juice pulp and pickle varieties. Such available selections, natural bud-sports and induced mutants need to be tested and recommended for commercial cultivation. In early times, the spread of mango took place through Voyages but now the exchange of plant material takes place in a systematic way through international germplasm exchange programmes. Most of the cultivars of Florida have been evolved as the 2nd or 3rd generation seedling selections from cv. Malgoa introduced from India. Some of the useful exotic collection available in India has gainfully been utilized. Exotic cv. Eldon (EC141457) introduced from Brazil has been released in the popular name ‘Pusa Surya’ by IARI, New Delhi for commercial cultivation in India. Exotic cvs. Sensation and Tommy Atkins have been used as parents to develop variety with red peel, pleasant sugar: acid blend in fruit juice and long shelf-life of fruit. Planned hybridization programmes in India have yielded many high yielding and regular bearing varieties with improved fruit quality and long shelf-life. Some of them are Pusa Arunima, Pusa Pratibha, Pusa Shreshth, Pusa Lalima, Ambika and Arka Anmol with red peel suitable for export. Efficient technique of hybridization has been standardized and inheritance pattern of many important traits has been studied. Some of the pre-selection indices have been established for selection of hybrids. Source of genes for resistance to various biotic and abiotic stresses have been found out for incorporation of resistance/tolerance to specific stresses in hybrid. Some endeavours have been made to induce useful mutations and some economically important natural bud-sports have been reported. Registration of elite accessions and newly developed varieties with Protection of Plant Variety and Farmers’ Rights Authority, Govt. of India, National Bureau of Plant Genetic Resources of ICAR and International Registration Authority of Mango Cultivars established at the Division of Fruits and Horticultural Technology of the Indian Agricultural Research, Institute, New Delhi has been suggested to protect the intellectual property right and to avoid the synonym and duplication of name of the variety.