Fruits and Nuts

Abstract

The climatic diversity of the Indian Subcontinent has generated significant genetic diversity in cultivated tropical, subtropical, temperate, and arid fruits. Rich diversity is also exhibited in the wild relatives of these fruit types. Tropical fruits constitute a major proportion of the spectrum of fruit diversity available with large cultivation of indigenous fruits like mango (Mangifera indica L.), banana (Musa spp.), citrus fruits (Citrus spp.), jackfruit (Artocarpus heterophyllus L.), litchi (Litchi chinensis), etc., which produces about 66.4% of the annual fruit production. Maximum concentration of wild species has been recorded in Citrus and Musa (Fig. 10.1) occurring in the northeast region. In Citrus, Singh and Chadha (1993) recorded 30 species/botanical varieties, indigenous to India. Shillong Plateau has Citrus assamensis, C. latipes, C. macroptera, and C. medica. Citrus indica has sporadic distribution around Tura range and Khasi Hills in Meghalaya and in the foothills of Nagaland, where C. ichangensis (cavaleriei), a cold-tolerant native of China, is also found (possibly a hybrid of C. latipes). Citrus jambhiri (considered a variety of C. limon) is found sporadically in the peninsular hills and is used as rootstock. Citrus aurantifolia has a comparatively wider distribution occurring in the sub-Himalayan tract extending eastward to Khasi Hills and southward to Nilgiris. Similarly, in Musa, maximum variability occurs in the northeast (Fig. 10.1), in the wild types of M. balbisiana and M. acuminata. Musa flaviflora (M. thomsonii) is confined to Manipur and Meghalaya, and M. nagensium is endemic to Naga Hills. Musa sikkimensis occurs in North Sikkim, West Bengal, Khasi Hills, and Manipur. Among others, M. superba occurs in the Western Ghats and Assam. In the foothills of Assam also occur M. cheesmanii, M. mannii, and M. velutina. Mangifera wild species are represented by M. sylvatica, M. khasiana, and M. camptosperma from northeast region and M. andamanica from tropical areas of wet evergreen forests of Andaman Islands. The northeast region also has diversity in other wild fruits such as Elaeocarpus floribundus, Myrica esculenta, Docynia indica, and D. hookeriana. The humid tropical zone of the Western Ghats is another region of concentration of wild relatives of cultivated fruits such as Artocarpus heterophyllus and A. lakoocha and wild forms of Garcinia indica, Mimusops elengi, and Euphoria longan (Dimocarpus longan). In case of Garcinia, there are two major centers of diversity in the Indian Subcontinent; the northeast region, extending from Assam up to Myanmar; and the Western Ghats. There are 36 species reported from India, out of which 15 are endemic. Of these, seven are endemic to the Western Ghats, six to the Andaman and Nicobar Islands, and four to the northeast region. Comparatively wider distribution in peninsular tracts are of species of Diospyros (temperate diffused to all over continent), Syzygium, and Vitis. Spondias pinnata also exhibits much variability in this tract.