Meghalaya which hosts India National Citrus Gene Sanctuary, has been reconfirmed as a critical global hub of citrus diversity, though many of its unique species are now facing significant threats. A comprehensive new study conducted by a team from the ICAR-National Bureau of Plant Genetic Resources (NBPGR) and regional institutes documented 13 different citrus species across the state hills including two Citrus aurantifolia (acid lime) and C. megaloxycarpa (giant wild orange) that had not been reported in previous surveys.
The research collected 57 accessions from nearly every district, establishing the Garo Hills and Khasi Hills as the primary hotspots, with each area representing 10 species. This underscores the region importance, given that North Eastern India harbors 23 out of the 27 citrus species reported nationwide.
Rare Wild Species Ringing Alarm Bells
While cultivated varieties like C. reticulata (mandarin) and C. jambhiri (rough lemon) are widespread, the study raised serious concerns about the status of wild citrus species, particularly in South Garo Hills and West Khasi Hills. These areas host rare species such as C. indica, C. megaloxycarpa, C. medica, and C. latipes.
Most critically only a single sample of the endangered C. indica (Indian Wild Orange), known for its tiny, dark-orange fruits, was collected in South Garo Hills. This finding reconfirms the species’ precarious status, which was already described as having a restricted spread in decades-old surveys of the Tura ranges. In contrast, the discovery of the giant C. megaloxycarpa, with fruits weighing over half a kilogram, highlights the immense and striking genetic variation present within Meghalaya’s wild citrus population.
Threats and Conservation Strategy
Scientists are warning that numerous wild citrus species are at high risk of extinction due to mounting environmental pressures. These threats include habitat destruction from shifting (‘jhum’) cultivation, the spread of exotic species, widespread deforestation, and the added pressure of climate change. Seven wild citrus species from Northeast India, including C. indica, C. latipes, and C. macroptera, are already classified as threatened or vulnerable by the IUCN.
To safeguard this invaluable citrus legacy, researchers are recommending a multi-pronged conservation strategy. This approach stresses the need for DNA barcoding to confirm species identities against complex hybridization, and GIS-based mapping to pinpoint micro-hotspots that require urgent protection.
Crucially the study emphasized that conservation efforts must actively involve local tribal communities, whose traditional knowledge and stewardship are essential, alongside the implementation of sustainable land-use practices and broader climate action. Protecting these species is vital not only for biodiversity but also for the future of citrus breeding and global food security.