Indigenous Arbuscular Mycorrhizal Fungi at tangerine cv. Tejakula (Citrus reticulata var. Tejakula) plantation and their colonization of the roots

Tangerine cv Tejakula (Citrus reticulata var. Tejakula) are now widely cultivated again in Tejakula District, Bali, Indonesia after not being cultivated for a long time since being attacked by Citrus Vein Phloem Degeneration (CVPD) in 1984. Organic cultivation makes these oranges relatively protected from CVPD attacks. This research aimed to observe and identify the indigenous Arbuscular Mychorrizal Fungi (AMF) on roots of tangerine cv. Tejakula for developing as biofertilizer. Exploration was carried out by taking soil and roots samples of tangerine CV. Tejakula at two different altitudes (lowlands at 0-400 m and midlands at 401-700 m above sea level). At each altitude 9 samples were taken randomly, so there were a total of 18 samples. Spore extraction was done using a wet filtration taken randomly, so there were a total of 18 samples. Spore extraction was done using a wet filtration technique while morphological identification was carried out of the genus and species using the Manual for identifying AME (Schenk and Perez, 1990). Calculation of root colonization was done using the trypan blue staining method. AMF species from the lowlands and midlands were being tested for their effectiveness to improve seedling growth of tangerine cv Tejakula in greenhouse. The results showed that only three genera of AMF (Glomus, Gigasprora and Scutelospora) were identified. The results also showed AMF species found in the lowlands and midlands were the same, consisting of 3 Glomus,1 Gigaspora and 1 Scutelospora species. Identification results based on morphological characters showed that all species in the genus Glomus consisted of 3 species, i.e., Glomus sp-1, Glomus sp-2, and Glomus sp-3, while one species in the genus Gigaspora and Scutellospora was Gigaspora and Scutelospora sp. The average root colonization on root of tangerine by AMF in the lowlands and midlands is very high, reaching 100%. AMF species from the lowlands and highlands significantly increased the height and number of leaves of tangerine cv. Tejakula seedlings compared the control (without AMF). The increase in seedling height of tangerine cv Tejakula for 2 months induced by AMF from the lowlands and midlands was l0.32 cm and 8.20 cm, respectively, whereas the in the control was only 3.26 cm. In addition, the increase increase in the number of leaves in seedlings induced with AMF from the lowlands and medlands was 16.62 and 12.58 leaves, respectively, whereas increase in the control it was only 5.80 leaves. This result indicated indigenous AMF from root of tangering can be developed as biofertilizer. The source of spores as an inoculant can be taken from the lowlands and midlands because they have the same genus and species of AMF and have the same effect on seedling growth.