Seed-Borne Fungal Organisms Associated With Germination Success of Terminalia Brownii (Fresen, 1837) In Drylands of Kenya

Abstract

Terminalia brownii (Fresen, 1837) is one of the important species distributed throughout the tropical and sub-tropical regions of the world. It is highly valued in the Kenyan drylands for its products such as timber for wood carving, medicine, and charcoal production, among others. Due to this high value, followed by overutilization, its population in the drylands is dwindling. Concern regarding its regeneration capacity has been raised, as shown by low germination both in situ and ex-situ. The main aim of this research was to assess seed-borne fungal organisms associated with germination success of T. brownii seeds in Kenyan drylands, which will contribute to the conservation of the species and in turn improve livelihoods of the dependent communities. The specifics objectives were to analyze germination success of T. brownii, assess seed-borne fungal organisms associated with T. brownii success and compare seed-borne fungal organisms associated with germination of T. brownii in Baringo, Kendu Bay, and Kitui areas. Sites with a high density of T. brownii trees were chosen for fruit probing and maturity confirmation. Random sampling was used in selecting thirty trees, fifty meters apart, from which fresh fruits were collected from the crowns at three height levels. A complete randomized block experimental design where one hundred T. brownii seeds from each of the three sites, were subjected to a germination test. Seeds that failed to germinate were assessed for the presence of fungal organisms. The present organisms were cultured, DNA extracted and sequenced for identification. The results were displayed an insignificant difference between the number of seeds that germinated and those that did not germinate (N=12, P=0.0000, t=16.29), and fungal organisms identified associating with germination failure were Fusarium equiseti, Pestalotia sp, and Alternaria alternata. Seeds that germinated were also tested for fungal infestation and Penicillium sp were found to be present. A Paired t-test between the number of seeds that did not germinate, and the number of fungal infected seeds gave N=12, a p-value of 0.000, t=-8.78. Fungal organisms associating with the germination success of T. brownii do not significantly affect the germination of freshly extracted seeds from the field, hence for maximum germination achievement, seeds should be sown while still fresh.