Available online at http://www.ifgdg.org Int. J. Biol. Chem. Sci. 14(3): 896-915, April 2020 ISSN 1997-342X (Online), ISSN 1991-8631 (Print) Original Paper http://ajol.info/index.php/ijbcs http://indexmedicus.afro.who.int Floristic diversity of Loranthaceae Family and their potential host species in Sudano-sahelian zone of Cameroon: case of Diamare plain in Far-North Region Souare KONSALA1*, Gilbert TODOU1, Froumsia MOKSIA1, Divine Tii MUNTING 1, Jeanne Flore NNANGA1, TCHOBSALA1 and Ibrahima ADAMOU2 1University of Maroua, Faculty of Science, Department of Biological Sciences, P.O. Box: 814 Maroua, Cameroon. 2University of Ngaoundéré, Faculty of Science, Department of Biological Sciences, P.O. Box: 454 Ngaoundéré, Cameroon. * Corresponding author; E-mail: [email protected] ABSTRACT There is an increasing interest in parasitic plants and infectious disease community ecology in intertropical regions. The study examined the floristic diversity of Loranthaceae family and their potential host species in the ecoregion of Diamare plain in Cameroon. Reasoned sampling method was performed and experimental device consisted of 02 main treatments (Diamare and Mayo-Kani divisions), 08 secondary treatments (councils) and 32 replications (villages), with four (04) villages per council. We used itinerary botanical survey method of 1000 m x 20 m in each village, totalizing 64 ha and all parasitic plants and their potential hosts were inventoried. A total of 11 645 ligneous individuals was inventoried in the Diamare division, distributed within 65 species, 44 genera, and 22 Families. In Mayo-Kani division, a total of 16 645 ligneous individuals were inventoried, distributed in 58 species, 41 genera and 19 families. There was a significant difference between the two divisions in terms of individuals (p < 0.001). In total, nine parasitic plants of the Loranthaceae family were inventoried, with five species identified at the level of species (55.55%) and four species at the level of genera (44.44%): Agelanthus dodoneifolius (DC.) Polh. and Wiens, Tapinanthus globiferus (A. Rich.) Van Tiegh., Tapinanthus oleifolus (JC. Wendl.) Danser; Tapinanthus voltensis Van Tiegh. ex Balle; Tapinanthus ophiodes (Sprague) Danser, Tapinanthus sp1., Tapinanthus sp2., Tapinanthus sp3. and Phragmanthera sp. Agelanthus dodoneifolius, Tapinanthus globiferus and T. ophiodes recorded a weak parasitic specificity (PSp = 81.39%; 72.09% and 30.23% respectively). Combretaceae and Mimosaceae families showed the greatest number of sensitive host species to Loranthaceae infestation (20.89% and 16.27% respectively). There was no significant difference between parasitic specificity of Loranthaceae and parasitic sensitivity of host species (p > 0.05), and both were positively correlated (r = 0.96). Efforts are required to control the development of Loranthaceae in sudano-sahelian zone especially in ecosystem plantations. © 2020 International Formulae Group. All rights reserved. Keywords: Floristic diversity, Loranthaceae, host species, Diamare plain, Cameroon INTRODUCTION which fix on aerian parts of their host (Koffi et Loranthaceae are locally and commonly al., 2014). These vascular parasites are called using the appellation "African responsible for varied economic, ecological, mistletoe". They are phanerogams, morphological and physiological damages on hemiparasites, chlorophyllian and epiphytes different cultures and ligneous vegetations © 2020 International Formulae Group. All rights reserved. 8447-IJBCS DOI: https://doi.org/10.4314/ijbcs.v14i3.20 S. KONSALA et al. / Int. J. Biol. Chem. Sci. 14(3): 896-915, 2020 (Sallé et al., 1998). They fix to their host using are already threatened in this zone, there was a a specialized organ called haustorium, which great necessity of carrying out a establishes contact with the host at the level of reconnaissance survey of these hemiparasites the xylem conductive tissues (Boussim et al., in order to take appropriate conservation 1993). These vascular parasites are present in measures to preserve its diversity and regulate all intertropical regions and in certain its growth in the study area. The survey aimed temperate zones and are sprawling to other at contributing to the knowledge of regions. In the world, a total of 950 species and Loranthaceae diversity and their potential hosts 77 genera belonging to this Family are known in the Sudano-sahelian zone of Cameroon in a (Boussim et al., op. cit.). view to fighting against degradation of In Africa, Polhill and Wiens (1998) resource plants. identified more than 500 species of the Loranthaceae Family, and the investigations MATERIALS AND METHODS dealed mostly with crop protection. In Study site Burkina-Faso, Boussim (2002) reported that The study was carried out in the Far- large agroforestry surface areas parasitized by North Region of Cameroon, in the Diamare Loranthaceae led to massive tree deaths, most plain including Mayo-Kani and Diamare often in the absence of human control and divisions. These divisions cover a total area of intervention through diverse techniques of 6450 km² and a population of 768 603 fight. In Ivory Coast, Soro et al. (2006) have inhabitants (MINATD, 2010). It is located raised an alert on the negligence of between 10°0’ N to 10°48’ N and 14°0’ E to Loranthaceae Family that has now become a 14°48’ E (Figure 1).The climate is of the veritable nightmare in both natural vegetation Sudano-sahelian zone and is characterized by and plantations alike. These vascular plants in two seasons, a long dry season (8 to 9 months) the form of small shrubs develop on the trunk spanning from October to May and a short of their hosts. The growth of the host is thus rainy season (3 to 4 months) from June to slowed down and often ends up with death. In September (Fotsing, 2009). Very high Cameroon, Ballé (1982) inventoried twenty six temperatures reaching 45 °C under shade and a (26) species regrouped into seven (07) genera. very dry atmosphere are experienced from Plantations and natural occurring woody March to June. Rainfall varies between 600 and species are main parasitic grounds of 900 mm/year, with maximum rainfall mostly Loranthaceae. Many countries by experience between July and August (Djibrilla, 2016). have testified that Loranthaceae are responsible Hydrography is made up of temporal flowing for decrease of productivity especially in rivers (Mayos) which dry up at the end of the agroforestry plantations. These parasitic rainy season. The main soil types encountered species which have not been sufficiently are vertisols, hardés, sandy soils, rocky soils in studied and vulgarized by research foundations mountain areas, and silty soils favorable to constitute a real threat to trees in home gardens market gardening (FAO, 2011). (Dibong et al., 2008). In East Cameroon, The vegetation is characterized by a Theobroma cacao, Coffea robusta, Dacryodes shrub steppe of the Sudano-sahelian type. The edulis plantations and coastal gardens along most important plant species are: Adansonia roads created by forest exploitation are major digitata, Guiera senegalensis, Tamarindus Loranthaceae targets (Dibong et al., 2012; indica, Acacia albida, Acacia spp., Ziziphus Azo’o et al., 2013). mauritiana and Ficus spp. Most of these plants The Diamare plain in the sudano- are used for livestock feed (Wafo, 2008). Other sahelian ecoregion of Cameroon is facing the African mistletoe and Acacia albida are challenges such as overexploitation and appreciated for their leaves serving as fodders degradation of plant resources, desertification and their fertilizing roots. The wildlife is poor and global warming. Being aware that and is endangered due to the lack of a Loranthaceae are parasites and capable of conducive environment for their development. accelerating plant resources degradation which Some species are mostly located in the 897 S. KONSALA et al. / Int. J. Biol. Chem. Sci. 14(3): 896-915, 2020 mountains, and include rodents (mice, rats, permit the group to identify the species. damans, squirrels, hares), reptiles (lambs, Notwithstanding, some hosts are inaccessible lizards, snakes), locusts and caterpillars, and Loranthaceae species found on them were sparrows; hyenas; panthers and wild cats; observed by means of a telescope that draws monkeys (IPCC, 2007). Most of the people rely the parasite closer for proper observation. on agriculture, livestock and forest resources to Assessment of parasitic specificity of meet their basic needs. Loranthaceae species and parasitic sensitivity of host species Data collection It is often stated that a good parasite Inventory of potential host species and does not kill its host. That said, variation in the parasitic plants degree of pathogenicity exhibited by various The two divisions, Diamare and Mayo- parasitic plants is great, from those which exert Kani, constituted the basis of the study (main little impact on their hosts to those which treatments). In each division, four (04) councils dramatically affect the host physiology and were sampled constituting the secondary fecundity. Pathogenicity depends upon many treatments and four (04) villages (replications) factors, such as the biomass ratio of parasite to in each council. We used reasoned sampling host, the number of parasites attached to an method developed by Grangé and Lebart individual host plant, the length of time (1992) for the selection of the councils, required for the parasite to complete its life considering the presence of ligneous plant cycle, and possibly the degree of formations