Effects of Host Specificity in Parasitic Loranthaceae for Sodium and Potassium Distribution in Coastal Region of Cameroon

In this study, the effect of host specificity in parasitic in some mineral nutrient distribution was investigated in four Loranthaceae/host couples grown in the coastal region of Cameroon in order to determine physiological criteria of identification for the degree of specificity of Loranthaceae-host relationship. The distribution of potassium and sodium in plant parts of generalist Loranthaceae/host couples (Phragmanthera capitata/Citrus maxima, P. capitata/Psidium guajava and P. capitata/Theobroma cacao) was compared to a specialist Loranthaceae/couple (Tapinanthus ogowensis/Dacryodes edulis). After mineralization of plant organs of the parasite and the hosts, sodium (Na+) and potassium (K+) concentrations were determined by Flame photometer on 36 samples belonging to four Loranthaceae/host couples. Results showed a significant difference (p<0.05) in Na+ and K+ partitioning in T. ogowensis and D. edulis except in the non parasitized host leaf and parasitized sucker (p>0.05). The K+ distribution in generalist Loranthaceae (P. capitata) and its hosts (C. maxima, P. guajava and T. cacao) were higher in the plant parts than Na+ for C. maxima and T. cacao. It was not significantly (p>0.05) different on Na+ distribution in plant organs of P. capitata and its hosts. The results also revealed high accumulation (p<0.05) of Na+ in non parasitized host leaf and parasite leaf of D. edulis and low storage in T. cacao roots. The accumulation of K+ in the plant parts of T. ogowensis and its host (D. edulis) was lower (p<0.001) than those of P. capitata and his hosts (C. maxima, P. guajava and T. cacao). The distribution of K+ in plant parts could contribute to verify the degree of the host specificity in parasitic which could contribute to determine the potential for infestation of plant population by Loranthaceae in a natural ecosystem.