Identification and Abundance of Plant-parasitic Nematodes Associated with Amenity Trees in the University of Port Harcourt, Rivers State, Nigeria

Abstract

Plant-parasitic nematodes contribute to unnoticeable damages which lead to gradual decline in the values and eventually death of amenity trees. Identification of these nematode pests is vital for their effective management. Reconnaissance survey was carried out to identify amenity tree species present in the University of Port Harcourt (UNIPORT). Composite bulked soil and root samples (126) were collected from amenity trees in UNIPORT and nematode pests were extracted from samples using modified Baerman method. The nematode pests were identified and their populations determined using standard procedures. Relative importance value (RIV) and diversity indices were calculated with appropriate software. Data were processed using descriptive statistics and with analysis of variance. 38 tree species were identified in UNIPORT belonging to 20 families. Terminalia mantaly, Cocos nucifera and Terminalia catappa with RIVs of 15.1, 9.35, and 9.12 respectively were the three most important amenity trees in UNIPORT. Fifteen nematode pest genera; Helicotylenchus, Aporcelaimus, Tylenchulus, Meloidogyne, Scutelonema, Pratylenchus, Tylenchus, Rotylenchoides, Criconema, Hemicyliophora, Trichodorus, Mesodorylaimus, Heterodera, Paratylenchus and Longidorus were associated with 21 of the amenity trees. The three most important nematode pest genera were Helicotylenchus, Tylenchulus and Aporcelaimus with RIVs of 42%, 16% and 5.34%, respectively. Helicotylenchus (RIV 45.41%) and Tylenchulus (RIV 30%) were the most important plant-parasitic nematode genera in the soil and roots of amenity trees, respectively. Helicotylenchus, Tylenchulus and Aporcelaimus were the three most important plant-parasitic nematode genera associated with amenity trees in UNIPORT.

Keywords: Amenity trees, Diversity indices, Identification, Nematode pests, Survey