Comparing interfertility data with random amplified microsatellites DNA (RAMS) studies in Ganoderma Karst. Taxonomy
The taxonomy of the causal pathogen of basal stem rot of oil palms, Ganoderma is somewhat problematic at present. In order to determine the genetic distance relationship between G. boninense isolates and non-boninense isolates, a random amplified microsatellites DNA (RAMS) technique was carried out. The result was then compared with interfertility data of G. boninense that had been determined in previous mating studies to confirm the species of G. boninense. Dendrogram from cluster analysis based on UPGMA of RAMS data showed that two major clusters, I and II which separated at a genetic distance of 0.7935 were generated. Cluster I consisted of all the biological species G. boninense isolates namely CNLB, GSDK 3, PER 71, WD 814, GBL 3, GBL 6, OC, GH 02, 170 SL and 348781 while all non-boninense isolates namely G. ASAM, WRR, TFRI 129, G. RES, GJ, and CNLM were grouped together in cluster II. Although the RAMS markers showed polymorphisms in all the isolates tested, the results obtained were in agreement with the interfertility data. Therefore, the RAMS data could support the interfertility data for the identification of Ganoderma isolates.
Ganoderma boninense Pat. from Basal Stem Rot of Oil Palm (Elaeis guineensis) in Peninsular Malaysia
Several hundred sporophores of Ganoderma were collected from 5 - 40 years old palm trees infected with basal stem rot in 5 oil palm estates in Peninsular Malaysia. Based on the morphometric studies of the pores, dessepiments and basidiospores dimensions and other morphological characteristics, the sporophores were identified as belonging to a single species, G. boninense Pat.
Genetic variation in Ganoderma spp. from Papua New Guinea as revealed by molecular (PCR) methods.
Basal stem rot of oil palm is a disease that has been found in almost all countries where oil palm is grown (Turner, 1981). The major causal agent of this disease has been found to be Ganoderma boninense Pat. in both Malaysia and Papua New Guinea but several species have been associated with the disease in other countries (Turner, 1981). Ganoderma species occur throughout the world in both temperate and tropical regions. They may be saprophytic, decomposing lignin of dead wood, or pathogenic on living trees. Several species of this genus are responsible for root and butt rots in tea (Varghese and Chew, 1973), rubber (Lim, 1977), temperate hardwoods (Ross, 1976; van der Kamp et al., 1979), coconut and betelnut palms (Reddy and Ananthanarayanan, 1984; Singh, 1985) and other tropical forest trees (Bakshi et al., 1976; Harsh et al., 1993; Masuka and Nyoka, 1995). In Papua New Guinea, where basal stem rot caused by G. boninense is the major disease, more effective control measures are required to limit the spread of this pathogen within oil-palm plantations. Miller et al. (1995) used vegetative compatibility, biochemical and molecular techniques to characterize isolates from Malaysia, and showed that root-to-root spread appears to be of limited occurrence. A later study by Ariffin et al. (1996) confirmed the findings