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.
Basal Stem Rot of Oil Palm : Incidence, Etiology and Control
Basal stem rot (BSR) caused by Ganoderma spp. is a disease of 
economic importance in oil palm in Malaysia. Although much is known 
on the occurrence of this devastating disease, fundamental studies on 
it and its pathogen are rather limited. At present, there appears to 
be ambiguity in the identity of the causal organisms: there is 
difficulty in getting oil palms to be artificially infected and that 
control measures advocated are largely inadequate to contain the 
disease. Present studies are thus focused on answering these issues. 
An assessment of the BSR situation on selected estates was also carried 
out to assist in the understanding of the disease. 
The assessment carried out showed that serious incidence of the 
disease was "confined to coastal and riverine estates. However, the 
disease can now be seen to occur in a few in land estates albeit 
sporadically and at very low incidence. It was demonstrated that 
previous crops did not necessarily dict ate significant incidence of 
BSR. The underplanting technique and certain soil types can predispose 
plantings to much higher BSR incidence.
The incidence of Ganoderma disease of Oil Palms in Malaya and its relation to previous crop.
SUMMARY 
Results of surveys on oil-palm estates in Malaya have shown that the incidence of Ganoderma infection of oil palms is greatest: (1) on old trees over 25 years of age, and (2) on younger plantings on sites which had previously borne coconut palms. The incidence of disease in stands either newly cleared from jungle or formerly planted with rubber was not serious. 
 
On former coconut sites disease levels were variable and probably due to a soil factor. On these sites infection appeared typically at about the fifth or sixth year after planting, and in some instances disease levels approaching 50% were reached by the fifteenth year. Coconut tissues colonized by Ganoderma are considered to become infection foci for disease spread, principally by root contact with stumps left in the ground. From limited information, disease hazard also appears serious in replanting oil palms on old oil-palm stands. The survey results are discussed in relation to potential losses and disease control. Complete removal and destruction of all coconut-palm and oil-palm tissues is suggested as the only method of disease control available at present.