MOLECULAR SCREENING OF BASAL STEM ROT RESISTANCE GENES IN OIL PALM

Abstract

Basal stem rot (BSR) is one of the main oil palm diseases that have led to tremendous losses in oil yields for almost a century. Having markers, especially those that are linked to resistance (R) genes could potentially alleviate this problem by providing the tools to select palms that are tolerant or resistant to the disease. This study aimed to develop oil palm genomic markers that can distinguish oil palm plants with different levels of resistance to BSR. We identified 144 homologous R genes in the oil palm genome based on the conserved domain structure of known R proteins. Six simple sequence repeat markers were identified and used to genotype 40 palms with different levels of resistance to BSR. The observed and effective number of alleles ranged from 2 to 7 and 1.57 to 4.30, respectively. The observed heterozygosity ranged from 0.13 to 0.67, with a mean of 0.46 while the expected heterozygosity ranged from 0.40 to 0.78, with a mean of 0.51. Analysis of genetic distances from the set of markers was able to differentiate susceptible and tolerant palm samples. These results may help in the early selection of durable BSR disease resistant oil palm cultivars.