INDUKSI KETAHANAN PISANG TERHADAP Fusarium Oxysporum F.Sp Cubense (Foc) DENGAN ASAM SALISILAT DAN ASAM FUSARAT DALAM KULTUR JARINGAN

The objectives of this research are to study the effect of salicylic acid and fusaric acid as the compounds to induce resistance against Fusarium wilt disease and to found out molecular resistance markers, namely, specific DNA fragments resulted from PCR-RAPD amplification related to the resistance. Shoots of 0,5-1,0 cm 3 in size were induced in liquid MS medium enriched by vitamin and BA, salicylic acid and fusaric acid on the concentration is 0 ppm, 1,22 ppm, 4,91 ppm, 9,82 ppm, 1,15 ppm, 2,33 ppm, 4,66 ppm and 9,32 ppm. The observations of healthy shoots, plant height, stem diameter, and number of leaf were done. The resistance was evaluated to shoots of five months old after acclimation, which was inoculated by Fusarium oxysporum f.sp cubense isolates A-13. The observations of wilting leaves were carried out on the basis of Leaf Symptom Index (LSI) and corn discoloration on the basis of Rhizome Discoloration Index (RDI). The data obtained were then adapted to Disease Severity Index (DSI). DNAs extracted from the leaves of the induced shoots of healthy banana plants and those with disease symptoms were used to analyze variation in DNA base composition by RAPD technique. Four random primers (Produksi Operon Technologies), including OPA-01, OPA-02, OPA-19, and OPK-03, were used to amplify the genome DNA sequence of banana plants. The markers of RAPD were identified on the basis of specific DNA fragments in both healthy banana plants and those with disease symptoms to distinguish the resistance of plants. Result of the research indicates that salicylic acid with a concentration of 2,45 ppm and fusaric acid with a concentration of 1,15 ppm could increase the resistance of banana plants. These concentrations were the best for the compounds inducing the resistance of banana shoots against Fusarium wilt disease in tissue culture by lowering the criteria of resistance from very vulnerable to vulnerable. The amplification of banana plant genome DNA by RAPD technique using single primer of OPK-03 with a sequence of CCAGCTTAGG produced DNA fragments of 500 bp only in banana plants with disease symptoms. The healthy banana plant did not produce such fragments. The DNA fragments of 500 bp could be used as a marker to identify the resistance of banana plants to Fusarium oxysporum f.sp cubense