Study of Biochemical Compounds Related to Defense Response on Banana Cultivar Mas and Kepok In Vitro Culture Infected with Fusarium oxysporum f. sp. cubense Tropical Race 4 (Foc TR4)

• Main Author: Ari Nugroho, Fajar
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/37117
• Institution: Institut Teknologi Bandung

Fusarium oxysporum f. sp. cubense Tropical Race (Foc TR4) is a soilborne fungal pathogen that causes Fusarium wilt (Panama disease) and is regarded as one of the most economically devastating disease worldwide that affects banana production. Altervative strategy to control and prevent Foc TR4 infection is by breeding cultivar of banana plants that are resistance or tolerant toward the disease. The objectives of this study was to analyze the biochemichal compounds that played a role in the defense response of banana cultivars Mas and Kepok after in vitro infection of Foc TR4. The methodology used consisted of phenotipic observation of symptoms, confirmation and evaluation of protein profiles related to defense response through SDS-PAGE, measuring the enzymatic activity of Peroxidases (PO), Polyphenol Oxidases (PPO), and Phenylalanine Amonia-Lyases (PAL) and measuring the total phenolic content from the sample and medium culture of the Mas and Kepok banana cultivars after Foc TR4 inoculation. Phenotipic observation lasted for 14 days which showed that the Kepok cultivar was more susceptible to Fusarium wilt compared to Mas cultivars. The Leaf Symtom Index (LSI) score of 2,2 for the Kepok cultivars was classified as susceptible, while that for the Mas cultivars was 1,67 and classified as tolerant. Results based on SDS-PAGE showed bands with varied molecular weights at 74 kDa, 34 kDa, and 18 kDa for the Mas and Kepok cultivars, which might indicate the presence of putative enzymes PAL, PO, and PPO. The activity of the PAL and PPO enzymes for the Mas cultivars was higher than for the Kepok cultivars, but the difference was not significant. The Mas cultivar showed higher phenolic content compared with the Kepok cultivar for both, tissue and medium samples. Based on these results, it was concluded that the Mas cultivar was relatively more tolerant to Foc TR4 infection compared to the Kepok cultivar.