Screening Indian Cardamom Accessions for Resistance to Major Pathogens and Correlating Responses with Biochemical Defense Parameters

Fifteen promising Indian cardamom [Elettaria cardamomum (L.) Maton.] accessions including released varieties and hybrid lines, were screened during 2022-24, to identify resistant sources against diseases viz., capsule rot/ Phytophthora rot, clump rot, pseudostem rot/ Fusarium rot, leaf blight, and tiller splitting/ Phoma disease. The screening studies were conducted at Cardamom Research Station, Pampadumpara utilizing cardamom accessions maintained at germplasm bank. The role of defense-related biochemical parameters viz., peroxidase (PO), polyphenol oxidase (PPO), phenylalanine ammonia-lyase (PAL), total phenol, OD phenol, β-1,3 glucanase, and chitinase that impart resistance against each pathogen in cardamom, as well as the correlation between percent disease index and biochemical parameters were investigated. The accessions Hybrid-6, Hybrid-17, and Hybrid-1 showed resistance to three or more diseases, indicating the possibility of using them as donor parents in future resistance breeding programmes. Among biochemical defense parameters studied, PO and β-1,3 glucanase were the significant biochemical defense indicators for Phytophthora rot resistance. In the case of clump rot and leaf blight, PPO and chitinase are the key indicators. The primary factor of resistance to Fusarium rot was PO activity. PAL and chitinase levels significantly influenced and correlated with resistance to Phoma disease. These indicators could be utilized in future to identify disease-resistant cardamom accessions and facilitate agile breeding initiatives.