The scientists of Plant Pathology section are engaged in conducting basic, applied and strategic research on various aspects of sugarcane diseases. The major area of research includes:

♦  Identification of disease resistance sugarcane clones – red rot, smut, yellow leaf disease etc.

♦  Developing precise diagnostic techniques for the detection of the pathogens.

♦  Characterization of genetic variability amongst sugarcane pathogen(s) by conventional and molecular approaches

♦  Molecular basis of disease resistance in sugarcane and functional analysis of pathogenicity determinants/genes in red rot pathogen.

♦  Management of sugarcane diseases through bioagents and chemicals and induced resistance.

♦ Epidemiology of newly emerging diseases in changing climatic scenario.

To identify red rot resistant sugarcane, a screening methodology with a 0-9 scale was developed by Srinivasan and Bhat (1961) in this Institute, which is universally accepted and followed by sugarcane researchers. Development of aerated steam therapy unit by the scientists led to three-tier seed nursery programmes to produce quality planting materials in the country. To overcome environment-induced variability in red rot disease reaction and to rapidly screen sugarcane genotypes for red rot resistance, a controlled condition testing (CCT) was developed by this group. Screening for smut resistance under field conditions is being carried out in the breeding and germplasm clones using the standard teliospore dip method.

The section has made significant contributions in understanding red rot resistance in sugarcane. Involvement of 3-deoxyanthocyanidin phytoalexins and pathogenesis-related proteins in red rot resistance was clearly established. Recently differentially expressed transcripts induced in response to red rot pathogen infection/inducers of resistance using the tools of transcriptomics were identified. The scientists have made landmark contributions in the field of proteomics by creating a reference map for sugarcane stalk proteome for the first time.

Similar to host resistance the scientists have made extensive contribution on molecular diagnostics. Red rot specific primers based on actin and calmodulin were developed to specifically amplify pathogen by duplex PCR in plant tissues and in soil. PCR techniques were developed to specifically detect grassy shoot phytoplasmas causing grassy shoot disease and Sugarcane bacilliform virus. Uniplex-, duplex- and multiplex- RT-PCR techniques were developed to detect Sugarcane mosaic virus (SCMV), Sugarcane streak mosaic virus (SCSMV) and Sugarcane yellow leaf virus (SCYLV) together, the three important RNA viruses causing yield decline in sugarcane, singly or in combination in the same reaction. All the diagnostics have been commercialized to index sugarcane for the virus and phytoplasma infection. The plant pathology lab has been accredited by Dept. of Biotechnology, New Delhi under National Certification System of Tissue Culture raised Plants (NCS-TCP), to index sugarcane seedlings for viruses.

Pathogen variability has been extensively studied in the section. Molecular variability in fungi causing red rot and wilt was established. Cause of wilt by Fusarium sacchari in India was established beyond doubt. Variability in viral pathogens infecting sugarcane also established and SCSMV was characterized as a new genus Susmovirus in Potyviridae.

In addition to host resistance, induced resistance approaches using both PGPR and abiotic inducers have been found to show promising results to manage red rot.

Meristem culture combined with virus indexing has been established to free SCYLV causing yellow leaf from sugarcane and yellow leaf disease management using this approach has been demonstrated under field conditions.

In view of the changing climatic scenario, surveillance and research on various aspects of the emerging new diseases viz. YLD, Pokkah Boeng etc are being carried out.