New species of fungi associated with basal stem rot


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    • Researchers from Kerala have identified two new species of fungi from the genus Ganoderma that are associated with coconut stem rot. 


    • Researchers have genotyped the two fungi species, named Ganoderma keralense and G. pseudoapplanatum and identified genetic biomarkers. 
    • This discovery was based on morphological characters, DNA sequences of the Kerala collections and phylogenetic analyses by comparing DNA of all Ganoderma species known worldwide. 
    • The DNA barcodes have been made publicly available in DNA sequence repositories so that future studies can use them for the early detection of the pathogen.
      • Species-specific disease prevention strategies can now be developed.

     What is Basal stem rot(BSR)?

    • The disease is caused by Ganoderma boninense.
    • It is a major disease in oil palm plantations and there is no effective fungicide to control this disease.
    • It is a disease that has a significant impact on oil palm crops in Malaysia and Indonesia. 
    • The butt rot or basal stem rot of coconut is known by several names in different parts of India: 
      • Ganoderma wilt (Andhra Pradesh), Anaberoga (Karnataka) and Thanjavur wilt (Tamil Nadu)
    • Symptoms: 
      • The infection begins at the roots, but symptoms include discolouration and rotting of stems and leaves.
    •  In the later stages, the flowering and nut set decreases and finally the coconut palm (Cocos nucifera) dies.
    • A reddish-brown oozing is seen. 
      • This oozing has been reported only in India.
    • Losses 
      •  This causes a huge loss: By some estimates made in 2017, in India, around 12 million people are said to depend on coconut farming.

    Source: TH