New species of fungi associated with basal stem rot

In News 

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

About 

• 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