Death Before Life to Dalbergia Sissoo (Shisham) : Unfolding the Mysteries

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Rabish Chandra

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'What will be its life'?...I asked.

'You have to contact a wood expert for that', he said. 

Wood expert!

Yes, he can only tell the life. 

But, I am a botanist, I can also tell it's life. Provided if you can tell the name of the plant of which it is made.

Gentleman, as a botanist you may tell the life of a live plant, but not the dead one and the life of any timber plants is counted only after it dies.

Ok. Ok. But is not made up of Shisham? I mean Dalbergia sissoo.

Dalbergia sissoo

No... No... these days we don't get any items made of shisham.

Why? 

There is a death before life, for sissoo. 

Death before life?

Yes, 'Number of shisham trees are drying immature', he said with a sorry face. It is difficult to procure it either wild or cultivated. 'I have heard even plant scientists are not aware of the cause of its early death', in a challenging tone he informed me.

....Now it was my turn...

'No, you need to be updated' I smashed his question before reching to me.

'Is it so'?, he asked with frawning face.

Wilted Dalbergia sissoo

Yes, scientists from Centre of Advanced Studies in Plant Pathology, G. B. Pant University of Agriculture & Technology, Pantnagar; Forest Pathology Division, Forest Research Institute, Dehradun; Department of Biosciences, Jamia Millia Islamia; and Department of Biotechnology, Jamia Hamdard, New Delhi have unfold the mysteries of unantural death of Dalbergia sissoo.

***

Though the cause of the disease remains uncertain.They have identified the causal agent of the disease. They obtained samples of infected roots, stems and the ooze exuded from infected trees from plants showing symptoms in different geographical regions of India for the isolation of microorganisms. Isolates were used to inoculate healthy plants. Based on the morphological characteristics and other bio-techniques, they identified 24 and 14 as Fusarium solani and Fusarium sp., respectively out of  the 38 fungal isolates. 

 ***

'But how they confirmed that the causal organisms were Fusarium solani only', he asked me with curiosity.

I was happy to elaborate the findings of  M. Arif, N. W. Zaidi,  Q. M. R. Haq, Y. P. Singh, S. Khan and U. S. Singh which was published online in Forest Pathology

Part of experiment; Arif et.al., 2013

***

In their pathotyping study, eighteen F. solani isolates, isolated from roots and stem parts of symptomatic plants, induced typical wilt symptoms when inoculated through soil and roots on D. sissoo seedlings of 1–15 months in age. 

The population of F. solani was the highest in infected roots and the lowest in parts of stems, gradually decreasing with height, and was isolated constantly up to approximately 40% height of the seedling.

 ***

'You mean to say they induced the same symptoms in the seedlings with the isolated pathogens'? 

He was going deep in the subject.

'Yes you are right'. I affirmed.

But whether the same pathogen was reisolated from the infected seedlings? He further interrogates me.

***

Yes, F. solani isolates used in inoculations were successfully re-isolated from the rhizosphere, infected roots and wilted stems. It was confirmed through DNA fingerprints.

Further thay found that molecular phylogenies based on rDNA-ITS sequences showed that the 38 isolates fell into 2 groups. Group I comprised of F. solani isolates from D. sissoo and F. solani sequences in the NCBI GenBank database, whereas group II included Fusarium isolates other than F. solani. 

***

If you want to know more you may refer their research paper published online on Forest Pathology .

'To a furniture sales person, the above information is enough and as the authors proposes that these results will be helpful in developing integrated control measures for this highly variable pathogen and to establish a base for future population studies, I will be selling some shisham (Dalbergia sissoo, in your language) furnitures too in future'. He ended the conversation with satisfactory expression on his face.

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Reference

Arif, M., Zaidi, N. W., Haq, Q. M. R., Singh, Y. P., Khan, S., Singh, U. S. (2013), Molecular phylogeny and pathotyping of Fusarium solani: a causal agent of Dalbergia sissoo decline. Forest Pathology. doi: 10.1111/efp.12060

(The story is an effort to communicate the scientific information in a language which can be understood even by our furniture sales man)