mildew on basil

Basil    Morocco

Good afternoon!. We have received basil which has a type of mildew that we think it is different that the normally we have (Peronospora belbahrii).
As you can see in the photos, with the new mildew (lets called it Mildew 1) , the surface of the leaves turn brown little by little. We cut it, it is perfect and after a day in the backhouse, the leaves are brown by patchs and on the reverse you can see easily the micelium; while in the normal mildew (Mildew 2), the fungus just develop the micelium on the reverse and on the surface you can note just a discoloration. Maybe they are both the same but just in different stages?.
I have seen both at the microscope and I have not noticed any significant morphologically difference between them, just in mildew 1 more quantity of hyphas and spores but maybe this could be because of the sample, I am not sure.
Do you have any experience about this or do you know what it is?.

Thank you.

Posted by: Sara (1 point) Sara
Posted: November 23, 2017

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As you know that the quantity of mycelium and spores depends on temperature, humidity, crop variety etc. And also there are two different mating types within Peronospora belbahrii which are required to produce oospores.


If you are interested, polymerase chain reaction (PCR) amplification and sequencing of the ITS1 and ITS2 regions might give further clues.




Posted by: Dr. Ravishankar Narayana (134 points) Dr. Ravishankar Narayana
Posted: November 24, 2017

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