Botrytis is a systemic mold infection in Cannabis. This mold is often called “Bud Rot” or “grey mold”. It can remain cryptic or dormant for long periods of time before it sporulates. youPCR can be used to detect this systemic infection before it spreads to other plants. Field portable colorimetric youPCR assays for Botrytis cinerea are shown below. Plants testing positive can be removed from grows. DNA based techniques are very sensitive and can detect the infection long before it is visible.
Here are a few captions from a paper on the topic titled “Analysis of Cryptic, Systemic Botrytis Infections in Symptomless Hosts“. Highlighted regions demonstrate the Botrytis is systemic and can be passed in seeds. There are also many publications demonstrating co-infection with Powdery mildew.