Breeding For Pm Resistance, Etc.

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Califlower

Califlower

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Do you think it is the lineage from parts of the globe that are damper. For example, Thai genetics might lend a resistance to powdery mildew. Super Skunk is very PM resistant, and I think the smelly volatile oils may play a part. For that strain perhaps the Columbian lineage plays a role in PM resistance, or maybe not...
 
Seamaiden

Seamaiden

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Do you think it is the lineage from parts of the globe that are damper. For example, Thai genetics might lend a resistance to powdery mildew. Super Skunk is very PM resistant, and I think the smelly volatile oils may play a part. For that strain perhaps the Columbian lineage plays a role in PM resistance, or maybe not...
Absolutely! Afghani-dom strains tend to be magnets for it, which makes sense. How much PM is there/are they observed/experienced/exposed to in the mountains of Afghanistan? Vietnam? Cambodia? Thailand? India highlands vs the south part of the subcontinent?

I don't know that the terpenes play a role, but it would make some sense. I think it's as much to do with the plant's immune response system as anything else, though.
 
zeke

zeke

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Last year was the first and only year Ive ever had pm. I've been at it twenty years. My most pm prone plant is blue magoo. My summer indoor had a tiny amount and my winter grow is pm free. Same rooms no obsessive compulsive cleaning routines... Pm is always around in the air. Sometimes conditions are right and the population explodes. Why? I think it has something to do with electrical charge in the air. More charge more magnetic ability for spores to disperse.
 
SonOfDaMourning

SonOfDaMourning

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I've gotten it before and sannies seeds jackberry resisted it but yet my black rose loved pm. They was side by side in the room.
Lol funny cause i hade a black rose hybrid that would be the only one to show pm out of 12. im making a case here lol.
 
SeaF0ur

SeaF0ur

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The best way to breed any resistances is to take a pheno run, take marked clones of everything, and do not ventilate properly... make stale aged air... add humidity... now watch the pheno run for an individual that lasts the longest without getting PM and use that plant for your next F-gen... rinse and repeat... by using only the plants that either do not get PM, or that last the longest without damage out of a seed group when these stale moist conditions are applied, you are effectively breeding for PM resistance. Replace stale moist air with introducing spider mites... find which plant is clear when others are all webbed up... the cleanest one is the most resistant... add any other pathogen or pest you can imagine and the last plant to die should have its clone used in the next generation.

And yeah... I said to purposefully cause your own infestations...
now you see why most breeders do not breed for resistances much, if at all.
 
waayne

waayne

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I've found resistance to pm to be both strain and pheno dependent......
I live in a forest where pm is always thriving in the outdoor environment.
So I occasionally have issues with it.

My Original Bubba/93 Bubba has amazing resistance to pm,and she's a pure Indica type.......
By comparison, my Katsu Bubba cut ,was a pm magnet..........
 
Califlower

Califlower

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The best way to breed any resistances is to take a pheno run, take marked clones of everything, and do not ventilate properly... make stale aged air... add humidity... now watch the pheno run for an individual that lasts the longest without getting PM and use that plant for your next F-gen... rinse and repeat... by using only the plants that either do not get PM, or that last the longest without damage out of a seed group when these stale moist conditions are applied, you are effectively breeding for PM resistance. Replace stale moist air with introducing spider mites... find which plant is clear when others are all webbed up... the cleanest one is the most resistant... add any other pathogen or pest you can imagine and the last plant to die should have its clone used in the next generation.

And yeah... I said to purposefully cause your own infestations...
now you see why most breeders do not breed for resistances much, if at all.

True, I was recently reading about that actually! My reading also said ideally for breeding an outdoor variety you should grow everything outdoor. However, using a grow room would be faster. Perhaps use a grow room at first, then finalize outdoor.
 
zeke

zeke

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Absolutely! Afghani-dom strains tend to be magnets for it, which makes sense. How much PM is there/are they observed/experienced/exposed to in the mountains of Afghanistan? Vietnam? Cambodia? Thailand? India highlands vs the south part of the subcontinent?

I don't know that the terpenes play a role, but it would make some sense. I think it's as much to do with the plant's immune response system as anything else, though.
The pure narrow leaved drug strains I've personally collected from Thailand and Cambodia were definitely not powdery mildew resistant. I would actually say they are susceptible. The same sorts of PM infect mangos and cashews in the equatorial areas. If anything the high temperatures and intense sunlight help keep the fungus at bay. Once the plants are away from that environment they seem to lack any inherent defenses to it.
 
xX Kid Twist Xx

xX Kid Twist Xx

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it is possible to do it. i used a g13/haze to start with and was able to select males that didnt show signs of pm from that cross and back cross to g13/haze again. test grows in many rooms show most females showed no signs in differnt gardens. i also used green manalishi 88 g13/hash plant crossed to pac g13. back crossed them to whitefire keeping the males that didnt show signs in infected room. even tho the mother would get pm very easy males from the bx1 would have plants that didnt show signs even after they were back crossed to the whitefire mom. start with a very resistant strain and it seems like its not to hard to pass on
 
Seamaiden

Seamaiden

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The pure narrow leaved drug strains I've personally collected from Thailand and Cambodia were definitely not powdery mildew resistant. I would actually say they are susceptible. The same sorts of PM infect mangos and cashews in the equatorial areas. If anything the high temperatures and intense sunlight help keep the fungus at bay. Once the plants are away from that environment they seem to lack any inherent defenses to it.
Interesting. Susceptible to the point of killing the plant? I can't say I've grown any pure Satties to this point, just smoked 'em. But, I'd love to give 'em a try.

PM was bad for the bull thistle this year. Such low RH and high temps I wouldn't have thought, but there it was.
 
QuantumGen

QuantumGen

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This raises a lot of interesting questions. It is my belief that a few hereditary factors are at play with pm resistance, but terpenes play a large role. Thick cell walls could play a role as well. Some plants just have hardier leaves. But i have definitely seen bug and mildew resistance with certain species and subsequent hybrid generations, with similar terpene profiles. Eucalyptol im sure is one. Who know what this plant creates. It could create compounds like the chrysanthemum flower(pyrethrin) or the sassafrass tree(piperonyl butoxide from safrole)or the neem tree(azadirachtin). Who knows. I think the terpene combinations that marijuana is able to create is one of its most unique and versatile evolutionary traits. And most important. I have been thinking lately that there is a natural terpene combination for SO MANY applications, its baffling. Protecting the plants from unwanted fungal or bacterial colonization is just one simple application of the infinate mixture this plant is capable of producing.
Learning how to extract the plant specific profiles, fresh, unadulterated is going to be a new technique that i like to learn about. My buddy has a big hoop house (organic op) so hes been juicing all his food leaf that he'd usually trash. I wonder if one could reduce the elaborated sap and juices in the leaves to get a concentration of a plant specific terpene profile...
 
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QuantumGen

QuantumGen

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Interesting. Susceptible to the point of killing the plant? I can't say I've grown any pure Satties to this point, just smoked 'em. But, I'd love to give 'em a try.

PM was bad for the bull thistle this year. Such low RH and high temps I wouldn't have thought, but there it was.
PM can thrive in high temp low RH. Downy mildew is the stagnant wet hot air shit in my experience.
 
QuantumGen

QuantumGen

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Califlower

Califlower

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The good thing about breeding with wild or feral populations is these may have adapted certain resistance through natural selection. In the Americas cannabis was introduced less than 500 years ago. At least the hemp type. I don't know if the locals bred the hemp to get today's Columbian, or if a more psychoactive variety was introduced later. The problem with strains bred to be true to type, and hybrids made from these, is one tends to loose some genes from the pool that might be desired for breeding programs later. So I think starting with a land race would be good. Either to select good phenos to stabilize for making hybrids, or to select individuals from the first seed crop to cross with elite strains, take the F2's, cross with each other, then select what is desired from the F3's, etc. etc. Or would you find a great male and cross to F2 then back cross to the mom? Some seeds should be left uncrossed, but selectively bred outdoors from the first seed crop in order to eventually create a nicely adapted variety for my climate. I'm new to this, so I hope I spoke correctly. Mostly I've read a basic book on vegetable plant breeding. So if cannabis is an out-crosser there are perhaps some undesirable recessive traits one can encounter when trying to stabilize a line?
 
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