The Random Thread

[fryge]

On 28-11-2020 at 7:29 PM, Amarillo slim said:

 

Slightly confusing that the article's authors seem to be presenting this as relating to botrytis, yet the science seems mainly aimed at powdery mildew..?  They mention targeting a few different types of mildew, but I don't think botrytis falls under that??  

 

Very true what they say that most breeding neglects disease resistance though... I see a lot of people growing indoors under 'ideal' conditions when making selections, essentially breeding blind when it comes to resilience, and as a result introducing more weak genetics to the gene pool.  Ive had people think I'm mad for purposefully introducing pathogens into cabs /rooms for selections, hopefully they read that article and see there is method to the madness  

 

Wish I had a £4.2 million genomics budget to help out, don't we all?  Nice that they are making the results public, will be interesting to see...

 

Canadians where always ahead of the game breeding hardy outdoor genetics.. Now its being taken to the next level with the help of science  

 

yes exactly this, pretty confusing article mixing them up. reading it, looks to me the actual research is on mildew, and the journalist made a weird mixup with botrytis. 

and the difference matters a lot, they're very different fungi. with different resistance mechanics for breeding. mildew is biotrophic as far as I know, botrytis is necrotrophic. (mildew is also not one species, there are many different mildews, which are often pretty specific to a few plant species. while at least the most known member of botrytis, botrytis cinerea, is a single species with a very wide host range)

 

for botrytis, complete resistance is most likely impossible. resistance is quantitative and caused by multiple genes. 

 

while for mildews you more often see race-specific resistance genes, where a certain resistancegene provides complete resistance to certain (fungus)races, but not at all to others. (there can still be quantitative resistance too though, but the race-specific complete resistance genes are often more interesting to breeders)

 

so I think with mildew this genetic aproach would be pretty feasible, since the desease-testing part is relatively easy(just score yes/no desease), and if it's just 1 gene finding the correlation with a marker should be feasible. then pyramid a few resistancegenes together and you've got a pretty durable resistance(best if you do know which races are going around in your region though).

but with botrytis you'd be looking at more subtle differences during the scoring(difference in lesion size, time between inoculation and first signs of lesion, etc), so more noise, and have to use statistics to really see the trends. and then linking it to the genetics is also harder than for mildew. 

 

so I think it makes sense the scientists chose mildew to look at, it's much easier. for botrytis even with the state of the art science at your disposal it's probably a challenge. personally if I had all the professional equipment, facilities etc. and my goal would be breeding for botrytis resistance, I'd not put all my bets on genetic markers. I'd still try to find some, but for best results I'd also do regular phenotyping, not go all-in on markers.  

 

regarding the selections indoors, I think another important factor that is easily missed is temperature. I've noticed in some plants that they faired pretty well in rainy autumnweather, not a speck of rot, but then 1 day when the temperature goes below a certain point they suddenly turn into mold magnets. while some other plants seemed less resistant at first, getting some specks of rot here and there, but show no difference in resistance when the temperature decreases. 

 

Quote

https://www.timesofisrael.com/israeli-startup-says-it-has-edited-cannabis-plant-gene-for-fungus-resistance/

I think there is some interesting things there in between the lines.

first off, the fact they managed to make a gmo-cannabis plant. going by how much it's used in other crops it may not seem that special, but a while ago I looked a bit into it, and in the literature there are multiple reports of people failing to regenerate shoots from callus(and none that succeeded). and for most methods of gmo, you need this step to finally get a plant out of it. otherwise you could succeed in transforming the dna, but the result is just some kind of cankersore with roots. not a usable plant.

so I wonder how they did it, unfortunatly the article does not mention it. either they managed to create a working tissue culture protocol for cannabis(from callus, I've seen some people online do tissue culture from nodal stem segments, but if you for gmo you have to go through callus), or they used a method that circumvents tissue culture(it could be for example that they used a flowering plant and then treated the flowers to get gmo seeds out of them, that's a technique that is feasible if you've got a plant with many flowers around the same age, like cannabis).

 

the other thing is that this is not a normal resistance gene. they altered the target for mildew. in contrast to a regular race-specific resistance gene, such an altered target would give recessive resistance(as opposed to dominant for a resistance gene), but it would be much more durable. as in, it's not very likely the fungus will be able to break the resistance through mutating. and it would work for all races of the fungus. 

Edited December 1, 2020 by fryge

[Toad81]

Good Book from 1999, 

 

Wouldn’t mind some of this guys seed stash !

[Ccs141]

how much would of a copy of that be now or were would you find this

[Guest]

not seen that book before  love to have a look  through that

[Toad81]

@Ccs141
I bought the book in 2001 , so don't know about now, 

 

,its a good read tells you what you need to know,,and a-bit about breeding for outdoor uk,,the guy was doing great work .

if i can get organised I'll try to scan it and post one day but if its still in print it deserves to be bought,

Edited December 1, 2020 by Toad81
Finish sentence

[Ccs141]

yeh man would be interested let us know if you do man gonna look for it now

[Alys]

@Ccs141 @Levantine Lane it’s on the river site for just under £8 in paperback. Save @Toad81a whole world of pain scanning it!

[Ccs141]

thanks man much appreciated

[ocb]

3 hours ago, Toad81 said:

Good Book from 1999, 

 

Wouldn’t mind some of this guys seed stash !

Jus ordered it  cheers for the heads up. Peace

Edited December 2, 2020 by ocb

[ocb]

Anyone know of any other UK based outdoor cannabis growing books? Would love to get a little collection of literature goin.

[Amarillo slim]

21 hours ago, fryge said:

resistance is quantitative and caused by multiple genes. 

 

Indeed.  In fact there are many different traits that can lead to the 'trait'' of resistance / lack off Imo, and these don't always merge well.  

21 hours ago, fryge said:

since the desease-testing part is relatively easy(just score yes/no desease)

 

Exactly. Its probably relatively easy. And this is what they are targeting in the project.  Don't know why the article's author is talking about botrytis, either purposefully mis-representing it for better publicity or perhaps they just don't have a clue.

21 hours ago, fryge said:

regarding the selections indoors, I think another important factor that is easily missed is temperature. I've noticed in some plants that they faired pretty well in rainy autumnweather, not a speck of rot, but then 1 day when the temperature goes below a certain point they suddenly turn into mold magnets. while some other plants seemed less resistant at first, getting some specks of rot here and there, but show no difference in resistance when the temperature decreases. 

 

Interesting. Out of interest did many of the ones that showed less variance following the temp drop also turn purple in response to the cold more?  

 

 

Edited December 2, 2020 by Amarillo slim

[Toad81]

11 hours ago, ocb said:

Anyone know of any other UK based outdoor cannabis growing books? Would love to get a little collection of literature goin.

European cannabis cultivation -mel Thomas (black book with leaf on cover) maybe what you looking for?

 

this has a section for outdoor,and think the author is from uk or at least grew in UK

 

this book did the rounds between mates mid 2000’s ,all the pages were falling out,,cant remember who had it last! 

 

These days there is so much information on this forums its great ! But always have time for a good grow book,

[Ch@ppers]

25 minutes ago, Toad81 said:

European cannabis cultivation -mel Thomas (black book with leaf on cover) maybe what you looking for?

 

this has a section for outdoor,and think the author is from uk or at least grew in UK

 

this book did the rounds between mates mid 2000’s ,all the pages were falling out,,cant remember who had it last! 

 

These days there is so much information on this forums its great ! But always have time for a good grow book,

Got to be honest mate, he is more an indoor than an outdoor grower, the outdoor section of his first print run was total crap, he actually contacted a guy on this forum to ask could he plagiarise some of his work on outdoor growing for a subsequent print-run, like I said Mel Thomas isn't or wasn't really an outdoor kind of guy. 

[Toad81]

@Ch@ppers fair enough its not an outdoor book and your not going to break records with it, but at the time when young it was better than nothing and we could fill in the gaps.

just thought if the OCB guy wanted an collection of books its cheap and does no harm.

[Ch@ppers]

5 minutes ago, Toad81 said:

@Ch@ppers fair enough its not an outdoor book and your not going to break records with it, but at the time when young it was better than nothing and we could fill in the gaps.

just thought if the OCB guy wanted an collection of books its cheap and does no harm.

True enough mate, true enough.