Breeding for mould and rot resistance. A strategy?

[covert]

My first serious grow a few years ago was almost annihilated by botrytis. I was using soil and organiva indoors and I think every mistake possible was committed.

The botrytis affected buds which were bearing seeds were all cut away and the plants revegged into another clean cycle in generic coco.

Now the disastrous grow notwithstanding those mould bearing buds are with someone whose been too busy to extract resin from them. I asked them how it had gone recently and they said they'd done nothing with them yet.

So my mind raced next tome I was soaring.... if the aeeds from those mouldy buds could be grown into viable plants would they be resistant to those moulds because they survived over 2 seasons in a highly mouldy environment.

Would recovery of the seeds be worthwhile to select for mould resistance.

Is this a good strategy for breeding for mould resistance generally?

A case of a disaster turned into a higher mould resistant strain?

What are your thoughts?

 

[Benny106]

Thin leaf cultivars are generally built for high humidity environments, with loose, open and airy flower formations. Also some terpenoids/flavenoids have antifungal properties.

Only keep seeds from buds that dont mould going forward would be the basic way, using a large and genetically diverse pool to select from in a high rh environment would be a good start.

 

[Bud Jones]

My first serious grow a few years ago was almost annihilated by botrytis. I was using soil and organiva indoors and I think every mistake possible was committed.

The botrytis affected buds which were bearing seeds were all cut away and the plants revegged into another clean cycle in generic coco.

Now the disastrous grow notwithstanding those mould bearing buds are with someone whose been too busy to extract resin from them. I asked them how it had gone recently and they said they'd done nothing with them yet.

So my mind raced next tome I was soaring.... if the aeeds from those mouldy buds could be grown into viable plants would they be resistant to those moulds because they survived over 2 seasons in a highly mouldy environment.

Would recovery of the seeds be worthwhile to select for mould resistance.

Is this a good strategy for breeding for mould resistance generally?

A case of a disaster turned into a higher mould resistant strain?

What are your thoughts?

Cannalope Haze checked all boxes for me . Last year was a nightmare with rain in the NE .. This strain got zero mold . Good backbone of a breeding project . Hope this helps .

 

[El Timbo]

Starting with seeds from a plant that was affected by mould doesn't sound like a good start to breeding a mould resistant strain.

 

[Im'One]

I specifically ordered some Indian Landrace seeds that ripen during their rain season to have that in my "arsenal" or tool box if I need to breed for that. Oklahoma typically as dry summers and wet falls but lately we have had rain all summer followed by rain in the fall as well.The strain Murree is by the real seed company.

 

[Koondense]

You need a selection from a generally resistent seed line.
Start with proven mold resistent plants, put them in your environment and observe their resistence during a full cycle. Then select the most resistend with traits you like, clone them and pollinate them with a resistent male from the same or another resistent line.
The offspring should be mostly what you seek.

A good starting point would be to look at real gorilla seed lines for outdoor, in my opinion.



Best of luck.



Cheers

 

[troutman]

The question is are you ready to work for it? The solution involves real breeding and there's no easy way to do it.

You could breed resistance in any strain. But some strains and/or Landraces are much better than others.

One problem is that most modern strains are bred indoors and not exposed to certain problems.
Thus, they are not very resistant and once affected all Hell breaks loose.

Hint: I would look in Landraces for resistance before looking in a modern strain.

The breeding strategy you want to read about is called Introgressive Hybridization.

It's a breeding method where you add genes or traits from one group of plants in this case to another group of plants while selecting plants
that exhibit the traits in the new hybrid that you want. Like imagine you have a very resistant Landrace that grows well in all kinds of bad
weather. But it doesn't yield well. Then you have a modern strain that yields well,etc. but isn't very resistant to bad weather,etc. You would
have to breed them together and select the plants that give you the best of both Worlds. The F1 generation would be mostly uniform and
may not yield that special plant you need. You're more likely to find what you want in the F2 generation while using as many plants as possible.
Then by selecting the best male and female F2 plants you can begin the process of stabilizing and also possibly backcrossing to one of the
recurrent parent plants (aka the 1st plants used in making the F1s) to give you what you want. It's not easy to do. But then again real
breeding is where you want to go if you're serious about obtaining what you want.

Introgression

Here's an 2 old books I've been reading that you can read for free or even download the PDF if you want.

Introgressive hybridization by Anderson, Edgar

Return to Resistance by Raoul Robinson

 

[djonkoman]

I 2nd a lot of stuff that already has been said(start from mold resistant strains, select for the ones showing the least budrot).

but also, look closely at your plants. botrytis is kind of complex. complete resistance is pretty much impossible, but it's certainly possible to create something that can handle more bad weather before it gets budrot, where it hits less hard, and progresses slower.

I'm focussed on budrot resistance too, and in my observation/opinion budrot resistance is not 1 single trait. there are different factors that all have an influence on how bad it gets. for example some plants tend do massively get budrot in all the oldest calyxes near the stem towards the end of flower. I think that's related to scenescense of individual flowers, you want those oldest calyxes to stay alive longer so they're not an easy infection point.

bud structure can also matter.

but also how fast it progresses once an infection starts. last year was a very bad season around here regarding budrot. most of my plants had some budrot. however, ironically enough the plants that first displayed rot ended up finishing with the least losses. while another plant stayed free of rot for weeks after it started in those first plants, but once it started it progressed so fast I had to harvest within a few days, or I'd lost everything(those other plants I could just cut out the few spots that appeared each time, and they flowered for at least a month after the first rot was sighted, some losses but still plenty leftover).

besides the rot resistance in itself, I also think there are indirect traits that matter, such as cold resistance. a plant that is stressed/weakened will succumb to budrot easier, so as temps decrease in autumn cold tolerance can also help to make the plant more resistant against budrot. that also means that a plant that is very resistant in a warmer climate may not do as well against rot in a colder climate.

and finally, harvest time is important, if it's ready before the weather gets too bad in autumn, you have way less risk of budrot.

 

[Breadwizard]

I 2nd a lot of stuff that already has been said(start from mold resistant strains, select for the ones showing the least budrot).

but also, look closely at your plants. botrytis is kind of complex. complete resistance is pretty much impossible, but it's certainly possible to create something that can handle more bad weather before it gets budrot, where it hits less hard, and progresses slower.

bud structure can also matter.

and finally, harvest time is important, if it's ready before the weather gets too bad in autumn, you have way less risk of budrot.

This! In my hunt for avoiding botrytis in a coastal climate with lots of fog I've focused on finding lines which finish very early, have open sativa style bud structures, and have mold resistance either from human guided selection, or from environmental pressures.

I've been doing some pollen chucks between selectively bred short flowering sativa lines such as NepJam, first lady, etc, and landrace lines which are known to begin flowering early and finish rapidly, such as hash plants from the Levant (Syria, Lebanon, Egypt, etc), Morroco, or some areas of the Himalayan valleys (Ace has one from the Lolab valley I have my eye on).

We'll see how they faire outdoors next year.

 

[THC123]

It is simple:

If you are outdoors only keep plants that don't mold and breed with those.

If you are indoors, increase humidity in flowering to 80-90% and keep the plants that don't mold.

And like others said: thin leave strains generally are more mold resistant. Lots of landraces like himalayan or some indian landraces etc are very mold resistant.

 

[djonkoman]

This! In my hunt for avoiding botrytis in a coastal climate with lots of fog I've focused on finding lines which finish very early, have open sativa style bud structures, and have mold resistance either from human guided selection, or from environmental pressures.

I've been doing some pollen chucks between selectively bred short flowering sativa lines such as NepJam, first lady, etc, and landrace lines which are known to begin flowering early and finish rapidly, such as hash plants from the Levant (Syria, Lebanon, Egypt, etc), Morroco, or some areas of the Himalayan valleys (Ace has one from the Lolab valley I have my eye on).

We'll see how they faire outdoors next year.

I'm now more breeding away from the really open bud structures, while bud structure does play a role in rot resistance, I think it's a bit overvalued, and the really open ones are often a pain in the ass to trim. and I hate trimming.

I'm now aiming for easy to trim nice buds(but not really dense nuggets), but still with good rot resistance. I think physiological resistance+earliness can achieve enough to get a rotfree harvest most years without needing the really open, foxtailed leafy kind of buds.

those early middle eastern landraces(especially the sinai seems interesting I think) I also have my eye on to do something with in the future, but I've already got the earliness from early danish strains(mostly from hfh stuff), and I fear those landraces may have less rot resistance due to growing in drier areas. so so far it's not high priority to try for me.

I used the kumaoni from rsc and have a few lines stemming from that cross, and those were also the plants that had the slower progression of budrot last year. but it did add late flowering, so I'm still in the process of getting those lines to finish early enough(there are early flowering plants present, had 1 plant last season and 1 plant the season before that from closely related lines that finished before mid september, but still more work needed to stabilise that, average is probably more around mid/late october with some plants still not fully finished mid november).

 

[troutman]

Location is also very important outdoors and those with more open spaces or on a slope probably helps a lot.
Places that hold fogs and humidity long like valley bottoms in the Fall are bad news for mold susceptible plants.

 

['Boogieman']

I grew a DP Durban Poison and Blue Widow that had dense buds and absolutely no mold or budrot and I have grown strains with a more open structure that molded badly. A friend of mine grew a cookie hybrid with the densest buds I have seen outdoors with no rot but had some powdery mildew.

 

[troutman]

^^^ I think Girl Scout Cookies is a Durban hybrid.

 

[harvestreaper]

worth trying anything imo you never can tell ive had some strains supposedly bred for outdoors that were pitiful and some supposedly indoor only do perfectly well ,, as mentioned you also have outdoor strains that are well proven by people like rgs ,,,some other strains that have done well for me g13 haze,sk haze,,nl5x haze ,blue velvet rsc mazar i shariff as for breeding breed off those that past the test in your enviroment just like nature does

 

[NEED 4 SEED]

Introgression

Here's an 2 old books I've been reading that you can read for free or even download the PDF if you want.

Introgressive hybridization by Anderson, Edgar

Return to Resistance by Raoul Robinson

I've started reading "Return to resistance" and I have to say this book is answering a lot of my questions in the first few pages. Very helpful! Thanks a lot!

 

[TychoMonolyth]

Indoor remove fans and increase humidity will help encourage mold. Expect leaf damage up top since immobile nutrients are moved around the plant with movement. I suggest you injure the plant. A slight cut with a knife, hand rip off leaves, especially sugar leaves. Mold can only attack an injured plant.

Introduce grapes. Wine grapes if you can get them. Blue grapes if you can't. Check the local grocery store for moldy grapes. If you can't find moldy grapes, put some on your counter and some in the fridge and forget about them until they mold. Botrytis is what attacks grapes and incidentally, also attacks cannabis (bud rot). Put moldy grapes in the same closet/tent as your injured plants.

Moldy Strawberries also rot well and get very fury.

Personally, I'd do like THC123 said. Just put many plants 6 inches apart so they don't get huge. Once they start flowering, wound the sugar leaves and drop your moldy grapes or Strawberries in with them. You want the least amount of air flow possible. Take cuttings from the best plants and repeat next year.

 

[Crooked8]

Also, cease is a product thats omri listed and seriously helps w botrytis.

 

[troutman]

I made this post about Great White a while back and highlighted 4 organisms that help control Botrytis.

I'm using some now.

https://www.icmag.com/ic/showpost.php?p=8340425&postcount=2