Basic info on how to hybridize Datura metel x D. wrightii

[Inyan]

Just wee bit of insight on how I go about producing these hybrid seeds. First, I emasculate each and every female flower before the pistil comes out of the calyx and before the anthers can ripen. I only grow one compatible male Datura wrightii so there is no fear of any other Datura pollinating my Datura metel hybrid girls. I also pollinate my Datura metel hybrids as soon as the emasculation is completed. Using stored dried frozen pollen (stored in micro centrifuge tubes)  if need be. Drying and freezing pollen can extend a pollens life from a mere day in some instances to several years so it makes sense to go that extra step of freezing pollen if your serious about your crosses. My Datura wrightii was sourced directly from the wild in the Mojave desert. Seed pods take 60 days to fully mature on average, but if you grow a bit impatient with many crosses... not just Datura you can create a window into the pod to see how things are progressing. When you finally open your pod, you may find that many gametes have aborted. This is of little concern if you get even a few seeds that are mature. As you can see, this particular  pod produced ~14 mature seeds.

[Halcyon Daze]

Great stuff!  I've never seen a window cut into a pod before. Although it's really cool, why not wait until the pod just looks ripe.

 

Why would you actually need to look inside?

Edited September 28, 2017 by Halcyon Daze

[Inyan]

On 9/12/2017 at 5:23 AM, Halcyon Daze said:

Great stuff!  I've seen a window cut into a pod before. Although it's really cool, why not wait until the pod just looks ripe.

 

Why would you actually need to look inside?

 

Seeing as no one else will answer this question. Why would you want to get seeds earlier and then plant them earlier?

 

Well, that is something only someone who is truly into hybridizing can answer. The answer of course is that those days shaved off add up over the years if one actually plants your seeds earlier as well. If you don't actually make use of that saved time to do something productive then your just having fun and or getting your seeds out to your friends faster. Of course there is nothing wrong with that either.

 

How many times have you opened or seen a seed pod open that had seeds that had already germinated? I'm not talking about Datura here now. But, I'm sure some of you have seen seeds that have germinated in a pod. A window cutting into that pod to see when they are mature is of course one way this could be eliminated. 

 

Yet another tactic... if one labels with the date of the cross and one knows how long it takes the gametes to reach the ovules and so on and so forth... one can understand that in a case like this cross it can take 60 days for the pod to crack open or mature on its own to the point that you can really know visually that you can harvest the seed. If one knows for instance that at 50 days you can often also harvest... you have saved 10 days. Your seeds have not spilled on the ground as your pod has not softened. Cutting a window into the pod of course lets you confirm your suspicions before you waste your pod. I often use old discarded grafting blades for this. Bottom line, if your unsure... cut a window or wait.

 

With Brugmansia seed pods... cutting a window allows  you to harvest your seeds early as well. Of course you could wait for the peduncle to turn yellow as that is a sure sign your seed pod is either mature or the pod is aborting early. The later typically happens when an incompatible pollen is used or the weather is too hot and or not enough water is available at peak heat times. Cutting a window with some species like Brugmansia also allows you to harvest those seeds before bugs can get to them. I've seen some people who like to let their Brugmansia seed pods dry naturally and many of those seeds then are often found to be empty. That is another good argument for a systemic insecticide a few weeks prior to the seeds finishing their maturation process with at least some species.

 

Of course, with some hybrids the seed pods may not give the typical warning signs of being ripe that one is used to. This might be true of a hybrid one has never made before... i.e. a new undertaking or genotype  combination that you are not familiar with.

 

Enough rambling, hope that helps clear some of that up.

 

 

[Halcyon Daze]

That is really fascinating, Inyan, thanks for laying it out for me like that, and not taking offense LOL. I feel like I have gained some new insight into plant breeding..... LITERALLY  

 

By the way I mis-spoke/ wrote, i meant to say I have NEVER seen a window cut into a pod before. But I guess you probably realized that. 

 

Great stuff man, really cool.

Edited September 28, 2017 by Halcyon Daze

[Inyan]

No problem @Halcyon Daze, It is only by sharing information that truly great strides are made. Empowering others to make great hybrids is what its all about. The best way to do that is for everyone to share their knowledge. If your making hybrids or interested in making hybrids your drying and storing your pollen in the freezer or making pollen dilutions to extend your pollen further then I can only assume you have more than a passing interest in hybridizing as you have reached the point where you are not at the whim of what is blooming, but you can make the exact cross you are after provided it has bloomed for you at some point in the last few years.