Safe alternatives to induce 4N in seeds?

[FairyInTheFlowers]

Totally agree with you. But there is also the fact that 4N's can arise out of 2N crosses, so its all really up in the air!

[orchidfever]

Originally Posted by Royal

This is the key point. You must apply the mutagen while multiplication/division is taking place. These type of treatments are usually done on developing protocorms.

That makes me wonder if it has been done on new buds with any success. Since new buds are growing and tiny, I would think that soaking them in Oryzalin solution could achieve conversion without the hassle of replating and so on.

There is never a guarantee that conversion takes place - the only sure way to know is to do a chromosome count. If you are set up to do conversions, you should also be able and willing to do counts to verify.

How much does it typically cost to do a count? And where can I find place to do that?

Thanks for your info!

[RobS]

You're absolutly right if you want to continue breeding with them.

[Royal]

Cody, That's a good point. But in that case it is extremely rare and completely unavoidable.

orchidfever, There are no commercial labs that I know of that will do chromosome counts. That's why I suggest you learn to do counts yourself if you intend on doing conversions. If you have the patience and equipment to successfully induce polyploidy - then counting chromosomes should be no problem.

[orchidfever]

Originally Posted by Royal

That's why I suggest you learn to do counts yourself if you intend on doing conversions. If you have the patience and equipment to successfully induce polyploidy - then counting chromosomes should be no problem.

That is true. I would be very interested in learning about chromosome counting, provided that it is a technique that can be learned by hobbyist without substantial investment of $. Please kindly direct me to the right resources.

[orchidfever]

Googled it and found this website:

Chromosome Counting - Root Tip Squash Technique | ORCHID VAULT

[Apimyces]

Originally Posted by orchidfever

Hi,

I know of Colchicine. But is there any other safer alternative to achieve the same thing? Please kindly direct me to the resources.

Thank you!

Originally Posted by RobS

Indeed I used Oryzalin on Nerine and Lilies when I was in university.

Oryzaline should first be disolved in DMSO (20 mg / ml) after that it can be diluted until the desired concentration. 0.001% and 0.002% (still both Oryzaline and DMSO are toxic). Treatment duration was 3 hours and after that rinsing during 1, 5, and 10 minutes. After that dry the plants so that any left over DMSO can evaporate.

Maybe you shouldn't use in on seeds but on protocorns?

Reference:

liliumbreeding.nl/oryzaline.pdf

Van Tuyl, J. M., Meijer B. and van Dien M., 1992.
The use of oryzalin as an alternative for colchicine in in-vitro chromosome doubling of Lilium and Nerine; Acta Horticulturae. vol 325 pag 625/630

Originally Posted by FairyInTheFlowers

This is a VERY interesting question orchidfever! I am also in Canada, and I plan on starting some small scale breeding in a few years, and would love to work with tetraploids. I also wonder where you could obtain Oryzalin?

This thread is SUPER old, but basically the only Google hit for the subject.

Have any of you gone ahead and tried creating your own polyploids? I have some oryzalin on hand, but I haven't yet gotten around to it.

[Louis_W]

Originally Posted by RobS

Well you could gamble and just take the largest most vigorous young plants. Chances are that they are the polyploids.

According to Roy Tokunaga this is the oppsite of what you should do. Tetraploids will lag behind diploods by a year or two so they will seem runty at first. They are big strong plants but they are not faster and more vigerous.

[Apimyces]

Originally Posted by FairyInTheFlowers

Totally agree with you. But there is also the fact that 4N's can arise out of 2N crosses, so its all really up in the air!

Originally Posted by Louis_W

According to Roy Tokunaga this is the oppsite of what you should do. Tetraploids will lag behind diploods by a year or two so they will seem runty at first. They are big strong plants but they are not faster and more vigerous.

I'm not familiar with orchids, but polyploid vigor depends on the species. Some species have usually vigorous tetraploids, in others, tetraploids tend to be runts. Generally, everything in tetraploids is bigger, if not diluted. For example: bigger but fewer stomata.