protocorms developing slowly? help
 

hey guys so here's the scoop
i have a variety of orchid seeds and protocorms, mostly phal hybrids and cattleya intergenerics, but development is SLOW. my slc "dorris and byron" × cattleya "aka tori" seeds were flasked on K400 with added pineapple, banana, and potato and took 6 weeks to start germinating. my paph seeds were flasked on half strength P668 in september! no growth yet. my phals take over a month to germinate, some pcorms turn white after replating. phytotech's guide says replate every 30-60 days, but i'm starting to doubt on account of slow growth.
i have a few guesses as to why growth is so slow. the temp is low 70s F, maybe too cold. also, maybe the lighting is too weak. here are vids of my setup:
The Orchid Chronicles S1E12: Early morning tc - YouTube
The Orchid Chronicles S1E10: TC updates - YouTube
any ideas??

I am no expert in this department, but you may have an issue with the amount or types of growth regulators you are using. Try asking Carol Stiff at Kitchen Culture Kits Inc.: carolstiff@kitchenculturekit.com. There is also (List Servers) from Carol's website as well.

Seeds can take a LONG time to germinate. I believe that it is normal to wait 8-12 months from sowing to go to the replate.

It really is difficult to say in overall general terms with regards to the family Orchidaceae that every single member within the family will have seeds that behave the same way and have it be a valid statement, (because it isn't).

Orchids as a family contain 5 different subfamilies, about 900 different genera, and between 25,000 to 30,000 species (not even taking into account the numerous natural and man-made hybrids that exist). There is no way to encapsulate all of Orchidaceae and boil it down to one way they behave, although some generalizations can still be made.

There are some number of generalities that someone can make regarding some types of orchids, but there are definitely variations within groups.

When compared to flowering plants of other families such as family Asteraceae/Compositae (aka Sunflower Family), yes, seeds of the family Orchidaceae take a relatively long time in order to germinate, (orchid seeds can germinate in the order of months whereas seeds belonging to the sunflower family can take a few days to a few weeks).

Comparing seed germination times between two different orchid subfamilies can also differ due to several factors. For example, it is comparing apples to oranges when comparing seed germination times between orchids in the subfamily Epidendroideae and those in the subfamily Cypripedioideae because the seeds in both subfamilies of orchids have different modes of survival and therefore will have different cues and times for germination. An example would be that seeds of orchids belonging to the subfamily Cypripedioideae does not behave the same way as orchid seeds belonging to the subfamily Epidendroideae because seeds of many members of the subfamily Cypripedioideae are known to have seed dormancies, whereas, for the most part, the seeds of members within the subfamily Epidendroideae do not necessarily have seed dormancies.

Even when comparing orchids that belong to the same subfamily, (for example, subfamily Epidendroideae), each genera of orchids within this subfamily will have seeds that generally have different seed germination times. For example, orchids in the genus Cattleya will have different germination times than those belonging to the genus Dendrobium even though both genera belong to the same subfamily (Epidendroideae).

Within the genus Cattleya, each species can have different germination times to one another as well. Cattleya maxima can, in general, have slightly different germination times compared to Cattleya iricolor.

Even within a particular species, (say, Disa uniflora), individual seeds will have differing germination times within the known range of germination times according to that one species itself. For example, Disa uniflora seed A may germinate on day 30, while Disa uniflora seed B may germinate on day 40, but both Disa uniflora seeds A & B have germinated within the known range of germination times of 30 - 50 days

When you are talking about general stats like this, you must consider mean, median, and mode for the data you are interested in finding out about.

I hope this addresses the question of germination times coming purely from the aspect of orchid seed behaviors.

In terms of micropropagation techniques enhancing germination times within the known range of germination times for the particular hybrid or species you are attempting to sow seeds of, that is a different story.

Protocorm growth rates will differ between orchids as well based on the same logic as mentioned above.

But, again, if you're looking for micropropagation protocols that enhance protocorm growth rates for each kind of orchid you're flasking, then I think you should be looking into the growth regulators you're utilizing.

there's a popular notion that orchids produce so many seeds because so few land in a spot with a micorhizum. i think that a good number of seeds GERMINATE in the wild, but subsequent protocorm and seedling mortality is very high. there are some species that can use a myriad of fungal species for germination, and others that are far more specialized. i can imagine that an epiphyte pcorm on a blotch of fungus can easily be dislodged by rain or desiccate, but i have a hard time believing suitable fungus in a tropical rainforest is rare. i reckon the proportion of seeds that land and germinate is about that of any endosperm producer, and that most mortality occurs between germination and rooting.
furthermore, i'm willing to bet that there's some bet-hedging going on, i.e. not every seed that lands somewhere nice germinates immediately. perhaps some seeds sit for a while before germinating in case conditions go poor. i don't think this has been proven, but it's a safe bet
i also think when we sow seeds, they vary in their receptivity to media and the TC environment
the thing is, we should be inadvertently selecting for seed growth on media when we breed orchids. bill steele told me his cyps grown in-vitro produce seed batches with proportions of germinating seeds that increase with each successive generation. why are tropicals any different?
what growth regulators increase germination speed??

This is, in part, roughly the current understanding of the correlated factors as to why orchids have evolved to produce so many seeds per pod.

This assertion may or may not be true in all cases. In some orchids it has been reliably demonstrated that only a small percentage of seeds actually germinate both in the wild and in-vitro. Case in point would be the large majority of Disa spp. With the deciduous Disa spp. germination rates are relatively low compared to something like Phalaenopsis spp. In the case of many deciduous Disa spp. I have read and have had second-hand experience with the germination rates being as low as 25% - 30%, and I'm being somewhat generous with this estimate. In some cases, it was even lower. My point being is that it depends on what orchid you're working with.

Mortality rates of protocorms are really high in the wild and can also be the case in tissue culture as well. I've been made aware of the lab I work closely with in sowing the orchid seeds I provide him that in some cases there are complete wipe outs of flasks or contamination of flasks. The probability of protocorm survival to adulthood can be very low in some cases. In other cases, it can be pretty decent.

What you said is my current understanding as well. Until there is more evidence otherwise, this notion still stands.

I am not certain of how rare suitable fungal symbionts are in the wild, but I'm sure there are a good number of colonies around a given area.

As far as the dislodging of seeds by rain or wind part, it is possible that a portion of the seeds gets washed or blown away. If you actually look for orchids in the wild, many orchids are not found in the kinds of numbers you'd find if you were to sow orchids in-vitro and grow out the seedlings. Tissue culture propagation is far superior to non-tissue culture propagation in producing large scale numbers. This is why I believe that to save endangered populations of wild orchids, this is the way to go. The difference in numbers with tissue propagating orchids versus letting nature take its course is staggeringly in favor of tissue culture.

Some of the seeds will get lodged in the nooks and crannies of their respective growing areas in the wild. This is part of the reason why there is a small percentage of orchids relative to the amount of seeds that were produced.

Desiccation doesn't usually occur on such a large scale in the wild if the habitat is very humid or rains a lot. Seasonally dry areas or areas that are semi-arid present this kind of selective pressure on orchids living in these kinds of climates. Hence why some orchids have prolonged dormancies, staggered germination, or unusual triggers such as germinating after fires.

Again, that is not necessarily true.

There is strong evidence for what you mentioned. I wouldn't really consider it a blind shot in the dark. You are on the money. Again, case in point would be something like the deciduous Disa spp. or even Cypripedium spp. It is not unusual for certain orchid seeds to germinate after 2 - 3 years.

That's true.

I'd argue that it is both inadvertent and in some cases done on purpose depending on the situation. If you're working with limited seed stock, then, yes, it'd be inadvertent to some degree. With limited seed stock, you'd be happy with what you get until you have the luxury of getting large enough of a supply on a consistent basis, then someone may be in the position to purposefully select for favorable traits. If you're working with a sufficient resource for orchid seeds, selection can be done on purpose.

They aren't. When you're breeding on a large scale, you are always selecting for plants that can survive the conditions you provide for it whether it is done with intent or not. That selection pressure is the same as the selection pressure encountered in the wild. Each subsequent generation will be better suited to cultivation. The plants have to reach sexual maturity and reproduce and the selection process repeats then gets refined over time. This is how natural selection works. Nay sayers to natural selection or evolution have never seen this work on a sped up scale. People like us who breed orchids definitely see it, (same for those who work with bacteria or viruses). Natural selection is very real and so is evolution.

It depends on the type of orchid you're working with. It is not the same for every orchid. Generally speaking, they'd be cytokinins. This is why I recommended you sign up for the ListServe. You will be quite surprised who you see on that. Some of the names are perhaps those you'd very easily recognize...

i have BAP and coconut water for media, should i add more to it? should i get kinetin? is cytokinin damaging to later growth??

From the little experience I have, growth regulators/hormones for seedlings can be more hassle than they're worth. Different story for micropropagation, obviously. But germination/replating etc, almost every experiment I've done with 4 or so spp. replated onto BA-containing media at various growth stages get good shoot reproduction but pay for it in overall biomass and then stall out at the rooting stage. As a hobbyist I'm becoming a huge fan of hormone-free or hormone-minimal germination and replating, and then sacrificing some mature seedlings for micropropagation & hormones if cloning is desired. Maybe not as industrial-scale-efficient, but waaaay simpler and less stressful.

that's my general approach as in microprop, growth regulatots r used to create somatic embryos or induce embryogenesis. orchid seeds r already embryos. if that means i let a flask sit idly for a few extra months, fine
also i read you can divide pcorms in vitro for cloning

I don't know what Catts and Paphs respond to best. The people on the ListServ can help you better than I ever could. My breeding projects do not include Catts and Paphs at the moment. I am currently working in concert with a lab to primarily produce orchids in the subfamily Orchidoideae.

Many of the people on the ListServ work in agricultural science, others work with orchids in TC labs or sell orchids to hobbyists by breeding their own stock. It is free to sign up. I am on it myself, but I am not actively participating on it.

---------- Post added at 06:01 PM ---------- Previous post was at 05:43 PM ----------

From what I understand, you do not have to really worry about damaging your protocorms if the correct amount is applied.

There are also TC books that you can buy or download that might be of some help too.