WEC - 2011 RUN # 4 (R. gigantea X R. longicuspis)

General Discussion
1

Girija and Viru also kindly sent me seed of this most interesting cross, R.gigantea X R. longicuspis!!!

Here are the achenes of this cross:



I have just started a real time WEC run on this material.

I just extracted these seeds from their pericarps. I used about half the total seed, and left the rest as a reserve in case there is a bad outcome in this run:



I’ll remove their papery coverings tomorrow morning, after they have soaked in tap water overnight, and post pix of the embryos then.

2

I just removed the papery coverings from these seeds. About 6 or 7 of the embryos were immediately eliminated due to mushiness or waxy appearances (bad signs). Here are the embryos I felt were reasonable prospects for the WEC, based on their physical appearance:



It is impossible to appreciate from such a photo the fine detail of the coloring of these, or indeed their turgidity, (all of which are important predictors of embryo quality IMO). Even though in the above picture these embryos appear “good”, in reality some are questionable based on waxy parts, and borderline mushiness.

In short this is the typical look of extremely dried seed which has travelled thousands of feet in the air in a freezing cargo hold.

The goal here is to get one to germinate, real fast!!! I expect there will be some germinations, but I would be surprised if there are many.

Today’s weather forecast: 104F, relative humidity 45% (unusually dry heat for what we normally get here).

These are not the best weather condtions for a WEC run, but it has been done before, with some success. As this seed is from the tropics, it probably will love this heat LOL!!

3

Here they are after 3 days of water soaking (I kept only the five most active prospects…none of the original total had moulded):



I have sown them exactly as the R.gigantea embryos, in a media containing hydrocrystal (1 part)+ perlite (10 parts).

These were the most delicate thread-like rose seeds and embryos I can ever remember processing…a real challenge!!!

4

N.B the hydrocrystal+perlite proportions quoted in the entry above, assumes pre-wetted hydrocrystal added to pre-wetted perlite.

Here is a shot to show how the complete set up looks like…the cling wrap has been sealed off with ordinary stationery adhesive tape. The plastic pot is sitting in a water level:



Here is the R.gigantea X R.longicuspis embryo contained in the above pot as viewed from above through the cling wrap (to show how it was sown):



In the above shot, you can make out some of the hydrocrystal if you look carefully amongst the perlite particles.

5

lol, it feels like snot and silicone in real life. It works awesome in pot culture too :slight_smile:

6

Michael, my early impressions of hydrocrystal are that it is a most marvellous idea you have given me. So far, I feel it is going to open new doors for WEC!!

7

I am about to start a new-real time WEC run, so refer to the link below, for further discussion regarding this R.gigantea X R.longicuspis run:

Link: www.rosehybridizers.org/forum/message.php?topid=34390&rc=0&ui=2829830532

8

I am going to do this next WEC run on R.clinophylla. The seed has been collected and supplied to me by Girija and Viru in India, thank you again Girija and Viru!!!

Jim P made me think twice about my prior readiness to abandon using the foam (polystyrene) coffee cups in WEC.

Previously I found that these cups were easy to deform when applying pressure around the top of the cups to get an elastic band tightly around them to seal the cling wrap…this often caused the embryos to fall deep inside the pure perlite media, a disaster!!

However since I have started using Michael G’s idea of a media that combines pre-wetted hydrocrystal + pre-wetted perlite, I have discovered that this combination media seems a lot more cohesive as a mass, and embryos tend to not move around or fall too deeply into the media with slight shifting of the pot sides during cling wrap application and securing.

This has massive practical advantages, amongst other great advantages!!!

Extrapolating these new findings, I just had a thought!!!

…why not go back to trialling the foam cups again, only this time using the h+p media, and see if the embryos can stay sitting in their intended positions, despite deforming movements of the foam cup sides (during the process of applying and taping the cling wraps to the tops of the cups)?!

I will not poke holes in the cup bases at the begining of the culture, which has the advantage of doing away with a tray of water at the base.

Assuming embryo germinations occur, I will later on poke drainage holes on the bases of these cups, by using say an electric soldering iron tip.

9

Here then are the R.clinophylla achenes I received:



A few hours ago, I took a small sample of the total number of achenes, and removed their woody pericarps. There are lots of remaining unextracted achenes, sitting as reserves.

Here are some R.clinophylla rose seeds after removal of the pericarp coverings:



Here is a close up of what R.clinophylla rose seed looks like after woody pericarp removal:

scale: 1 gap = 1/16 inch



I will let these soak overnight, and then remove their papery coverings tomorrow, and then show you pix of the newly extracted embryo appearances.

10

George,

I poke holes in the cups with a regular kitchen fork! Just do it slowly so as not to break the bottom of the cup.

Fill the cup with media, then water, then do a “dry” run poking the holes. I usually poke 3, possibly 4 times. The holes are tiny but there are enough for drainage or use a cooking 2 tined fork with fewer but larger holes.

Do it over the sink, LOL.

Jim

11

George,

Afterward I had a moment of PANIC! I was wondering if you were referring to plastic cups; to tough for fork tines to penetrate… reread it and saw you meant the styrofoam coffee cups. Yes, I reuse mine for plants too!

Jim

12

Hi Jim, yeah I am thinking foam cups (polystyrine).

Actually after just removing their papery coverings, virtually all but two of the pictured embryos below were very hard and waxy. I eliminated all of them!!!

Here they are…some are hard to make out due to poor embryo quality/translusency/waxiness…some of the better (but still very waxy) ones are easier to spot in this pic:



Here is a close up of two of the better embryos:



I am going to extract a few more today, to see if I can get a few real good looking ones, as doing WEC requires additional time and resources (compared to throwing achenes in a baggie in the fridge)…I have no time for experiments to see how “marginal”" cases can be revived!!!

Stay tuned.

13

OK… refer to the link below for additional commentary on this R.clinophylla WEC run #5.

Link: www.rosehybridizers.org/forum/message.php?topid=34437&rc=0&ui=2829830532

14

I feel confident enough now to list some points regarding the things I have learned about WEC, over the last few months of messing around with it.

I would like to firstly thank David Zlesak for so generously supplying me with hundreds of dried seeds, which helped me step up my exrtaction skills, and which offerred me an opportunity to investigate WEC even further than I previously had. I also have Girija and Viru Viraraghavan to thank, for offerring me dried species seed, which has been very helpful to verify the same sort of observations I seemd to get from David’s seed.

Firstly, I define WEC as rose embryo culture using typically 3 days of tap water soaking of embryos, followed by culture, which I now do in a drinking glass with wetted perlite (thanks to Don Holeman’s excellent advice). This glass is sealed off with cling wrap and an elastic band (the cling wrap’s inside surface is misted say once daily to keep up humidity near the embryos on the surface of the wetted perlite).

No additional chemicals are used during any step.

Things I have learned:

  1. Dry achenes which have been travelling in air cargo long distances have shown generally poor results with WEC. I would not advise using WEC on embryos which are of a waxy or waxy/pearly white mosaic appearance. These embryos seem to have undergone a physical alteration of their tisssues, and show a type of “dormancy” in the WEC cultures, which often results in whitened non-responsive embryos which most often decline and die.

  2. Some very dry achenes do contain healthy pearly white embryos which easily slip out of their papery coverings (testa). Such embryos typically will do well in WEC. Such embryos are very typical of freshly harvested rose achenes (seeds).

  3. If one is considering to do WEC on dried achenes (seeds), I think it is best to sample a small number of achenes first, say 10, and see how the embryos look. If the embryos are predominantly of the waxy or waxy/pearly white mosaic type, I would stronlgy suggest to not embark on WEC, and to try other methods of germination on that particualr batch of seed.

15

Some suspicions and further questions, I now also have:

  1. Might rose embryo waxy changes (whether patchy/mosaic or dense in distribution) which are typical of some dried rose seeds, correlate with true rose “embryo dormancy” (as opposed to “seed coat dormancy”)??

  2. Might it be possible to develop, through some modification to WEC, a rose embryo culture protocol which can efficiently deal with waxy embryos to give more acceptable germination rates??

  3. I wonder if waxy embryos do better with 3 days of water soaking, followed by immediate sowing/burying in a seedling mix/perlite media.

I would love to one day test these ideas out!!

16

As I wrote in another thread, I am back to sowing embryos directly into seed raising mix, after their 3 days water soak. Only this time I am incorporating perlite in the mix (~1:1)… I find the results have been good this way, for whatever reason.

Here is one example where I used this method recently, with embryos of Flower Carpet White X OP:



All I do is water the pot where the embryos have been sown near the surface once daily, with a hand held water sprayer/mister, and they germinate like seeds would have a few days later.

This method eliminates the need to transfer embryos from sterile perlite into seed raising mix, if I were to use pure perlite in the initial germination step (and so there is less chance of rootlet breakage).

I decided that if critters in the seedling mix cause problems, I’ll just replace the mix with a different brand/batch, I prefer not to mess around with pasteurization or insecticides.

17

Here, ten days later, are the above three Flower Carpet White X OP seedlings, individually potted up:




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