Re: Nepenthes flowering, crossing, grafting, etc.

dave evans (T442119@RUTADMIN.RUTGERS.EDU)
Mon, 24 Jun 96 17:28 EDT

> From: Fernando Rivadavia <ss69615@ECC-XS09.HONGO.ECC.U-TOKYO.AC.JP>
>
> I remember reading an article about nepenthes grafting in CPN a
> few years ago and was wondering if this is easy or not. If it is, then
> wouldn't it be possible to graft a branch from a male plant onto a female
> plant, for example? This way when the plant flowers, we would get both
> male and female spikes and be able to get fertile seeds.

Hi Fernando,

I really doubt this would help at all. Nepenthes have strong
apical dominance and this in itself would probably have ill effects
on any grafts. Second, grafts work alot better if the part being
grafted is dormant or at least just a bud. Nepenthes have no domancy
and causing one particular bud to start growing (gibberillins?)
would be tricky. The easiest way of doing that is to cut to the vine
off one (at most) buds above the one you want to grow. Third, after
going through this trouble and flowering the plant, there is no way
to tell if the new opposite sexed branch would even flower. Most Nep
of flowering size, will have several ground rosettes and other vines
(adult or usually not) and only one of these tends to flower at any
given time.

> is that the flowering of female plants may be induced by factors
> different than those needed to induce male flowers. Not to mention
> that I have no idea if sex in Nepenthes is controlled genetically
> (like an X and Y chromosome system) or by hormonal factors, in
> which case maybe the grafted male branch would become female in time.

Since they flower at the same this of year (if not the species would
soon die out or need to flower all year long) I'd assume they are
induced to flower by the same factors. Also, if it was hormonal
factors inducing the sex, then plants would probably be able to
change their sex but I have not heard of this yet.

> The last question is if it is worth the trouble to attempt it at
> all (if not only for curiosity). I believe it's possible to store pollen
> in a refrigerator as with Sarracenia, correct?

Yes, at least for a couple of weeks anyway. I froze some N.ventricosa
pollen and when/if a female Nep of mine flowers I'll see if it's still
viable.

Here's a little secret for you all: It takes quite a few growth points
and they need to be in the adult stage for this but it works very well.
Take cuttings with about four or more leaves to them from two opposite
sexed plants. At least 75% of these will flower within three to five
months of being cut. Works like a clock (must be something hormonal)!
You would have good chances by taking two cuttings from each plant and
almost be guaranteed success with three from each. I would be producing
seed this way if I had the room to grow good sized adult pairs from
which to take these cuttings. BTW, this can also be used to sex your
plants.

Dave Evans