Embryo-Rescue now – that has a few more variables to it, though the basic lab technique and culture-medium are the same. First of all, a given seedpod of wide-cross parents - fat and promising though it may be – may or may not contain any seeds with viable embryos. (Sometimes just the hormones present in the cross may cause the pod to swell; the small, lumpy pods may very well be the ones with seeds and the big ones filled with nothing but bits of chaff.) A newly-planted lily may not cross well. The weather plays a big part in a successful crosses of any kind, but wide ones especially - the first summer I tried ER was so cold that absolutely nothing worked; the second gave a fair number of successes, maybe 30-40, but the third time was our unusually warm summer of 2004, and doing the same things as in previous attempts, I ended up with over three hundred cultured embryos! Nearly half of that number came from just one pod, an Aurelian/Oriental cross that I never expected to do much of anything.
The ER seedpod should be “somewhere” between forty and sixty days old – too young, and the embryos will be too tiny to find without a long and frustrating search – and anything that slows you down increases the chance of airborne contaminants getting into the act. A seed that is too mature will be dry and difficult to open - there may be no food-supply and the embryo has “starved to death,” or if one is present it may be woody, and the embryo impossible to extricate from it without damage. Even if you do get it out intact, a wide-cross embryo may already have been poisoned by chemicals in the endosperm, and die anyway (like the occasional blood-type problems in human pregnancies.)
The trouble is, every cross is different - too early for one may be too late for another. In general, the ER seedpod should be green and still hard, or just barely beginning to soften; if your pods are ready and you aren’t, you can hold them in plastic bags in the refrigerator – dry, so they don’t get moldy – for up to several weeks, while you get your supplies together. If you open a pod and find that it was immature, you can let it ripen slowly in the fridge – I have to admit that hasn’t worked for me, but as Judith says, you never know; it’s always worth a try!
It is always a good idea to open a pod cautiously, and examine the contents under the hood, one chamber at a time – in the case of the unexpectedly productive Aurelian/Oriental cross above, I quickly ran out of prepared tubes and had to stash the rest of the pod in the refrigerator for two days, while I made up more. (As you may have figured, the contamination-rate of that batch was high, though I still had plenty left!)
In Vitro Embryo Rescue 
