Plumalmondterine

One of the universal benefits of working in an ag lab is the leftovers. Especially in California. We used to get everything from pesticide trial "control" strawberries to extra non-inoculated avocados, to thank you gifts from growers of almonds (not to mention wine!).

One of the coolest treats was an accident.

My grad school PI ran disease screens for a peach breeder who, I think, was trying to introgress some pathogen resistance gene from almond to peach. Peaches and almonds (along with plums, cherries and apricots) are in the genus Prunus. It seems odd at first until you see what an almond fruit actually looks like (pic.) and realize that that the almond "nut" is homologous to the seed inside a peach pit. Almond fruits are even fuzzy! My Jordanian friend once told me that the fruits themselves (when immature and green) are a popular snack in the Middle East.

During the summer we received weekly deliveries of hybrid peach x almond fruits to inoculate - the extras we ate. One week stands out in my memory. This batch looked like nectarines but had deep red-purple flesh with the taste and rubbery texture of a plum. And in the center of each fruit there was an almond where the pit should have been! It was like eating a fruit that came with a candy dessert at the end.

We carefully nibbled at pieces of the "almond," as the wild relative of this crop, the bitter almond, releases cyanide when chewed. It tasted like a normal almond but we threw it out just in case. My almond lab friend was pretty alarmed we even tried it. Apparently this kind of haywire genetic mixing happens a lot in Prunus species and it's not unusual for a fruit to look like a mix of different fruits that we normally think of as distinct.

Most of us think we've got nature pretty well figured out, but it always surprises me just how amorphous and unpredictable biology really is.