Breeing Barley with Slender Wheatgrass

[Matt Porter]

Greetings,

My name is Matt, and it is an honor to be a part of this forum!

I want to breed domesticated barley with slender wheatgrass, and this project has many hurdles due to how distant they are genetically. I read a paper by researchers who successfully did this, but they noted how the embryos aborted at insanely high rates. Does anyone know any modern procedures that could prevent so many terminations during fertilization?

The hybrids in this study were made by emasculating barley seeds and pollinating them with wheatgrass pollen.

[Carol Deppe]

Welcome to the forum, Matt.

Whether an interspecific or other wide cross succeeds or not can depend a lot on the particular strains, varieties, populations, and even particular individual plants involved. It can also depend on which plant is used as the female parent. So one thing you might do is spread your efforts by trying crosses involving as many different strains and individual plants as possible from the two varieties. And always try each cross in both directions.

Wide crosses are more likely to succeed if the parents are each genetically heterogeneous instead of homogeneous.

Sometimes self-incompatibility mechanisms break down if the plant has had none of its flowers fertilized. My guess is this might also be true of the incompatibility mechanisms between species. That is, I would guess that all incompatibility mechanisms are the plant's Plan A. But there is also a Plan B where the plant says, "#$%! If I can't get the pollen I love, I'll love the pollen I can get!" Most plants have a small but significant tendency toward chromosome doublings. Meaning many accidental interspecific crosses can lead to new species in one generstion, where fertile branches with doubled chromosomes are sectors on the accidental hybrids. So one approach might be to do the hand pollinations on sexually deprived plants with possibly lower standards.

Another approach might be to use a bridge species. That is, find a species that both your two desired parent species will cross to. Ideally without your having to do embryo rescue.