Breeding a new plant is extremely easy provided the parents are
genetically compatible. However, it becomes infinitely more complex
when you want to raise a successful new plant with specific qualities
that are a significant improvement on the parent species or any
current hybrid. Above all, it must have qualities that make it
commercially desirable and if it fails on this last count, it fails on
every count.

Before you even start to raise new hybrids, you need very clear
objectives about what you want to achieve and why. Those objectives
must take heed of what is required commercially. It's all about what
will sell I'm afraid and if you don't take this into account, you're
onto a non-starter.

Identify the market place and research thoroughly. Is there a real
need for what you want to do? Will it provide significantly
improvements over existing plants and will it sell in quantity?
Creating hybrids just because they don't exist at the moment is not
the aim of plant breeders. Hybrids need to demonstrate measurable
improvements, otherwise there's no point in creating them.

Some key points to bear in mind a

1) It must be desirably different or significantly improved and have
qualities that make it commercially attractive.

2) It must be healthy and not easily prone to disease.

3) It must be stable and not liable to debilitating reversion after a
few years.

4) It must be relatively easy to propagate on a large scale either by
cuttings or preferably by tissue culture.

5) You need determination, skill, patience and ... luck.

With the above in mind, every possible parent needs to be considered
for qualities it may introduce. You should be looking to combine
strengths at the same time as suppressing weaknesses. You may need to
raise thousands of hybrids before arriving at a few pairings that
might provide you with your 'Eureka' offspring. Unfortunately it is
exceptionally rare that a simple 'one-off' crossing results in
success.

This requires enormous skill, sound experience and a very thorough
knowledge of all of your target plants. Since an element of chance is
ever-present in plant breeding, you will probably have to make many
attempts at the same crossing just to achieve one desirable
characteristic or repress a flaw. Quite often, the flaws don't
exhibit until you have started to breed for improvements and then you
have to back-cross in order to remove them.

Assuming you eventually produce your perfect hybrid, a tranche of
obstacles to success need to be considered, least of all presenting
the plant to the trade. Countless thousands of new varieties hit the
market every year, only a tiny fraction make the grade and only a very
small percentage of those are still around after 5 years. A good
agent is essential in marketing and helping you with growers, but you
have to do all of the groundwork and come up with the goods in the
first place. That's where 95% of the work is and there's no short
cut.

If after all of that, your plant is a success your work as a breeder
is far from finished. You need to remain in the lead since there's
always someone ready to take your plant and make further
improvements. Most professional breeders are already part-way towards
those improvements by the time one or several of their plants hit the
market, which enables them to keep ahead of the competition.

I'm curious as to why you have chosen Alnus, since it has limited
value as an amenity tree and its primary use is in the improvement of
soil-quality of poorly drained and nutrient deficient areas prior to
afforestation or re-afforestation. Vigorous primary hybrids using the
European/Black Alder and several other species have been around for
some years, so anything you produce would need to show major
advantages.

Whether there's a market for such plants remains to be seen. My
understanding is that the forestry industry is quite happy with the
plants already at its disposal. Is there a need for a 'super Alder'?
I don't know, but there's nothing I've heard or read that suggests
anyone is crying out for such plants.