Quote:
Originally Posted by Caloosamusa
I had read that about the KM-5, that is produces erect stalks, sounds like a Fe'i, but the question should be why is that a problem? Does it cause the plant to be vunerable to winds? Its other contributions, nematode and disease resistance, are more important as the problems can be outcrossed, leaving the disease resistance.
Breeding diploids with tetraploids has its advantages but if more than two Bs, or adding up to more than two Bs, the naviruses will present destroying the prodogy or carrying the virus forward.
The progenators I use have very little Bs in them, and the most in a cross is one. I also am trying new wild musa as male prodgenators.  |
With the B genomes and "naviruses", I believe you are referring to Banana Streak Viruses, badnaviruses commonly associated with being integrated into B genomes. Two or more B genomes in a plant has been shown to infer a silencing effect in terms of activation and replication from the integrated sequences.BB, ABB, AABB and ABBB genomes will certainly contain the integrated viral sequences, but activation is inhibited. Also, what is being revealed is that there are many different types and even sequences that are integrated into A genomes. The state of BSV and its relevance to breeding is not entirely understood. Some progeny populations with only one B genome segregate for BSV activation, and of course there are countless AAB landraces which never show BSV activation, so all of the mechanisms and relevance are at this point still very poorly understood. Additionally, there are other possibly integrated, as yet unidentified viruses associated with Musa of which almost nothing is known about them.
Quote:
Originally Posted by DoctorSteve
Erect or semi-erect bunches does not bother me. Maybe it has something to do with gathering them when they are ready. Or like you said Caloosamusa, maybe it has to do with wind or something. The only thing I was wondering about was the abnormal leaves in its progeny. How abnormal are they, are they abnormal enough to cause the plant to die?
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Erect bunches are a problem to breeding programs if the bananas they are trying to create do not normally have erect bunches. These programs are trying to improve existing groups of bananas, not make something completely new. They will hold onto these creations most of the time because indeed they may be of use for something else in the future, but they may have many other non-desirable traits for the current breeding aims. If the same resistance can be acquired from a different plant with better traits such as bunch position, then they will use that other different one instead. Breeding programs must always stay balanced between completely experimental breeding and staying within the specific breeding objectives.
For the casual hobbyist, bunch orientation is no big deal. But if breeding a banana for millions of people to rely on as a staple and for farmers to depend on for their livelihoods, bunch orientation, along with many otherwise seemingly non-important issues can become very important. If the hybrid has increased disease resistance, but decreased overall yield due to some other factor, or is for whatever reason not up to par, it is unlikely to be successful within the aims of the breeding program.