Breeding for resistance

A major reason that motivated us to look into JcL breeding goes back to a devastating pest attack. Starting about 2 years ago the Papaya Mealy Bug arrived. It settled down heavily on all our JcL hedges and also infected tomato and pepper plantings. During the very dry year 2010 we lost almost all our crops to this bug.

Studying the little options available to fight the plague (of course the industry is willing to sell you tons of different pesticide products, but they don’t really work) of course breeding for resistance was an interesting way forward. As we had started looking at breeding for yield and removal of negative toxic effects anyway, it soon became clear what the three primary objectives for our breeding program would be: (1) yield (2) absence of toxicity and (3) resistance.

Breeding for resistance is an extremely controversial subject and past attempts have done a lot of damage to specific crops and ecosystems that play a major role in today’s overzealous use of chemicals in agriculture.

Recently I stumbled over the very enlightening books of Raoul A. Robinson, especially the one called “Return to Resistance”. (All of Mr. Robinson’s books can be downloaded for free from the internet, just google his name) In this book he lays out the problems around vertical (one gene) resistance and makes the case for horizontal resistance, with the latter being a potential remedy for many of the current food shortages.

Horizontal resistance is a multi-gen trait of a plant that is permanent similar to the kind of resistance wild plants obviously have. In commercial corps in can be achieved through continuous cycles of mass selection from self crossing accessions which will inevitably improve resistance more and more until an upper limit is reached. The larger the range of genetic variability in the breeding population, the better.

We have decided, that we will give this approach a similar chance as the “Mendelian” approach where we cross breed intra- and interspecific hybrids looking for the best combination of traits (pedigree breeding). We actually believe, that introducing interspecific hybrids with their greater genetic variance can help improve the start-up population for the mass selection population.

Anyone with some interest in the subject should definitely have a look at Raoul Robinson’s books. You don’t have to be an agronomist or a plant breeder to understand his work. I can only highly recommend it.

Leave a Reply