Understanding resistance

Simon, it is Sunday, I am going outside know, this one is a bit deep for today, can you give me a simple intro of what you are saying, please

What's wrong wif ya Roseman...can't ya understand plain English ????

Ok, smarty duds, I have read your conversation on chemistry with Simon, so you can explain it to me in simple terms so I can understand can you manage this

Yeh, no probs...ummm...errr....ahhhh oh bugger it Simon, you explain it to him will ya...i gotta go work on the awning and carport i'm building on me shed !!!

Yep - it's Sunday... a nice day... I have pollen ready to use... and I've buggered my back yesterday morning and can hardly move (think I zigged when I should have zagged and something gave way) and I'm confined lying down or sitting indoors... Murphy has a sad sense of humour

The gist of the article is this:

Resistance in plants like roses is not only due to a single specific genes. It is also due to lots of genes all working together. Single gene resistance is called vertical resistance and multigenic resistance is called horizontal resistance. So when choosing which seedlings you should keep you should not really be looking for the absence of disease (though in an ideal world this would be nice), but the degree to which it is resistant because the more resistant it is the greater compliment of genes it has causing this resistance and you can, by selecting the most resistant in each generation gradually accumulate these genes that contribute to resistance. The reason for thinking about it as polygenic (or horizontal) is that this resistance is less specific. It's like broad spectrum resistance. Black spot in one area is not the same as black spot in another area and roses with vertical, or signle gene, resistance to one strain of black spot will not necessarily be resistant to another in another area. Roses with a greater range of resistance genes (i.e. horizontal resistance) are able to withstand a broad range of strains or races of black spot because their reponses are less specific and will work on a wider range of strains. These responses will show degrees of success and it can be assumed that roses showing the greatest level of success are those possessing the widest range of genes that contribute to good general resistance. This is why it is important to test roses in a range of different circumstances to expose them to a greater variety of pathogens. So in theory, it shoudl also be possible to take a rose like 'Julia's Rose' as discussed previously, and by choosing the most resistant each time gradually improve it... it's just by using roses of proven broad resistance you will greaty reduce the time and effort required.

How was that

I knew that !!!! I'm gob - smacked Simon !! It's a very interesting subject but i'm damned if i know why you aren't working for the CSIRO instead of teaching kids !! Ok Roseman...over to you !! Hehe.

Nah Dave... I'm investing in our future mate... maybe I'll do something different later on but for now I see the best way to ensure a good future is to take it to the kids and be up on the issues myself...

Yeh, i can understand that m8 !! Talking of kids, i notice we never have any interest in the junior forum on this site....more's the pity !!!