Julia,
I have no idea why it shows up like this, hah! I am using pages on my Mac. This is not what the document looks like until I copy and paste. I made the PDF file because it seemed to work better and shows the highlights and bullet points. I’m not great with computers though. Not sure how to make it work out right.
EDIT: Thank you Christopher, that fixed it right up!
Lora, if you edit your post, you’ll notice that the part in the scroll-box thing is where your paragraphs are tab-indented. If you remove those tabs, that effect will go away. In order to bullet something, put a * at the start of the line before it. You can italicize text by wrapping it in single-* markers and bold it by wrapping it in double-. (Triple- before and after causes both effects.) And I think underlining is either discouraged or impossible because it’s hard to read.
Here’s Chapter 3:
Chapter 3 (2013 PDF version)
Plant resistance to a viral, bacterial, or insect parasite may be controlled by a single gene (vertical resistance) or by a combination of genes (horizontal resistance). For the most part, vertical resistance is all-or-nothing, while horizontal resistance is variable.
Vertical resistance is like a lock that protects against a specific parasite “key” (also controlled by a single gene in the parasite). The mechanism is analogous to the human system of antibodies protecting against specific antigens. Only if the parasite’s key fits the plant’s lock can infection take hold at all.
Once the parasite infects the plant, horizontal resistance operates as a second line of defense to prevent the infection from killing the plant.
Mendelian (pedigree) breeding, which was the predominant technique used throughout the 20th century, focused on developing vertical resistance. Breeders discarded plants showing any infection, thus eliminating most horizontal resistance from the new cultivars they developed.
(Summary from Chat gpt) This is the chapter that talks about dealing with the best performing plants in a population.
Chapter 4, “Horizontal Resistance,”
Robinson introduces the concept of horizontal resistance, which is a type of resistance that provides broad protection against a wide range of pests and diseases. This resistance is controlled by multiple genes, making it more difficult for pests and pathogens to overcome through mutation or adaptation.
Robinson contrasts horizontal resistance with vertical resistance, which is controlled by single genes and provides specific protection against particular pests or diseases. Vertical resistance, while effective in the short term, is often rendered ineffective over time as pests and pathogens evolve to overcome it.
Robinson explains that the key to breeding crops with horizontal resistance is to use recurrent mass selection, which involves selecting the best plants for resistance and crossbreeding them in each successive generation.
The Best Performing Plants
Robinson cautions against solely focusing on the top-performing plants, as they might exhibit vertical resistance rather than the desired horizontal resistance. The concern is that vertical resistance can be easily overcome by pests and diseases due to its single-gene control, leading to a temporary and unsustainable protection.
To avoid this issue, Robinson recommends using recurrent mass selection in horizontal resistance breeding. This method involves selecting a larger number of plants that show good resistance and performance instead of just the few top-performers. By doing so, the breeder preserves genetic diversity and increases the likelihood of selecting plants with horizontal resistance.
In summary, when breeding for horizontal resistance, it is important to avoid selecting only the very best plants, as they might possess vertical resistance. Instead, select a larger group of well-performing plants to maintain genetic diversity and increase the chances of developing true horizontal resistance.
Actionable Takeaways:
Diversify crops: Avoid monoculture, as it encourages the spread of pests and diseases. Planting diverse crops or cultivars helps maintain a balanced ecosystem, which can limit the buildup of pest populations and disease pressure.
Use resistant varieties: Choose plant varieties that have been bred for horizontal resistance.
Observe and select: Growers should pay close attention to how different plants perform under local conditions. Select healthy plants and save seeds from them for future planting, as these plants are more likely to possess horizontal resistance traits.
Foster beneficial organisms: Encourage the presence of beneficial insects, birds, and microorganisms in your farming or gardening environment. These natural predators can help control pest populations and contribute to the overall health of the ecosystem.
Practice crop rotation: Rotate crops to disrupt the life cycle of pests and diseases, and to maintain soil fertility.
Chapter 5 “Stability in Agriculture.” This chapter discusses the importance of stability in agriculture.
Robinson emphasizes the need for stability in agriculture, which he defines as the ability to maintain consistent yields and resist the impacts of pests, diseases, and other stresses. He explains that stability can be achieved through the use of horizontal resistance, which is a more sustainable and long-term approach to crop protection compared to the short-lived protection offered by vertical resistance.
Robinson argues that modern agriculture, with its reliance on monoculture, chemical inputs, and genetically uniform crops, has inadvertently promoted instability by creating environments that favor the rapid evolution of pests and diseases. He suggests that by incorporating traditional landrace varieties, which often possess horizontal resistance, gardeners and small-scale farmers can promote stability and resilience in their agricultural systems.
Main Takeaways:
Incorporate landrace varieties: Landrace varieties have been cultivated and selected by local farmers over generations, often resulting in inherent horizontal resistance. Use these varieties in your garden or farm to promote stability and resilience.
Maintain genetic diversity: Genetic diversity is crucial for horizontal resistance and long-term stability. Preserve and propagate diverse landrace varieties to ensure a wide range of resistance traits.
Observe and select: Closely observe how different landrace varieties perform in your local environment, and save seeds from the best-performing plants for future planting. This process helps maintain and improve horizontal resistance over time.
Share knowledge and seeds: Collaborate with other gardeners and farmers to exchange seeds, knowledge, and experiences related to landrace varieties and horizontal resistance breeding.
The link is not working.
Here’s the PDF.
Return-to-Resistance.pdf (1.7 MB)
Maybe somebody could train our own AI Bot with a few books like this, that would make generating summaries or whatever we want much easier…
For whatever reason, when they originally published the book online years ago they left the appendices out. The Spanish version still has them, though, and I have a copy. Anyone who’s interested, feel free to send me a private message. (As I recall from when I read it the first time, having appendix B in particular makes vertical versus horizontal resistance make more sense.)
Thanks,
I think regular ai bots can do that.
I am intersted on the appendices. I can not send you private or chat messages.
Oops, sorry, didn’t realize I needed to change a setting to allow that. Folks should be able to now.
I just noticed that Google Books has the appendices in English.