review by Jack Kittredge
This has been the go-to book for plant breeders in the organic and small farming world for a generation now. Like many plant breeders, Deppe feels it is fundamental to good farming to manage the biological as well as the agricultural systems involved. She has herself developed new varieties appropriate to her farming situation and believes it is a responsibility of any craftsperson to understand and control the materials of the craft. On top of that good reason, she also points out that no seed company, given the small level of seed sales involved, can devote resources to developing seed for gardeners and small growers. So if anyone is going to, we must.
Carol is an engaging writer. She brings you into her life as a farmer right away, introducing you to others – from the very young to the very old — who have developed important varieties, as well as into her own work. The principles she stresses – patience, respect for detail, judgment about traits and how they will impact the final product – are basic to any craft and she brings their importance home in her stories.
She organizes the bulk of the book around stepping through the basic factors any breeder will have to consider.
- How much of your life do you want to devote to this effort?
- What do you want to get at the end?
- How will you get useful germplasm to start with?
- How will you evaluate your work and get useful information?
- How do normal plant genetics work?
- Are there special genetic processes you need to understand?
These pages include as good a lecture on Mendelian genetics as I’ve seen. It explains the predictable traits you find, and their mathematical distribution when you cross different pure breeding diploid varieties in F1, F2, and F3 generations. They also include a good lecture on modern genetics: chromosomes, linkage, mitosis and meiosis, alleles, as well as the ways in which Mendelian laws do not always apply — codominance, mutation, lethals, aberrant segregation, expressivity and penetrance, and many more. These are explained simply and clearly, and will doubtless become reference material for anyone who begins actual breeding work and comes up with some unusual results!
Also included is a table of 801 plants (selected from 3000 in Stephen Facciola’s book Cornucopia), listed alphabetically by scientific name, and giving for each plant such vital information as type (annual, biennial, perennial, herb, shrub, tree, etc.), diploid chromosome number, genomic formula, breeding system (outbreeding, inbreeding), flower type, percent contamination frequency, self-compatibility information, recommended isolation distances from various sources, yield of seed, location in USDA plant germplasm system, and sources of this information. The fledgling breeder will not need most of this right away, but once questions pop up such answers are invaluable.
Also, the 2000 2nd edition has been expanded to include 50 pages – 6 chapters – on seed saving, and another 2 chapters on crops for a sustainable future, focusing on a negative example (the corporate FlavrSavr tomato that bombed so badly in the 1990s) and a positive one (the Sandwich Slice summer squash that showed up in Carol’s squash patch in 1998). These additions are valuable. The seed saving section has helped create a serious movement among growers to select and save seed – the first step of plant breeding. The section on developing crops for our collective future takes the reader into a discussion of pleiotropy – the tendency of genes to work holistically and impact many traits, not just the ones the engineer wants to affect. And it gives an excellent example of a farmer’s quest to improve on a variety that has presented itself, to find the flavor, convenience, marketability, size, healthfulness and all the other traits that will make it a winner.
All told, this is a solid basic text for the aspiring plant breeding grower. My only complaint, however, is that I would have liked a lot more illustrations. The many various flower types, the simple logic of the laws of inheritance, the generational steps in making and unmaking hybrids – all would benefit from simple drawings. I am a visual learner and for me an illustration is often worth many words. The two pages of drawings of various vegetable flowers in Appendix A seem almost to flout the lack of such useful help anywhere else in the book. But don’t let that keep you from getting a copy. Right now this is the best book available for the small amateur plant breeder. Have fun!