Hybrid, The History and Science of Plant Breeding

 by Noel Kingsbury, University of Chicago Press, 2009

The author is a British horticulturalist who has also written several books about garden design.  From my reading of this book I can attest that it is comprehensive, and from the reviews that acquainted me with it, I can attest that it is authoritative.  From seeking such a book for many years to fill a gap in my scientific education, I can attest that nothing comparable to it has appeared at least in modern times, so the book should excite considerable interest. 

If you wait for a second edition, you should be spared many typographical errors—even missing words that will slow your reading (“noone” became, after appreciable reinterpretation, “no one”).  If you decide to read it soon, here is a useful suggestion:  make a glossary of the quasi alphabet soup that applies seemingly to all the many combinations of NGOs (nongovernmental organizations), academic departments, and government institutes which cooperate in plant breeding—even the locations in the text where each string of capital letters is explained, are not mentioned in the index; so create your glossary continuously.  (I have no other quarrel with the index). The following are just a sample of many interesting details from the book.  

 Shuttle breeding.  Norman Borlaug, father of the Green Revolution on the 1930s, invented shuttle breeding for the purpose of cutting in half the time required to achieve a useful new variety of wheat.  He transported seed back and forth twice a year from central Mexico to northern United States—in Mexico wheat is grown in winter.  The new variety was achieved in five years instead of ten.  The conventional wisdom had been that new varieties should be developed locally to be well adapted to local conditions.  The serendipity: Borlaug’s new variety of wheat was not only successful in Mexico but also in all similar climates of widely varying latitude.  He had inadvertently bred out of wheat its natural photoperiod sensitivity whereby its ability to develop flowers and seed depended on rather fixed durations of daylight at particular times in its development.  Shuttle breeding now includes shuttling between the northern and southern hemispheres. 

Organic farming.  Many of us are sympathetic with organic farming methods because they avoid use of toxic chemicals. However, I have long suspected that strictly organic farming throughout the world could not even come close to supporting our existing population.  This is the second book that confirms my suspicion (the first was Tomorrow’s Table by Ronald & Adamchak).  The way forward is for all of us to accept and select the most sustainable aspects of both modern agriculture and the organic movement.

Hybrid corn is the first generation cross of two distinct strains for parents.  To get a consistent result from this cross both parents must be selected to breed true for several generations and  the “female” parent must be detasseled (corn, like most plants, is a natural hermaphrodite).  Otherwise the progeny would be so varied that only a very few would have the desired inheritance.  Hybrid corn was a turning point in plant breeding and the protection of “intellectual property.”  Prior to hybrid corn, breeders of food plants were relatively non-acquisitive idealists attempting to improve nutrition for all of mankind.  Individuals, academic departments, and seed companies shared genetic material quite freely.  Hybrid corn created the biological equivalent of a patented product because it is too complicated for individuals to produce it, and its seeds are worthless for next year’s crop—the same chaotic variation that would have resulted if the parents had not been selected to breed true.  So farmers must buy new seed from industry absolutely every year—very profitable for agribusiness (and for the farmers because yields are so high).  Now that patents of plants and genes are accepted, breeders are secretive, especially those depending on stockholders for support.  The way forward may come from Asia in unexpected ways.

By pilfering from test plots of agribusiness and by bribery, some of the patented varieties of crops have already entered the pool of available genetic material for local breeders in Asia.  Small farmers in the underdeveloped world are reluctant to try new methods, and they much prefer saving seed compared to buying new seed.  Recently local breeders there are overcoming this reluctance by hiring small farmers to manage small test plots of possibly improved varieties.  Genetic theory tells us that selective breeding can ultimately achieve the performance of hybrid corn by creating an equivalent genome to that of the hybrid, but its seed would breed true, so farmers could again save seed from the previous crop for future planting.  This trend of local experts learning from foreigners and learning to involve farmers in making improvements and quite recently, working on improving crops of only more local significance, such as pulses (beans and peas) is very encouraging. Will what goes around, come around?  Quite likely, and with unintended side effects like improving the status of women. 

Most of the farmers in the underdeveloped world are women.  Their new status as employees of breeders antagonized the men until the resulting improvement in the crops spoke for the benefits of their new status.  The book is full of such gems.  The summary of the history of plant breeding on pages 399- 402 is excellent.  Frankenfood is mentioned on page 399 as “a headline writer’s dream and a nightmare for researchers and those who had invested in the technology”—referring to GM (genetically modified crops).  However, Frankenfood would be an appropriate name for any food crop contaminated with pollen from an agriceutical, a GM crop modified to produce a pharmaceutical chemical.  By law such crops must be produced in greenhouses with special filters and airlocks to prevent escape of any pollen to a food crop intended for human consumption.  Incidentally, agriceuticals would have been worthy of mention in a book as comprehensive as this one.

Finally, when I hear that Thomas Malthus has been proven wrong yet again, it concerns me that the postponement of his predictions of a population crisis with mass starvation does not prove Malthus wrong.  Noel Kingsbury does concede that the genocide in Rwanda had some of its origin in overpopulation.  Overpopulation is the ultimate threat to the environment even if we manage to achieve excessive population without mass starvation. 

John A. Frantz, MD, NASW                                                                                          September15, 2010