8

Prospecting for Seeds

If science ceases to be a rebellion against authority, then it does not deserve the talents of our brightest children.

—Freeman Dyson, The Scientist as Rebel

Potatoes fueled the economic success of Europe, wheat and corn that of North America, and sweet potatoes that of Asia. These crops were nearly all farmed using one or a few varieties, varieties that grew bountifully in the absence of their enemies. But by the late 1800s the pests and pathogens to which those varieties were susceptible started to arrive in force. There was the potato blight, of course, but also the potato beetle, and then wheat rusts, corn smuts, and so many more maladies that no one could really keep track of them. To continue to farm crops borrowed from other regions, the developed world was going to need new varieties of seeds, and ideally they would be available in advance, not just when some crop failed. The question was whether anyone could actually go back and gather the seeds that the conquistadors had missed.

In the early 1900s, crops failed as frequently in Russia as they did in any temperate region. Those failures led, again and again, to famine. Nikolai Vavilov grew up during several Russian famines. His family was relatively affluent, but not so affluent as to be shielded from bad years and the failures of crops. As a result, they ate simple food, whatever was most available in a particular season or what had been stored, fermented, from the previous season. Vavilov’s father, a textile merchant, encouraged Nikolai and his brother to follow him into business. It was a path to success in a country that historically had few such paths. But times were changing, and the old paths to success were no longer the only ones. Vavilov’s generation believed in the power of science to help transform society. His brother became a physicist, one of his sisters a microbiologist, the other a doctor. Nikolai, in turn, studied at the Moscow Agricultural Institute. In doing so he embarked upon a professional life focused on plants, agriculture, and food. Just what he would do in such a career, and whether it would be anything other than ordinary, was not obvious at the time.

Vavilov graduated from the institute in the spring of 1911, having focused on breeding varieties of oat, barley, and wheat that were resistant to pathogens.1 As a student, he learned about the work of Charles Darwin, whose Origin of Species, published in 1859, revealed the process of natural selection by which nature, red in tooth and claw, winnows the fittest form from all others.² To young Vavilov, Darwin’s insights seemed both revolutionary and useful. Vavilov would come to think of himself as a student of Darwin; he always kept a portrait of Darwin in his office. Vavilov had also learned about the even more recent work of Gregor Mendel, an Austrian monk. Mendel, who died in 1884, developed the basic theory of the laws of inheritance traits—be they the fuzziness of pea pods or their resistance to pathogens. Regarding the experiments of Mendel and those who built upon them, Vavilov wrote, “The recent experiments in genetics have unveiled much more opportunities than a researcher of the past could… dream about.”³ At the time, the informal history of plant breeding stretching back some ten thousand years or more focused on strategies enabling farmers to choose, in each generation, the individual plants that had the traits they desired or at least were the closest match available. Darwin’s and Mendel’s insights suggested another model, one in which a scientist could systematically cross particular varieties of crops so as to produce offspring with, say, the fast growth of one variety and the resistance of another.

Vavilov wanted to understand how crop varieties were related to each other, how they varied around the world, and where one might find crop varieties with the most extreme traits—the strongest resistance to a pest; the highest tolerance for cold or drought. Such information seemed key to modern plant breeding. Vavilov wrote to professor Robert E. Regel, at the Bureau of Applied Botany, in Petrograd (now Saint Petersburg), expressing this interest. Subsequently Regel mentored Vavilov during the fall of 1911 and spring of 1912 at the bureau. Vavilov then returned to Moscow, where he organized a series of seminars. In one of these seminars, Vavilov gave a talk in which he argued for the value of the theory of genetics to agriculture.4

By 1912 Vavilov had done practical work on plant breeding and resistance and had intensely studied plant pathogens, plant taxonomy, and plant geography. Then in 1913, he was offered the opportunity to tour western Europe to visit the labs of scientists working there and, in doing so, learn about the cutting-edge research in plant breeding and genetics going on outside Russia.

Vavilov left Petrograd carrying letters of introduction from Regel; the letters became tickets into the laboratories of some of the most esteemed scientists of western Europe. He visited the lab of William Bateson, by then director of the John Innes Horticultural Institution, in Merton, and Reginald Punnett and Rowland Biffen at Cambridge. It was Bateson who had coined the term genetics and helped rediscover the work of Gregor Mendel. Bateson advocated a new way of understanding and working with all of life. With Bateson, Vavilov saw modern genetics being applied.

As he traveled, Vavilov was starting to envision the future. He believed Bateson’s argument that generations of scientists would use genetics to breed new crops in ever more controlled ways; it was an idea he had held even before arriving in England, one that seemed forcefully validated by Bateson. But he also knew that if this was to happen it would require that scientists have access to the fullest possible diversity of genes and traits engendered in crops over thousands of years of human and agricultural history—thousands of years of selection of just the right crops for each region and culture on earth. Vavilov foresaw that as the tools of genetics improved, the only limit to human ingenuity would be whether or not geneticists had access to the full diversity of existing varieties. In October of 1914, just after World War I erupted, Vavilov was forced to return home. He arrived in Russia having collected both new knowledge and, from any place he could, new seeds. He made it home safely, but his collection of the seeds of western Europe was on a ship that hit a mine. The ship exploded. The collection disappeared. This was to be Vavilov’s first experience—but not the last—with the challenge of collecting and saving seeds.

Vavilov continued his work back at the Moscow Agricultural Institute. He studied Russian wheat varieties and their resistance to various pathogens. He also began to work with younger researchers, training them and, as he did, expanding the scope of his projects. His studies included work on an unusual Persian (Iranian) wheat resistant to powdery mildew.5 This Persian wheat could be bred with other varieties of wheat to produce new varieties that were both resistant to powdery mildew and high-yielding. But, he thought, it would be useful to get more samples. In 1915, he took brief trips to the Trans-Caspian region and Turkmenistan, which was adjacent to Persia and so might also be a place where Persian wheat was farmed. He found many new varieties of crop plants, but no Persian wheat.

Then after two years of steady work came a big opportunity. In May of 1916 the Russian ministry of defense contacted the Moscow Agricultural Academy. The ministry of defense had a problem of a botanical nature: “Could someone come help?” The academy recommended Vavilov for the job. The next morning Vavilov stood out in front of his house, eager and self-assured, wearing a gray woolen suit, a white fedora, and carrying an enormous backpack.⁶ He had plant presses, too, and a working knowledge of the plants of the region—those that were known and those whose presence he could infer. He was an agronomist reporting for duty, eagerly.

Vavilov was told that many of the soldiers stationed in Persia at the time were getting sick when they ate bread made from the local wheat. The bread seemed to make the soldiers drunk and hallucinatory. The military wanted Vavilov to figure out what was happening. Vavilov had a good guess as to what the problem was. He probably could have recommended a solution in a letter,⁷ but why would he? He was eager to get to Persia to collect more plants.

Vavilov was especially interested in finding new varieties of wheat and barley. He, like Biffen at Cambridge, was making good progress in breeding new wheats but was limited by the varieties he had to work with. Wheat sustained Russia and much of Europe, but just as conspicuously often failed during years when pathogens wiped out the crops or in regions such as much of the Eurasian steppe, where most of the time the short seasons and cold weather prevented Russian wheat varieties from growing at all.

When Vavilov arrived at the camp where the troops were getting sick, near Ashkhabad, he quickly diagnosed the cause of the illness. His guess had been right. The soldiers were accidentally consuming the seeds of a weed called darnel (Lolium temulentum), which were inadvertently being baked along with the wheat grains in bread. The darnel seeds were similar enough to wheat seeds to be gathered by accident.8 The weeds themselves were not toxic but were home to a fusarium fungus, ergot, that lives as a partner of the plant within its stems and seeds. Ergot produces lysergic acid diethylamide, a.k.a. LSD. Hot bread contaminated with the weed and its fungus was making the soldiers high when it was eaten immediately after baking. The soldiers were told to not eat bread made from local grain, and the problem ceased. Pleased with his ability to solve the great military mystery in a day, Vavilov traveled on to the east.

Vavilov took his three horses and began to explore Persia. En route, he found a new wild perennial flax ripe with seeds, which he gathered in abundance. A new rice. New wheat varieties (though not the disease-resistant wheat he thought he might encounter). And more. He sped down the path, grabbing, studying, questioning. He was collecting new varieties and starting to get a sense of the regions in which farmers had bred the greatest diversity of wheat.

While collecting, Vavilov stumbled upon Russian Cossacks marching toward the Tigris River. Biologists in the field often look suspicious to authorities. Their behavior seems unusual and irrational, their equipment vaguely military, and their explanations (“I’m collecting plants to save humanity”) beyond belief. In this Vavilov was no exception. He was taken immediately to the guard post. He was questioned, and each of his answers made the Cossacks surer he must be a spy. Vavilov’s first language was, of course, Russian, but he was taking notes in English, as he had done since his trip to the UK. This was odd and suspicious. More suspiciously, he had with him books written in German.

Vavilov and his team were passed along from the guard post to another authority, this one charged with the specific task of exterminating German “vermin.” The vermin detector was given one thousand gold rubles for every German spy he found. With that incentive, and considering Vavilov’s strange behavior, the detector felt he had clearly hit the jackpot. Fortunately, Vavilov was freed after three days, having talked his way to freedom.9

Upon his release, Vavilov kept going east, another thousand kilometers on horseback. He had planned to return home to Moscow in August. But he decided on another plan. He would instead trek up along the border between Turkmenistan (then part of the Russian Empire) and Afghanistan toward the high plateaus of the Pamir Mountains, at the intersection of Tajikistan, Afghanistan, and China. It was in these plateaus that Vavilov would make the biggest discoveries—though not until after he was chased by a mob during an uprising. He narrowly escaped the mob only to be arrested, and then, once more, he was, very fortunately, released.

Beyond the political and social challenges Vavilov faced, his travel to the Pamir Mountains was physically arduous. It would have been hard at any time (especially after having already logged several thousand kilometers with a growing collection of dried seeds and plants in tow), but because he was traveling very near to the line that separated Russia’s troops from those of Turkey—one of the front lines in World War I—he could not take the normal route. He would have to go, in the middle of winter, up and over glaciers to get to the plateaus. He was by then traveling with six horses, two porters, and a local guide, Khan Kil’dy Mirza-Bashi, who taught Vavilov about local crop varieties, translated for him, coordinated logistics, and, more than once, saved his life. They walked along a path, six feet wide at its widest, at the edge of a cliff above a valley that dropped hundreds and then thousands of feet below them. Vavilov found totally unknown varieties of wheat, rye, peas, and lentils, many of them resistant to powdery mildew. Then, he found a wheat that ripened earlier than any he had yet seen. It was perfect for use in the cold, dry, northern reaches of Russia, where seasons were short and wheat varieties needed to be able to take advantage of as many days of sunlight as possible. With this wheat, a variety highly valued in the Pamirs at the time (as it is today), Vavilov might expand agriculture north in Russia and save lives—or he would, anyway, if he ever went home.10

On his grand journey from Persia to the Pamir highlands (and, later, on each of his many subsequent trips to Africa, the Americas, and Asia), Vavilov saw particular plant varieties of interest, but he also saw broad patterns, the rules of both nature and human societies. For example, while an individual village might farm relatively few kinds of peas, wheat, and corn, in traveling from one village or region to the next, one could find thousands. This seemed to be especially true in mountainous regions, where plants might vary not only with climate (up and down the mountain) but also with longitude and latitude (in one valley relative to another similar valley). Some aspects of the diversity of crops seemed to him to be predictable: he was revealing, it seemed, the mysteries of the evolution of the diversity of crops. How many more varieties of crops might exist, hidden in one or another village? No one knew. Even the varieties known to scientists had never been gathered systematically in one place.

Vavilov returned from his odyssey in the spring of 1917, the year of the October Revolution. He was just thirty years old and had not yet defended his PhD (that would come in 1918). But he had already made a range of important discoveries, on the basis of which he was appointed professor in the department of agriculture and plant breeding at Saratov University. There he set up an experimental research station that became the Saratov branch of the Bureau of Applied Botany. At the time, the Saratov branch was essentially the only place in Russia where plant breeding was actively taking place. By virtue of their accomplishments, and despite the vicissitudes of war and revolution, Vavilov and his students had become responsible for the future of food in the biggest country on earth. This was partly because of the paucity of work being done elsewhere in the country and partly because of the ambitiousness of Vavilov’s efforts. In 1918, Vavilov’s mentor, Robert E. Regel, felt comfortable writing that although many had studied plants’ resistance to pathogens and pests (immunity, he called it), no one had ever approached the problem “with such a breadth of views and comprehensive coverage of this problem, as Vavilov has done.”11

The work of seed collection and breeding new crop varieties Vavilov was leading at Saratov was a work of contrasts. On the one hand, it involved Vavilov’s adventures, his travels, his diligent attempts to learn everything he could from each farmer he met, no matter where that farmer lived and no matter what language he spoke. On the other hand, it also required the more monastic duties of saving the seeds, growing them out, documenting their details, and curating them carefully, all of which took time, patience, and a mind-numbing diligence.

The more Vavilov’s endeavor expanded, the more monklike work there would be. The more, too, there would be the need for exploration. And his work expanded a lot. In 1920, after Regel died from typhus, Vavilov became the head of the Bureau of Applied Botany¹² and moved to Petrograd with twenty researchers. By 1920, he employed sixty researchers. By 1921, things were going so well that Vavilov set up a division of the bureau’s department of applied botany and breeding at 136 Liberty Street in New York City, a division that would find and buy seeds from the Americas. This division alone would add more seed varieties to the Russian seed collection than existed in the years before Vavilov started his work. Vavilov would use these varieties for breeding and to understand the evolution of the diversity of crops on earth. He was, some had already begun to say, “the Mendeleyev of biology.”¹³ This comparison was not, however, perfectly apt. Mendeleyev brought order to the elements. Vavilov wanted to bring not just order to the diversity of plants but also, based on that order, an understanding of ways to improve agriculture in the future in light of its history.

Vavilov could have done great work with only the seeds he brought back from Persia and those being supplied from North America, but he wanted far more. He needed to keep collecting. But where? As of 1920, much of Vavilov’s work had focused on wheat, barley, and rye, and in considering these plants he documented their diversity, cleared up ambiguities in their nomenclature, and tried to understand their evolutionary history. He not only unraveled aspects of the particular stories of these crops but also discerned general features—rules, really—of the domestication of crops. He used his understanding of these rules, when coupled with detailed study of the literature on various domesticated plants,14 to begin to predict which regions would be most productive for study of each kind of domesticate. He identified geographic centers where farmers working with wooden plows, clay tools, and their hands seemed to have engendered or moved a disproportionate number of crops and varieties over millennia, crops perfect for the conditions—the climates and cultures—in which they lived. He called these regions centers of origin, with the dual implication that they were not only the locations where the greatest diversity existed but also the locations where that diversity arose. For example, the diversity of barley and wheat was greatest in Asia Minor, and hence it was in that region where this diversity likely arose. The diversity of potato varieties was highest in the Andes and Chile, and so this, too, was a center of origin. The diversities of chilies, cacao, tomatoes, and corn were highest in Mesoamerica, and so that region was their center of origin. And so on. Breeding crop varieties took time, and farmers had the most time to breed new varieties near where a crop was first farmed. He published a major work on this idea, “The Centers of Origin of Cultivated Plants,”¹⁵ in 1926, but long before then he had begun to use the germ of this theory to guide his exploration.

On the basis of his centers of origin theory, Vavilov could predict where one might find new kinds of crops in the greatest numbers. In doing so he could finish the work the conquistadors had started, gathering the seeds most likely to be of use rather than simply those that traveled most readily or seemed most appealing to a hungry traveler. Repeatedly he left what was by that time the Soviet Union for those remote regions. On each trip he took risks. On each trip he came back with riches—camel loads of seeds, elephant loads of seeds, horse loads of seeds, boatloads of seeds. He went on expeditions, on every continent except Antarctica, in sixty-four countries.¹⁶ On each trip, he found more seeds; after each trip, his institute, which in 1930 had come to be called the All-Union Institute of Plant Industry (now the N. I. Vavilov Institute of Plant Genetic Resources, or VIR), would grow larger and more ambitious.¹⁷

Figure 8. Crop centers of diversity, with exemplar crops and their centers of diversity in circles. Figure by Neil McCoy, Rob Dunn Lab.

We think of modern humans as destroyers of diversity. We humans do battle against the dark worlds of pathogens and pests. We killed the mastodons and mammoths and then, when they were gone, hacked at the wolves and bears. But farmers in villages around the world also created; they chose wild plants and carefully, by replanting favored forms in just the right ways, created more diversity—more diversity than nature offered on its own. They created thousands, perhaps hundreds of thousands, of new, useful crop varieties. Most crops in the world depended on an individual culture, village, or even just a family who tended to them. Every species of crop you eat, every variety within a species, has a history linked to villages, people, and places that is mostly lost to the anonymous grind of time. As the world became ever more connected and industrialized, and as local knowledge and farming approaches gave way to global approaches, these varieties would, Vavilov knew, be lost. This is partly why he often chose to travel to difficult-to-reach destinations. In places that were easy to get to, many of the most interesting folk varieties were already gone.

In the early 1900s, as populations around Russia and around the world grew, the need to produce more food on a finite amount of land was increasing. Politicians noticed. The hungry noticed. Vavilov himself had lived through multiple famines. In central Russia alone droughts would occur in both 1920, when Vavilov was still in Saratov, and 1924, by which time Vavilov had moved to Petrograd. There would be another drought in 1936. It was becoming easier to envision a time when the whole world might be similarly susceptible.

Vavilov’s work was lauded and rewarded by Lenin, who spoke of a society that offered opportunity for artists, scholars, and scientists such as Vavilov. His work was also lauded by society at large and by other scientists. Soon Vavilov employed researchers and staff all across Russia. Some were stationed at the core seed collection in Leningrad (the former Petrograd). Many others, though, were at the thirty-six plant breeding centers across the Soviet Union. At these sites, Vavilov and his team carried out the breeding of many varieties of crops. They then tested the most interesting of the new varieties against the diverse climates of Russia through use of 115 sites. The stations were located so as to cover each of the climates of the Soviet Union, to maximize the number of varieties from Vavilov’s collections that could be grown.

In 1925, at the age of thirty-eight, Vavilov was elected a corresponding member of the Academy of Sciences of the USSR; five years later he became the youngest person to become a full member. He was, he believed, on track to build a cathedral of science out of which future innovations in seeds and crops and sustenance would come. In his near-religious enthusiasm for this project, Vavilov had gathered a community of men and women around him who shared not only his belief in the power of plants but also his determination to build something dedicated to civilization that was far more ambitious than any of them might achieve in their lifetimes. He had, he told one reporter, “a hundred year plan.”18 Vavilov even had a plan for the order of things. He started with wheat, barley, oats, and cabbages. He would move next to melons and strawberries.

Vavilov knew that in order to sustain the species we depend on, we—the collective we, the big human we—would ultimately need several things. We would need to save the knowledge and varieties produced by traditional farmers around the world. We would need to understand the history of those varieties and the people associated with them. We would need scientists and farmers who tinker with those varieties in light of particular problems. This tinkering, of course, includes the production of new hybrids, a process that is nothing more than what traditional farmers have long done but informed by the insight that the science of genetics gives us. We would also need new sorts of tinkering—genetic engineering, some call it—which speeds up the process. Finally we would need an understanding of the basic biology of the forests and grasslands in which traditional crop varieties and their ancestors evolved. Vavilov made each of these points and, one can argue, hoped that these research agendas would be part of an even bigger plan, a five-hundred-year plan—after he completed the first hundred years of work, gathering the seeds.

By 1935, Vavilov and his team had gathered between 148,000 and 175,000 varieties of crops and their wild relatives.¹⁹ Each variety contained the story of the people who’d bred it from its wild stock or from other domesticated seeds. Back on the farms, the stories of these varieties, of course, continued, unfolding in each place he had gone as new crops were traded, favored, and created. From this collection, new forms could be systematically bred, forms that would complement whatever ingenuity continued in farmers’ fields. Vavilov, of course, did not gather all the traditional knowledge associated with each crop, though he tried to gather as much as he could. Nor did he gather the species on which each crop depended—the microbes associated with its roots, the bees with its flowers, the predators that controlled its pests. Nor did he understand all the connections among these species. The seeds, though, were a first step. Then came World War II. By the time the war began, Vavilov had disappeared, and his collections, his precious collections, were under siege.