by Robert Connell Clarke
Preface
Cannabis is one of the world’s oldest cultivated plants. Currently, however, Cannabis cultivation and use is illegal or legally restricted around the globe. Despite constant official control, Cannabis cultivation and use has spread to every continent and nearly every nation. Cultivated and wild Cannabis flourishes in temperate and tropical climates worldwide. Three hundred million users form a strong undercurrent beneath the flowing tide of eradication. To judge by increasing official awareness of the economic potentials of Cannabis, legalization seems inevitable although slow. Yet as Cannabis faces eventual legalization it is threatened by extinction. Government-sanctioned and supported spraying with herbicides anddd other forms of eradication have chased ancient Cannabis strains from their native homes.
Cannabis has great potential for many commercial uses. According to a recent survey of available research by Turner, Elsohly and Boeren (1980) of the Research Institute of Pharmaceutical Sciences at the University of Mississippi, Cannabis contains 421 known compounds, and new ones are constantly being discovered and reported. Without further understanding of the potentials of Cannabis as a source of fiber, fuel, food, industrial chemicals and medicine it seems thoughtless to support eradication campaigns.
World politics also threaten Cannabis. Rural Cannabis farming cultures of the Middle East, Southeast Asia, Central America and Mrica face political unrest and open aggression. Cannabis seeds cannot be stored forever. If they are not planted and reproduced each year a strain could be lost. Whales, big cats, and redwoods are all protected in preserves established by national and international laws. Plans must also be implemented to protect Cannabis cultures and rare strains from certain extinction.
Agribusiness is excited at the prospect of supplying America’s 20 million Cannabis users with domestically grown commercial marijuana. As a result, development of uniform patented hybrid strains by multinational agricultural firms is inevitable. The morality of plant patent laws has been challenged for years. For humans to recombine and then patent the genetic material of another living organism, especially at the expense of the original organism, certainly offends the moral sense of many concerned citizens. Does the slight recombination of a plant’s genetic material by a breeder give him the right to own that organism and its offspring? Despite public resistance voiced by conservation groups, the Plant Variety Protection Act of 1970 was passed and currently allows the patenting of 224 vegetable crops. New amendments could grant patent holders exclusive rights for 18 years to distribute, import, export and use for breeding purposes their newly developed strains. Similar conventions worldwide could further threaten genetic resources. Should patented varieties of Cannabis become reality it might be illegal to grow any strain other than a patented variety, especially for food or medicinal uses. Limitations could also be imposed such that only low-THC strains would be patentable. This could lead to restrictions on small-scale growing of Cannabis; commercial growers could not take the chance of stray pollinations from private plots harming a valuable seed crop. Proponents of plant patenting claim that patents will encourage the development of new varieties. In fact, patent laws encourage the spread of uniform strains devoid of the genetic diversity which allows improvements. Patent laws have also fostered intense competition between breeders and the suppression of research results which if made public could speed crop improvement. A handful of large corporations hold the vast majority of plant patents. These conditions will make it impossible for cultivators of native strains to compete with agribusiness and could lead to the further extinction of native strains now surviving on small farms in North America and Europe. Plant improvement in itself presents no threat to genetic reserves. However, the support and spread of improved strains by large corporations could prove disastrous.
Like most major crops, Cannabis originated outside North America in still-primitive areas of the world. Thousands of years ago humans began to gather seeds from wild Cannabis and grow them in fields alongside the first cultivated food crops. Seeds from the best plants were saved for planting the following season. Cannabis was spread by nomadic tribes and by trade between cultures until it now appears in both cultivated and escaped forms in many nations. The pressures of human and natural selection have resulted in many distinct strains adapted to unique niches within the ecosystem. Thus, individual Cannabis strains possess unique gene pools containing great potential diversity. In this diversity lies the strength of genetic inheritance. From diverse gene pools breeders extract the desirable traits incorporated into new varieties. Nature also calls on the gene pool to ensure that a strain will survive. As climate changes and stronger pests and diseases appear, Cannabis evolves new adaptations and defenses.
Modern agriculture is already striving to change this natural system. When Cannabis is legalized, the breeding and marketing of improved varieties for commercial agriculture is certain. Most of the areas suitable for commercial Cannabis cultivation already harbor their own native strains. Improved strains with an adaptive edge will follow in the wake of commercial agriculture and replace rare native strains in foreign fields. Native strains will hybridize with introduced strains through wind-borne pollen dispersal and some genes will be squeezed from the gene pool.
Herein lies extreme danger! Since each strain of Cannabis is genetically unique and contains at least a few genes not found in other strains, if a strain becomes extinct the unique genes are lost forever. Should genetic weaknesses arise from excessive inbreeding of commercial strains, new varieties might not be resistant to a previously unrecognized environmental threat. A disease could spread rapidly and wipe out entire fields simultaneously. Widespread crop failure would result in great financial loss to the farmer and possible extinction of entire strains.
In 1970, to the horror of American farmers and plant breeders, Southern corn leaf-blight (Helm in thosporium maydis) spread quickly and unexpectedly throughout corn crops and caught farmers off guard with no defense. H. maydis is a fungus which causes minor rot and damage in corn and had previously had no economic impact. However, in 1969 a virulent mutant strain of the fungus appeared in Illinois, and by the end of the following season its wind-borne spores had spread and blighted crops from the Great Lakes to the Gulf of Mexico. Approximately 15% of America’s corn crop was destroyed. In some states over half the crop was lost.
Fortunately the only fields badly infected were those containing strains descended from parents of what corn breeders called “the Texas strain.” Plants descended from parents of previously developed strains were only slightly infected. The discovery and spread of the Texas strain had revolutionized the corn industry. Since pollen from this strain is sterile, female plants do not have to be detasseled by hand or machine, saving farmers millions of dollars annually. Unknown to corn breeders, hidden in this improved strain was an extreme vulnerability to the mutant leaf-blight fungus.
Total disaster was avoided by the around-the clock efforts of plant breeders to develop a commercial strain from other than Texas plants. It still took three years to develop and reproduce enough resistant seed to supply all who needed it. We are also fortunate that corn breeders could rise to the challenge and had maintained seed reserves for breeding. If patented hybrid strains of Cannabis are produced and gain popularity, the same situation could arise. Many pathogens are known to infect Cannabis and any one of them has the potential to reach epidemic proportions in a genetically uniform crop. We can not and should not stop plant improvement programs and the use of hybrid strains. However, we should provide a reserve of genetic material in case it is required in the future. Breeders can only combat future problems by relying on primitive gene pools contained in native strains. If native gene pools have been squeezed out by competition from patented commercial hybrids than the breeder is helpless. The forces of mutation and natural selection take thousands of years to modify gene pools, while a Cannabis blight could spread like wildfire.
As Cannabis conservationists, we must fight the further amendment of plant patent laws to include Cannabis, and initiate programs immediately to collect, catalogue, and propagate vanishing strains. Cannabis preserves are needed where each strain can be freely cultivated in areas resembling native habitats. This will help reduce the selective pressure of an introduced environment, and preserve the genetic integrity of each strain. Presently such a program is far from becoming a reality and rare strains are vanishing faster than they can be saved. Only a handful of dedicated researchers, cultivators, and conservationists are concerned with the genetic fate of Cannabis. It is tragic that a plant with such promise should be caught up in an age when extinction at the hands of humans is commonplace. Responsibility is left with the few who will have the sensitivity to end genocide and the foresight to preserve Cannabis for future generations.
Marijuana Botany presents the scientific knowledge and propagation techniques used to preserve and multiply vanishing Cannabis strains. Also included is information concerning Cannabis genetics and breeding used to begin plant improvement programs. It is up to the individual to use this information thoughtfully and responsibly.