Читать книгу The Cannabis Grow Bible - Greg Green - Страница 34

2005. K.W. Hillig discovers genetic evidence for speciation in Cannabaceae.

Sample populations of 157 Cannabis accessions of diverse geographic origin were surveyed for allozyme variation at 17 gene loci. The frequencies of 52 alleles were subjected to principal components analysis. A scatter plot revealed two major groups of accessions. The sativa gene pool includes fiber/seed landraces from Europe, Asia Minor, and Central Asia, and ruderal populations from Eastern Europe. The indica gene pool includes fiber/seed landraces from eastern Asia, narrow-leafleted drug strains from southern Asia, Africa, and Latin America, wide-leafleted drug strains from Afghanistan and Pakistan, and feral populations from India and Nepal. A third putative gene pool includes ruderal populations from Central Asia. None of the previous taxonomic concepts that were tested adequately circumscribe the sativa and indica gene pools. A polytypic concept of Cannabis is proposed, which recognizes three species, C. sativa, C. indica and C. ruderalis, and seven putative taxa.²⁵

ANCIENT NAMES

BC	Qunubu, Konaba27,28, qěnēh bośem29, κανναβɩς, kannabis and hemp
AD	hemp, Indian hemp, cannabis, and marijuana30
Early Suggestions for Single Species
1753 by Carolus Linnaeus	C. sativa L. or Cannabis sativa L. subsp. sativa
Early Dispute / Reputed New Species
1785 by Jean-Baptiste Lamarck	C. indica Lam
1849 A. R. Delile31	C. chinensis Delile
Modern Dispute / Reputed New Species
1924 by D. E Janischevsky32	C. ruderalis Janisch. or C. sativa L. f. ruderalis (Janisch.) or C. sativa L subsp. spontanea Serebr
1929 by Nikolai Ivanovich Vavilov33 C.	indica var. kafiristanica (Vavilov)
Modern Research
1974 by Richard E. Schultes and Loran Anderson34 C.	C. indica
C. ruderalis
sativa
Modern Dispute / Research Dispute
1976 by Ernest Small & Cronquist35	C. indica Lam to Cannabis sativa L. subsp. indica (Lam.)
C. indica var. kafiristanica (Vav) to C. sativa subsp. indica var. kafiristanica (Small & Cronquist)
C. chinensis Delile to C. sativa subsp. sativa var. sativa (Small & Cronquist)
2005 by Karl W. Hillig	Cannabis sativa L. subsp. indica (Lam.) to C. indica

Hillig understood that there was a need to know whether or not speciation had occurred in cannabis. In a follow-up paper Hillig writes,

Botanists disagree whether Cannabis (Cannabaceae) is a monotypic or polytypic genus. A systematic investigation was undertaken to elucidate underlying evolutionary and taxonomic relationships within the genus. Genetic, morphological, and chemotaxonomic analyses were conducted on 157 Cannabis accessions of known geographic origin. Sample populations of each accession were surveyed for allozyme variation at 17 gene loci. Principal component (PC) analysis of the allozyme allele frequencies revealed that most accessions were derived from two major gene pools corresponding to C. sativa L., and C. indica Lam. A third putative gene pool corresponds to C. ruderalis Janisch. Previous taxonomic treatments were tested for goodness of fit to the pattern of genetic variation. Based on these results, a working hypothesis for a taxonomic circumscription of Cannabis was proposed that is a synthesis of previous polytypic concepts. Putative infraspecific taxa were assigned to “biotypes” pending formal taxonomic revision. Genetic variation was highest in the hemp and feral biotypes and least in the drug biotypes. Morphometric traits were analyzed by PC and canonical variates (CV) analysis. PC analysis failed to differentiate the putative species, but provided objective support for recognition of infraspecific taxa of C. sativa and C. indica. CV analysis resulted in a high degree of discrimination of the putative species and infraspecific taxa. Variation in qualitative and quantitative levels of cannabidiol (CBD), tetrahydrocannabinol (THC), and other cannabinoids was determined, as were frequencies of alleles that control CBD and THC biosynthesis. The patterns of variation support a two-species concept, but not recognition of C. ruderalis as a separate species from C. sativa. PC analysis of terpenoid variation showed that the wide-leaflet drug (WLD) biotype of C. indica produced enhanced mean levels of guaiol and isomers of eudesmol, and is distinct from the other putative taxa. In summary, the results of this investigation show that a taxonomic revision of Cannabis is warranted. However, additional studies of putative wild populations are needed to further substantiate the proposed taxonomic treatment.²⁶