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The 20th century has seen an enormous transitionin our appreciation of plant genetic diversity. Thecentury began with the rediscovery of Mendel’s lawsof inheritance, and through Johanssen the dawningof modern plant breeding. The basis and methodfor scientific plant improvement were to hand. Inaddition, the post-Darwinian world saw no shortsupply of genetic diversity within crop species, norwas such diversity viewed as threatened.Then through the century awareness has grownthat genetic resources are indeed limited. With thespread of agricultural development worldwide, localvarieties and minor species have given way to mod-ern introduced varieties of major crops. By themid-1970s, concern for plant genetic resources(PGR) was widespread and efforts to conserve themunderway. PGR were generally divided into domes-ticated populations (landraces, obsolete cultivars,breeders’ populations, modern varieties of crops,genetic stocks) and wild populations (wild plantspecies especially those related to crops). The domi-nant strategies were to conserve domesticatedgermplasm in genebanks |
