Crop wild relative was Nikolai Vavilov, the Russian botanist who first realized the importance of crop wild relatives in the early 20th century. Genetic material from CWRs has been utilized by humans for thousands of years to improve the quality and yield of crops. Farmers have used traditional breeding methods for millennia, wild maize ("Zea mexicana") is routinely grown alongside maize to promote natural crossing and improve yields. More recently, plant breeders have utilised CWR genes to improve a wide range of crops like rice ("Oryza sativa"), tomato ("Solanum lycopersicum") and grain legumes. CWRs have contributed many useful genes to crop plants, and
Cannabis sativa Cannabis sativa Cannabis sativa is an annual herbaceous flowering plant indigenous to eastern Asia but now of cosmopolitan distribution due to widespread cultivation. It has been cultivated throughout recorded history, used as a source of industrial fiber, seed oil, food, recreation, religious and spiritual moods and medicine. Each part of the plant is harvested differently, depending on the purpose of its use. The species was first classified by Carl Linnaeus in 1753. The flowers of "Cannabis sativa" are unisexual and plants are most often either male or female. It is a short-day flowering plant, with staminate (male) plants usually taller