Maca, or Peruvian Ginseng, an
Andean crucifer
Maca, Lepidium
meyenii Walp. [L. peruvianum Chacon sp. nov. (syn.)],
is an Andean crop of narrow distribution, restricted today to the Departments
of Junin and Cerro de Pasco of Peru at elevations
above 3500 and often reaching 4450 meters. The popularity of this crop is
steadily increasing not only in its area of production but also in large cities
because of its putative medicinal properties. Maca is
cultivated for consumption of the root and hypocotyl.
The underground parts are eaten fresh, cooked in "pachamancas"
or stored dried for later consumption. The dried roots are eaten after boiling
in water or milk, and sometimes mixed with honey bee and fruit for preparation
of juices , and addition of sugar cane
rum for cocktails and other alcoholic beverages. According to folk belief, maca enhances female fertility in humans and domestic
animals which tends to be reduced at higher altitudes. Chemical analysis
suggests that this medicinal property may be due to the presence of
biologically active aromatic isothiocyanates, and specifically
due to p-methoxybenzyl isothiocyanate,
which is also found in mashua (Tropaeolum
tuberosum Ruiz and Pavon),
another species reputed to increase fertility in humans. These compounds have
been found to protect against cancer. Today, dried maca roots are ground to
power and sold in drug stores in capsules as a medicine and food supplement to
increase stamina and fertility. Because of these properties, it is also known
by the name of Peruvian ginseng. Maca was domesticated at least 2000 years ago in San Blas, Junin. It has one of the highest frost tolerance among other native cultivated plants, since maca is able to grow in the puna
where only alpine grasses and bitter potatoes thrive.
Maca is also cultivated as a
valuable food crop. The nutritional value of the maca
dry hypocotyl is high, resembling that found in
cereal grains such as maize, rice and wheat. Fresh hypocotyls content 80% of
water. Dry maca hypocotyls have the following
composition: 59% carbohydrates, 10.2% proteins, 8.5% fiber and 2.2% lipids. It
has a large amount of essential amino acids and higher levels of iron and
calcium than the white potato. In addition, it contains important amounts of
fatty acids, of which linolenic, palmitic
and oleic acids are the most prominent. Maca is also
rich in sterols and has high mineral content, in particular Fe, Ca and Cu.
Alkaloids are also present, but these have yet to be determined.
Our recent studies
indicate that maca grows
better in soils of neutral pH than in the prevalent acidic soils of it native
area of production. It has a wide range of adapation
developing enlarged hypocotyls under either long day or short day, or high or
low altitude locations. Maca is a disomic
octoploid of 2n=8x=64 chromosomes.
Maca relies mainly on
self-fertilization for its reproduction. It has low genetic variability. A
survey by molecular markers of Lepidium wild
species collected in Andes, including tetraploid and octoploid species, failed to disclose close relatives that
could be considered ancestral to the cultivated species. Phylogenetic map of 53 accessions based on RAPD
markers.
