黑桑种

其种加词“nigra”意为“黑色的，暗色的”。

异名

Morus atrata Raf.

Morus cretica Raf.

Morus laciniata Mill.

Morus petiolaris Raf.

Morus scabra Moretti

Morus siciliana Mill.

Morus nigra, or the black mulberry, is a species of flowering plant in the family Moraceae that is native to southwestern Asia, where it has been cultivated for so long that its precise natural range is unknown. The black mulberry is known for its large number of chromosomes.

Description

Morus nigra is a deciduous tree growing to 12 metres (39 feet) tall by 15 m (49 ft) broad. The leaves are 10–20 centimetres (4–8 inches) long by 6–10 cm (2–4 in) broad – up to 23 cm (9 in) long on vigorous shoots, downy on the underside, the upper surface rough with very short, stiff hairs. Each somatic cell has 308 chromosomes in total, and exhibits tetratetracontaploidy (44x), meaning that its genome contains seven chromosomes, and each somatic cell has 44 copies of each. This is reported as ”the highest number of polyploidies among any known spermatophyte species“.

The fruit is a compound cluster of several small drupes that are dark purple, almost black when ripe, and they are 2.5 cm (1 in) in diameter. Black mulberry is richly flavoured, similar to the red mulberry (Morus rubra) rather than the more insipid fruit of the white mulberry (Morus alba). Mulberry fruit color derives from anthocyanins.

Sometimes other mulberry species are confused with black mulberry, particularly black-fruited individuals of the white mulberry. Black mulberry may be distinguished from the white mulberry by the uniformly hairy lower surface of its leaves.

Cultivation and uses

Black mulberries (Morus nigra) are thought to have originated in the mountainous areas of Mesopotamia and Persia (i.e. Armenian highlands). Black mulberry is planted, and often naturalised, west across much of Europe, including Ukraine, and east into China. Now they are widespread throughout Armenia, Afghanistan, Iraq, Iran, India, Pakistan, Syria, Lebanon, Jordan, Palestine, and Turkey.

The fruit is edible and the tree has long been cultivated for this property. Both the tree and the fruit are known by the Persian-derived names toot (mulberry) or shahtoot (شاه توت) (king's or "superior" mulberry), or, in Arabic, as shajarat tukki. Often, jams and sherbets are made from the fruit in this region.

The fruit has been present in the Southern Levant since antiquity. In the Books of Maccabees, it is noted that the Greeks used the fruit to provoke their war elephants in preparation for battle against Jewish rebels during the Maccabean Revolt in the 2nd century BCE. The fruit is also mentioned in the Mishnah and later rabbinic texts. In the 9th century CE, Al-Kindi referenced the fruit as having healing seeds, while Ibn Badis, writing in the 11th century, noted its use in the production of ink.

In Europe, the largest-documented local concentration of black mulberries may be found in the vineyards of Pukanec in Slovakia, which contain 470 black mulberry trees. Approximately 400 additional trees can be found in the surrounding villages.

The black mulberry was imported into Britain in the 17th century in the hope that it would be useful in the cultivation of silkworms (Bombyx mori). It was unsuccessful in that enterprise because silkworms prefer the white mulberry. However, the plantings have left a legacy of large and old trees in many country house gardens. The cultivars, M. nigra 'Chelsea' (Syn. 'King James'), and M. nigra 'Jerusalem' have been awarded the Award of Garden Merit by the Royal Horticultural Society. Both cultivars are female (F) and self-fertile. M. nigra was much used in folk medicine, especially in the treatment of tapeworm.

Research of genetic diversity of over 250 old black mulberry trees in Turkey, Iran and Azerbaijan has found no genetic diversity. This suggests that all existing black mulberry trees in the hypothesized area of origin and also elsewhere in the world are clones. This might be the result of propagation by cuttings and layering complemented by apomictic seed formation.