DNA story of when life first gave us lemons

All citrus fruits can trace their roots to the southeast foothills of the Himalayas, according to DNA evidence.

The first citrus trees appeared about eight million years ago, before spreading around the world, say international scientists.

The trees eventually gave rise to the fruit on our kitchen tables, from sweet oranges to bitter lemons.

Citrus trees are among the most widely cultivated fruit trees in the world, but their history has been unclear.

To get a better understanding of where citrus trees came from, scientists in the US and Spain analysed the genomes of over 50 varieties of citrus fruit, from the Chinese mandarin to the Seville orange.

The study, published in Nature journal, found that modern citrus trees derive from several natural species found in a region that includes the eastern area of Assam, northern Myanmar, and western Yunnan.

When the climate changed millions of years ago, bringing weaker monsoons and drier weather, the plants were able to spread out of the Himalayas, and throughout southeast Asia.=read more