Timbuktu or to study. By 1300, the population increased to 10,000 and kept increasing until it reached about 50,000 in the 1500s. There is insufficient rainfall in the Timbuktu region for purely rain-fed agriculture and crops are therefore irrigated using water from the River Niger. The main agricultural crop is rice. African floating rice ("Oryza glaberrima") has traditionally been grown in regions near the river that are inundated during the annual flood. Seed is sown at the beginning of the rainy season (June–July) so that when the flood water arrives plants are already in height. The plants grow up to in
Plant genome assembly products were used to clone remaining gaps, and YACs allowed the characterization of telomere sequences. The resulting sequenced regions were 115.4 Mb of the 125 Mb predicted size of the genome and a total of 25,498 of protein-coding genes. To sequence and assemble the genome of Oryza Sativa (japonica), the same strategy was used. For Oryza Sativa a total of 3,401 mapped clones in a minimum tiling path were selected from the physical map and assembled. One of the most important crops in the world, maize (Zea mays), is the last plant genome project primarily based on Sanger BAC-by-BAC strategy.