Genome Sequencing of Cucurbita Species

Cucurbita plants (pumpkins, squashes and gourds) are important and valuable vegetable crops and are grown throughout the world. The genus comprises 12–14 species and some of them are among the earliest plants to be domesticated for cultivation. Currently, Cucurbita genetics is largely lagging behind that of other important vegetable crops, including those from the same Cucurbitaceae family such as melon, watermelon and cucumber. To facilitate research and breeding in this genus, we initiated sequencing of the genomes for the three most economically important species in the genus, C. pepo, C. maxima, and C. moschata, by employing high throughput Illumina sequencing technologies. For each species, we have constructed and sequenced paired-end libraries with insert sizes of 200 bp, 300 bp, 500 bp and 1Kb, and mate-pair libraries with insert sizes of 3-5 Kb, 8-10 Kb and 15-20 Kb. We have generated high-quality genome assemblies and currently are in the process of annotating these three genomes. High-density genetic maps are also being constructed for genome scaffold anchoring and ordering. These resources will provide a solid foundation for extensive QTL mapping and comparative genomics of Cucurbita species.