A new genomic resource available for Annonaceae

From Plant Press, Vol. 26, No. 2, April 2023.

Cherimoya (Annona cherimola) has been an appreciated food source since Pre-Columbian times in the Americas. Although it is currently considered an underutilized fruit crop, it is still important at the local level in several regions of Central and South America. It is commercially cultivated in several countries such as Chile, Ecuador, Peru, Spain, and USA (California), among others, and has a clear niche for expansion in regions with subtropical climates. It belongs to the Annonaceae, the largest family on the Magnoliid clade, sister to the eudicot and monocot clades of angiosperms. But, unfortunately, the progress on cherimoya breeding is hindered by the little genetic and genomic information available, which is a critical bottleneck for breeding, selection, diversification, conservation, and evolutionary studies not only of cherimoya but also in other species in the Annonaceae.

Annona cherimola tree, flower, and fruit morphology. (a) Pruned tree; (b) leaves; (c) female stage of the flower; (d) male stage of the flower; (e) fruit; (f) open fruit. (photos by Alicia Talavera; images from Plants People Planet, doi:

In a recently published paper in Plants People Planet (doi: 10.1002/ppp3.10366), Smithsonian Botany postdoctoral fellow Alicia Talavera, researchers Noé Fernandez-Pozo, Antonio J. Matas Arroyo, and professor Iñaki Hormaza from Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora (IHSM La Mayora-UMA-CSIC), Málaga, Spain in collaboration with Aureliano Bombarely from Instituto de Biología Molecular y Celular de Plantas, IBMCP (CSIC-UPV), Valencia, Spain have provided an important resource to fill this knowledge gap, a chromosome-scale genome sequence, which is available at the IHSM subtropicals database, https://ihsmsubtropicals.uma.es/easy_gdb/index.php.

Overview of Annona cherimola genome assembly. (a) Assembled pseudochromosomes; (b) density of genes in a 1 Mb sliding window and 100 kb overlap; (c) long terminal repeats density in a 1 Mb sliding window and 100 kb overlap; (d) tandem duplications in a 1 Mb sliding window and 100 kb overlap; (e) whole-genome duplication, the color indicated in the duplication corresponds to the color of one of the locations (chromosome) of the duplicated gene. (image from Plants People Planet, doi: 10.1002/ppp3.10366)

The final reference genome resulted in an assembly of 1.13 Gb and N50 of 170.86 Mb, anchored into 7 pseudomolecules and with a completeness of 95.6%. A total of 41,413 protein-coding genes were identified, many of which were related with secondary metabolism, defense mechanisms, stress response and development. The results of this study provide novel significant genomic resources not only for cherimoya and other species of the Annonaceae but also for understanding the evolution of the earlier divergent angiosperms.