The Draft Genome Assembly of the Critically Endangered Nyssa yunnanensis, a Plant Species with Extremely Small Populations Endemic to Yunnan Province, China

Nyssa yunnanensis is a deciduous tree species in family Nyssaceae within the order Cornales. As owning only eight individuals in two sites recorded in Yunnan province of China, this species was listed as the China’s national grade-I protection species in 1999, and also as one of 120 PSESP (Plant Species with Extremely Small Populations) in Implementation Plan of Rescuing and Conserving China’s Plant Species with extremely Small Populations(PSESP) (2011-2-15). N. yunnanensis was also been evaluated as Critically Endangered in IUCN red list and Threatened Species List of China's Higher Plants. Hence understanding the genomic characteristics of this highly endangered Tertiary relict tree species is essential, especially for developing conservation strategies. Here we present the draft genome assembly of N. yunnanensis. Using 10X genomics linked-reads sequencing data, we carried out the de novo assembly and annotation analysis. The N. yunnanensis genome assembly is 1475 Mb in length containing 288,519 scaffolds with a scaffold N50 length of 985.59 kb. 799.51 Mb of the assembled genome was identified as repetitive elements, accounting for 54.24% of the sequenced genome. And a total of 39,803 protein-coding genes were annotated. The genomic data of N. yunnanensis provided in this study will provide basic information for future genomic and evolutionary studies. With the genomic characteristics of N. yunnanensis available, our study might also facilitate in future conservation biology studies to help protecting this extremely threatened tree species.