Characterization of genome-wide genetic variation between two varieties of tea plant (Camellia sinensis) and development of InDel markers for genetics research
Abstract Single nucleotide polymorphisms (SNPs) and Insertions/Deletions (InDels) are the major genetic variations and distributed extensively across the plant whole genome. Few investigations of these variations, however, have been performed in the long-lived perennial tea plant. Here, we have investigated the genome-wide genetic variation between Camellia sinensis var. sinensis ‘Shuchazao’ and Camellia sinensis var. assamica ‘Yunkang 10’, generating 7,511,731 SNPs and 255,218 InDels based on their whole genome sequences, and subsequently analyzed their distinct types and distribution patterns. A total of 48 InDel markers that yielded polymorphic and unambiguous fragments were developed when screening six tea cultivars. These markers were further deployed on forty-six tea cultivars for transferability and genetic diversity analysis, exhibiting informative with an average 4.02 of the number of alleles ( Na ) and 0.457 of polymorphism information content (PIC). The dendrogram showed that the phylogenetic relationships among these tea cultivars are highly consistent with their genetic backgrounds or original places. Interestingly, we observed that the content of catechin/caffeine between ‘Shuchazao’ and ‘Yunkang 10’ were significantly different, and a large number of SNPs/InDels were identified within catechin/caffeine biosynthesis-related genes. The identified genome-wide genetic variation and newly-developed InDel markers will provide a valuable resource for tea plant genetics and genomics studies, especially those SNPs/InDels within catechin/caffeine biosynthesis-related genes can be served as pivotal candidates for elucidating the molecular mechanism of catechin/caffeine biosynthesis.