Work

Divergence and relationships of Cymbidium tortisepalum cultivars by EST-SSR markers

Year: 2022

Type: preprint

Abstract: Cymbidium tortisepalum has a variety of excellent ornamental properties and value, but no further work has been done on population genetics and evaluating genetic variation to establish molecular marker-assisted breeding and molecular identification. In this study, the HiSeq platform and the Illumina sequencing platform were used for transcriptome sequencing of 'Lianbansu' and library construction respectively. A total of 9485 putative EST-SSRs were identified from 28,235 unigenes. Of the 192 primer pairs randomly selected from the 9485 primer pairs designed, 90 pairs of primers gave accurate amplification products, and 86 pairs of primers showed polymorphism in the 8 orchid cultivars detected. 38 pairs of highly polymorphic primers with good repeatability and stability were screened from 90 pairs of primers with amplification capability to study the genetic diversity, population structure and evolution history of 51 orchid cultivars were studied. The number of alleles ranging from 3 to 12, with an average of 6. The effective allele is 1.2436–5.8188, with an average of 2.8189. The observed and expected heterozygosity with the average of 0.4662 and 0.5973 ranged from 0.1569 to 0.8431 and 0.1978 to 0.8363. The first two principal coordinates detected 39.66% of the total variation. It was found the ΔK-value had one peak (When K = 2). It can be seen that many orchid cultivars have multiple sources, rich genetic diversity and diversified strains, which are caused by long-term natural evolution and artificial hybridization. Taken together, the primers developed in this study have the transferability of many cultivars and hybrids in Chinese orchids.

Source: Research Square

DOI: 10.21203/rs.3.rs-1591776/v1