Abstract Detail

Genomics / Proteomics

Sigmon, Brandi [1], Adams, Robert [2], Mower, Jeffrey [3].

Identifying diagnostic plastid polymorphisms for the non-fertile vetiver grass ‘Sunshine’ (Chrysopogon zizanioides).

Vetiver grass, the roots of which produce an important essential oil, has been utilized in many parts of the world for soil and water management. Botanical and agronomic literature distinguishes two broad complexes of vetiver, including wild fully-fertile populations across Northern India, Pakistan, and Bangladesh and cultivated non-fertile vetiver originating from Southern India. Previously, a survey of 121 accessions found that 86% of vetiver appeared to be a single sterile clone named ‘Sunshine.’ Since fertile vetiver has a high probability of spreading as an invasive weed wherever it is introduced, sterile vetiver is preferred for soil and water management uses. DNA fingerprinting (RAPDs) has been previously used to identify fertile and non-fertile vetiver, but the technique is unreliable due to problems with band homology and reproducibility. Therefore, a new DNA-based test is needed to reliably distinguish non-fertile vetiver from its more invasive, fertile relatives. Complete chloroplast (cp) genome sequencing has been used to identify polymorphisms that distinguish between closely related subspecies in rice and ecotypes in switchgrass. In this research, we completed next-generation sequencing of the cp genomes of three non-fertile and two fertile vetiver grasses in order to identify distinguishing polymorphisms between these vetiver types. Following genome assembly and annotation, the vetiver cp genome was found to be typical of other grasses suggesting that cp genome size and content is highly conserved in the Andropogoneae. Also, the total polymorphism rate of 0.02% is 5- to 7-fold lower than rates found in other grass cp genomes studies examining closely related ecotypes or subspecies, suggesting that non-fertile and fertile vetiver recently diverged. By comparing fertile and non-fertile cp genomes, 28 distinguishing polymorphisms including 14 SNPs, two small indels, 11 microsatellites, and one stem loop variation were identified. In a broader panel of 26 accessions, these polymorphisms reliably distinguish non-fertile Sunshine-like vetiver from fertile accessions. However, two sterile accessions not derived from Sunshine genotyped as fertile, which indicates multiple origins of sterility complicate the genetic history of vetiver. These variations in cp genome sequence can be used to genotype other accessions through sequencing or by restriction fragment length polymorphism (RFLP) in order to verify sterility.

1 - University of Nebraska-Lincoln, Agronomy and Horticulture, 1901 Vine St., Beadle Center, E249A, Lincoln, NE, 68588, USA
2 - Baylor University, Biology, Baylor University, Waco, TX, 76798, USA
3 - University of Nebraska-Lincoln, Agronomy and Horticulture, 1901 Vine St., Beadle Center, E130, Lincoln, NE, 68588, USA

Keywords:
vetiver
Chrysopogon zizanioides
chloroplast
plastid
genome
polymorphism.

Presentation Type: Poster
Session: P, Genomics/Proteomics Posters
Location: Exhibit Hall/Savannah International Trade and Convention Center
Date: Monday, August 1st, 2016
Time: 5:30 PM This poster will be presented at 6:15 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PGP008
Abstract ID:732
Candidate for Awards:None