Abstract Detail

Hybrids and Hybridization

Salony, Susnata [1], Ajay, Anjitha [1], ASHOKAN, AJITH [2], Saryan, Preeti [3], GOWDA, VINITA [4].

Can genome size and chromosome number help in resolving taxonomic confusions in the genus Hedychium? .

The genus Hedychium J.Koenig, a member of the family Zingiberaceae is a taxonomically complex genus known for its natural hybridization and polyploidization, which makes species delineation a problematic task in this group. Many of the morphological characters were found to be homoplasious across all the four clades of Hedychium, and clade 4 with the largest representation of Indian species, was highlighted for its polytomies. We found that H. coccineum and H. forrestii which both fall in clade 4 are incompatible with each other. However, H. forrestii can hybridize with at least two other species from the same clade. Several taxa were not identified to the species level due to the overlapping character states. We recognized around 25 intermediates growing in sympatry with H. marginatum and H. coronarium. As molecular and morphological data are insufficient to determine the species relationships in this group, we investigated the use of genome size and chromosome count in resolving the taxonomic confusion.
In this study, flow cytometric analyses and chromosome metaphase plates were used to assess the level of genome size and chromosome count variations as well as to identify the putative origin of the hybrids. We also tried different preservation methods to test the quality of samples required for flow cytometry in cases when fresh leaves may not be available.
Successful crossing experiments suggested ploidy compatibility among the species, which explains the morphological variants and the intermediates across species. Upon character mapping, hybridization was found to be correlated with geographic populations and we couldn’t find any specific pattern across the clades based on genome size and chromosome counts. However, taxa that are known to be widely distributed and part of species complexes did show high variability in their ploidy (n = 21 to 68 in H. spicatum, n = 18 to 54 in H. coronarium). Hence a combination of cytological, molecular, morphological, and ecological data is important for delimiting the species in Hedychium and achieving a better resolution for understanding the evolutionary relationships between the species. Preserving the samples at 4°C for 1 month yielded the best flow cytometry results in all the analyzed species.

1 - Indian Institute of Science Education and Research Bhopal, Biological Sciences, Bhopal, MP, 462066, INDIA
2 - Indian Institute of Science Education and Research Bhopal, Biological Sciences, Bhopal By-Pass Road, Bhauri, Bhopal, Madhya Pradesh, 462066, India
3 - IISER Bhopal, Near Bhauri Village, Bhopal, AB3, Biological Sciences, IISER Bhopal, Near Bhauri Village, Bhopal, Bhopal, MP, 462066, India
4 - Indian Institute of Science Education and Research Bhopal, Biological Sciences, Bhopal, Madhya Pradesh, 462066, INDIA

Keywords:
genome size
Chromosome
Taxonomic confusion
gingers
Hedychium
Species Complex.

Presentation Type: Poster
Session: P, Hybrids and Hybridization Posters
Location: Virtual/Virtual
Date: Wednesday, July 29th, 2020
Time: 5:00 PM Time and date to be determined
Number: PHH006
Abstract ID:854
Candidate for Awards:None