AgResearch
Browse

Seed transmission of Epichloë endophytes in Lolium perenne is heavily influenced by host genetics

Download (3.22 MB)
journal contribution
posted on 2023-05-03, 15:34 authored by Milan Gagic, Marty FavilleMarty Faville, Wei Zhang, Christina MoonChristina Moon, Natasha Forester, Richard JohnsonRichard Johnson, Siva Ganesh, John Koolaard, H. Sydney Easton, Debbie HudsonDebbie Hudson, Linda JohnsonLinda Johnson, Christine VoiseyChristine Voisey
Vertical transmission of symbiotic Epichloë endophytes from host grasses into progeny seed is the primary mechanism by which the next generation of plants is colonised. This process is often imperfect, resulting in endophyte-free seedlings which may be selected against if the endophyte confers protective benefits to its host. In this study, we investigated the influence of host genetics and environment on the vertical transmission of Epichloë festucae var. lolii AR37 in the temperate forage grass Lolium perenne. The efficiency of AR37 transmission into the seed of over 500 plant genotypes from five genetically diverse breeding populations was determined. In Populations I-III, which had undergone previous selection for high seed infection by AR37, mean transmission was 88%, 93% and 92% respectively. However, in Populations IV and V, which had not undergone previous selection, mean transmission was 69% and 70% respectively. A genomic prediction model for AR37 seed transmission was developed using this data, and host single nucleotide polymorphism (SNP) data obtained by genotyping by sequencing (GBS). The predictive ability of the model was estimated at r = 0.55. While host genotype contributed greatly to differences in AR37 seed transmission, undefined environmental variables also contributed significantly to seed transmission across different years and geographic locations. There was evidence for a small host genotype by environment effect, however this was less pronounced than genotype or environment alone. Analysis of endophyte infection levels in parent plants within Populations I and IV revealed a loss of endophyte infection over time in Population IV only. This population also had lower average tiller infection frequencies than Population I, suggesting that AR37 fails to colonise all the daughter tillers and therefore seeds. However, we also observed that infection of seed by AR37 may fail during or after initiation of floral development from plants where all tillers remained endophyte-infected over time. To our knowledge, this is the first study that quantifies the relative impacts of host genetics and environment on endophyte vertical transmission.

History

Rights statement

Copyright © 2018 Gagic, Faville, Zhang, Forester, Rolston, Johnson, Ganesh, Koolaard, Easton, Hudson, Johnson, Moon and Voisey. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

Language

  • English

Does this contain Māori information or data?

  • No

Publisher

Frontiers Media

Journal title

Frontiers in Plant Science

ISSN

1664-462X

Citation

Gagic, M., Faville, M. J., Zhang, W., Moon, C., Forester, N. T., Johnson, R. D., … Voisey, C. R. (2018). Seed transmission of Epichloë endophytes in Lolium perenne is heavily influenced by host genetics. Frontiers in Plant Science, 9, 1580. doi:10.3389/fpls.2018.01580

Funder

Strategic Science Investment Fund (SSIF)

Contract number

A20067

Job code

50200X01

Usage metrics

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC