Evaluation of agronomic performance and exploratory genome-wide association study of a diverse oat panel for forage use in Taiwan

Authors: HUANG, CHUNG-WEN - National Taiwan University; LIANG, WEI-HONG - The Livestock Research Institute; Esvelt Klos, Kathy; CHEN, CHIA-SHEN - The Livestock Research Institute; HUANG, YUNG-FEN - National Taiwan University

Submitted to: Grassland Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/1/2020
Publication Date: 3/1/2020
Citation: Huang, C., Liang, W., Esvelt Klos, K.L., Chen, C., Huang, Y. 2020. Evaluation of agronomic performance and exploratory genome-wide association study of a diverse oat panel for forage use in Taiwan. Grassland Science. Available: https://doi.org/10.1111/grs.12276.
DOI: https://doi.org/10.1111/grs.12276

Interpretive Summary: The need for economically viable, locally produced forage is driving the expansion of oat production from traditional temperate production regions into tropical and subtropical zones where fall-planted oats may be grown over the mild winter season for grazing or spring harvest. Field evaluation of a diverse panel of oat lines in Taiwan found differences in flowering time and forage yield when grown in tropical and subtropical climates that may be partially attributed to the interplay between temperature and effective sunlight. Thirteen lines with early maturity and medium to high forage yield were identified as germplasm with potential for oat breeding in Taiwan. Over 50 genomic regions were suggested to contribute to forage-related traits, some unique to a single environment and some observed in multiple environments. This preliminary view of the genetic architecture of oat forage-related traits under subtropical and tropical production may be used to guide breeding efforts.

Technical Abstract: Oats (Avena sativa L.) produce not only the well-known highly nutritious grain, but also valuable forage. In Taiwan, imported oat hay is a popular forage with the dairy cattle industry. However, local forage oat breeding and production have been virtually absent. Therefore, this study aimed to evaluate the forage performance of oats in Taiwan in order to assess their potential for local oat production. We have introduced 178 oat accessions from 18 breeding programs across North and South America. These breeding lines were evaluated in Northern Taiwan (Taipei) and Southern Taiwan (Hengchun) between autumn 2016 and spring 2017. Early maturing lines reached the flowering stage after ca. 70 or ca. 90 days after sowing in Hengchun and Taipei, respectively, while 49 and 159 lines remained vegetative throughout the growing season in Hengchun and Taipei, respectively. On average, plant height was taller in Taipei than in Hengchun (99.8 cm vs. 53.2 cm), while dry matter yield per plot was higher in Hengchun than in Taipei (596 g Plot–1 vs. 388.4 g Plot–1). Maturity and dry matter differences may be related to the differences in daily effective sunlight between locations. Using 1,164 genome-wide single nucleotide polymorphisms (SNPs), we explored the population structure and the genetic architecture of traits of interest within a subset of 73 oat lines. No obvious sub-populations were observed, which reflected the frequent material exchanges among oat breeders. Fifty-three loci were associated with days to flowering, plant height, and dry matter yield; and 12 of them overlapped with loci identified in previous work. The data and results of this study lay the foundations and provide guidelines for further forage oat breeding work in Taiwan.