Unlocking the Genetic Diversity and Population Structure of a Wild Gene Source of Wheat, Aegilops biuncialis Vis., and Its Relationship With the Heading Time.

László Ivanizs,Andrzej Kilian,Andrea Lenykó-Thegze,István Molnár,András Farkas,István Monostori,Eszter Gaál,Mária Megyeri,Éva Szakács,Tibor Kiss,Edina Türkösi,Éva Darkó,Kitti Szőke-Pázsi,Péter Mikó

doi:10.3389/fpls.2019.01531

Abstract

Understanding the genetic diversity of Aegilops biuncialis, a valuable source of agronomical useful genes, may significantly facilitate the introgression breeding of wheat. The genetic diversity and population structure of 86 Ae. biuncialis genotypes were investigated by 32700 DArT markers with the simultaneous application of three statistical methods— neighbor-joining clustering, Principal Coordinate Analysis, and the Bayesian approach to classification. The collection of Ae. biuncialis accessions was divided into five groups that correlated well with their eco-geographic habitat: A (North Africa), B (mainly from Balkans), C (Kosovo and Near East), D (Turkey, Crimea, and Peloponnese), and E (Azerbaijan and the Levant region). The diversity between the Ae. biuncialis accessions for a phenological trait (heading time), which is of decisive importance in the adaptation of plants to different eco-geographical environments, was studied over 3 years. A comparison of the intraspecific variation in the heading time trait by means of analysis of variance and principal component analysis revealed four phenotypic categories showing association with the genetic structure and geographic distribution, except for minor differences. The detailed exploration of genetic and phenologic divergence provides an insight into the adaptation capacity of Ae. biuncialis, identifying promising genotypes that could be utilized for wheat improvement.

Highlights

The genome of wild relatives of common wheat (Triticum aestivum L.) can be considered as a potential reservoir of gene variants for wheat improvement (Schneider et al, 2008; Zhang et al, 2015; Kishii, 2019)
A total of 47,777 polymorphic dominant silicoDArT markers were generated from 86 Ae. biuncialis accessions originating other three formed a heterogeneous subgroup
Three statistical methods gave consistent results for the genetic diversity and population structure: The Ae. biuncialis accessions clustered into five subpopulations in accordance with their place of origin

Summary

Introduction

The genome of wild relatives of common wheat (Triticum aestivum L.) can be considered as a potential reservoir of gene variants for wheat improvement (Schneider et al, 2008; Zhang et al, 2015; Kishii, 2019). Interspecific hybridization is a promising approach to enlarge the genetic diversity of cultivated bread wheat by the chromosome-mediated transfer of the wild alleles present in related species (Jauhar, 1993; Jauhar and Chibbar, 1999; Kishii, 2019). In the case of biotic stresses, the 41 resistance genes that have so far been integrated into the wheat genome originated from only 30 accessions from 12 Aegilops species, most of them belonging to the primary gene pool of hexaploid wheat (Zhang et al, 2015). There are numerous Aegilops accessions in gene banks in various parts of the world (Monneveux et al, 2000) that have not yet been utilized for wheat improvement, so their introduction into breeding programs would be desirable

Methods

Results

Discussion

Conclusion