A donor-specific QTL, exhibiting allelic variation for leaf sheath hairiness in a nested association mapping population, is located on barley chromosome 4H

Abstract

Leaf sheath hairiness is a morphological trait associated with various advantages, including tolerance to both abiotic and biotic stresses, thereby increasing yield. Understanding the genetic basis of this trait in barley can therefore improve the agronomic performance of this economically important crop. We scored leaf sheath hairiness in a two-year field trial in 1,420 BC1S3 lines from the wild barley nested association mapping (NAM) population HEB-25. Leaf sheath hairiness segregated in six out of 25 families with the reference parent Barke being glabrous. We detected the major hairy leaf sheath locus Hs (syn. Hsh) on chromosome 4H (111.3 cM) with high precision. The effects of the locus varied across the six different wild barley donors, with donor of HEB family 11 conferring the highest score of leaf sheath hairiness. Due to the high mapping resolution present in HEB-25, we were able to discuss physically linked pentatricopeptide repeat genes and subtilisin-like proteases as potential candidate genes underlying this locus. In this study, we proved that HEB-25 provides an appropriate tool to further understand the genetic control of leaf sheath hairiness in barley. Furthermore, our work represents a perfect starting position to clone the gene responsible for the 4H locus observed.

Prospects for the accelerated improvement of the resilient crop quinoa

“…Quinoa is also studied as a model organism to investigate water stress tolerance in plants that use the large volume of bladder cells as a water reservoir ( Tester and Davenport, 2003 ). Hair cells probably contribute to the drought tolerance of cereal grasses by reducing water loss ( Hameed et al , 2002 ; Saade et al , 2017 ). Likewise, bladder cells can be viewed as a kind of secondary epidermis that serves as a protective cover that reduces transpiration rates ( Shabala and Mackay, 2011 ).…”

Overcoming barriers to the registration of new plant varieties under the DUS system

“…Examples of these traits are: 3 (lowest leaves: hairiness of leaf sheaths), 12 (ear: number of rows), 23 (grain: husk), 26 (grain: hairiness of ventral furrow), and 27 (grain: disposition of lodicules). A major QTL for trait 3 is tightly linked to Vrn-H2 , a major vernalization locus 24 while traits 12, 23, and 27 are largely monomorphic in the UK barley breeding pool due to preferences for two-rowed barley with hulled grains and clasping (collar type) lodicules. In comparison with previous work on DUS traits GWAS 7 , the number of loci increased from 16 to 32 with 12 loci in common.…”