The effect of water and nitrogen availability during grain filling on the timing of dormancy release in malting barley crops

Abstract

Pre-harvest sprouting (PHS) causes immediate loss of seed viability, making barley (Hordeum vulgare L.) grains worthless for malting purposes. Grain dormancy release rate in barley crops is genetically and environmentally controlled. A 2 year experiment was conducted to evaluate the effect of soil nitrogen and water availability during grain filling on the dormancy release pattern (and then on the PHS susceptibility) for five malting barley commercial cultivars. Drought and well-irrigated control treatments were imposed from anthesis onwards, and contrast nitrogen fertilization treatments were applied at tillering. Nitrogen availability showed no effects on dormancy release. Drought during grain filling accelerated dormancy release with respect to well-irrigated control in 2004, but not in 2005 year. Mean temperatures during the last stages of grain filling were much higher (ca. 6°C) in 2005 than in 2004, indicating that high-dormancy loss promoting temperatures had masked drought effects on dormancy release.

Seed dormancy QTL identification across a Sorghum bicolor segregating population

“…Seed dormancy is governed by multiple genes and is clearly influenced by the environment to which the mother plant is exposed during seed development (Black et al 1987;Nakamura et al 2011;Biddulph et al 2005;Gualano and Benech-Arnold 2009). Therefore, determining the genetic structure of dormancy in agronomically relevant species such as grain sorghum emerges as a priority, and one of the most appropriate approaches to achieve this goal is to dissect that variability into quantitative trait loci (QTL).…”

Can the Tetrazolium Test be Used as an Alternative to the Germination Test in Determining Seed Viability of Grass Species?

“…However, interaction between high temperature and moisture stress induced dormancy in some wheat genotypes (Biddulph et al, 2007). In barley, drought stress conditions released dormancy, causing preharvest sprouting and reducing seed viability (Gualano and Benech‐Arnold, 2009). This may explain the difference in dormancy level from year to year.…”

Malt quality during the post-harvest maturation of barley.

“…To má za následek nedostatečné rozluštění (modifikaci) škrobového endospermu [2], a tím i sní-žení kvality sladu. Dormance je založena geneticky [3] a pokusy konané při posklizňové úpravě zrna působením vyšších či nižších teplot dormanci obilek výrazně neovlivnily [4,5].…”

“…This results in an insufficient modification of starch endosperm [2], and, thus, also in a reduced quality of malt. The process of dormancy is determined genetically [3] and it was experimentally found out that the effect of both higher Jarní ječmeny nejsou schopny v období krátce po sklizni poskytnout kvalitní slad. Důvodem je vstup obilek do dormance, kdy obilky špatně a nevyrovnaně klíčí.…”