Nitrogen fertilizer and seed rate effects on Hagberg falling number of hybrid wheats and their parents are associated with α‐amylase activity, grain cavity size and dormancy

Abstract

Field experiments were carried out to assess the effects of nitrogen fertilization and seed rate on the Hagberg falling number (HFN) of commercial wheat hybrids and their parents. Applying nitrogen (200 kg N ha −1 ) increased HFN in two successive years. The HFN of the hybrid Hyno Esta was lower than either of its parents (Estica and Audace), particularly when nitrogen was not applied. Treatment effects on HFN were negatively associated with α-amylase activity. Phadebas grain blotting suggested two populations of grains with different types of α-amylase activity: Estica appeared to have a high proportion of grains with low levels of late maturity endosperm α-amylase activity (LMEA); Audace had a few grains showing high levels of germination amylase; and the hybrid, Hyno Esta, combined the sources from both parents to show heterosis for α-amylase activity. Applying nitrogen reduced both apparent LMEA and germination amylase. The effects on LMEA were associated with the size and disruption of the grain cavity, which was greater in Hyno Esta and Estica and in zero-nitrogen treatments. External grain morphology failed to explain much of the variation in LMEA and cavity size, but there was a close negative correlation between cavity size and protein content. Applying nitrogen increased post-harvest dormancy of the grain. Dormancy was greatest in Estica and least in Audace. It is proposed that effects of seed rate, genotype and nitrogen fertilizer on HFN are mediated through factors affecting the size and disruption of the grain cavity and therefore LMEA, and through factors affecting dormancy and therefore germination amylase.

CO2-Induced Changes in Wheat Grain Composition: Meta-Analysis and Response Functions

“…A reduction in gluten proteins results in lower elasticity and resistance of the dough and smaller bread loaf volume, but also longer mixing time [33]. In addition, the falling number was reduced under eCO 2 reflecting an increase in α-amylase activity, which is associated with poor baking properties, such as sticky dough and poorly structured loaves [34], but also shortens the storage time of flour and grains [35].…”

CO₂-Induced Changes in Wheat Grain Composition: Meta-Analysis and Response Functions

“…A reduction in gluten proteins results in lower elasticity and resistance of the dough and smaller bread loaf volume, but also longer mixing time [31]. In addition, the falling number was reduced under eCO2 reflecting an increase in α-amylase activity, which is associated with poor baking properties, such as sticky dough and poorly structured loaves [32], but also shortens the storage time of flour and grains [33].…”

Ozone effects on wheat grain quality – A summary

“…Low falling numbers represent high a-amylase activity and thus more germinated grains, resulting in poor baking qualities, such as sticky dough and poorly structured loaves (Kindred et al, 2005). Additionally, a higher falling number enables longer storage time for flour and grains (Hruskova et al, 2004).…”