Disease‐yield relationship in barley. II. Contribution of stored stem reserves to grain filling

Abstract

The effect of disease in two cultivars of barley, sown at different times in two seasons, on the relative importance of stored carbohydrate reserves and current photosynthesis for grain filling was assessed. Three methods of measuring stem reserve contributions to grain filling are reviewed and compared. Disease reduced stem dry weight and the amount of stored carbohydrate in most situations. In contrast, the total amount of stored carbohydrates used for grain filling was often increased by disease. The magnitude of these effects varied with the method used for estimation, and was also different in the crops sown at different times and in different seasons. The estimates of stem reserve contributions to grain filling ranged up to a maximum of 50% in some cases. At least 10 t/ha of reserve material was retranslocated in the healthy 1984 crop studied using 14C pulse feeding, and up to 0.3 t/ha more was utilized in a diseased crop. The effect of disease on the storage and utilization of stem reserves depended on the time of epidemic development, its duration, and the yield potential of the crop. This suggests that crops could be characterized as those which are very sensitive to disease during grain filling, with low stem reserves or high yield potential, and those with lower sensitivity, with more stem reserves or lower yield potential. Such interacting factors could be incorporated in future plant and yield‐loss mechanistic models.

Understanding grain yield responses to source–sink ratios during grain filling in wheat and barley under contrasting environments

“…In this growing condition, the remobilization of reserves from stems was an important source of assimilates for growing grains. These results are in agreement with previous reports where wheat crops exposed to different stresses during grain filling period increased the remobilization of reserves (Zilberstein et al, 1985;Gaunt and Wright, 1992;Serrago et al, 2011).…”

Arbuscular mycorrhiza increased the activity of a biotrophic leaf pathogen - is a compensation possible?

“…Barley stores fructan in veg- etative tissues (Gaunt and Wright 1992) and this accumulated from the onset of flowering (EC 61) and reallocation started with milky ripeness (EC 71, Fig. 3).…”

Grain Filling Mechanisms in Two Wheat Cultivars, Haruyutaka and Daichinominori, grown in Western Japan and in Hokkaido

“…The culm reserves play a vital role in buffering grain yield when canopy photosynthesis is restricted by senescence (Austine et al, 1980;Gaunt and Wright, 1992;Takahashi and Kanazawa, 1996;Tahir and Nakata, 2005;Ehdaie et al, 2006). The culm elongates and stores water soluble carbohydrate (WSC) mainly during initial and early period of grain fi lling (from anthesis to milk ripe, at around 15 DAA) and it is remobilized to grains during the late and final period (from milk ripe to maturity) (Takahashi et al, 1993).…”