Pre‐anthesis Interaction of Cytokinins and ABA in the Transport of ¹⁴C‐sucrose to the Ear of Winter Wheat (Triticum aestivum L.)

Abstract

The effect of the application of abscisic acid (ABA, lO""* mol • 1"'), benzyl adenine (BA, 10^^ mol • T'), N*'-m-hydroxybenzyl-adenosine (HBA, 10""^ mol • T') and combinations of these cytokmins with ABA on the transport of '"^C-sucrose into the developing kernels of winter wheat, their number and mass, was studied. Growth substances were applied in the period 10 to 5 days before anthesis and their effects were exammed 4 and 18 days after anthesis on ears that were detached 10 days before anthesis and then cultivated on a complete nutrient solution. The stimulating effect of HBA on the transport of ''^C-sucrose, number of kernels and their mass was higher than that of BA. ABA partly decreased the stimulating effect of cytokinins and reduced up to several days after anthesis the transport of '"'C-sucrose to the developing kernels, their number and mass. The results revealed that a higher level of cytokinins in the period before anthesis could effectively interact with the inhibiting effect of ABA in that period and influence the accumulation of assimilates in the kernels.

Effects of foliar application of BAP on source and sink strength in four six-rowed barley (Hordeum vulgare L.) cultivars

“…Apparently, BAP was not translocated from treated leaves to grains, because considerable increases in ear weight were observed only in treatments in which BAP was sprayed on ears. Borkovec and Procházka (1992) and Gupta et al (2003) demonstrated that exogenous cytokinins do not move readily from the site of application/ production to non-treated areas. Again, it seems that there was no effect of cytokinin on source strength or there was no source limitation in grain filling of these cultivars.…”

Effects of Benzyl Adenine and Abscisic Acid on Grain Yield and Yield Components in Triticale and Wheat

“…The reduced grain and ear weights might be due to a reduced number of grains per ear andor inhibition of assimilate transport to the grains, as suggested by the reduction in 1000-grain weight. In wheat, it has been reported that ABA aects the photosynthetic apparatus, decreasing photosynthesis by reducing the ribulose-1,5-bisphosphate regeneration capacity (Raschke and Hedrich 1985), and inhibits assimilate transport to the grain (Saini et al 1984, Borkovec andProchazka 1992).…”

“…In wheat, it has been reported that ABA affects the photosynthetic apparatus, decreasing photosynthesis by reducing the ribulose‐1,5‐bisphosphate regeneration capacity (Raschke and Hedrich 1985), and inhibits assimilate transport to the grain (Saini et al. 1984, Borkovec and Prochazka 1992).…”

The role of genetic diversity and pre‐breeding traits to improve drought and heat tolerance of bread wheat at the reproductive stage

“…Application of the CK zeatin promoted spike development and grain number in wheat (Wang et al, 2001). The exogenous application of CKs improves the transport of sugars to cultured spikes and achieved a higher grain set (Borkovec & Procházka, 1992; Lejeune et al, 1998). Another study indicated that the interactive effect of ABA and CKs is involved in grain filling at reproductive stage drought stress (Liu et al, 2016).…”