Role of nonproductive tillers as transient sinks of assimilates in wheat

Abstract

Although source-sink relationships in wheat are well studied, the performance of tillers as transient sinks is still unclear, especially under stress conditions. Thus, this work aimed to study the yield relationships of wheat stems in contrasting genotypes as affected by tiller treatment under stress conditions. Two experiments were conducted under greenhouse conditions using BRS Guamirim (high tillering) and BRS Parrudo (low tillering) wheat cultivars. Four tillering treatments were applied on late tillers in the first growing season (2016) and three in the second (2017): (i) free-tillering, (ii) detillering, (iii) physical suppression (only in the first season) and (iv) "spikes removal". The main stem and the first four emitted tillers were considered as primary tillers. Plants were submitted to drought (2016) and defoliation stress (2017) at preanthesis. Intraspecific competition among tillers increased under drought stress conditions and decreased the plant performance. Nonproductive late tillers do not improve the performance of primary tillers of wheat plants under drought stress, mainly in high-tillering cultivars. The reduction on the thousand grain weight of only 'Parrudo' detillered plants indicates that assimilate remobilization from late tillers to primary tillers and main stem seems to be more effective in low-tillering cultivars.

Waterlogging Effects in Adventitious Roots, Tillering and Yield of Bread Wheat Germplasm

“…According to Xie (2016) [45], tillering ceases just prior to elongation and the remaining axillary buds become dormant. This dormancy, however, can be reversed in response to damage to the main shoot or lodging [46], which is consistent with the observed results and point to some genotypic variability regarding recovery ability following waterlogging Decreased tillers viability may also result from nutrient resources remobilization from late tillers to primary tillers [47]. Additionally, tillers can serve as reservoirs of assimilates for the main culm during growth cycle [48].…”

Physiological and yield parameters of wheat as affected by tiller removal and defoliation

“…This finding can be attributed to the higher tillering potential of 'TBIO Audaz' (seven tillers per plant, n = 4) compared with 'BRS 394' (four tillers per plant, n = 4). Fioreze et al (2020Fioreze et al ( , 2021 highlighted that, the greater the competition between main stem and tillers, the greater the effect of tiller removal.…”

“…A promising approach to enhance sink strength in wheat plants is the use of signaling molecules, such as trehalose-6-phosphate, to increase sugar allocation in reserve tissues (Griffiths et al, 2016). Tiller inhibition (tin) mutants (Kebrom et al, 2012;Kebrom & Richards, 2013;Hendriks et al, 2016) and artificial tiller removal (Guo & Schnurbusch, 2015;Fioreze et al, 2020Fioreze et al, , 2021 can also be used to increase the yield potential of the ear and provide important information about the effect of inter-stem competition on source-sink relationships.…”

Characteristics of physiology, phenology, and drought susceptibility index of two varieties of Job’s tears under water deficit stress

“…Present study found that water deficit conditions could stimulate the formation of more unproductive tiller rather than normal irrigated conditions, in both varieties. The higher rate of unproductive tillers formation could lead to a decrease in crop yield (Fioreze et al 2020;Wang et al 2020).…”