Changes in grain weight as a consequence of de-graining treatments at pre- and post-anthesis in synthetic hexaploid lines of wheat (Triticum durum x T. tauschii)

Abstract

Grain weight is a trait which has hardly been exploited for raising genetic yield potential of wheat. A clearer understanding of physiological determinants of grain weight potential would be useful in establishing the potential value of this trait in future breeding programs. The objective of this study was to improve understanding of how intra-spikelet competition for assimilates pre- and post-anthesis affect grain weight potential, and to evaluate possible mechanisms determining final grain weight in wheat. Two experiments were carried out under field con-ditions. Proximal or distal grains from the two central spikelets of spikes of three synthetic hexaploid lines were detached at heading or 7 d after anthesis. Synthetic wheats were used since they represent a potential source of genetic variability for grain weight potential. Carpel size at anthesis and grain weight during the grain filling period were measured. The de-graining treatment at heading significantly increased grain weight, especially in distal posi-tions. On the contrary, the de-graining treatment carried out after anthesis caused no increase in final grain weight. The largest response to pre-anthesis de-graining occurred in grain positions with the lowest grain mass. In addition, the effect of de-graining prior to anthesis was associated hyperbolically with weight of carpels at anthesis within each grain position. Therefore, carpel weight at anthesis could be partially associated with the regulation of grain weight potential.

Volume, water content, epidermal cell area, and XTH5 expression in growing grains of wheat across ploidy levels

“…5 and 6), giving a key role to the processes that control cell expansion of pericarp in growing grains. Regarding that cell size already showed differences between small and large grains at the first sampling, the period immediately previous to anthesis is also confirmed in the present study as a clue for potential grain weight determination (Calderini and Reynolds, 2000).…”

“…The number and volume of endospermic cells were positively correlated with grain size in wheat (e.g., Gleadow et al, 1982;Gupta et al, 2006). However, it has been hypothesized that maternal tissues, which become the pericarp of grains after pollination, impose an upper limit to grain size in wheat by constraining endosperm expansion, and in turn, controlling grain volume (Calderini and Reynolds, 2000). This hypothesis is supported by the positive association between final grain weight and the size of the floret organs, among other evidences (Millet and Pinthus, 1980;Calderini et al, 1999;Ugarte et al, 2007;Hasan et al, 2011).…”

Grain Yield Potential Strategies in an Elite Wheat Double‐Haploid Population Grown in Contrasting Environments

“…To maintain or even improve current levels of expression for HI, extra assimilates produced must be partitioned to more grains and/or higher potential GW (Calderini and Reynolds, 2000;Foulkes et al, 2011). The current study demonstrated the importance of enhancing biomass production as a strategy to increase GY potential and suggests likely variation in RUE among DH lines.…”

Amelioration of Photosynthesis and Quality of Wheat under Non-thermal Radio Frequency Plasma Treatment

“…Reduction of seed reserves is the most important factor determining the efficiency and initial growth and development of the seedling 35 . A higher transferred reserves potential in wheat is mostly dependent on the amount of assimilates that resulting in greater seed weight on mother plant 36,37 . Under stress condition seed yield is dependent on the amount of assimilants 38 .…”