Posts Tagged ‘spike fertility’

Relationships between physiological traits, grain number and yield potential in a wheat DH population of large spike phenotype

Posted by Carelia Juarez on , in Journal Articles

Published in Field Crops Research, 2014

 Gaju, O.Reynolds, M.P.Sparkes,D.L.Mayes, S.Ribas-Vargas, G.Crossa, J.Foulkes, M.J. 

Our objective was to investigate the relationships between spike traits, grain number and yield potential and their physiological basis in a doubled-haploid (DH) population derived from a cross between a CIMMYT spring wheat (Triticum aestivum L.) advanced line of large-spike phenotype (LSP2; +Tintiller inhibition gene) and the UK winter wheat cultivar Rialto (R; −Tin1) of conventional spike phenotype. Field experiments were carried out in high radiation, irrigated conditions in NW Mexico in two seasons. Comparing the two groups of +Tin1 and −Tin1 DH lines, results showed the presence of the +Tin1 gene for tiller inhibition increased spike partitioning index (spike DM/above-ground DM at GS61 + 5 d; SPI) from 0.32 to 0.34 (+6.3%) (P < 0.01) and grains spike−1 by 5.1 (+13.9%) (P < 0.001), but reduced spikes m−2 by 20.7 (−5.7%) (P < 0.01). Overall a significant increase in grains m−2 of 865 (+6.6%) was observed in +Tin1 DH lines compared to −Tin1 DH lines (P < 0.05), but the effect on grain yield was not statistically significant. Above-grouund biomass at anthesis was not significantly affected by the presence/absence of the Tin1 gene; although results indicated the presence of the Tin1 gene increased photosynthetically active radiation interception from onset of stem elongation to anthesis, but decreased radiation-use efficiency during this phase. Our results indicated that introgressing the +Tin1 gene into modern wheat germplasm may offer scope to increase grains spike−1 and grains m−2 in irrigated, high radiation environments.

New article from CIMMYT – Raising yield potential in wheat

Posted by on , in Journal Articles

Published in Journal of Experimental Botany 60(7):1899-1918 (2009)

Raising yield potential in wheat

Matthew Reynolds, M. John Foulkes, Gustavo A. Slafer, Peter Berry, Martin A. J. Parry, John W. Snape and William J. Angus.

Abstract. Recent advances in crop research have the potential to accelerate genetic gains in wheat, especially if co-ordinated with a breeding perspective. For example, improving photosynthesis by exploiting natural variation in Rubisco’s catalytic rate or adopting C4 metabolism could raise the baseline for yield potential by 50% or more. However, spike fertility must also be improved to permit full utilization of photosynthetic capacity throughout the crop life cycle and this has several components. While larger radiation use efficiency will increase the total assimilates available for spike growth, thereby increasing the potential for grain number, an optimized phenological pattern will permit the maximum partitioning of the available assimilates to the spikes. Evidence for underutilized photosynthetic capacity during grain filling in elite material suggests unnecessary floret abortion. Therefore, a better understanding of its physiological and genetic basis, including possible signalling in response to photoperiod or growth-limiting resources, may permit floret abortion to be minimized for a more optimal source:sink balance. However, trade-offs in terms of the partitioning of assimilates to competing sinks during spike growth, to improve root anchorage and stem strength, may be necessary to prevent yield losses as a result of lodging. Breeding technologies that can be used to complement conventional approaches include wide crossing with members of the Triticeae tribe to broaden the wheat genepool, and physiological and molecular breeding strategically to combine complementary traits and to identify elite progeny more efficiently.