Physiological Processes Associated with Winter Whe

Authors: M J Foulkes J W Snape V J Shearman R SylvesterBradley

Publish Date: 2007

Volume: , Issue: , Pages: 591-597

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Abstract

Knowledge of the changes in physiological traits associated with genetic gains in yield potential is essential to improve understanding of yieldlimiting factors and to inform future breeding strategies The growth and development of eight representative UK wheat Triticum aestivum L cultivars introduced from 1972 to 1995 was examined in field experiments in 1997–1999 Significant genetic changes over time and positive correlations with grain yield were found for preanthesis radiationuse efficiency 0012 g MJ1 yr1 RUE and water soluble carbohydrate WSC content of stems and leaf sheaths at anthesis 46 g m2 yr1 Results suggested that yield of modern UK cultivars although still sink limited might be closer to sourcelimitation than their predecessors Therefore breeders may eventually need to take further steps to increase source size postanthesis alongside improvements in grain sink size In this respect greater accumulation of stem carbohydrate reserve may be beneficial providing this is not competitive with ear growth Results further suggested that the 1BL1RS wheatrye translocation may be associated with greater harvest biomass in modern cultivars The relationship between the amount of stem WSC measured shortly after flowering and grain yield was further tested in two doubled haploid DH populations Rialto x Spark and Beaver x Soissons in 2001 and 2002 There was a positive linear relationship between stem WSC and grain yield in both populations The effects of 1BR1RS were further examined in two DH populations Beaver 1BL1RS x Soissons 1B and Drakesib 1BL1RS x Welton 1B in 1998–2002 1BL1RS increased harvest biomass in both populations although grain yield was only increased in the Beaver x Soissons population In the Drakesib x Welton population the physiological basis of the increased harvest biomass was investigated and found to be associated with greater preanthesis biomass There was no change in green area index or light extinction coefficient in the preanthesis period indicating 1BL1RS may have conferred an increase in RUE

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