Avoiding lodging in irrigated spring wheat. II. Genetic variation of stem and root structural properties

Abstract

Lodging-related traits were evaluated on the CIMMYT Core spring wheat Germplasm Panel (CIMCOG) inthe Yaqui Valley of North-West Mexico during three seasons (2010–2013). Genetic variation was signif-icant for all the lodging-related traits in the cross-year analysis, however, significant G × E interactiondue to rank changes or changes in the absolute differences between cultivars were identified. The incon-sistences on cultivar performances across seasons particularly reduced the heritability of key charactersrelated to root lodging resistance (anchorage strength). Target characters related to stem lodging resis-tance (stem strength) showed good heritability values equal or above 0.70. Positive correlations betweenstem strength and stem diameter and between root plate spread and root strength were found. Select-ing for greater stem diameter and wall width, greater root plate spread and shorter plant height couldenable breeders to increase lodging resistance by increasing stem strength, root strength and decreasingplant leverage, respectively. Achieving a lodging-proof crop will depend on finding a wider root platespread and implementing new management strategies. Genetic linkages between lodging traits will notconstrain the combination of the key lodging-trait dimensions to achieve a lodging-proof ideotype. How-ever, strong association between stem strength and stem wall width will increase the total biomass costneeded for lodging resistance.

Lodging-related traits were evaluated on the CIMMYT Core spring wheat Germplasm Panel (CIMCOG) inthe Yaqui Valley of North-West Mexico during three seasons (2010–2013). Genetic variation was signif-icant for all the lodging-related traits in the cross-year analysis, however, significant G × E interactiondue to rank changes or changes in the absolute differences between cultivars were identified. The incon-sistences on cultivar performances across seasons particularly reduced the heritability of key charactersrelated to root lodging resistance (anchorage strength). Target characters related to stem lodging resis-tance (stem strength) showed good heritability values equal or above 0.70. Positive correlations betweenstem strength and stem diameter and between root plate spread and root strength were found. Select-ing for greater stem diameter and wall width, greater root plate spread and shorter plant height couldenable breeders to increase lodging resistance by increasing stem strength, root strength and decreasingplant leverage, respectively. Achieving a lodging-proof crop will depend on finding a wider root platespread and implementing new management strategies. Genetic linkages between lodging traits will notconstrain the combination of the key lodging-trait dimensions to achieve a lodging-proof ideotype. How-ever, strong association between stem strength and stem wall width will increase the total biomass costneeded for lodging resistance.