engleski

Environmental and genotypic effects for western corn rootworm tolerance traits in American and European maize trials

The western corn rootworm (Diabrotica virgifera virgifera LeConte) (WCR) is the most destructive pest of maize in North America currently causing considerable economic losses also in Central and Southeast Europe. Developing and releasing of commercial hybrids with higher level of native (host-plant) resistance to WCR could be a sustainable alternative to transgenic approaches. For WCR native resistance breeding strategies, it is important to examine size and patterns of genotype by environment interaction (GEI). The objectives of the study were to determine i) environmental and genotypic effects of host- plants and ii) patterns of GEI for maize root traits associated with WCR resistance (damage, size, regrowth) at two distinct locations. Field experiments were conducted in 2001-2003 in Missouri (manual infestation) and from 2001 to 2006 in Croatia (natural infestation, continuous growing in 2004-2006). Environmental variances were much greater than respective genotypic variances for root damage and root size resulting in low repeatability estimates for both traits, especially in Croatia. The high repeatabilities for root regrowth under both natural and manual infestation indicated that susceptible and/or tolerant maize genotypes to WCR can be reliably identified under both infestation treatments. No specific interaction between host genotypes and putative WCR populations for a given geographic region, nor the threefold interaction maize genotypes × putative WCR population × edaphic/climatic factors were identified for root regrowth.

Diabrotica virgifera virgifera ; maize genotypes ; genotype by environment interaction ; root damage ; root regrowth ; root size ; western corn rootworm

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