engleski

Evaluating four secondary stress-related traits in high planting density in testcrosses of maize IBM population

High planting density increases the deleterious effects of various classes of abiotic and biotic stresses and so increases the need for genetic improvements in multiple-stress tolerance of maize. Fusarium verticillioides is one of the most prevalent maize ear rotting pathogen in Southeast Europe, known to produce fumonisins. Higher disease severity occurs if plant has previously been weakened by other stress. The objective of the study is to evaluate four secondary stress-related traits including Fusarium ear rot percentage and fumonisin concentrations in testcrosses of intermated B73xMo17 (IBM) population grown in moderate and high planting densities. 212 testcrosses of the IBM maize population test- crossed with an Iodent inbred line were planted in two densities - moderate (55 000 plants/ha) and high (86 000 plants/ha). Anthesis –silk interval and the maximum efficiency of photosystem II (Fv/Fm) parameter of chlorophyll fluorescence were secondary stress-related traits during flowering. Primary ears from all plants were visually rated for severity of Fusarium ear rot as the percentage of the ear with symptoms. Concentration of fumonisin in grain was determined by lateral flow assay (Charm®ROSA® FUMONISIN Quantitative test). While ASI differed significantly between the two densities (2.6 days and 3.7 days in moderate and high planting density, respectively) indicating stress, Fv/Fm values of 0.80 did not differ between both plant densities demonstrating no stress . Disease severity differed significantly between the densities with the average ear rot 7.63% in moderate and 14.82% in high planting density. Fumonisin concentration ranged from 0 to over 60000 ppb. Upcoming quantitative genetic and QTL studies should eventually elucidate genetic properties and relations of these and other secondary stress-related traits for tolerance to high planting density.

maize IBM testcrosses ; multiple stress ; plant density ; Fusarium ear rot ; fumonisins ; anthesis-silk interval ; chlorophyll florescence

nije evidentirano