Authors:M. Ivezic, J. Tollefson, E. Raspudic, I. Brkic, M. Brmez, and B. Hibbard
The western corn rootworm (
Diabrotica virgifera virgifera
LeConte (WCR)) is a major pest of corn in USA. The pest arrived in Croatia in 1995, and today over 250.000 ha are infested. Insecticides are regularly used to control WCR, but the cost is high, can pose environmental risks, and may become ineffective due to resistance. Growing corn that is resistant to corn rootworms would be a valuable alternative to insecticides. Nine Croatian (Institute of Agriculture, Osijek) and two Pioneer Hi-Bred Int. Inc. (Johnston, Iowa, USA) commercial corn hybrids were evaluated for WCR resistance at two locations using complete randomized block design with four replications. One location was in east Croatia (Osijek) and one was in the USA (Iowa). The hybrids’ tolerance to larval feeding was rated using root injury, root regrowth and root size. Root injury was rated using the Node-Injury Scale 0–3 and evaluation of root size and root regrowth were done by scale 1–6. In an analysis of variance combined across locations, root injury didn’t show any significantly differences among hybrids, but root regrowth and root size were significantly different.
Authors:P. Martins-Lopes, B. Maças, and H. Guedes-Pinto
Genetic improvement in aluminium tolerance is one of the most cost-effective solutions to improve the productivity of wheat (
L.) in acid soils. Sources of tolerance to this abiotic stress within adapted germplasm are limited, so the identification and characterisation of new sources are of some priority for the future of plant breeding in target areas. The aim of this study was to evaluate the response to aluminium stress of an old Portuguese wheat collection and to select the most tolerant ones for genetic and breeding purposes. An old collection of Portuguese wheat cultivars and some ‘Barbela’ lines were tested and classified in relation to aluminium tolerance and compared to modern wheat cultivars using a hydroponic approach. Three bread wheat cultivars (‘Viloso Mole’, Magueija’ and ‘Ruivo’) showed greater tolerance to 5 ppm aluminium than the international wheat standard cultivar ‘BH1146’, and so represent excellent material for understanding the genetic control of aluminium tolerance. In addition, several accessions of the Portuguese landrace ‘Barbela’ were outstanding in terms of aluminium tolerance. In particular, line 7/72/92 had a pronounced advantage over ‘BH1146’ in terms of root regrowth.