Prediction of final grain protein content with plant protein content of malting barley under Mediterranean conditions

The prediction of protein content in mature barley grain using the protein content of the plant at heading time is assessed in two experiments. In the first, 32 barley varieties of wide genetic origin were grown in two contrasting environments in Spain, with two sowing dates in one of them. In the second, a collection of 102 doubled haploid (DR) lines front a cross between two high quality two-row spring malting barleys Beka (European, high protein) and Logan (North-American, low protein), was grown in three contrasting environments in Spain, the former two plus a third, with a high incidence of drought and heat stresses during grain filling. The regression equations obtained from the data of both experiments showed a very good fit, as did the equation calculated over all data. The range of protein values used for the overall calculation was from 9 to 21.5%, thus covering the complete spectrum of variation. We conclude that it is possible to predict grain protein in this way, but we suggest that prediction for each combination of variety and growing region should be calculated.