480 Journal of Food, Agriculture & Environment, Vol.10 (2), April 2012 www.world-food.net Journal of Food, Agriculture & Environment Vol.10 (2): 480-484. 2012 WFL Publisher Science and Technology Meri-Rastilantie 3 B, FI-00980 Helsinki, Finland e-mail: info@world-food.net Spike yield stability in wheat grown under stress conditions of alkaline soil Sofija Petrović 1 , Miodrag Dimitrijević 1 , Cimpeanu Sorin Mihai 2 , Daniel Bucur 3 , Ana Andreea Gurita 3 , Maria Harja 4 , Livija Maksimović 5 and Milivoj Belić 1 1 University of Novi Sad, Faculty of Agriculture, , Dositeja Obradovica 8, 21000 Novi Sad, Serbia. 2 University of Agronomical Sciences and Veterinary Medicine Bucharest, Marasti 59, 011464 Bucharest, Romania. 3 University of Agricultural Sciences and Veterinary Medicine Iasi, M. Sadoveanu 3, 700490 Iasi, Romania. 4 Technical University of Iasi, Faculty of Chemical Engineering and Environmental Protection, Blv. D. Mangeron 73, 700050, Iasi, Romania. 5 Institute of Field and Vegetable Crops, M. Gorkog 30, 21000 Novi Sad, Serbia. e-mail: sonjap@polj.uns.ac.rs, mishad@polj.uns.ac.rs, mscimpeanu@yahoo.fr, dbucur@uaiasi.ro, maria_harja06@yahoo.com, livija.maksimovic@ifvcns.ns.ac.rs Received 9 February 2012, accepted 4 May 2012. Abstract Bread wheat requires a fertile soil with good physical and chemical characteristics. Halomorphic soil (solonetz type) could be utilized to increase agricultural production when combined with soil amelioration measures and by growing suitable crops and varieties. This paper deals with the effect of ameliorating the soil using phosphogypsum at two application levels (25 and 50 t ha -1 ) on grain yield per spike (GYS), which is a sensitive quantitative trait affecting the yield component in wheat, especially under abiotic stress conditions. Eight wheat varieties examined showed positive reactions to soil amelioration leading to improved use and bioremediation of less productive soil. The differences between varieties grown with three treatments in three seasons were expressed through averages for a given trait showing that weather conditions during the vegetation period strongly influenced the effect of amelioration. In the first year of study the yield per spike showed the highest overall improvement. In the following 2 years, environmental conditions had a greater influence on the traits being investigated than the effects of the soil amelioration treatments. Key words: Amelioration, AMMI, solonetz, spike yield, wheat. Introduction Bread wheat (Triticum aestivum ssp. vulgare) is considered to be one of the most important crops grown, playing a significant role in human diet, and covering a vast agricultural area. Being of significant value as a food source, wheat is the subject of intensive breeding efforts. The main goal is high yield, as well as good quality. Yield represents the ultimate ability of a plant to live and survive in a certain environment. Yield components are a number of recognized factors that strongly influence yield. High, stable levels of a desirable trait under variable agro-ecological conditions can only be achieved by reducing the influence of environmental interactions and conditions on the stability of the selected genotype 4, 8, 19, 28, 29 . Mainstream wheat breeding programs in Europe often create varieties suitable for intensive agro-ecological conditions 7 and assume that soil productivity will be high 17, 18 . However, there is great untapped potential in ‘so called’ less productive soils. Solonetz soil, which commonly occurs in dry climatic zones, typically provide stressed environments for bread wheat production. Solonetz soil has unfavorable physico-chemical properties and the accumulation of sodium salts in solonetz soil leads to a higher pH together with a subsurface layer that contains a significant amount of clay. According to recent data, about 0.5% of Europe is covered with solonetz soils, known as alkaline, clay and sodium reach land. They are mainly found in Russia, Ukraine, Hungary, Bulgaria, Romania, and Kazakhstan 13 . These soils could be more intensively utilized if ameliorative measures, such as chemical treatment and drainage, together with growing suitably adapted crops, were adapted 1, 3, 6, 14, 16, 30 . The search for wheat genotypes tolerant to salinity stress, as well as other stress conditions, could result in the selection of more tolerant genotypes that are adapted to soil bioremediation, thus allowing wheat production to spread into these currently less productive soils 2, 11, 25-27 . In the Banat area in Vojvodina Province (North Serbia) there are about 80,000 ha of halomorphic solonetz soil, which is predominantly used as pasture 31 . The aim of this study was to evaluate wheat varieties grown on solonetz soil with and without ameliorative measures to identify the extent and variation in genotype caused by the interaction of the environment with a yield component. Studies of wheat trait behavior could be of use in improving varietal cultivation and enhancing their yield potential 23 . Grain yield per spike (GYS) represents an important component of yield and shows an individual plant’s potential 20-22 . GYS does not have a pronounced positive correlation to grain yield under normal conditions, but under stress conditions, there is a high positive correlation between these two traits 9, 5 . This suggests GYS is a promising phenotypic marker of prospective genotypes that may lead to increased grain yield in the segregating generation (F2) of wheat crossing programs, especially as it is hard to select desirable