DIFFERENTIAL ALUMINUM TOLERANCE OF HIGH-YIELDING, EARLY-MATURING CANADIAN WHEAT CULTIVARS AND GERMPLASM

Abstract

Twenty-eight spring wheat (Triticum aestivum) cultivars were tested for tolerance to aluminum (Al) using solution culture techniques. Fourteen of these cultivars were also grown in the field under two different management levels, Conventional and Intensive Crop Management (ICM), to determine maximum yield potentials in the Edmonton region and to determine if individual cultivars respond differently to management levels on high fertility fallow conditions. Based upon a root weight index (RWI), seven of the 28 spring wheat cultivars tested (K.Kongoni, PT741, K.Nyumbu, PT726, Norquay, PF7748, Maringa) were more tolerant to Al than the winter wheat standard for Al tolerance, Atlas 66. The winter wheat standard for Al sensitivity, Scout 66, ranked most sensitive to Al, but 11 spring wheat cultivars were equally sensitive (Lancer, Wildcat, Columbus, Park, Bluesky, Kenyon, Benito, BW92, Neepawa, Conway, Katepwa). In the field, cultivars varied in yield potential and days to maturity in both the Conventional and ICM treatments; however, ICM provided no additional benefit in terms of yield. Six genotypes (Bluesky, Norquay, Oslo, PT726, PT741, PT742) were significantly higher yielding than Neepawa and matured as early as Park. Six of the nine highest yielding cultivars from the field trials had Al tolerance ratings (RWI values) greater than 0.80 (80% of control), while five Canadian Western Red Spring (CWRS) cultivars, the lowest yielding from the field trials, had RWI values less than or equal to 0.43. The reason for the apparent association between high yield potential and tolerance to Al is unknown.Key words: wheat, Triticum aestivum, aluminum tolerance, high yield, early maturity, intensive crop management