Differential Response of Wheat Cultivars to A

Previous observations indicate that the adaptability of certain wheat (Triticum aestivum L. em Thell) cultivars to strongly acid conditions is due to their ability to tolerate high levels of free aluminum. Studies were conducted to determine the differential response of cultivars to high levels of exchangeable Al in soil and to correlate these data to nutrient solution screening techniques. Field plots were located on a naturally low pH (4.5) Wooster silt loam soil (fine, loamy, mixed, mesic Typic Fragiudalf) in which pH levels, and, thus, available Al were controlled by liming. Data on yield, height, maturity, and winter survival of 43 wheat cultivars and experimental lines and two barley (Hordeum vulgare L. emend.) cultivars were obtained in 1973, 1974, and 1975. Field results were related to measurements of root length, weight, and number, leaf length and top weight of plants grown for 10 days in nutrient solutions containing O and 8 ppni Al. Many cultivars developed in the eastern USA appeared to have been selected unconsciously for Al tolerance. ‘Fultz’, ‘Trumbull’, ‘Fulcaster’, ‘Thorne’, ‘Seneca’, ‘Lucas’, ‘Butler’, ‘Fulton’, ‘Atlas 66’, ‘Blueboy’, and ‘Pennoll’ were classified as tolerant; whereas, most Indiana developed varieties such as ‘Abe’, ‘Arthur’, ‘Arthur 71’, ‘Redcoat’, ‘Reed’, and ‘Riley’ tended to lack aluminum tolerance. ‘Logan’, ‘Fairfield’, ‘Ruler’, and many of the experimental lines exhibited intermediate degrees of tolerance, indicating that this trait was not simply inherited. Root length in nutrient solutions containing Al was a good indicator of varietal response to the high acid conditions of the field. Nutrient solution techniques provide an efficient nondestructive screening method for use in the development of Al-tolerant wheat cultivars.