Aluminum tolerance in triticale, wheat, and rye

Abstract

Acid soils containing high levels of aluminum (Al) are known to severely limit plant growth on over 1.6 billion hectares worldwide. In the United States, a gradual decline in the pR of many soils both in the Great Plains as weil as the Southeast, has caused many soils to become high in levels of free Al. This worldwide condition encouraged the analysis of wheat (Triticum aestivum L. em Thell.), triticale (X Triticosecale Wittmack), and rye (Secale cereale L.) germplasm from one of the major acid soi! regions of the world (Brazil) in order to evaluate and compare the genetic potential of Al genes for cereal improvement. The objectives were to compare Al-tolerance levels in wheats, triticales, and ryes by measuring root elongation responses in Al-containing hydroponic nutrient solutions. Root elongation was impaired for all species grown in Img/L concentrations of Al. Rye had the longest root regrowth and Al-sensitive wheats had the shortest root regrowth. The triticaies containing a 2D(2R) substitution developed in the mid-1970s bad the poorest root regrowth of all triticale types. The newly developed advanced triticaie lines (AABBRR) yet to be released for commercial production showed the highest degree of Al tolerance of all the triticaie types and approach or exceed the levels observed in rye. This indicated that progress is being made in improving triticaie's Al-tolerance in Brazil. Of all the old and new wheat varieties showing the highest degree of Al-tolerance, none ofthem were better than 'BR 1146' a variety that is at least 50 years old. This indicated that over the past 50 years, although Brazilian wheat breeders have made yield improvements in wheat production, they have not improved Al-tolerance. Rye showed a higher degree of Al-tolerance than the other cereals, when tested in 1 mg/L of al, but as expected some variation was noted.

The abiotic stress response and adaptation of triticale — A review

“…Because of the widespread problem in Brazilian soils, triticale was expected to (Kim et al 2002) that while Rye was indeed more Al resistant than wheat, early triticale containing a 2D(2R) substitution developed in the mid-1970s in Brazil had poor tolerance. Later improved hexaploid triticale selected for tolerance approached the tolerance level of rye.…”

AnALMT1Gene Cluster Controlling Aluminum Tolerance at theAlt4Locus of Rye (Secale cerealeL.)

“…Within the cultivated Triticeae, tolerant genotypes of rye (Secale cereale L.) are equally or more Al tolerant than the most tolerant wheats and triticales (3 Triticosecale Wittmack), while tolerant barleys are the least Al tolerant (Mugwira et al 1976;Aniol and Gustafson 1984;Kim et al 2001). Sets of wheat-rye addition lines, wheat chromosome translocation lines, and triticale substitution lines have demonstrated the existence of rye genes that can contribute Al tolerance in the presence of a wheat genetic background (Aniol and Gustafson 1984;Ma et al 2000).…”

The effect of 2D(2R) substitution on the agronomical traits of winter triticale in early generations of two connected crosses

“…However, 2D(2R) substitution decreases resistance to stem rust and tolerance to the presence of aluminium ions and to high soil acidity (Royo et al 1993;Darvey et al 2000;Kim et al 2001;Budzianowski and Woś 2004).…”

“…Most previous studies on the effects of 2D(2R) substitution in hexaploid triticale were performed in backcrossed lines of late generations that were subjected to selection or lines and cultivars with 2D from different sources (Reddy and Zereena 1999;Kim et al 2001;Rybka 2003;Budak et al 2004;Budzianowski and Woś 2004;Kurkiev 2008;Gill et al 2010;Divashuk et al 2010b). Thus, the study of the effect of 2D(2R) substitution on agronomic traits in early generations of crossing that have not been subjected to selection, is useful for planning breeding strategies.…”