Aluminum tolerance association mapping in triticale

Abstract

BackgroundCrop production practices and industrialization processes result in increasing acidification of arable soils. At lower pH levels (below 5.0), aluminum (Al) remains in a cationic form that is toxic to plants, reducing growth and yield. The effect of aluminum on agronomic performance is particularly important in cereals like wheat, which has promoted the development of programs directed towards selection of tolerant forms. Even in intermediately tolerant cereals (i.e., triticale), the decrease in yield may be significant. In triticale, Al tolerance seems to be influenced by both wheat and rye genomes. However, little is known about the precise chromosomal location of tolerance-related genes, and whether wheat or rye genomes are crucial for the expression of that trait in the hybrid.ResultsA mapping population consisting of 232 advanced breeding triticale forms was developed and phenotyped for Al tolerance using physiological tests. AFLP, SSR and DArT marker platforms were applied to obtain a sufficiently large set of molecular markers (over 3000). Associations between the markers and the trait were tested using General (GLM) and Multiple (MLM) Linear Models, as well as the Statistical Machine Learning (SML) approach. The chromosomal locations of candidate markers were verified based on known assignments of SSRs and DArTs or by using genetic maps of rye and triticale.Two candidate markers on chromosome 3R and 9, 15 and 11 on chromosomes 4R, 6R and 7R, respectively, were identified. The r2 values were between 0.066 and 0.220 in most cases, indicating a good fit of the data, with better results obtained with the GML than the MLM approach. Several QTLs on rye chromosomes appeared to be involved in the phenotypic expression of the trait, suggesting that rye genome factors are predominantly responsible for Al tolerance in triticale.ConclusionsThe Diversity Arrays Technology was applied successfully to association mapping studies performed on triticale breeding forms. Statistical approaches allowed the identification of numerous markers associated with Al tolerance. Available rye and triticale genetic maps suggested the putative location of the markers and demonstrated that they formed several linked groups assigned to distinct chromosomes (3R, 4R, 6R and 7R). Markers associated with genomic regions under positive selection were identified and indirectly mapped in the vicinity of the Al-tolerant markers. The present findings were in agreement with prior reports.

The abiotic stress response and adaptation of triticale — A review

“…Al tolerance in wheat was associated with 1 to 3 QTLs (Riede et al 1996;Ma et al 2006;Cai et al 2008;Navakode et al 2009). A study with triticale (Niedziela et al 2012) concluded that putative markers were associated with 3R, 4R, 6R and 7R chromosomes, which essentially confirm previous cytogenetic studies. Transporter genes are now widely recognized to regulate of malate and citrate excretion from root of wheat (and other plants), as the case is for the malate transporter ALMT1 gene (e.g.…”

Linkage disequilibrium and association mapping of drought tolerance in cotton (Gossypium hirsutum L.) germplasm population from diverse regions of Pakistan

“…Currently, association mapping methods has been used in diverse plant species such as bread wheat (Yu et al, 2012;Phumichai et al, 2012), barley (Cockram et al, 2008), triticale (Niedziela et al, 2012) and bean (Shi et al, 2011). For molecular studies, there should be a reasonable degree of variability present among the organism of interest; only then the molecular approaches can identify the genetic case underlying this variability.…”

“…It is a powerful technique used to identify genomic regions linked to specific variants of a phenotypic trait (Saeed et al, 2014). Genome-wide association in plants has wide range of use and there are many reports of association studies on many crops such as barley (Gutiérrez et al, 2011;Cockram et al, 2010), rice (Shao et al, 2011), bread wheat (Yu et al, 2012), maize (Poland et al, 2011), triticale (Niedziela et al, 2012), bean (Shi et al, 2011), sugar beet (Würschum et al, 2011), cotton fiber quality traits (Abdurakhmonov et al, 2009) and cotton salinity stress tolerance (Saeed et al, 2014). Cotton Gossypium spp.…”

Genetic variability and inheritance to aluminum tolerance in nutrient solution in triticale

“…Genotypes of triticale have demonstrated different reaction in the presence of Al 3+ toxicity in trials using nutrient solution (Camargo et al, 2006;Niedziela et al, 2012). This technique has been used in winter cereal breeding programs due to the difficulty presented to evaluate the tolerance to Al 3+ toxicity in field, demonstrating great representativeness when associated to the field condition (Portaluppi et al, 2010).…”