Putative Quantitative Trait Loci for Physical and Chemical Components of Common Bean

Abstract

tannins and phytic acid) reduce the bioavailability of Ca, Fe, and Zn (Frossard et al., 2000). In common bean (Phaseolus vulgaris L.), some nutritional traitsDuring the past 25 yr, substantial progress has been such as proteins and mineral content are lower in the cultivated form as compared with the wild counterpart. To assess the feasibility of made on the clinical, biochemical, and immunological wild bean as the putative source of desirable traits such as minerals aspects of the role of Zn in humans (Ganapathy and or tannins, this study was performed to identify quantitative trait loci Volpe, 1999). Extensive research has shown that Zn is (QTL) associated with seed mass, Ca, Fe, Zn, and tannin content in involved in a myriad of critical reactions in the human bean seed. Two-hundred-ninety-one amplified fragment length polybody and is associated with cellular growth and repair, morphism (AFLP) markers were scored in 120 F 2:3 segregating individappetite, behavior, and susceptibility to infection. Reuals derived from a cross between cultivated 'Bayo Baranda' and cent studies have identified Zn deficiencies in children wild common bean accession G-22837. Seed weight and minerals and who consume diets high in cereals (Ranum, 1999). tannin contents were quantified on the seed harvested from the 120 individual plants. Significant transgressive segregation was observed Moreover, it is recognized that a nutritional deficiency among the F 2:3 individuals for some characteristics. A total of 57 AFLP in Zn is common throughout the world, including the markers were distributed among five linkage groups with a coverage USA. (Ganapathy and Volpe, 1999). of 497 centiMorgans (cM). Five putative QTL were significantly asso-Plant breeding has been mainly focused on increasing ciated with seed mass, two with Ca, two with Fe, one with Zn, and yield and disease resistance in crops, but not at improvfour with tannin content in the seed. These QTL explained ≈42, 25, ing the micronutrient concentration in grain (Frossard 25, 15, and 42% of the phenotypic variance, respectively. Due to et al., 2000). Developing cultivars with higher capacity known environmental effect on most nutritional traits, the use of QTL to accumulate Ca, Fe, and Zn could contribute signifiwith larger effects could be used to screen segregating populations cantly to the improvement of the micronutrient status that include wild genotypes, wild populations, and ancestral landraces from the region where outstanding wild populations are identified.

Genetic variability for iron and zinc content in common bean lines and interaction with water availability

“…The extent of the correlation varied widely among the different experiments and ranged from no association to intermediate association, indicating the influence of environment and other associations on these characteristics. The results were similar to those found in other studies (Guzman-Maldonado et al, 2003;Gelin et al, 2007;Cichy et al, 2009;Blair et al, 2009Blair et al, , 2011) that examined recombinant lines obtained from crosses between one parent with high CFe and CZn and another with low levels of these minerals. In contrast, some studies using lines with different genetic backgrounds showed that this relationship does not exist (Ribeiro et al, 2008), while others reported a significant relationship (Welch et al, 2000;Silva et al, 2012) between the levels of the two minerals.…”

Selection of common bean lines with high grain yield and high grain calcium and iron concentrations

“…The environmental variance was more expressive than the genetic variance for iron concentration in both methods of advancing segregating populations (Table 1) Iron concentration had continuous distribution in F 7 lines and transgressive segregation was observed for both low and high values (Figure 1). Previous studies also showed that the iron concentration of common bean grains had continuous distribution among F 2:3 lines (Guzmán-Maldonado et al, 2003), F 7:11 lines (Blair et al, 2009), F 5:7 lines (Cichy et al, 2009) and among F 10 lines . These results confirm the hypothesis that inheritance of iron concentration in common bean grains is quantitative .…”

“…cultivated and wild common bean (Guzmán-Maldonado et al, 2003). According to these authors, the existence of transgressive variation, such as that observed for calcium concentration, should encourage plant breeders as it indicates that gene combination exists, which can result in enhanced performance of the characteristic in the absence of overdominance.…”

“…Weak positive correlation was observed between calcium and iron concentrations (r = 0.38) in common bean lines (Guzmán-Maldonado et al, 2003). The association between grain yield and the concentrations of calcium and iron in the common bean grains has not yet been investigated.…”

Moving micronutrients from the soil to the seeds: Genes and physiological processes from a biofortification perspective

“…One case in point is the discovery of NAM-B1, a transcription factor in bread wheat that influences timing of leaf senescence, grain protein concentration, and grain Fe and Zn concentrations [24,163]. QTL mapping of seed mineral concentration has been carried out in Arabidopsis [195][196][197], Medicago truncatula [198], Lotus japonicus [199], common bean [200][201][202], Brassica napus [203], Brassica rapa [204], rice [205][206][207], and wheat [208,209]. These studies have identified several QTL for seed mineral concentrations localized in different regions and several of these mineral QTL co-localized with each other, pointing to common transport mechanisms.…”