The total level of chlorophyll per seedling weight was calculated using the following equation: Ch = 0. 8 × (17.
Anthocyanins per seedling weight was calculated using the following equation: Antho = (Abs 530 − Abs 657 ) × 1000 × powder weight (mg ) − 1 For chlorophyll extraction the method used was described.
Tissue was homogenized in a 1 1 seedling weight (mg) to buffer (μl) ratio using 5x Laemmli sample buffer (125 mM Tris pH 6.8, 20% SDS, 10% β-mercaptoethanol, 20% glycerol, 0.2 mg/mL bromophenyl blue).
The germination percentage, shoot length, root length, seedling fresh weight and seedling dry weight (Milner and Hughes 1968; Sundaramoorthy et al. 2006; Sajani and Muthukkaruppan 2011) were taken and recorded on the 15th day seedlings.
Foliar application of Zn and Mn increased concentration of these two elements in seed, germination rate, germination percentage, seedling dry weight and final seedling emergence, and water deficit stress had negative impacts on most these parameters.
Thus, as observed in the path analysis, fine roots are an important component to improve the root surface area, which played a strong contribution to total seedling dry weight and to P content in maize seedlings cultivated in low-P conditions.
These root traits also showed strong correlation coefficients with total seedling dry weight (0.77 to 0.86), moderate correlations with total P content in the seedling (0.31 to 0.48), and negative correlations with root:shoot ratio (−0.29 to −0.38) (Table 1).
In contrast, root diameter was negatively correlated with root length, root surface area and total seedling dry weight, but no significant correlation was found with total P content.
Similar phenotypic assays of AtOCD mutants or overexpression lines found no difference in root elongation or seedling fresh weight under either control or low water potential conditions.
Comprehensive QTL analyses revealed important regions associated with root traits, seedling dry weight and P content in maize under low-P concentration.
