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Characterization of mature maize (Zea mays L.) root system architecture and complexity in a diverse set of Ex-PVP inbreds and hybrids.

Hauck AL, Novais J, Grift TE, Bohn MO - Springerplus (2015)

Bottom Line: For each trait, per se line effects were highly significant and the most important contributor to trait performance.The interaction between the environment and the additive line effect was also significant for all traits.Inbreds with contrasting effects on complexity and architecture traits were observed, suggesting that root complexity and architecture traits are inherited independently.

View Article: PubMed Central - PubMed

Affiliation: Department of Crop Sciences, University of Illinois, 1102 S. Goodwin Ave., Urbana, IL 61801 USA.

ABSTRACT
The mature root system is a vital plant organ, which is critical to plant performance. Commercial maize (Zea mays L.) breeding has resulted in a steady increase in plant performance over time, along with noticeable changes in above ground vegetative traits, but the corresponding changes in the root system are not presently known. In this study, roughly 2500 core root systems from field trials of a set of 10 diverse elite inbreds formerly protected by Plant Variety Protection plus B73 and Mo17 and the 66 diallel intercrosses among them were evaluated for root traits using high throughput image-based phenotyping. Overall root architecture was modeled by root angle (RA) and stem diameter (SD), while root complexity, the amount of root branching, was quantified using fractal analysis to obtain values for fractal dimension (FD) and fractal abundance (FA). For each trait, per se line effects were highly significant and the most important contributor to trait performance. Mid-parent heterosis and specific combining ability was also highly significant for FD, FA, and RA, while none of the traits showed significant general combining ability. The interaction between the environment and the additive line effect was also significant for all traits. Within the inbred and hybrid generations, FD and FA were highly correlated (rp ≥ 0.74), SD was moderately correlated to FD and FA (0.69 ≥ rp ≥ 0.48), while the correlation between RA and other traits was low (0.13 ≥ rp ≥ -0.40). Inbreds with contrasting effects on complexity and architecture traits were observed, suggesting that root complexity and architecture traits are inherited independently. A more comprehensive understanding of the maize root system and the way it interacts with the environment will be useful for defining adaptation to nutrient acquisition and tolerance to stress from drought and high plant densities, critical factors in the yield gains of modern hybrids.

No MeSH data available.


Root samples of maize inbreds B73, LH1, PHJ40, and Mo17 and of hybrids obtained from their crosses. Roots of inbreds displayed in the first column and row, respectively, were obtained from plants sampled from different field plots.
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Fig2: Root samples of maize inbreds B73, LH1, PHJ40, and Mo17 and of hybrids obtained from their crosses. Roots of inbreds displayed in the first column and row, respectively, were obtained from plants sampled from different field plots.

Mentions: Least square means of the five highest and lowest performing F1 hybrids for FD and RA traits are shown in Table 5. The hybrids with the highest and lowest performance for root traits generally agrees with expectations derived from Table 4, which is expected, given the importance of additive effects for the phenotypes. There are some notable deviations, however. For example, inbreds LH1 and LH82 had the strongest negative effects for FD, but there were nine hybrids with lower FD estimates. PHG47 and PHG84 were estimated to have non-significant effects for RA compared with the mean of the set, but their cross had the 4th widest root angle. This is consistent with the detection of significant SCA among the hybrids for root traits and evidence for the role of dominance in root trait expression. A summary overview of hybrid performance rankings, genetic effect magnitudes, F1 means and mid-parent values for root traits is provided in Additional file 1: Figs. S1–S4. The general additivity of root traits can be seen in comparisons of inbred and hybrid images, where the F1s have mid-parent characteristics (Fig. 2). The specific dominance detected in the cross of B73 by LH1 for root angle can also be seen; the F1 has a wider root angle more closely resembling LH1.Table 5


Characterization of mature maize (Zea mays L.) root system architecture and complexity in a diverse set of Ex-PVP inbreds and hybrids.

Hauck AL, Novais J, Grift TE, Bohn MO - Springerplus (2015)

Root samples of maize inbreds B73, LH1, PHJ40, and Mo17 and of hybrids obtained from their crosses. Roots of inbreds displayed in the first column and row, respectively, were obtained from plants sampled from different field plots.
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4537857&req=5

Fig2: Root samples of maize inbreds B73, LH1, PHJ40, and Mo17 and of hybrids obtained from their crosses. Roots of inbreds displayed in the first column and row, respectively, were obtained from plants sampled from different field plots.
Mentions: Least square means of the five highest and lowest performing F1 hybrids for FD and RA traits are shown in Table 5. The hybrids with the highest and lowest performance for root traits generally agrees with expectations derived from Table 4, which is expected, given the importance of additive effects for the phenotypes. There are some notable deviations, however. For example, inbreds LH1 and LH82 had the strongest negative effects for FD, but there were nine hybrids with lower FD estimates. PHG47 and PHG84 were estimated to have non-significant effects for RA compared with the mean of the set, but their cross had the 4th widest root angle. This is consistent with the detection of significant SCA among the hybrids for root traits and evidence for the role of dominance in root trait expression. A summary overview of hybrid performance rankings, genetic effect magnitudes, F1 means and mid-parent values for root traits is provided in Additional file 1: Figs. S1–S4. The general additivity of root traits can be seen in comparisons of inbred and hybrid images, where the F1s have mid-parent characteristics (Fig. 2). The specific dominance detected in the cross of B73 by LH1 for root angle can also be seen; the F1 has a wider root angle more closely resembling LH1.Table 5

Bottom Line: For each trait, per se line effects were highly significant and the most important contributor to trait performance.The interaction between the environment and the additive line effect was also significant for all traits.Inbreds with contrasting effects on complexity and architecture traits were observed, suggesting that root complexity and architecture traits are inherited independently.

View Article: PubMed Central - PubMed

Affiliation: Department of Crop Sciences, University of Illinois, 1102 S. Goodwin Ave., Urbana, IL 61801 USA.

ABSTRACT
The mature root system is a vital plant organ, which is critical to plant performance. Commercial maize (Zea mays L.) breeding has resulted in a steady increase in plant performance over time, along with noticeable changes in above ground vegetative traits, but the corresponding changes in the root system are not presently known. In this study, roughly 2500 core root systems from field trials of a set of 10 diverse elite inbreds formerly protected by Plant Variety Protection plus B73 and Mo17 and the 66 diallel intercrosses among them were evaluated for root traits using high throughput image-based phenotyping. Overall root architecture was modeled by root angle (RA) and stem diameter (SD), while root complexity, the amount of root branching, was quantified using fractal analysis to obtain values for fractal dimension (FD) and fractal abundance (FA). For each trait, per se line effects were highly significant and the most important contributor to trait performance. Mid-parent heterosis and specific combining ability was also highly significant for FD, FA, and RA, while none of the traits showed significant general combining ability. The interaction between the environment and the additive line effect was also significant for all traits. Within the inbred and hybrid generations, FD and FA were highly correlated (rp ≥ 0.74), SD was moderately correlated to FD and FA (0.69 ≥ rp ≥ 0.48), while the correlation between RA and other traits was low (0.13 ≥ rp ≥ -0.40). Inbreds with contrasting effects on complexity and architecture traits were observed, suggesting that root complexity and architecture traits are inherited independently. A more comprehensive understanding of the maize root system and the way it interacts with the environment will be useful for defining adaptation to nutrient acquisition and tolerance to stress from drought and high plant densities, critical factors in the yield gains of modern hybrids.

No MeSH data available.