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Genetic variation for maize root architecture in response to drought stress at the seedling stage.

Li R, Zeng Y, Xu J, Wang Q, Wu F, Cao M, Lan H, Liu Y, Lu Y - Breed. Sci. (2015)

Bottom Line: Significant genetic variation, with medium to high heritability and significant correlations, was observed for root traits.Of the tested lines, 7, 42, 45, and 9 were classified as drought sensitive, moderately sensitive, moderately drought tolerant, and highly drought tolerant, respectively.Seven of the 9 extremely drought tolerant lines were from the TST group, suggesting that TST germplasms harbor valuable genetic resources for drought tolerance that could be used in breeding to improve abiotic stress tolerance in maize.

View Article: PubMed Central - PubMed

Affiliation: Maize Research Institute, Sichuan Agricultural University , Wenjiang 611130, Sichuan , China ; China Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Ministry of Agriculture , China ; Agronomy College, Sichuan Agricultural University , Wenjiang 611130, Sichuan , China.

ABSTRACT
Although the root system is indispensable for absorption of nutrients and water, it is poorly studied in maize owing to the difficulties of direct measurement of roots. Here, 103 maize lines were used to compare root architectures under well-watered and water-stressed conditions. Significant genetic variation, with medium to high heritability and significant correlations, was observed for root traits. Total root length (TRL) and total root surface area (TSA) had high phenotypical diversity, and TRL was positively correlated with TSA, root volume, and root forks. The first two principal components explained 94.01% and 91.15% of total root variation in well-watered and water-stressed conditions, respectively. Thus, TRL and TSA, major contributors to root variation, can be used as favorable selection criteria at the seedling stage. We found that stiff stalk and non-stiff stalk groups (temperate backgrounds) showed relatively higher mean values for root morphological diversity than the TST group (tropical/subtropical background). Of the tested lines, 7, 42, 45, and 9 were classified as drought sensitive, moderately sensitive, moderately drought tolerant, and highly drought tolerant, respectively. Seven of the 9 extremely drought tolerant lines were from the TST group, suggesting that TST germplasms harbor valuable genetic resources for drought tolerance that could be used in breeding to improve abiotic stress tolerance in maize.

No MeSH data available.


Related in: MedlinePlus

Frequency distribution of variation for 9 traits in 103 maize lines. TRL: total root length; TSA: total root surface area; RAD: root average diameter; TRV: total root volume; TRT: total root tips; RF: root forks. WW: well-watered condition; WS: water-stressed condition.
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f1-65_298: Frequency distribution of variation for 9 traits in 103 maize lines. TRL: total root length; TSA: total root surface area; RAD: root average diameter; TRV: total root volume; TRT: total root tips; RF: root forks. WW: well-watered condition; WS: water-stressed condition.

Mentions: ANOVA revealed significant genetic variation among genotypes for nine traits (Table 3). Genotypic variation was significant for six traits at P < 0.001 and eight traits showed significant variation under different water regimes, the exception being average root diameter. The results indicate that these traits were significantly affected by water supply in the tested maize lines. The level of variation was also reflected by the distribution of traits representing different drought resistance criteria (Fig. 1). Histograms of frequency distribution of root traits showed approximately normal distributions. Under the WS condition, the values for seven traits (TRL, TSA, RAD, TRV, TRT, and RF) decreased significantly.


Genetic variation for maize root architecture in response to drought stress at the seedling stage.

Li R, Zeng Y, Xu J, Wang Q, Wu F, Cao M, Lan H, Liu Y, Lu Y - Breed. Sci. (2015)

Frequency distribution of variation for 9 traits in 103 maize lines. TRL: total root length; TSA: total root surface area; RAD: root average diameter; TRV: total root volume; TRT: total root tips; RF: root forks. WW: well-watered condition; WS: water-stressed condition.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4542930&req=5

f1-65_298: Frequency distribution of variation for 9 traits in 103 maize lines. TRL: total root length; TSA: total root surface area; RAD: root average diameter; TRV: total root volume; TRT: total root tips; RF: root forks. WW: well-watered condition; WS: water-stressed condition.
Mentions: ANOVA revealed significant genetic variation among genotypes for nine traits (Table 3). Genotypic variation was significant for six traits at P < 0.001 and eight traits showed significant variation under different water regimes, the exception being average root diameter. The results indicate that these traits were significantly affected by water supply in the tested maize lines. The level of variation was also reflected by the distribution of traits representing different drought resistance criteria (Fig. 1). Histograms of frequency distribution of root traits showed approximately normal distributions. Under the WS condition, the values for seven traits (TRL, TSA, RAD, TRV, TRT, and RF) decreased significantly.

Bottom Line: Significant genetic variation, with medium to high heritability and significant correlations, was observed for root traits.Of the tested lines, 7, 42, 45, and 9 were classified as drought sensitive, moderately sensitive, moderately drought tolerant, and highly drought tolerant, respectively.Seven of the 9 extremely drought tolerant lines were from the TST group, suggesting that TST germplasms harbor valuable genetic resources for drought tolerance that could be used in breeding to improve abiotic stress tolerance in maize.

View Article: PubMed Central - PubMed

Affiliation: Maize Research Institute, Sichuan Agricultural University , Wenjiang 611130, Sichuan , China ; China Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Ministry of Agriculture , China ; Agronomy College, Sichuan Agricultural University , Wenjiang 611130, Sichuan , China.

ABSTRACT
Although the root system is indispensable for absorption of nutrients and water, it is poorly studied in maize owing to the difficulties of direct measurement of roots. Here, 103 maize lines were used to compare root architectures under well-watered and water-stressed conditions. Significant genetic variation, with medium to high heritability and significant correlations, was observed for root traits. Total root length (TRL) and total root surface area (TSA) had high phenotypical diversity, and TRL was positively correlated with TSA, root volume, and root forks. The first two principal components explained 94.01% and 91.15% of total root variation in well-watered and water-stressed conditions, respectively. Thus, TRL and TSA, major contributors to root variation, can be used as favorable selection criteria at the seedling stage. We found that stiff stalk and non-stiff stalk groups (temperate backgrounds) showed relatively higher mean values for root morphological diversity than the TST group (tropical/subtropical background). Of the tested lines, 7, 42, 45, and 9 were classified as drought sensitive, moderately sensitive, moderately drought tolerant, and highly drought tolerant, respectively. Seven of the 9 extremely drought tolerant lines were from the TST group, suggesting that TST germplasms harbor valuable genetic resources for drought tolerance that could be used in breeding to improve abiotic stress tolerance in maize.

No MeSH data available.


Related in: MedlinePlus