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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

The mean values and standard deviations of drought resistance coefficient for 9 traits in three groups classified for drought tolerance. Groups 1, 2, 3 and 4 represent inbred lines identified with drought sensitivity, moderate sensitivity, moderate drought tolerance and high tolerance ability under drought stress. N = 7, 42, 45 and 9 for groups 1, 2, 3 and 4, respectively. Bars are the standard deviation. TRL: total root length; TSA: total root surface area; RAD: root average diameter; TRV: total root volume; TRT: total root tips; RF: root forks.
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f4-65_298: The mean values and standard deviations of drought resistance coefficient for 9 traits in three groups classified for drought tolerance. Groups 1, 2, 3 and 4 represent inbred lines identified with drought sensitivity, moderate sensitivity, moderate drought tolerance and high tolerance ability under drought stress. N = 7, 42, 45 and 9 for groups 1, 2, 3 and 4, respectively. Bars are the standard deviation. TRL: total root length; TSA: total root surface area; RAD: root average diameter; TRV: total root volume; TRT: total root tips; RF: root forks.

Mentions: The mean values and standard deviations of the drought resistance coefficient (DRC) for each trait in the four groups with different levels of drought tolerance are shown in Fig. 4. The mean values of DRC for all root traits were lowest in group 1, moderate in groups 2 and 3, and highest in group 4, except for RAD. This result indicates that drought tolerant maize lines with higher D values also had higher drought resistance coefficients, and consistent results were obtained when these two indices were calculated based on the root morphology traits used for drought tolerance screening.


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)

The mean values and standard deviations of drought resistance coefficient for 9 traits in three groups classified for drought tolerance. Groups 1, 2, 3 and 4 represent inbred lines identified with drought sensitivity, moderate sensitivity, moderate drought tolerance and high tolerance ability under drought stress. N = 7, 42, 45 and 9 for groups 1, 2, 3 and 4, respectively. Bars are the standard deviation. TRL: total root length; TSA: total root surface area; RAD: root average diameter; TRV: total root volume; TRT: total root tips; RF: root forks.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f4-65_298: The mean values and standard deviations of drought resistance coefficient for 9 traits in three groups classified for drought tolerance. Groups 1, 2, 3 and 4 represent inbred lines identified with drought sensitivity, moderate sensitivity, moderate drought tolerance and high tolerance ability under drought stress. N = 7, 42, 45 and 9 for groups 1, 2, 3 and 4, respectively. Bars are the standard deviation. TRL: total root length; TSA: total root surface area; RAD: root average diameter; TRV: total root volume; TRT: total root tips; RF: root forks.
Mentions: The mean values and standard deviations of the drought resistance coefficient (DRC) for each trait in the four groups with different levels of drought tolerance are shown in Fig. 4. The mean values of DRC for all root traits were lowest in group 1, moderate in groups 2 and 3, and highest in group 4, except for RAD. This result indicates that drought tolerant maize lines with higher D values also had higher drought resistance coefficients, and consistent results were obtained when these two indices were calculated based on the root morphology traits used for drought tolerance screening.

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