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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

Box plot showing the medians and ranges of phenotypic variation in three heterotic groups of maize. 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. NSS: non-Stiff Stalk; SS: Stiff Stalk; TST: subpopulation including tropical/subtropical lines.
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f2-65_298: Box plot showing the medians and ranges of phenotypic variation in three heterotic groups of maize. 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. NSS: non-Stiff Stalk; SS: Stiff Stalk; TST: subpopulation including tropical/subtropical lines.

Mentions: A comparison of the root characteristics of the different heterotic groups identified clear variation for all traits in the three groups. For most root traits, the SS and NSS groups (temperate maize backgrounds) showed higher mean values, while the TST group (tropical and subtropical backgrounds) displayed relatively lower mean values. Remarkable variation was found for total root length, and the mean values in the three heterotic groups, NSS, SS, and TST, were 501.8 cm, 526.8 cm, and 472.9 cm, respectively. Similar results were also observed for other traits including the number of root forks and tips, total root surface area and total root volume. The mean, median, and range of phenotypic variation in NSS, SS, and TST groups are shown in Fig. 2.


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)

Box plot showing the medians and ranges of phenotypic variation in three heterotic groups of maize. 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. NSS: non-Stiff Stalk; SS: Stiff Stalk; TST: subpopulation including tropical/subtropical lines.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f2-65_298: Box plot showing the medians and ranges of phenotypic variation in three heterotic groups of maize. 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. NSS: non-Stiff Stalk; SS: Stiff Stalk; TST: subpopulation including tropical/subtropical lines.
Mentions: A comparison of the root characteristics of the different heterotic groups identified clear variation for all traits in the three groups. For most root traits, the SS and NSS groups (temperate maize backgrounds) showed higher mean values, while the TST group (tropical and subtropical backgrounds) displayed relatively lower mean values. Remarkable variation was found for total root length, and the mean values in the three heterotic groups, NSS, SS, and TST, were 501.8 cm, 526.8 cm, and 472.9 cm, respectively. Similar results were also observed for other traits including the number of root forks and tips, total root surface area and total root volume. The mean, median, and range of phenotypic variation in NSS, SS, and TST groups are shown in Fig. 2.

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