Evaluation of genus Cenchrus based on malondialdehyde, proline content, specific leaf area and carbon isotope discrimination for drought tolerance and divergence of species at DNA level

Carbon isotope discrimination (Δ) has been proposed as a selection criterion for improving adaptation to water-limited environments because it provides a measure of seasonal transpiration efficiency ( WUE). In cowpea (Vigna unguiculata (L.) Walp.), consistent genotypic and drought-induced differences in Δ and WUE have been observed which were correlated as expected based on theory. Values of Δ and WUE for reciprocal hybrids grown under field conditions indicated nuclear inheritance for both characters. High WUE and low Δ were partially dominant under dry field pot conditions, whereas high Δ was partially dominant under natural wet soil conditions. Studies were conducted to test whether differences in rooting environment and xylem ABA levels are responsible for this change in dominance relations. Cowpea accessions and hybrids were grown in the field and subjected to wet or dry treatments with three different pot sizes. The experiment was conducted twice, giving similar results. The dry treatment resulted in decreases in Δ, and increases in WUE and ABA concentration in the xylem sap. Under drought, genotypes with higher WUE had higher xylem ABA, and the hybrids exhibited greater increases in ABA concentration in response to the dry treatment than either parent. Partial confounding was present in that the hybrids had substantial leaf area and water-use rate, and may have experienced greater soil drought in some conditions than some parents, with interacting effects of pot size. Plants in larger pots produced more biomass and leaf area but with no changes in xylem ABA. Concentration of ABA in the xylem sap was correlated with Δ and WUE for genotypic and drought treatment effects but not for pot size effects. Hybrids tended to have higher Δ and lower WUE in relation to mid-parent means when grown in large wet pots than in small dry ones. Changes in hybrid performance with respect to Δ and WUE were more consistent with changes in xylem ABA for drought treatment effects than for pot size effects. Another chemical signal might be involved in mediating pot size effects.

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Variation in carbon isotope discrimination and other traits related to drought tolerance in upland cotton cultivars under dryland conditions

Field Crops Research ◽

10.1016/s0378-4290(98)00151-8 ◽

1999 ◽

Vol 61 (2) ◽

pp. 109-123 ◽

Cited By ~ 37

Author(s):

E.O Leidi ◽

M López ◽

J Gorham ◽

J.C Gutiérrez

Keyword(s):

Drought Tolerance ◽

Carbon Isotope ◽

Upland Cotton ◽

Carbon Isotope Discrimination ◽

Isotope Discrimination

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Carbon isotope discrimination and drought tolerance in Citrus limon genotypes and in a cultivar of Citrus sinensis grafted on different rootstocks

Giornale botanico italiano ◽

10.1080/11263509509440961 ◽

1995 ◽

Vol 129 (4) ◽

pp. 1110-1111

Author(s):

Marco Lauteri1 ◽

M. Antonietta Germana ◽

Luciano Spaccino ◽

Andrea Scartazza ◽

Enrico Brugnoli

Keyword(s):

Drought Tolerance ◽

Carbon Isotope ◽

Citrus Sinensis ◽

Carbon Isotope Discrimination ◽

Citrus Limon ◽

Isotope Discrimination

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Toward a New Use for Carbon Isotope Discrimination in Wheat Breeding

Agronomy ◽

10.3390/agronomy9070385 ◽

2019 ◽

Vol 9 (7) ◽

pp. 385

Author(s):

Dixon ◽

Carter

Keyword(s):

Drought Tolerance ◽

Carbon Isotope ◽

Water Use ◽

Carbon Isotope Discrimination ◽

Wheat Breeding ◽

Drought Severity ◽

Deep Roots ◽

Breeding Programs ◽

Isotope Discrimination ◽

Drought Tolerant

A major obstacle in the effort to develop drought tolerant varieties of wheat (Triticum aestivum L.) is phenotyping. Traits known to contribute to improved drought tolerance, such as water-use behavior, reliance on stem reserve carbohydrates, and the ability to develop deep roots, require time and resource-intensive screening techniques. Plant breeding programs often have many thousands of experimental genotypes, which makes testing for each of these traits impractical. This work proposes that carbon isotope discrimination (∆) analysis of mature grains may serve as a relatively high-throughput approach to identify genotypes exhibiting traits associated with drought tolerance. Using ∆ as a proxy for stomatal conductance and photosynthetic capacity, assumptions can be made regarding fundamental plant physiological responses. When combined with knowledge of the terminal drought severity experienced in a particular environment, genotypes exhibiting conservative and rapid water use, deep roots, and reliance on stem reserve carbohydrates may be identified. Preliminary data in support of this idea are presented. Further verification of this use for grain ∆ will better equip wheat breeding programs to develop more drought tolerant varieties.

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