Relationships between relative water content and growth parameters under water stress in barley: a QTL study

Abstract

SUMMARYDrought strongly affects cereal yield in several regions of the world. Plant growth and plant water status in response to soil water deficit play an important role in tolerance to drought and in yield stability. In order to investigate the relationship between plant growth and w^ater relations, 187 barley {Hordeum vulgare L.) recombinant inbred lines from a cross between two Mediterranean varieties, Tadmor and Fr/Apm, were studied in a growth chamber for RWC , number of leaves on the main tiller (NL), number of tillers (NT) and total shoot fresh and dry biomass (TSFM and TSDM). Measurements were made at the beginning of tillering on well watered plants and at a soil moisture content of 14% of field capacity. A negative phenotypic correlation between RWC and growth parameters was obtained in both treatments. Under water stress, a negative genetic correlation was also found between the same characters. QTLs involved in RWC, NL and TSFM variation were positioned on a RFLP-RAPD genetic map. Different DNA regions involved in constitutive and water stress responses were detected. In the stress treatment, one region on chromosome 1 was involved in RWC and NL variation giving a genetic basis to the phenotypic correlations found. Separated map positions were also found for RWC and NL. Epistatic interactions between several QTLs and between QTLs and other markers were detected only in the water stress treatment, suggesting that some chromosomal regions might be involved in the regulation of the expression of the traits under water stress. This work suggested that even if some parameters are strongly correlated, finding QTLs for only one trait is not sufficient to detect all the candidate regions which might be involved in the control of the correlated traits. The results of localization and co-localization of QTLs are physiologically interpreted.

Physiological and biochemical traits of drought tolerance inArgania spinosa

“…There are some interesting differences in leaf RWC between ecotypes with different watering regimes. Leaf RWC is an important indicator that enables to evaluate physiologically the plant water status (Teulat et al 1997;Farouk & Abdul Qados 2013). It can control the plant response to drought stress considering as an indicator of plant resource use (Garnier et al 2001).…”

The Edaphic Factor in the Origin of Plant Species

“…In fact, the genetic basis for many of the traits discussed above-salt tolerance (Hurkman, 1992;Taeb et al, 1992;Quesada et al, 2002), drought tolerance (Teulat et al, 1997;Haake et al, 2002;Hsieh et al, 2002), copper tolerance (Macnair, 1983;Fogel et al, 1988), and flowering-time differences (Law and Worland, 1997;McKay et al, 2003)-have already been investigated in wild or model plant species such as Arabidopsis thaliana and cereal crops or in yeast, and it will only be a matter of time before investigators apply this knowledge to their research species. Further, the genetic architecture of serpentinite tolerance is now being investigated by several groups (Bradshaw, Schemske, and colleagues;Bratteler et al, 2002) and will no doubt soon provide a much persuasive picture of the role of the edaphic factor in the diversification of plant lineages.…”

Genetic Analysis of Relative Water Content (RWC) in Two Recombinant Inbred Line Populations of Soybean [Glycine max (L.) Merr.].

“…Mapping QTL for agronomic traits including traits involved in drought tolerance such as water use efficiency (WUE), RWC, and root traits have been identified and mapped in wheat (Dhanda and Sethi, 1998), barley (Teulat et al, 1997(Teulat et al, , 2003, sunflower (Kiani et al, 2007), corn (Frova et al, 1999), soybean (SoyBase, 2011), and many other crop species. However, the genes controlling these traits and many others are still widely unknown (Keurentjes et al, 2008).…”