Gas exchange, stable carbon and nitrogen isotopes and real-time PCR reveal genotypic differences in durum adaptation to drought and salinity
Material type:
TextPublication details: 2009Description: p. 157-158Summary: Durum wheat is the most cultivated crop in the south and east Mediterranean basin where drought is the main stress limiting productivity. One of the ways of increasing yield is irrigation. However, this may expose soils to progressive salinisation. Selecting genotypes more resistant to drought or with a higher salt tolerance are complementary ways of improving durum wheat adaptation in the Mediterranean. We compared growth, physiological response and gene expression of different durum wheat genotypes placed under diverse water and salinity conditions. Four recombinant inbred lines (RILs) derived by single seed descent from the cross ICD-MN91?0012 between Lahn and Cham 1 were selected based on their contrasting tolerance to grow under continuous salinity while showing quite similar biomass in absence of stress. Genotypes were grown in pots within a growth chamber for over one month. Treatments were imposed one week after germination. The combination of two water regimes (container capacity and 35%) and three salinity levels (Hoagland solution formulated with deionized water, 12 dS m-1 and 17 dS m-1 water, respectively) were assayed, accounting for a total of 5 different treatments (35% pot capacity and 17 dS m-1 water was not tested). Watering at 100% and 35% of container capacity with 17 dS m-1 and 12 dS m-1, respectively, were the most stressful treatments, diminishing biomass near 75% compared with stress-free plants. For each of the four stress treatments the two tolerant RILs showed consistently higher biomass, nitrogen concentration, photosynthesis, stomatal conductance, and stable carbon isotope discrimination and nitrogen isotope composition than the two susceptible RILs. In the other hand the transcript levels of specific genes reported for wheat to have a role in response to water stress (TaDREB1 A, TaDREB 2B) salinity (NHX) or involved in key steps of nitrogen metabolism (GS1, GS2) were quantified with real-time PCR based in SYBR green. Tolerant RILs did not show a consistent pattern of transcriptional response across treatments and candidate genes assayed.
| Item type | Current library | Collection | Call number | Status | Date due | Barcode | Item holds | |
|---|---|---|---|---|---|---|---|---|
| Conference proceedings | CIMMYT Knowledge Center: John Woolston Library | CIMMYT Staff Publications Collection | CIS-5781 (Browse shelf(Opens below)) | Available |
Poster Abstract
Durum wheat is the most cultivated crop in the south and east Mediterranean basin where drought is the main stress limiting productivity. One of the ways of increasing yield is irrigation. However, this may expose soils to progressive salinisation. Selecting genotypes more resistant to drought or with a higher salt tolerance are complementary ways of improving durum wheat adaptation in the Mediterranean. We compared growth, physiological response and gene expression of different durum wheat genotypes placed under diverse water and salinity conditions. Four recombinant inbred lines (RILs) derived by single seed descent from the cross ICD-MN91?0012 between Lahn and Cham 1 were selected based on their contrasting tolerance to grow under continuous salinity while showing quite similar biomass in absence of stress. Genotypes were grown in pots within a growth chamber for over one month. Treatments were imposed one week after germination. The combination of two water regimes (container capacity and 35%) and three salinity levels (Hoagland solution formulated with deionized water, 12 dS m-1 and 17 dS m-1 water, respectively) were assayed, accounting for a total of 5 different treatments (35% pot capacity and 17 dS m-1 water was not tested). Watering at 100% and 35% of container capacity with 17 dS m-1 and 12 dS m-1, respectively, were the most stressful treatments, diminishing biomass near 75% compared with stress-free plants. For each of the four stress treatments the two tolerant RILs showed consistently higher biomass, nitrogen concentration, photosynthesis, stomatal conductance, and stable carbon isotope discrimination and nitrogen isotope composition than the two susceptible RILs. In the other hand the transcript levels of specific genes reported for wheat to have a role in response to water stress (TaDREB1 A, TaDREB 2B) salinity (NHX) or involved in key steps of nitrogen metabolism (GS1, GS2) were quantified with real-time PCR based in SYBR green. Tolerant RILs did not show a consistent pattern of transcriptional response across treatments and candidate genes assayed.
English
Lucia Segura
CIMMYT Staff Publications Collection