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

Abstract

Cenchrus (family Poaceae) is an important component of major grass covers of the world. Largely it is apomictic and both annual and perennial species exist in nature. Variations in contents of malondialdehyde, proline, specific leaf area and carbon isotope discrimination for drought tolerance were estimated among eight prominent species of Cenchrus. Simultaneously, genetic variations were also estimated by employing 187 RAPD primers. Of these, 23 primers did not react, 2 performed poorly and 7 produced many non-scorable bands and one primer yielded a single monomorphic band. Rest of the 154 primers generated one or more unambiguously scorable fragments. Twelve hundred and four of the 1,296 putative loci were polymorphic (93%) between at least one pair-wise comparisons among eight species. Dice coefficient and neighbor-joining algorithm analyses showed clustering patterns that fit with the known habitat of the species except perennial, C. myosuroides which formed a node between two annuals species. When these species were subjected to water stress tolerance test, a correlation (r = 0.612) between specific leaf area (SLA) and carbon isotope discrimination (CID) and difference in levels of drought tolerance based parameters among eight species were observed. Of the eight species investigated two annuals viz., C. biflorus and C. echinatus showed highest level of genetic similarity which was also evident from the similar levels of SLA, MDA, proline contents and carbon isotope discrimination values observed in these two species.

Interspecific hybrids between Chrysanthemum grandiflorum (Ramat.) Kitamura and C. indicum (L.) Des Moul. and their drought tolerance evaluation

“…EL and MDA are generally regarded as two indicators of the level of plant membrane damage under drought stress (Bai et al 2006;Chandra and Dubey 2008). In the present study, EL value and MDA content of leaves were almost higher in C. grandiflorum 'Yuhuaxingchen' than in the six hybrid lines under the same PEG treatment.…”

“…Drought stress can cause membrane injury and the extent of membrane damage is often used to measure plant drought tolerance (Chandra and Dubey 2008;Moussa and Abdel-Aziz 2008;Liu et al 2009). EL and MDA are generally regarded as two indicators of the level of plant membrane damage under drought stress (Bai et al 2006;Chandra and Dubey 2008).…”

Tradeoffs between nitrogen- and water-use efficiency in dominant species of the semiarid steppe of Inner Mongolia

“…Thus, leaf N mass and N area both correlated negatively with Δ in studies of wheat exposed to drought and nitrogen stress (Cabrera-Bosquet et al 2009). Others observed a strong effect of SLA on Δ of grass species (Chandra and Dubey 2008) and peanut (Nageswara Wright et al 1994) subjected to drought. This effect may be related to an increased internal resistance to CO 2 transport in thick leaves (Evans et al 2009;Kogami et al 2001).…”

Physiological and biochemical traits of drought tolerance inArgania spinosa

“…When the generation of ROS is excessive under drought conditions and exceeds the scavenger capacity of the antioxidant system, they cause important oxidative damage to membrane lipids (Smirnoff 1993). This damage is quantified by variation in the malonyldialdehyde (MDA) level which essentially reflects lipid peroxidation (Chandra &Dubey 2008;. Lipoxygenases (LOX,EC 1.13.11.12) catalyse the dioxygenation of polyunsaturated fatty acids, generating hydroperoxy fatty acids which are highly reactive to initiate cell damage (Feussner & Kindl 1994;Ye et al 2000).…”