Evaluation of chlorophyll fluorescence as a tool for the identification of drought tolerance in upland cotton

Abstract

Chlorophyll Xuorescence (CF) is one tool used by researchers to quantify plant water status during periods of limited water availability. The research reported herein was designed to evaluate a CF-based protocol as a tool for use in cotton, Gossypium spp. breeding programs for the identiWcation of drought tolerant genotypes. Twenty genotypes were selected to represent diverse and distinct US germplasm pools. Replicated tests were performed in Lubbock and College Station, TX in 2006 and 2007. Dryland and irrigated treatments, as main plots, were applied in a randomized complete block design, split to genotypes. CF measurements were taken at mid-bloom and late bloom growth stages. Source leaf tissue was harvested at predawn and subjected to high temperature incubation with CF measurements subsequently taken hourly for 5 h. Drought stressed plants had not mobilized their carbohydrate reserves from their source leaves overnight and thus maintained cell viability and therefore higher CF values throughout the incubation and measurement period with the opposite being true for non-stressed plants. Fiber lint yield and Wber properties were measured for comparison with the CF data. Genotype £ treatment eVects complicated the classiWcation of genotypic response to drought. Few and inconsistent correlations were found among CF values and lint yield or Wber properties. Data suggested that this procedure provides little potential in selecting plants for drought tolerance when plants are grown under Weld culture.

Iron Deficiency Tolerance at Leaf Level in <i>Medicago ciliaris</i> Plants

“…In this study, the chlorophyll fluorescence parameter, which is related to the photosynthetic activity, well reflected the different tolerance to Fe deficiency in the two genotypes, suggesting that it could be usefully employed for rapid screening of iron deficiency tolerance in Medicago ciliaris. According to many authors, this parameter provides useful information about plant photosynthetic performance under abiotic stresses [27] [28]. Our data showed that the maximal potential photochemical efficiency of PSII under dark-adapted conditions (Fv/Fm) and the excitation-energy trapping capacity at the reaction centre of PSII (1/F 0 -1/F m ) were significantly affected by Fe deficiency treatment especially in the sensitive line TN8.7.…”

Abiotic Stress Tolerance in Cotton

“…In cotton seedlings, a number of lateral roots are produced, which depends on the xylem poles for water absorption [17]. The amount of vascular bundles increases due to the increase of branching intensities of lateral roots in the cotton crop [18]. In cotton, decreasing leaf transpiration by stomatal transpiration (TRst) and cuticular transpiration (TRcu) is the important physiological indicator of water stress [19].…”

Characterization of water-stress tolerant cotton cultivars based on plant growth and in activity of antioxidant enzymes

“…Figure 3 displays the graphical dispersion of cultivars. (Longenberger, 2008); 2: Represented by FMT 705 and FMT 701, both late cycle cultivars, developed for Cerrado region, with high technological input (Freire and Vidal Neto, 2013;Anselmo et al, 2009); and 3: represented only by CNPA 5M, a perennial type, with broad adaptation to dry environments (Souza and Silva, 1994). The relative contribution of traits to the genetic divergence was estimated based on S.j statistical (Singh, 1981).…”