photosynthetic active radiation [ PAR (400 to 700 nm)] at plant level. The plants were fertilized weekly with water-soluble 20.0N–4.4P–24.9K (Scotts, Marysville, OH) at 300 mg·L −1 nitrogen. Leaf cell membrane thermostability measurement for different
Ching-Hsueh Wang, Der-Ming Yeh and Chian-Shinn Sheu
Neil O. Anderson, Mi-kyoung Won and Dong-chan Kim
membrane thermostability and plant morphology in cowpea Crop Sci. 39 1762 1768 Karlsson, M.G. Heins, R.D. Erwin, J.E. Berghage, R.D. 1989 Development rate during four phases of chrysanthemum growth as determined by preceding and prevailing temperatures J
John M. Ruter
Membrane thermostability of `Needlepoint' Chinese holly (Ilex cornuta Lindl. & Paxt.), `Albo-marginata' English holly (Ilex aquifolium L.), and `Nellie R. Stevens', an Ilex aquifolium × Ilex cornuta hybrid, was determined by measuring electrolyte leakage in excised leaves and roots. The critical midpoint heat-killing temperature (T,) after a 30-min exposure was 54.4 ± 0.4C for `Nellie R. Stevens' leaves and was ≈ lC higher than that for Chinese (52.9 ± 0.3C) or English holly (52.9 ± 0.4C). The Tm for English holly roots (53.9 ±_ 1.5C) was higher than that for either `Nellie R. Stevens' (51.7 ± 0.3C) or Chinese holly (50.1 ± 0.3C). The results of this study suggest that English holly and `Nellie R. Stevens' leaves and roots can withstand direct heat injury equal to or greater than that of Chinese holly.
John M. Ruter
Membrane thermostability of Heritage river birch (Betula nigra L. Heritage) was measured by electrolyte leakage from excised roots of plants grown in pot-in-pot (PIP) and conventional aboveground production systems (CPS). The predicted critical midpoint temperature (Tm) for a 30-min exposure was 54.6 ± 0.2 °C for PIP and 56.2 ± 0.6 °C for CPS plants. Plants grown PIP had a steeper slope through the predicted Tm, suggesting a decreased tolerance to high root-zone temperatures in relation to plants grown aboveground. Since the root systems of Heritage river birch grown PIP are damaged at lower temperatures than plants grown aboveground, growers should prevent exposure of root systems to high temperatures during postproduction handling of plants grown PIP.
Magaji G. Usman, Mohd Y. Rafii, Mohd Razi Ismail, Mohammad Abdul Malek and Mohammad Abdul Latif
damage to plant function, affecting various physiological and metabolic processes in plants, and is detrimental in terms of growth and productivity ( Ahmed and Hassan, 2011 ; Hall, 2010 ). Cell membrane thermostability is a phenotypic parameter used in
Bandara Gajanayake, Brian W. Trader, K. Raja Reddy and Richard L. Harkess
germination (PG, %) and pollen tube length (PTL, μm), cell membrane thermostability (CMT, %), canopy temperature depression (CTD, °C), and chlorophyll stability index (CSI, %) of 12 ornamental pepper cultivars. Pollen viability was positively correlated ( r
Ockert Greyvenstein, Terri Starman, Brent Pemberton, Genhua Niu and David Byrne
has appeared more susceptible to high temperatures in field evaluations ( Table 1 ). Fig. 2. Chlorophyll fluorescence measured as the ratio of variable fluorescence ( F v ) over maximum fluorescence ( F m ) ( A ) and cell membrane thermostability
D.M. Yeh and H.F. Lin
Identification of heat-tolerant chrysanthemum [Dendranthema ×grandifolia (Ramat.) Kitamura] genotypes for commercial production in hot areas of the world is desirable. The extent to which electrolyte leakage from chrysanthemum leaf discs, measured using a test for cell membrane thermostability (CMT), could be related to the delay in flowering induced by heat in the field-grown plants was determined. The relationship between the relative injury (RI) occurring in leaf tissue discs of chrysanthemum cultivars and treatment temperature was sigmoidal. A single temperature treatment at 50 °C resulted in injury values near the midpoint of the sigmoidal response curve and showed the greatest sensitivity in detecting genotypic differences in heat tolerance. The cultivars with a low RI value are those with the greater CMT and shorter heat-induced delay to flowering.
Karl J. Sauter, David W. Davis and James S. Beaver
184 random F2 plants from a high temperature (HT) sensitive X HT tolerant snap bean cross were advanced to the F5 by single seed descent. At anthesis and after HT pre-treatment, all plants in each generation were evaluated in the laboratory for leaf ethylene evolution (EE), % viable pollen (VP), and leaf cell membrane thermostability (CMT). Population means among generations differed significantly for VP and CMT in a paired t-test, while EE means in the F3, F4, and F5 were similar. Correlations among traits were very low (≤.25) with a consistent negative correlation between VP and the others (high VP is a positive trait while low EE and CMT are considered positive). VP and total pollen were highly correlated (r≤.81). To determine if the 3 traits might predict HT tolerance in the field, F5-derived F6 lines were grown at Becker, MN (control), and Isabella, PR (HT environment). Yield component data were collected at both locations. Tolerance may be computed as % yield of the lines in the HT vs. the control environment for any or all of the yield components. Regression analysis showed a very low r2 (≤.16) when EE, VT, and CMT were used to predict tolerance as estimated by pod production. However, as expected, the F5 best predicted F6 performance. Further results from Minnesota field and greenhouse and from Puerto Rico field data will be discussed.
Wei-Ling Chen, Cheng-Hung Hsiao and Hsueh-Shih Lin
cell membrane thermostability (CMT) was measured according to the method by Yeh and Hsu (2004) . Two accessions, F 1 ‘Mascot’ (Known-You Seed Co. Ltd., Kaohsiung, Taiwan) and S 4 pure line 1993-11, were selected as female and male parents based on