evaluated as cell membrane stability of leaves, which was determined by measuring electrolyte leakage (EL) ( Blum and Ebercon, 1981 ). For EL analysis, 0.2 g of fresh leaves was placed in test tubes containing 20 mL deionized water and then shaken for 24 h
Jingjin Yu, Hongmei Du, Ming Xu and Bingru Huang
Mario Valenzuela-Vázquez, Geno A. Picchioni, Leigh W. Murray and Wayne A. Mackay
, electrolyte leakage, and vase life longevity. We held racemes in vase solutions with or without ethephon [(2, chloroethyl) phosphonic acid, or CEPA] to investigate the ability of 1-MCP to counteract the influence of an exogenous ethylene source (ethylene
Lixin Xu, Liebao Han and Bingru Huang
drought stress and rewatering were evaluated by measuring turf quality (TQ), leaf relative water content, F v /F m , and cellular membrane stability expressed as electrolyte leakage (EL). Measurements were taken at various time points after the initiation
Abdul Hakim and Irma Voipio
Mature green tomatoes (Lycopersicon esculentum Mill. cv. Vibelco) were immersed in 38, 42, 46, 50, and 54C for 90 min prior to storage at 2C for 2, 4, or 6 weeks in paper bags. After storage, they were kept at 20C. Fruits immersed in heated water showed lower ethylene production, rate of respiration, electrolyte leakage, and visible chilling injury than nontreated fruits. During storage and after removal at 20C, hot-water-treated fruits ripened faster than nontreated fruits The increase in water temperature from 38 to 46C resulted in declined ethylene production, rate of respiration, electrolyte leakage, and visible chilling injury, but, with further increase in water temperature (46 to 54C), they increased. Of all the pretreatments, the treatment at 42 or 46C were most effective in enhancing fruit color changes. Inhibition in ethylene production, rate of respiration, electrolyte leakage, and visible chilling injury was highest on fruits immersed at 42 and 46C.
Feifei Li, Da Zhan, Lixin Xu, Liebao Han and Xunzhong Zhang
difference in EL between the two cultivars was found at normal temperature conditions. Fig. 1. Changes in leaf electrolyte leakage [EL ( A )] and malondialdehyde (MDA) content ( B ) of two kentucky bluegrass cultivars during heat stress. Bars on the top
Lili Zhuang, Mengxian Liu, Xiuyun Yuan, Zhimin Yang and Bingru Huang
) of WT and transgenic plants under normal and drought conditions. ( B ) Electrolyte leakage (EL) in WT and transgenic plants under normal and drought conditions. Different letters atop bars indicate significant differences ( P ≤ 0.05) between WT and
Yingmei Ma and Emily Merewitz
. Percent electrolyte leakage of leaves in ( C ) Expt. 1 and ( D ) Expt. 2. Treatment means were separated using Fisher’s least significant difference (n = 4) ( P ≤ 0.05), which is represented by the vertical bar. Rating was from 1 = poor to 9 = excellent
Frank B. Matta, Gena R. Silva and James M. Spiers
Cold acclimation of `Tifblue' rabbiteye blueberry was determined using differential thermal analysis (DTA). Electrolyte leakage and tissue browning test results were correlated with DTA. DTA showed that three exotherms occurred: exotherm 1 (ET) associated with extracellular freezing, exotherm 2 (CT) associated with tissue injury, and exotherm 3 (LTE) not associated with tissue injury. Maximum hardiness (–20C) occurred in January. The LT50 measured by electrolyte leakage and tissue browning was about –17C and –15C, respectively. Acclimation began in November and deacclimation in mid-Feb. 1994.
Abha Upadhyaya, Tim D. Davis and Narendra Sankhla
Moth bean (Vigna aconitifolia Jacqu. Marecbal cv. Jaadia) seeds were germinated in 0, 0.1, 1, or 2 μm EBL. After 72 hours, seedlings were exposed to 22 or 48C for 90 minutes. At 48C, EBL increased total electrolyte, K+, and sugar leakage from the seedlings relative to the control. Following exposure to 48C, EBGtreated seedlings bad higher malondialdebyde concentrations than controls, indicating that EBL enhanced high-temperature-induced lipid peroxidation. At 48C, EBL increased ascorbic acid oxidase activity but decreased superoxide dismutase activity relative to the control. Taken collectively, these data do not support a hypothesis that brassinosteroids confer beat shock tolerance to moth bean. Chemical name used: 24-epibrassinolide (EBL).
Stephen J. Colombo
Black spruce [Picea mariana (Mill) B. S. P.] first-year seedlings were exposed to 8-hr photoperiods and warm temperatures (26C maximum, 15C minimum) and tested weekly to determine bud dormancy status, frost hardiness, shoot moisture content, and the amount of damage caused. by a period of frozen storage (- 3C). Bud dormancy status, frost hardiness, and shoot moisture content were all strongly correlated to the time of bud initiation. Frost hardiness was low (- 5 to - 7.5C) during the period of needle primordia initiation until week 3 (3 weeks after 100% bud initiation), but bud dormancy decreased linearly over this period, from 37 days to budbreak for seedlings sampled at week - 1 (1 week before 100% of the seedlings had initiated terminal buds) and placed under conditions favoring shoot elongation, to 14 days to budbreak for seedlings sampled on week 3. From week 5 to week 8, there was a strong (r2 > 0.999) linear correlation between frost hardiness and bud dormancy status. Shoot moisture content declined linearly from 84% on week - 1 to 74% on week 8 (r2 = 0.97), and shoot moisture content was correlated with both frost hardiness (r2 = 0.87) and the percentage of seedlings that suffered needle damage in frozen storage (r2 = 0.85). Bud dormancy status, measured as number of days to 50% budbreak, was curvilinearly correlated with seedling damage following frozen storage, whereas linear relationships with damage in storage were found for dormancy release index (r2 = 0.92) and frost hardiness (r2 = 0.85).