High Night Research Articles

Effects of day-length and temperature on floral structure and fertility restoration in a season-dependent male-sterile Solanum villosum Mill. mutant

Solanum villosum is an important African leafy vegetable whose yield is limited mainly by competition from early and excess fruit-set. Induced male-sterility is a potential tool to reduce this competition and enhance yields. This study was conducted to investigate the influence of photoperiod and temperature on the floral dynamics of a season-dependent male-sterile mutant. The mutant, named T-5, has flowers which are sepaloid, mostly stamenless, indeterminate and partially restored in winter, late-spring, summer and autumn, respectively. Floral organ restoration was found to be largely independent of photoperiod conditions. Day/night temperatures of 25/25 and 30/20°C were found to favour restoration of the floral organ but most flowers were stamenless and infertile. High night temperature favoured the formation of indeterminate flowers both in the growth chamber (30°C) and in the greenhouse (>25°C). On the other hand, low growth chamber (10°C) and greenhouse (<15°C) night temperature favoured the formation of sepaloid flowers. The optimum temperatures for floral structure and fertility restoration were between 20°C and 25°C (day) and 15–20°C (night). Propagation of T-5 mutant can thus be achieved by growing in regions or seasons with such temperature ranges. Under temperatures unfavourable for fruit-set, leaf productivity is expected to be high.

Weather conditions associated with the potential for pollen recirculation in a coastal area

AbstractThis study aims to characterise the main synoptic field patterns associated with the potential for recirculation of pollen. A recirculation index (R) was calculated in the area of Mar del Plata, Argentina. The daily development of sea–land breeze and the related monthly frequencies of wind directions were studied. The sea breeze was present for 36.2% of the time, with a mean lifetime of about 2 h in winter and 15–20 h in summer. Recirculation of the air had an annual frequency of around 7%, with a net transport from the city outskirts towards the sea, for 39.4% of the year, and a net inland transport frequency of 38.4%. The Rotated Principal Component Analysis (PCA) was applied to obtain synoptic field patterns associated with potential conditions for recirculation in the area. It was shown that low‐pressure systems or troughs between 45° and 60°S (i.e. over the country, the South Pacific and/or the South Atlantic and two anticyclones located in the Atlantic or South Pacific Oceans) are the most common weather conditions associated with air recirculation in the coastal area of Buenos Aires province. A case study with high night pollen concentrations was also analysed. Copyright © 2007 Royal Meteorological Society

Partial Fertility Restoration as Affected by Night Temperature in a Season-dependent Male-sterile Mutant Tomato, Lycopersicon esculentum Mill.

This study was conducted to investigate the influence of night temperature on the restoration of fertility in a season-dependent male-sterile tomato mutant (T-4). Plants were grown in greenhouses, in which minimum and maximum temperatures were set at 10℃ and 28℃ by heating and ventilation, respectively. Flowers were hand-pollinated and the fruit-set, seed-set, and number of seeds were examined. The rate of fruit-set was high and did not differ much from October to February; almost all fruits formed in October had self-fertile seeds, but 80% of the fruits from November to February were parthenocarpic. The rate of fruit-set dropped from 70% in March to below 10% in May. During this period, most of the fruits were seeded, though fruit-set was low. The number of seeds per seeded fruit varied with the season, being as high as 50 seeds in October, 1-2 seeds per fruit between November and March, and 1-20 seeds per fruit between April and June. A low night temperature of 12℃ did not affect fruit-set but resulted in a better seed-set than a high night temperature of 18℃ in the greenhouse. Further, pollination of the plants in phytochambers also resulted in a better fruit- and seed-set at 12℃ than 24℃. In all cases, the influence of low temperature was more pronounced in autumn than in spring. Fruit-set was 70% at 12℃ and 46% at 24℃. Of these fruits, 50% at 12℃ and 10% at 24℃ were seeded. It was inferred that partial fertility restoration in T-4 can be achieved by manipulation of night temperatures. The female organ was shown to be normal, functional, and compatible with wild-type pollen. From these results, the potential of the male-sterile T-4 mutant for use in a two line hybrid-seed production system was apparent.

Influence of sympathectomy in humans on the rhythmicity of 6-sulphatoxymelatonin urinary excretion

The amount of 6-sulphatoxymelatonin, the chief metabolite of melatonin, in the urine was measured in nine patients, who were subjected to bilateral sympathectomy at the second thoracic ganglionic level for treatment of hyperhidrosis of the palms. All patients showed before surgery a normal 6-sulphatoxymelatonin excretion with a peak in the excretion during the night time. After the sympathectomy, the high night time excretion was clearly abolished in five patients but remained high in four patients. This indicates that the segmental locations of the preganglionic sympathetic perikarya in the spinal cord, stimulating the melatonin secretion in the pineal gland in humans, vary between individuals. An increase in daytime melatonin excretion was observed in the patients responding to the sympathectomy with an abolished 6-sulphatoxymelatonin rhythm. This increase could indicate that the final sympathetic neurons innervating the pineal gland might have a both stimulatory and inhibitory function.

Impact of renin angiotensin system blockade on night to day blood pressure ratio in diabetic nephropathy

Sir, Elevated systemic blood pressure is a risk factor for progression of diabetic nephropathy. Ambulatory blood pressure measurements offer additional risk stratification compared to office blood pressure in patients with hypertension [1]. In addition, an abnormal diurnal blood pressure pattern characterized by an elevated night to day ratio is found more commonly in diabetic patients and, as reviewed by Miller et al. [2], is associated with poor renal outcome. The renin angiotensin system (RAS) is involved in both initiation and progression of diabetic nephropathy and blocking this system with ACE-inhibitors (ACE-I) and/or angiotensin II receptor blockers (ARBs) improves kidney survival and prognosis. Miller et al. [2] reported that treatment with enalapril (0.1 mg/kg BID) corrects the abnormally high night to day blood pressure ratio found in 10 uncomplicated adolescents, and this could contribute to the beneficial renoprotective effects of RAS blockade. In this letter, we further investigate whether RAS blockade corrects an abnormal 24 h blood pressure pattern by presenting data on the short-term effects of single and dual blockade of the RAS on a 24 h blood pressure profile and a night to day blood pressure ratio in type 1 diabetic patients with diabetic nephropathy. Our data are a post-hoc analysis of three earlier studies [3–5]. As described previously [3], we performed a randomized, double blind, cross-over trial, in which 18 patients received 8 weeks of placebo, benazepril 20 mg once daily, valsartan 80 mg once daily and a combination of benazepril 20 mg and valsartan 80 mg once daily in random order [3]. The main findings were: (1) mono-therapy with ACE-I or ARBs treatment was equally effective with regard to antialbuminuric and antihypertensive effects; (2) dual blockade of the RAS caused a further reduction in albuminuria of 43% and 7/6 mmHg in 24 h blood pressure compared with both mono-therapies; (3) night to day ratio of 24 h blood pressure on each treatment is shown in Table 1. A post-hoc power calculation estimated a power in each study of � 0.80 to detect a difference of 0.05 in night to day ratio with a significance level of 0.05. In agreement, when looking at the fraction of patients with night to day blood pressure ratio above the median on placebo treatment (>0.91), we found no changes in the night to day ratio on RAS blockade. Furthermore, in two other studies demonstrating that dual blockade of the RAS

Effects of High Night Temperature on Crassulacean Acid Metabolism (CAM) Photosynthesis of Kalanchoë pinnata and Ananas comosus

The effects of the night temperature on CO2 exchange rate and organic acid accumulation in the leaves of two crassulacean acid metabolism (CAM) plants, Kalanchoë pinnata and Ananas comosus (pineapple), were examined under a fixed day-temperature condition of 30°C. With the increase of the night temperature, the CO2 exchange rate decreased in both species, and K. pinnata completely lost nocturnal CO2 uptake under a high night temperature (30/37°C in day/night) condition (HNT). Malate accumulation in the leaves of pineapple and K. pinnata in the morning decreased with increasing night temperature, but that in the afternoon was not influenced by the night temperature. Diurnal changes of ten kinds of metabolites were investigated under HNT. Pineapple accumulated a large amount of nocturnal malate under HNT, but K. pinnata did not. Four kinds of hexose-phosphate (hexose-P) were accumulated at the same levels during the day/night cycle under HNT in both plant species. Nocturnal accumulation of oxaloacetate (OAA) was observed but phosphoenolpyruvate (PEP) was kept at a high level both in day and night under HNT in both plant species. The concentrations of malate required for 50% inhibition of the activities of day and night forms of PEP carboxylase (PEPC) from the pineapple leaves were 1.2 and 0.7 mM, respectively, whereas those from the K. pinata leaves were 3.7 and 2.0 mM, respectively. In both plants, NAD-MDH activity in vitro increased with increasing temperature. It is therefore suggested that under HNT, phosphorylation may not be the major factor controlling PEPC activity in pineapple, and therefore CAM mode in pineapple was maintained under HNT. The nighttime phosphorylation of PEPC in K. pinnata would disappear under HNT leading to the loss of nocturnal malate accumulation.

Rice Milling Quality, Grain Dimensions, and Starch Branching as Affected by High Night Temperatures

ABSTRACTImportant rice grain quality characteristics such as percentage of chalky rice kernels are affected by both high and low night temperatures and by different day and day/night temperature combinations. High nighttime temperatures have also been suspected of reducing rice milling quality including head rice yields. Experiments to confirm or refute this have not been reported. A controlled climate experiment was conducted. Conditions in the chambers were identical except between 2400 and 0500 hours (midnight and 5 am). For those times, two temperature treatments were imposed: 1) 18°C (low temperature treatment) and 2) 24°C (high temperature treatment). Two cultivars were tested: LaGrue and Cypress. The high temperature treatment reduced head rice yields compared with the low temperature treatment. Grain widths were reduced for the high temperature treatment compared with the low temperature treatment. There was no effect of temperature on grain length or thickness. Amylopectin chain lengths 13–24 were increased by the high temperature treatment by ≈1%. Future research will focus on determining whether genetic variability exists among cultivars in their head rice yield response to high temperatures. After identifying a source of resistance to high temperature effects, this characteristic can be incorporated into rice cultivars. In addition, ways to reduce this effect, including biotechnological remedies, have the potential for increasing rice yield and quality.

Decreased anthocyanin biosynthesis in grape berries grown under elevated night temperature condition

In grape cultivation, high night temperature generally reduces anthocyanin accumulation in berry skin. To clarify the regulatory mechanism of anthocyanin biosynthesis under the conditions of high night temperatures, we examined flavonoid accumulation, the activities of related enzymes and gene expression in the anthocyanin biosynthetic pathway in grape berries grown under cool and warm night conditions. Anthocyanin accumulation in the skin of berries grown at high night temperatures (30 °C continuous) was reduced as compared to that of berries grown at low night temperatures (30 °C in daytime/15 °C in night time). On the other hand, flavonol levels in the skin of berries were not significantly different between low and high night temperature conditions. High night temperatures also inhibited the gene expression of chalcone synthase ( CHS), flavanone 3-hydroxylase ( F3H), dihydroflavonol 4-reductase ( DFR), leucoanthocyanidin dioxygenase ( LDOX) and UDP-glucose: flavonoid 3-O-glucosyltransferase ( UFGT) at veraison and an increase in UFGT activity after veraison. These results suggest that the inhibition of anthocyanin biosynthesis in grape berries grown under high night temperature condition could be caused by lower expression levels of anthocyanin biosynthetic genes at an early stage of ripening and lower activities of anthocyanin biosynthetic enzymes, particularly UFGT.

Effects of water stress and nocturnal temperature on carbon allocation in the perennial grass, Leymus chinensis

Water deficit and high temperature often occur simultaneously, but their effects on plants are usually investigated separately. The aim of this study was to test how interactions between water stress and nocturnal warming affect carbon allocation in the perennial grass, Leymus chinensis. Plant biomass, dry mass allocation, 14C partitioning and carbon isotope composition (δ13C) were measured. Severe and extreme water stress during nocturnal warming decreased the allocation of dry mass and 14C partitioning below ground to the roots, but moderate water stress significantly increased the below‐ground allocation of dry mass and 14C, especially at the lower night temperature. The δ13C values were more positive at day/night temperatures of 30/20°C than at 30/25°C, and greater in the roots than in the leaves. By plotting the δ13C values of the leaves against the δ13C values of the roots, the slopes of regressions were steeper at low than at high night temperature, also indicating that nocturnal warming reduces carbon allocation below ground to the roots. The results suggest that nocturnal warming may weaken acclimation during water stress in this species by regulating carbon allocation between source and sink organs.

Effects of water stress and high nocturnal temperature on photosynthesis and nitrogen level of a perennial grass Leymus chinensis

Water deficit and high temperature are important environmental factors restricting plant growth and photosynthesis. The two stresses often occur simultaneously, but their interactions on photosynthesis and nitrogen level have been less studied. In the present experiment, we measured photosynthetic parameters, stomatal density, and nitrogen levels, as well as soluble sugar content of leaves of a perennial grass, Leymus chinensis, experiencing two day/night temperature regimes of 30/20 °C and 30/25 °C, and five different soil moisture contents (the soil relative-water content ranged from 80% to 25%). Leaf relative water content, leaf biomass, whole plant biomass, the ratio between the leaf biomass and total plant biomass, and the photosynthetic rate, as well as water-use efficiency decreased at high night temperature, especially under severe water stress conditions. Stomatal index was also increased by soil water stress except very severe water stress, and high nocturnal temperature decreased the leaf stomatal index under soil water stress. Nocturnal warming decreased nitrogen concentration in the leaves and increased it in the roots, particularly when plants were subjected to severe water stress. There were significant positive correlations between the photosynthetic rate and both soluble sugar concentration and nitrogen concentration at low nocturnal temperature. It is suggested that nocturnal warming significantly exacerbates the adverse effects of soil water stress, and their synergistic interactions might reduce the plant productivity and constrain its distribution in the region dominated by L. chinensis, based on predictions of global climate change.

Grain Growth and Endosperm Cell Size Under High Night Temperatures in Rice (Oryza sativa L.)

High night temperatures are more harmful to grain weight in rice than high day temperatures. Grain growth rate and growth duration were investigated to determine which was the cause of the decrease in final grain weight under high night temperatures. Endosperm cell number and cell sizes were also examined to determine which might cause the decrease in final grain weight. Rice plants were grown outdoors in plastic pots and moved at heading time to three temperature-controlled glasshouses under high night temperature (HNT; 22/34 degrees C), high day temperature (HDT; 34/22 degrees C) and control conditions (CONT; 22/22 degrees C). Grains were sampled periodically, and the time-course of grain growth was divided into rate and duration by logistic regression analysis. Endosperm cell numbers and cell sizes were analysed by digitalized hand-tracing images of endosperm cross-sections. The duration of grain growth was reduced by high temperature both day and night. However, the rate of grain growth was lower in HNT than in HDT. The number of cells in endosperm cross-sections in HNT was similar to that in HDT, and higher than that in CONT. The average cell area was smaller in HNT than in either CONT or HDT. The differences in average cell areas between HNT and HDT were greater at distances 60-80 % from the central point of endosperm towards the endosperm surface. The results show that HNT compared with HDT reduced the final grain weight by a reduction in grain growth rate in the early or middle stages of grain filling, and also reduced cell size midway between the central point and the surface of endosperm.

Lichen carbon gain under tropical conditions: water relations and CO2 exchange of Lobariaceae species of a lower montane rainforest in Panama

Diel (24-h) time courses of microclimate, water relations, and CO2 exchange were measured under quasi-natural conditions at a forest edge in a lower montane, tropical rainforest in Panama for six Lobariaceae (Lobaria crenulata, L. dissecta, Pseudocyphellaria aurata, P. intricata, Sticta sublimbata, S. weigelii). Responses to experimentally controlled water content (WC), photosynthetic photon fluence rate (PPFR), and temperature were studied in most detail with P. aurata.Photosynthesis was well adapted to high temperatures, and all species exhibited ‘shade plant’ characteristics with low light compensation points and low light saturation. Lobaria and Pseudocyphellaria species suffered from a strong depression of net photosynthesis (NP) at suprasaturating WC; suprasaturation depression was less in cyphellate Sticta species.Photosynthetic capacity correlated with thallus nitrogen concentration, and maximal NP rates of the cyanobacterial Sticta species was 4 to 5 times higher than that of the green algal Lobaria species. However, high rates of NP were uncommon and brief events under natural conditions; the different environmental factors were rarely optimal simultaneously. Similar to earlier observations with other rainforest lichens, NP ceased during the period of highest irradiation on most days due to desiccation. During moist periods low light often limited carbon fixation, and high thallus hydration was often detrimental to NP. In spite of these limitations the maximal daily integrated net photosynthetic carbon income (ΣNP) was quite high especially for the Sticta species [17·3 and 24·1 mgC (gC)−1 day−1 for S. sublimbata and S. weigelii, respectively]. High nocturnal carbon loss, due to high night temperatures and continuous hydration, resulted in frequent negative diel carbon balances (ΣC) in all species. The average nocturnal carbon loss amounted to 83 and 70% ΣNP for P. aurata and P. intricata, respectively and to 64 and 59% of ΣNP for S. sublimbata and S. weigelii, respectively. Their average diel ΣC was as high as 3·7 and 5·3 mgC (gC)−1 day−1. In contrast, ΣC was much lower for the other species, it amounted to only 0·18 mgC (gC)−1 day−1 for L. crenulata. Thus, the Sticta species stood out amongst the species studied for their most successful adaptation of photosynthetic productivity to the habitat conditions in the lower montane rainforest.

Actigraphy in patients with depression and schizophrenia concerning activity levels, sleep estimation and circadian rhythm

Disturbances of the rest-activity rhythm and sleep are frequent in psychiatric patients. A quantitative method for measuring both is provided by actigraphy. Six inpatients, four with major depression and two with schizophrenia were included. All patients underwent 72-h actigraphic monitoring and were evaluated by a number of psychiatric rating scales. The same procedure was repeated after four weeks of treatment for the severely depressed patients. Schizophrenic patients showed the highest night activity and the lowest day/night activity ratio with irregular activity levels during the day and more active phases also at night. Slightly depressed patients had higher day activity levels and a higher day/night activity ratio than the severely depressed (SD). After four weeks of treatment, the SD showed a increased day/night activity ratio suggesting a normalisation of circadian rhythm. Therefore, actigraphy seems to be a useful and easily applicable method to measure rest-activity rhythm disturbances in depressive and schizophrenic patients.

Effect of night salinity level on water use, physiological responses, yield and quality of tomato

SummaryThe aim of the research work was to evaluate the effects of two levels of electrical conductivity (EC) of the nutrient solution, i.e. high night and low day EC v continuously low EC, on water consumption, physiological responses, yield, and fruit quality of two tomato cultivars (Diana and Naomi). The use of a nutrient solution with high EC during the night (6.dS m±1) did not modify plant growth. The daily water consumption of tomato plants was not modi®ed by the nutrient solution EC, however water consumption during the night was on average 9±19% of the total daily uptake. Both at the second cluster setting stage and beginning of harvests, the high night and low day EC treatment decreased stomatal conductance (13%) and leaf net CO2 assimilation (8%). The values of `Diana' and `Naomi' of yield of tomato (4.5 and 3.0.kg plant±1, respectively, for `Diana' and `Naomi') or mass of fruits, fruit dry mass, titratable acidity, and ascorbic acid were not in¯uenced by the nutrient solution EC. However, in the cherry tomato type (`Naomi') the number of fruits within optimal size values (<40.mm), which is of crucial importance for their marketability, was higher with high EC in the night hours. The total soluble solids were higher with low/high (day/ night) EC than continuously low EC (7.0 v 6.6 8Brix for `Naomi' and 4.6 v 4.3 for `Diana'), so nutrient solutions with high night and low day EC appear to improve the quality of fruits of soilless grown tomato plants without affecting fruit yield.

Comparison of selection for either leaf-electrolyte-leakage or pod set in enhancing heat tolerance and grain yield of cowpea

Cowpea is a warm-season adapted grain legume, however, moderately high night temperatures reduce pod set of most cultivars. Breeding for heat resistance, i.e. enhanced grain production under hot field conditions, has been achieved by selecting for reproductive-stage heat tolerance. This selection is not efficient because heritability of heat tolerance during pod set is low. We tested whether selection for slow leaf-electrolyte-leakage under heat stress may be useful in breeding heat-resistant cowpea cultivars. Reciprocal crosses were made between a heat-sensitive cultivar and a breeding line that has greater pod set and slower leaf-electrolyte-leakage in hot conditions and similar genetic background. Divergent selection for leaf-electrolyte-leakage under heat stress was imposed on 120 F 2 plants and again in the F 3 generation. Lines were advanced two generations by single-seed descent, producing 16 lines with slow and 16 lines with fast leaf-electrolyte-leakage. Another population was selected out of 600 F 2 plants based on either abundant flower production and pod set or minimal flower production in a very hot, long-day field environment. Lines were advanced three generations by single-seed descent, producing 66 lines selected for heat tolerance during reproductive development and 40 heat-sensitive lines. The two populations were evaluated in F 6 and F 7 generations in three hot environments and a moderate-temperature environment. Selected F 8 lines were evaluated in a very hot field environment. Leaf-electrolyte-leakage had low to intermediate realized heritabilities indicating selection can be effective but will require several cycles to identify lines with leaf-electrolyte-leakage as slow as the slow parent. Slow leaf-electrolyte-leakage selections had high pod set, and high pod-set selections had slow leaf-electrolyte-leakage indicating that these traits are closely associated. Strong negative genetic correlations were observed between leaf-electrolyte-leakage and pod set in hot long-day environments. Both selection schemes enhanced pod set, harvest index and grain yield in hot long-day environments but not in a hot short-day glasshouse or a moderate-temperature long-day field environment. Leaf-electrolyte-leakage measured in three contrasting environments was negatively correlated with grain yield of cowpea grown in a very hot field environment. Under very hot conditions, grain yield was positively correlated with pod production, pod set and harvest index, and negatively correlated with vegetative shoot dry weight and plant height. Heat-resistant cowpea cultivars may be more efficiently bred by combining selection for slow leaf-electrolyte-leakage under heat stress in the fall and winter, using plants grown in moderate-temperature glasshouses, with selection for abundant flower production and pod set in the summer, using plants grown under very hot long-day conditions.

Growth and Physiological Response of Creeping Bentgrass To Elevated Night Temperature

Growth of cool-season grasses declines with increasing temperatures. The objective of this study was to determine the effects of elevated night temperature on turf quality, root mortality, and carbohydrate metabolism in creeping bentgrass (Agrostis stoloniferous L. var. palustris (Huds.) Farw (syn. A. palustris Huds.). Plants of `Penncross' were exposed to two night temperature regimes: 24 °C (higher night temperature); and 19 °C (lower temperature control) under the same day temperature (24 °C) in growth chambers for 45 days. Prolonged exposure of plants to higher night temperature reduced turf quality, canopy photosynthetic rate, whole-plant and root respiration rates during the day, translocation of newly fixed 14C assimilate to roots, and total nonstructural carbohydrate content in shoots and roots (including dead and live roots). Elevated night temperature increased root mortality and whole-plant and root respiration rates at night. Our results indicated that a decline in turf quality and increase in root dieback with high night temperature was mainly associated with increased night respiration rates of whole plant and roots and reduced carbohydrate availability.

Renin, Angiotensin, Sodium and Organ Damage

Angiotensin II and sodium balance affect the status of each other and both--either separately or together--can lead to an increase in blood pressure. They also can cause vascular and cardiac damage due to direct effects and effects mediated by the blood pressure increase. This paper reviews the important interactions among these three variables. Acute blood pressure elevation during sleeping but not during waking hours causes cardiac hypertrophy in rats. Similarly, lowering of blood pressure with an angiotension converting enzyme (ACE) inhibitor during sleep but not when awake causes regression of cardiac hypertrophy in rats with 2kidney (K)-1clip (C) Goldblatt hypertension. If angiotensin is given to rats on a low (0.4%) NaCl diet, blood pressure rises but there is less cardiac hypertrophy. Cardiac hypertrophy is greatest after angiotensin administration in rats on a high (4%) NaCl diet. In both the 2K-1C and 1K-1C Goldblatt models, a high salt intake reduces the blood pressure lowering effect of captopril and losartan and prevents regression of cardiac hypertrophy. Combined administration of an ACE inhibitor and an angiotensin type 1 (AT1) receptor blocker to rats on a low (0.2%) NaCl diet produces a syndrome that leads to death with cardiac involution. All features of the syndrome are reversed or prevented by 4% NaCl intake. It is hypothesised that the interaction between angiotensin II and sodium intake can be explained by differences in the way protons produced by contracting cells are neutralized. The sodium hydrogen exchanger and the sodium 2 bicarbonate cotransporter are stimulated by the AT1 and angiotensin type 2 (AT2) receptor, respectively. If the ratio of receptors is altered in favour of the AT2 receptor, then less cardiac hypertrophy will result from the same workload. Review of the clinical literature reveals that many of these results in rats have correlations in clinical medicine. Thus high night time blood pressure is associated with a greater morbidity and high salt intake causes cardiac hypertrophy and vascular stiffness independent of blood pressure levels. When deciding on treatment in human hypertension these results have important clinical implications.

Seed germination in the Great Basin halophyte Salsola iberica

Salsola iberica Sennen &amp; Pau, a halophytic forb in the family Chenopodiaceae, is widely distributed in inland salt deserts of Utah and widespread in North America. Experiments were conducted to determine the effects of NaCl and temperature on seed germination and their recovery of germination from saline conditions after being transferred to distilled water. Seeds of S. iberica were germinated at various temperatures and at various salinities in a 12 h light : 12 h dark photoperiod to determine their germinability under these conditions. Increases in NaCl concentration progressively inhibited seed germination. Few seeds germinated at 1000 mM NaCl. Cooler temperatures significantly inhibited germination, while high night (25°C) and high day (35°C) temperature regimes showed higher germination. Rate of germination decreased with an increase in salinity. Germination rate was higher at 25–35°C and lower at 5–15°C temperatures. Seeds were transferred from salt solutions to distilled water after 20 days, and those from low salinities recovered quickly at cooler temperature regimes. Recovery germination percentages substantially decreased with an increase in salinity and temperature.Key words: halophyte, recovery of seed germination, Salsola iberica, salt desert, thermoperiod, Utah.

Influences of High Night Temperature on Flowering and Pod Setting in Soybean

Soybean (Glycine max (L.) Merr. cv. Enrei) plants were grown in pots (15-L volume) placed in a greenhouse with ventilation. At the time when the first flower opened, pots were transferred to growth chambers with natural lighting under day temperature of 30°C and night temperatures of 20, 25 or 30°C. The numbers of flowers opened and pods set each day were recorded and the seed yield and yield components were investigated after harvest. The increase in night temperature decreased the seed size and increased the number of flowers and pods. As a result, the seed weight per plant was unaffected by night temperature. However, high night temperatures increased the number of flowers on the secondary and tertiary racemes. These flowers opened after the 18th day of the flowering period and showed a high rate of pod setting. These results suggest that a high night temperature stimulated flower opening and pod setting in the secondary and tertiary racemes. The increases in the numbers of flowers and pods could serve to moderate the reduction of seed yield caused by a high night temperature.

Relationship between autonomic function, 24-h blood pressure, and albuminuria in normotensive, normoalbuminuric patients with Type 1 diabetes

We performed a battery of cardiovascular reflex tests, 24-h ambulatory blood pressure (AMBP) and 24-h urinary albumin excretion (UAE) in 116 normoalbuminuric and normotensive patients with Type 1 diabetes. Tests of heart rate variation (HRV) included the coefficient of variation (CV) and the low-frequency (LF), mid-frequency (MF), and high-frequency (HF) bands of spectral analysis at rest, HRV during deep breathing (CV, mean circular resultant — MCR), Valsalva ratio, and maximum/minimum 30:15 ratio. Autonomic neuropathy, characterized as an abnormality of more than two tests, was found in 33 patients. Patients with neuropathy compared to those without neuropathy showed significantly higher mean day and night diastolic blood pressure (dBP), mean systolic night blood pressure (sBP), and mean day and night heart rate (HR). Mean night dBP was inversely related to MF, HF, and HRV during deep breathing; mean day dBP and mean night sBP to HF; mean night HR to CV at rest, MF, HF, HRV during deep breathing, 30:15 ratio; mean day HR to HF, HRV during deep breathing, Valsalva, and 30:15 ratio. Mean 24-h UAE was not significantly different in neuropathic than in nonneuropathic patients. UAE was inversely related to CV at rest and HF. In the stepwise multiple regression analysis, reduced MF, HF, HRV during deep breathing, and high levels of UAE and HbA1c were associated with high night dBP. Autonomic neuropathy is already present in normotensive Type 1 diabetic patients at the normoalbuminuric stage and related to BP and albuminuria.