Effects of walnut/Rosa roxburghii compound planting on growth, fruit yield, quality of Rosa roxburghii and soil properties.

Walnut and Rosa roxburghii are important arbor and shrub fruit trees cultivated in the southwest mountainous area of China. Furthermore, those two species are compound cultivated in this area. In this study, we investigated the growth, yield, fruit quality, photosynthesis, and soil fertility of R. roxburghii in a 7-year typical 'Qianhe 7'/ 'Guinong 5' compound planting pattern in Guizhou. The results showed that compared with the monoculture, photosynthetic pigment content and photosynthetic rate of R. roxburghii leaves were significantly lower in the compound plantation. The growth and yield of R. roxburghii decreased significantly, with a 77.7% reduction of yield. Fruit quality of R. roxburghii was improved. The content of ascorbic acid (Vc), total phenol, carbohydrate, K, Ca, Mg, Fe, Mn, Zn, and other substances increased significantly. Fruit Vc and Mn content increased by 34.1% and 64.1%, respectively. The contents of total N, available N and K in the soil increased by 45.8%, 34.8% and 67.8%, respectively. The abundance of soil microorganisms and functional bacteria increased significantly, with the increase of bacteria and fungi being more than 36.0%. The increase of potassium bacteria and nitrogen fixing bacteria was 71.3% and 124.8%, respectively. However, the contents of organic matter, carbon-nitrogen ratio, total P, total K, available mineral nutrient (P, Ca, Mg, Fe, Mn, Cu, Zn) contents decreased. While the activities of soil urease and catalase were increased, the activities of other soil enzymes (sucrase, cellulase, protease, phosphatase) were significantly reduced. In summary, with continuous growth of walnuts in the walnut/R. roxburghii compound plantation, there was obvious shade and soil fertility competition for R. roxburghii, which affected its yield, but had a improvement effect on fruit quality.

Within-visit and between-visit intra-individual blood pressure variability in an unselected adult population from rural China.

OBJECTIVE: To assess the association between the variability of blood pressure (BP) readings within an initial clinic visit, the variability within subsequent visits and the variability between visits over 1 week in a general population. METHODS: This study included 1401 adult residents, who were not taking antihypertensive drugs, having BP measurements at three visits over 1 week. The difference between maximal and minimal BP readings (ΔBP), ΔBP/BPm (the mean BP value in a visit), the standard deviation (SD) and coefficient of variation (coefficient of variation = SD × 100/mean) of three BP values in each visit were used to estimate the within-visit BP variability (BPV). The SD and coefficient of variation of all nine BP readings over the three visits were calculated as SD9 or CV9 to reflect the overall BPV during the study visits. The SD and coefficient of variation on the mean BP values (BPm) of three visits were computed as SD-3 or CV-3, whereas the difference between maximal and minimal BP in three visits was computed as ΔBP-3 to estimate visit-to-visit BPV. The average BP or HR was the mean values of nine BP or HR readings over three visits. RESULTS: The systolic and diastolic mean BP (SBP and DBP) decreased from the first to the third visit. The ΔBP, SD and coefficient of variation for both SBP and DBP at the first visit were positively and significantly correlated with the corresponding variables computed at the second and third visits, as well as with overall BPV (ΔBP9, SD9 and CV9). A positive correlation was also found between overall BPV and visit-to visit BPV (SD-3, CV-3 and ΔBP9). Multivariate analysis showed: no association between average SBP and systolic coefficient of variation or ΔBP/BPm but a negative association between average DBP and coefficient of variation or ΔBP/BPm for DBP at the first visit, DBP-3 and DBP9. Age was positively correlated with coefficient of variation or ΔBP/BPm for SBP at the first visit, SBP-3 and SBP9, and correlated with coefficient of variation and ΔBP/BPm for DBP only at the first visit. CONCLUSION: In a general population, within-visit BPV at an initial visit is associated with within-visit BPV at subsequent visits and with visit-to-visit BPV over three visits within 1 week.

The impact of changes in population blood pressure on hypertension prevalence and control in China.

In China, there are approximately 250 million adults who have hypertension with low rates of awareness, treatment and control. Changes in lifestyles at a population level have the potential to enhance or deteriorate the prevention and control of hypertension. We used data from a regional hypertension survey to examine the impact of 2/1 mm Hg decreases or increases in population blood pressure on hypertension prevalence, and rates of unawareness of the hypertension diagnosis, treatment, and control. The primary analysis was based on the average blood pressure of respondents from three visits and a diagnostic threshold of 140/90 mm Hg for hypertension. Secondary analyses examined average blood pressure from the first survey visit and also a diagnostic threshold of 130/80 mm Hg for hypertension. The baseline hypertension prevalence was 33.4%, and rates of unawareness of the hypertension diagnosis, treatment, and control were 74.2%, 25.8%, and 9.7%, respectively. Decreases or increases in blood pressure by 10/5 mm Hg resulted in changes in hypertension prevalence (22.1% vs 53.4%) and rates of unawareness of the diagnosis (60.9% vs 83.8%), treatment (39.1% vs 16.2%), and control (21.2% vs 3.6%), respectively. Similar trends were seen in the secondary analyses. Population changes in lifestyle could have a very large impact on the prevalence and control of hypertension in China. The results support implementation of programs to improve population lifestyles while implementing health services policies to enhance the clinical management of hypertension.

The usefulness of 24-hour blood pressure monitoring for the patients with atrial fibrillation: based on the variability of blood pressure parameters.

OBJECTIVE: The aim of this study was to test whether ambulatory blood pressure monitoring (ABPM) in patients with atrial fibrillation is reliable as in patients with sinus rhythm. METHOD: This study included 92 persistent atrial fibrillation patients (50% females; mean age 70.49 ± 11.56 years) and 92 matched sinus rhythm patients (46% females; mean age 69.23 ± 12.63 years). The participants were examined simultaneously with 24-hour ABPM and 24-hour Holter electrocardiography. The mean 24-hour (24-hour-), daytime (day-) and nighttime (night-) BP, types of BP curve, morning systolic BP (SBP) surge (MBPS), the SD of BP readings and the coefficient of variability (the SD/mean BP × 100%) were compared between atrial fibrillation and sinus rhythm patients. RESULTS: No differences of 24-hour-, day- and night-SBP levels were observed between two groups. Meanwhile, the 24-hour-SD, day-SD and night-SD, as well as the coefficient of variability for SBP were also similar between two groups. There was no significant difference in the number of MBPS between the two groups. On diastolic BP (DBP), the similar 24 hour and day levels, the 24-hour-SD, day-SD and night-SD as well as the coefficient of variability were also similar between two groups. But the nighttime DBP levels and the night-SD were higher in atrial fibrillation than in sinus rhythm. CONCLUSION: ABPM provides data with similar SBP variability in patients with atrial fibrillation as in subject with normal cardiac rhythm. The ABPM on oscillometric method may be suitable for the atrial fibrillation patients, especially for the SBP evaluation.

[Effects of different mulching materials on nitrate metabolism in soil of apple root-zone in summer and autumn.] / ä¸åŒè¦†ç›–ææ–™å¯¹å¤ç§‹è‹¹æžœæ ¹åŒºåœŸå£¤ç¡é ¸ç›ä»£è°¢çš„å½±å“.

This study explored the effects of mulching straw mat, agricultural carpet, transparent-plastic film and horticultural fabric on nitrification-denitrification, nitrate reductase (NR), nitrite reductase (NiR), ammonium, nitrate and nitrite nitrogen in root-zone soil grown with three-year old apple trees (Malus domestica cv. Starkrimson) during summer and autumn. Results showed that the four treatments decreased nitrification intensity in summer soil, NiR activity in summer-autumn soil and the variation coefficient of nitrification-denitrification intensity and NR in both summer and autumn soil. The treatments increased the denitrification intensity, NR activity, ammonium nitrogen contents in summer-autumn soil and ammonium nitrogen contents in autumn soil. Straw mat treatment increased denitrification intensity and nitrate nitrogen contents in both summer and autumn soil and decreased the activity of NR and NiR in summer soil. The coefficient of variation of nitrification-denitrification intensity and NR activity treated by mulching straw mat was lower than those in the other treatments in both summer and autumn soil. Agricultural carpet increased the NR and NiR activity in summer soil, the nitrate nitrogen contents in summer-autumn soil and the denitrification intensity in autumn soil and decreased denitrification intensity in summer soil. Transparent-plastic film increased the nitrite nitrogen contents in summer soil, the contents of nitrate nitrogen in summer-autumn soil, the nitrification intensity and NiR activity in autumn soil, and decreased nitrate nitrogen contents in summer soil. Horticultural fabric increased denitrification intensity in summer soil, nitrification intensity in summer-autumn and autumn soil and the nitrate nitrogen contents in autumn soil. The four mulching treatments all promoted plant growth. In the four mulching treatments, the new shoot and trunk thickening growth were more under straw mat and horticultural fabric treatments. The four mulching treatments had different effects on nitrate metabolism in summer and autumn soil, but they were able to stabilize the soil nitrate metabolism and transformation. Among the treatments, straw mat had the best stable effect.

[Relationship between drought resistance and endogenous hormone content in different citrus species].

Eight plant seedlings of citrus species, Citrus tangerina, C. erythrosa, C. chuana, Poncirus trifoliate, C. sinensis x P. trifoliate, C. grandis, C. sinensis and C. vessucosa were used to investigate the effects of drought stress on plant biomass, drought resistance coefficient and leaf hormone (ABA, GA1+3 , ZR, IAA) changes. The results showed that, on the condition of precipitation less than 1200 mm, the biomass of different citrus species reduced obviously, and drought-resistance index and drought resistance showed in order of C. erythrosa > C. tangerina > P. trifoliate > C. chuana > C. sinensis x P. trifoliate > C. grandis > C. sinensis > C. vessucosa. The leaf ABA contents of the eight species increased whereas GA1+3 , ZR and IAA decreased, under the condition of drought stress. The ratios of ABA/GA1+3 and ABA/ZR in the species of C. erythrosa and C. tangerina increased drastically, yet there was no significant correlation between the ratio of ABA/IAA and the drought tolerance. The drought-resistance index was significantly positively related to the relative content of ABA (P < 0.01), while significantly negatively related to the relative content of GA1+3. The function to enhance drought resistance by those endogenous hormones in the citrus species showed in order of ABA > GA1+3, ZR > IAA.

[Relationship between ascorbic acid accumulation and related enzyme activities in fruit of Rosa roxburghii Tratt].

Ascorbic acid (AsA) and sugar levels, together with activities of L-galactono-1,4-lactone dehydrogenase (GalLDH, a key enzyme in AsA biosynthesis in higher plant), AAO, AAP, MDAR and DHAR in fruit of Rosa roxburghii Tratt were measured during development. The result showed that AsA accumulated continually but with a slow, fast and slow accumulating rate in the R. roxburghii fruit during its development, in which the period from the end of June to the early of August was the most important period of AsA accumulation, since the AsA accumulated in this stage accounting for approximately 90% of the final level (Fig.1B). Changes in GalLDH activity coincided with AsA accumulating rate during fruit development (Fig.2B). The extremely significant positive correlation existed between the GalLDH activity and AsA accumulating rate (r(2)=0.783**) (Fig.3). Transitory and low activities of AAO and AAP in the fruit were detected in the initial stage of development (Table 1), suggesting that little AsA degraded by the activities of the two oxidative enzymes during the whole development. This data elucidated, at least in part, the reason for high accumulation of AsA in the R. roxburghii fruit. Furthermore, no activity of MDAR or DHAR in the fruit was detected during the whole development, implying that the two enzymes are not key factors for contribution of AsA level. No correlation was found between AsA content and sugar contents in the R. roxburghii fruit.