[Effects of lower limit of subsurface drip irrigation on tomato growth and its yield in plastic tunnel].

A subsurface drip irrigation experiment was conducted in a plastic tunnel to study the effects of different lower limits of subsurface drip irrigation on tomato growth and its yield. The lower limits of subsurface drip irrigation were expressed by soil water suctions detected by tensiometers placed in 30 cm soil layer. The designed values of soil water suction in this experiment were 10, 16, 25, 40 and 63 kPa, respectively. The results showed that the height and biomass of tomato plant decreased significantly with increasing lower limits of subsurface drip irrigation. Parabolic regression curves were suitable to simulate the relationships of stem diameter of tomato plant, yield, and water use efficiency (WUE) with lower limits of subsurface drip irrigation. The relationship between the ratio of stem diameter to plant height of tomato and lower limit could be simulated by three-dimensional multinomial regression curve. The growth of tomato root and shoot and their ratio R/S) varied under different lowerlimits of subsurface drip irrigation. The tomato plant grew well, RI/S was favorable, and the yield and WUE were higher when soil water suction was in the range of 25- 33 kPa. When this range was served as the criteria for subsurface drip irrigation, the soil water content at the beginning of irrigation should be lower, and the irrigation frequency should be fewer than that of conventional irrigation. This range of soil water suction was in favor of improving the WUE and decreasing labor cost for tomato cultivation in plastic tunnel.

EFFECT OF BLACK RICE ANTHOCYANIN ON BIOCHEMICAL INDICATORS IN BLOOD AND MACROPHAGES OF RATS / 营养学报

Objective To investigate the immunomodulatory effect of black rice anthocyanin(BA) on biochemical indicators in blood and macrophages in rats.Method Twenty four female SD rats were randomly divided into 4 groups:control group,BA low,middle and high-dose groups(BAL 25;BAM 50;BAH 100 mg/kg bw).The control group was treated with normal saline,while BA groups were i.g.administered with defferent doses for 30 d.The blood biochemical indicators were detected by automatic biochemistry analyzer.The activities of lactate dehydrogenase(LDH),acid phosphatase(ACP),superoxide dismutase(SOD),and maleic dialdehyde(MDA) contents in peritoneal macrophage(PM) and alveolar macrophage(AM) were determined by biochemical methods.The ability of macrophages to phagocytose neutral red was measured by colorimetric method.Results The levels of urea nitrogen(UN),uric acid(UA),triglyceride(TG),total cholesterol(TC) and low density lipoprotein(LDL) in blood were reduced.The activities of ACP,LDH in PM were increased.and the activities of SOD in PM and AM were increased whereas MDA was reduced.The ability of PM and AM to phagocytose neutral red was strengthened significantly.Conclusion BA shows significant immunomodulatory effection blood biochemical indicators and macrophages in rats.