Author Keywords: Thermal acclimation; thermal hardening; hardening; heat hardening; cold hardening; critical thermal maxima; critical thermal minima; developmental stage; metamorphosis; tadpoles; Rana catesbeiana 相似文献
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31.
Summary Organic components leaked fromSorghum bicolor seedlings (‘root exudates’) were examined by recovering14C labelled compounds from root solutions of seedlings inoculated withAzospirillum brasilense, Azotobacter vinelandii orKlebsiella pneumoniae nif-. Up to 3.5% of the total14C recovered from shoots, roots, and nutrient solutions was found in the root solutions. Inoculation with Azospirillum and
Azotobacter increased the amounts of14C and decreased the amounts of carbohydrates in the root solutions. When sucrose was added as a carbon source for the bacteria,
the increase of14C in the solutions did not occur. Quantities of14C found in the root solutions were proportional to amounts of mineral nitrogen supplied to the plants. Bacterial growth also
was proportional to nitrogen levels. When sorghum plants were grown in soil and labelled with14CO2, about 15% of the total14C recovered within 48 hours exposure was found in soil leachates. 相似文献
32.
Summary Millet plants (Pennisetum glaucum) were grown at three levels of nitrogen fertilization with and without an inoculum of live nitrogen-fixing Azospirillum cells. The highest average rate of nitrogen fixation as estimated from acetylene reduction by excised preincubated roots was only 23g N2 fixed per ha per day and occurred after treatment with low levels of nitrogen amendment. The average rates of acetylene reduction for intact plants at all treatments were also low. The lack of significant nitrogen fixation due to an Azospirillum-millet association in this study was substantiated by plant dry weight analysis, and determination of the nitrogen content of plants, pot leachate, and soil. There was significant correlation between the total nitrogen content of the plants per pot at the termination of the experiment and the amount of nitrogen fertilizer added initially, but there was no effect of inoculum on final total nitrogen content. 相似文献
33.
1. 1.|Critical thermal maxima (CTMax) and minima (CTMin) were measured to evalute thermal hardening in Rana catesbeiana.
2. 2.|Tadpoles show heat hardening and CTMax acclimation, and both responses are influenced by developmental stage.
3. 3.|The first evidence of cold hardening in vertebrates is reported here.
4. 4.|Heat hardening significantly reduces cold tolerance, but there is otherwise no evidence of a cross-hardening effect.
34.
Leaf photosynthetic rates were measured on field-grown soybeans during the 1980 season. Comparisons were made between different cultivars and isolines representative of maturity groups I–IV. Mature, fully expanded leaves at different nodes on the plant were measured in high light to determine which had the highest potential photosynthetic rates at any one time. Successive leaves during the growing season had maximum rates which increased from about 22 mol CO2 m-2 s-1 on 25 June to a peak of 30–44 mol CO2 m-2 s-1 in early August.The persistency and eventual decline in the maximum rate was associated with the maturity group and related dates of flowering, pod fill and onset of senescence. Early maturing cultivars (groups I and II) had higher peak rates (38–44 mol CO2 m-2 s-1) than later maturing cultivars (30–35 mol CO2 m-2 s-1, groups III and IV). However, the photosynthetic rates of early maturing cultivars declined rapidly after attaining their peak, whereas the leaves of later maturing cultivars maintained their photosynthetic activity for much longer. 相似文献
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All motile stages of Pratylenchus coffeae infected mature and immature tissues of Citrus jambhiri (rough lemon) seedling tap roots. The nematodes fed primarily in the cortex and colonized in pockets or cavities. Intra- and intercellular migration within the cortex occurred in either direction from the point of entry. When P. coffeae invaded a root tip the meristem often was destroyed and lateral root initiation usually occurred near the destroyed root tip. Males were essential for reproduction and survived at least 2 1/2 months within root tissues, but with males alone used as inoculum, no cortical pockets were formed. On infected trees in the field P. coffeae were most numerous in C. jambhiri feeder roots. 相似文献
37.
《Bioscience, biotechnology, and biochemistry》2013,77(10):1958-1959
A sandwich chemiluminescence enzyme immunoassay for measuring the level of VEGF /VPF in serum was constructed. The detectability of the assay is very low (1.0pg/ml) and the measurable range of the assay was very wide (1–1000 pg/ml). The assay showed that the average level of VEGF /VPF in human sera from healthy blood donors was approximately 19 pg/ml. 相似文献
38.
The current study investigated the effect of developmental stages on the chemical composition and the antioxidant activity of fifteen crude oil samples obtained from Pistacia atlantica Desf. leaves, galls, and fruits. Twelve fatty acids were detected by GC/FID, linolenic acid (C18 : 3) was the major fatty acid detected in leaves crude oils that registered [41.73 % (P<0.05)] on the last stage. The best content of tocopherols and carotenoids was recorded at the last stage for leaves and galls oils, respectively, with values of [1.530±0.01, 0.52±0.01 (P<0.05) mg α‐tocopherol equivalent/g DW] and [86.60±0.95, 69.15±0.13 (P<0.05) μg β‐carotene equivalent/g DW]. For fruits oils, the content varied depending on the levels of fruits maturation. The results from DPPH, FRAP, and ABTS assays revealed that the antioxidant activity increased with the increasing content of tocopherols and carotenoids in leaves and galls oils during development stages, and varied for fruits oils depending on the ripening stages. Moreover, according to PCA analysis, the best phytoconstituent content and antioxidant activity were attributed to P. atlantica Desf. fruit's crude oils. Also, a strong relationship was found between the antioxidant activity and bioactive phytochemical components, such as tocopherols, carotenoids, and omega‐three fatty acid, which confirmed that P. atlantica Desf. crude oils present a valuable source of natural antioxidant that could be used for pharmaceutical and food industries purposes. 相似文献
39.
目的:研究布地奈德福莫特罗粉吸入剂(ST)联合孟鲁斯特对支气管哮喘急性发作期(ASBA)患者肺功能及血清细胞因子水平的影响。方法:选择2015年2月到2017年8月在我院治疗的86例ASBA患者作为研究对象,根据随机数字表法将患者分成观察组(n=43)以及对照组(n=43),对照组予以ST治疗,观察组则在此基础上联合孟鲁司特治疗,两组均治疗3个月,对比两组患者治疗前及治疗3个月后的肺功能、细胞因子水平、咳嗽评分、St·George's呼吸疾病问卷(SGRQ)以及用药安全性。结果:治疗后两组患者的第1秒的用力呼气容积(FEV1)、用力肺活量(FVC)及FEV1/FVC均较治疗前升高,且观察组高于对照组(P0.05)。治疗后两组患者的白细胞介素-4(IL-4)、白细胞介素-5(IL-5)、γ-干扰素(INF-γ)及肿瘤坏死因子-α(TNF-α)水平均较治疗前降低,且观察组低于对照组(P0.05)。治疗后两组患者的咳嗽评分较治疗前升高,且观察组高于对照组(P0.05),而治疗后两组患者的SGRQ评分均较治疗前降低,且观察组低于对照组(P0.05)。观察组不良反应的总发生率为20.93%,与对照组的16.28%相比无统计学差异(P0.05)。结论:ASBA给予ST联合孟鲁司特治疗能够有效改善患者的症状,缓解机体炎症反映的同时还可有效改善患者肺功能和生活质量,其用药安全性较好。 相似文献
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