Tissue culture responses of explants taken from branch sources with different degrees of juvenility in mature black locust (Robinia pseudoacacia) trees     

Han KH  Shin DI  Keathley DE 《Tree physiology》1997,17(10):671-675

We studied the in vitro responses of cambial tissue and dormant vegetative buds obtained from top and epicormic branches of three mature black locust (Robinia pseudoacacia L.) trees. Cambial tissues isolated from epicormic branches produced more callus than cambial tissues isolated from top branches, whereas in vitro shoot cultures derived from buds excised from top branches grew faster than those derived from buds excised from epicormic branches. There were no significant differences between the two branch sources in in vitro bud break or shoot multiplication from bud explants or cambial-derived callus tissue, respectively. Furthermore, the top branches, generally considered to be the most mature in a tree, were not recalcitrant in terms of morphogenic capacity compared to epicormic branches.  相似文献   

Enhanced selective extraction of hexane from hexane/soybean oil mixture using binary gas mixtures of carbon dioxide     

Eller FJ  Taylor SL  Palmquist DE 《Journal of agricultural and food chemistry》2007,55(8):2779-2783

Carbon dioxide (CO2) can effectively separate hexane from a mixture of soybean oil (SBO) and hexane with a slight coextraction of SBO. Previous research demonstrated that CO2 entrained with helium significantly reduced SBO solubility in CO2. In this study, CO2 was mixed with three gases (He, N2, or Ar) (0.5-30 vol %) to decrease SBO solubility while attempting to maintain hexane solubility. The binary gas mixtures (at 25 degrees C and 9.31 MPa) were passed through a 25 wt % hexane/SBO mixture inside a 2.5 m fractionation column. Coextracted SBO was inversely proportional to binary gas concentration, whereas residual hexane in the raffinate was proportional to binary gas concentration. The 10% binary mixture of N2 or Ar was the best compromise to obtain both low residual hexane levels (i.e., 26 ppm) and low SBO coextraction (i.e., only 40 mg). This carry-over of SBO represents a 95% reduction in SBO carry-over compared to neat CO2.  相似文献   

Ten-year comparison of the influence of organic and conventional crop management practices on the content of flavonoids in tomatoes     

Mitchell AE  Hong YJ  Koh E  Barrett DM  Bryant DE  Denison RF  Kaffka S 《Journal of agricultural and food chemistry》2007,55(15):6154-6159

Understanding how environment, crop management, and other factors, particularly soil fertility, influence the composition and quality of food crops is necessary for the production of high-quality nutritious foods. The flavonoid aglycones quercetin and kaempferol were measured in dried tomato samples (Lycopersicon esculentum L. cv. Halley 3155) that had been archived over the period from 1994 to 2004 from the Long-Term Research on Agricultural Systems project (LTRAS) at the University of California-Davis, which began in 1993. Conventional and organic processing tomato production systems are part of the set of systems compared at LTRAS. Comparisons of analyses of archived samples from conventional and organic production systems demonstrated statistically higher levels (P < 0.05) of quercetin and kaempferol aglycones in organic tomatoes. Ten-year mean levels of quercetin and kaempferol in organic tomatoes [115.5 and 63.3 mg g(-1) of dry matter (DM)] were 79 and 97% higher than those in conventional tomatoes (64.6 and 32.06 mg g(-1) of DM), respectively. The levels of flavonoids increased over time in samples from organic treatments, whereas the levels of flavonoids did not vary significantly in conventional treatments. This increase corresponds not only with increasing amounts of soil organic matter accumulating in organic plots but also with reduced manure application rates once soils in the organic systems had reached equilibrium levels of organic matter. Well-quantified changes in tomato nutrients over years in organic farming systems have not been reported previously.  相似文献   

Classification of gilthead sea bream (Sparus aurata) from 1H NMR lipid profiling combined with principal component and linear discriminant analysis     

Rezzi S  Giani I  Héberger K  Axelson DE  Moretti VM  Reniero F  Guillou C 《Journal of agricultural and food chemistry》2007,55(24):9963-9968

The combination of (1)H NMR fingerprinting of lipids from gilthead sea bream (Sparus aurata) with nonsupervised and supervised multivariate analysis was applied to differentiate wild and farmed fish and to classify farmed specimen according to their areas of production belonging to the Mediterranean basin. Principal component analysis (PCA) applied on processed (1)H NMR profiles made a clear distinction between wild and farmed samples. Linear discriminant analysis (LDA) allowed classification of samples according to the geographic origin, as well as for the wild and farmed status using both PCA scores and NMR data as variables. Variable selection for LDA was achieved with forward selection (stepwise) with a predefined 5% error level. The methods allowed the classification of 100% of the samples according to their wild and farmed status and 85-97% to geographic origin. Probabilistic neural network (PNN) analyses provided complementary means for the successful discrimination among classes investigated.  相似文献   

A quantitative review of tebuconazole effect on fusarium head blight and deoxynivalenol content in wheat     

Paul PA  Lipps PE  Hershman DE  McMullen MP  Draper MA  Madden LV 《Phytopathology》2007,97(2):211-220

ABSTRACT A meta-analysis of the effect of tebuconazole (e.g., Folicur 3.6F) on Fusarium head blight and deoxynivalenol (DON) content of wheat grain was performed using data collected from uniform fungicide trials (UFTs) conducted at multiple locations across U.S. wheat-growing regions. Response ratios (mean disease and DON levels from tebuconazole-treated plots, divided by mean disease and DON levels from untreated check plots) were calculated for each of 139 studies for tebuconazole effect on Fusarium head blight index (IND; field or plot-level disease severity, i.e., mean proportion of diseased spikelets per spike) and 101 studies for tebuconazole effect on DON contamination of harvested grain. A random-effects meta-analysis was performed on the log-transformed ratios, and the estimated mean log ratios were transformed to estimate the mean (expected) percent control for IND ( C(IND) ) and DON ( C(DON)). A mixed effects meta-analysis was then done to determine the effects of wheat type (spring versus winter wheat) and disease and DON levels in the controls on the log ratios. Tebuconazole was more effective at limiting IND than DON, with C(IND) and C(DON) values of 40.3 and 21.6%, respectively. The efficacy of tebuconazole as determined by the impact on both IND and DON was greater in spring wheat than in winter wheat (P < 0.01), with a 13.2% higher C(IND) and a 12.4% higher C(DON) in spring wheat than in winter wheat. In general, C(IND) and C(DON) were both at their lowest values (and not significantly different from 0) when mean IND and DON in the controls, respectively, were low (相似文献   

HIGHLIGHTS OF THE SPECIAL ISSUE “PROGRESS ON NITROGEN RESEARCH FROM SOIL TO PLANT AND TO THE ENVIRONMENT”     

Wim DE VRIES  Xuejun LIU  Lixing YUAN 《农业科学与工程前沿(英文版)》2022,9(3):313

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Cynoscion striatus（条纹犬牙石首鱼）的幼鱼在海里和水族箱内生长的研究     

J．D．DE  CIECHOMSKI  ANDM.C.CASSIA  匡纬远 《广西水产科技》1980,(2):24-28

本文报导了有关长度为20～140毫米的条纹犬牙石首鱼的幼鱼在海里和水族箱内长情况的研究情况．这些幼鱼在海里逐月生长情况是通过全年抽测5500尾个体的体频率分布的分析来确定的．在水族箱内的鱼每两周测一次体长、体重，并用已知的相数量的饲料投喂之，在鱼的体长与体重之间；在鱼的体长与耳石的长、宽、  相似文献   

谈谈奶牛常见疾病的诱因、症状、诊断及防治     

付刚  王艳波  王晓颖  李永红 《山东饲料》2010,(10)

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NEW DISCOVERIES AT BAOUSSE ROUSSE,NEAR MENTONE     

DE Nadaillay M 《Science (New York, N.Y.)》1892,20(503):170-171

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THE WAR WITH THE MICROBES     

DE Schweinitz EA 《Science (New York, N.Y.)》1897,5(119):561-570

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