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71.
哺乳犊牛的消化特点与蛋白质需要 总被引:7,自引:0,他引:7
本文从犊牛的消化生理特点出发,综述了犊牛出生后的生理特征及蛋白质、必需氨基酸的需要量,并对代乳品中蛋白质原料进行了论述。 相似文献
72.
模糊隶属法对玉米苗期耐旱性的拟合分析 总被引:14,自引:1,他引:14
在略高于玉米萎蔫系数的干旱条件下,以出苗率和生物学产量耐旱系数之乘积为指标,测定了17个玉米自交系和10个杂交种的苗期抗旱性。并用模糊隶属法,以干旱胁迫下的胚芽鞘长度,出苗率,根重,生物学产量,脯氨酸含量,电导率和离体叶片保水力等指标对各品种耐旱性进行了拟合分析。结果表明,在略高于萎蔫系数的干旱条件下,以出苗率和生物学产量的耐旱系数之乘积为指标,可以准确鉴定玉米苗期的耐旱性,与耐旱性的综合评价拟合良好(相关系数r=0.914)。 相似文献
73.
Achmadi PRIYATMOJO Ryo YAMAUCHI Koji KAGEYAMA Mitsuro HYAKUMACHI 《Journal of General Plant Pathology》2002,68(1):1-7
Cellular fatty acids were analyzed to characterize and differentiate 34 isolates of Rhizoctonia species representing binucleate Rhizoctonia AG-D (I), AG-D (II), R. solani AG 2-2 IIIB, AG 2-2 LP, R. circinata var. circinata and var. oryzae associated with turfgrass diseases in Japan. Myristic, pentadecanoic, palmitic, palmitoleic, stearic, oleic, linoleic and
linolenic acids were consistently present in varying quantities in all isolates. Heptadecanoic and 9-heptadecenoic acids were
present in isolates of Rhizoctonia AG-D (I), AG-D (II), R. solani AG 2-2 IIIB and AG 2-2 LP but not in isolates of R. circinata var. circinata and var. oryzae. Palmitic, oleic and linoleic acids were the major fatty acids found, constituting 88.30-98.37% of the whole-cell fatty acid
content. The remaining fatty acids were present in smaller amounts. Isolates within a single group were closely clustered,
whereas isolates from different groups were clearly distinguishable based on average linkage cluster analysis of cellular
fatty acids. Principal component analysis, based on all fatty acids detected, confirmed the distinct separation of isolates
representing the six groups of Rhizoctonia species obtained from turfgrasses. These results suggested that fatty acid analysis is useful for the characterization and
differentiation of isolates of Rhizoctonia species associated with turfgrass diseases.
Received 21 May 2001/ Accepted in revised form 28 September 2001 相似文献
74.
水稻不同品种或组合对甲磺隆耐药性差异的机制研究 总被引:2,自引:2,他引:2
以水稻乙酰乳酸合成酶(ALS)比活力为研究对象,通过在离体和活体条件下比较其对甲磺隆的敏感性水平,探讨了水稻不同品种或组合的耐药性差异机制。结果表明,离体条件下不同水稻品种或组合ALS对甲磺隆均较敏感,当甲磺隆浓度为100 μg/L时,对ALS比活力抑制率达60%以上,且活力百分比与甲磺隆浓度对数成直线负相关关系,相关程度显著或极显著;活体条件下ALS活力均受到甲磺隆不同程度的抑制,但同一品种ALS活力不随甲磺隆浓度的变化而呈现规律性变化。在甲磺隆浓度相同时,活体条件下所有供试水稻品种ALS活力均显著高于离体条件下的ALS活力,影响程度与植株耐药性差异基本一致,说明甲磺隆在水稻体内存在较强代谢失活作用,代谢失活差异是水稻不同品种或组合对甲磺隆的耐药性差异机制。 相似文献
75.
76.
LI Yue-hong ZHANG Xiang-hong YANG Yong-bin YAN Xia WANG Jun-ling HUANG Xiang-hua YANG Jian-zhu LIU Yan-li WANG Feng-rong 《园艺学报》2002,18(11):1353-1356
AIM: To explore the effects of riboflavin and ascorbic acid on the apoptosis induced by deoxynivalenol(DON) in mouse thymocytes. METHODS: The effects of riboflavin and ascorbic acid on the apoptosis and proliferation inhibition of thymocytes induced by DON in KM mice were studied with animal experiment, DNA agarose gel electrophoresis and flow cytometric DNA content analysis. RESULTS: Apoptosis rate of thymocytes in DON (4 mg/kg) treated group was13.73%±15.3% The percentages of apoptosis in riboflavin (1.25 mg/kg-10mg/kg) and ascorbic acid (25 mg/kg-100mg/kg) pretreated thymocytes groups were significantly lower than that in DON group (P <0.05). The result of DNA agarose gel electrophoresis showed that the characteristic ladder pattern of apoptosis was found in DON-treated thymocytes, but not in control and riboflavin pretreatment and ascorbic acid pretreatment groups The significant differences in proliferation index were not found among DON-treated thymocytes and riboflavin and ascorbic acid-pretreated thymocytes CONCLUSION: Pretreatment with riboflavin and ascorbic acid inhibit apoptosis of mouse thymocytes induced by DON in certain extent and have no effect on proliferation inhibition by DON. 相似文献
77.
The response of Cuscuta campestris Yuncker, a non‐specific above‐ground holoparasite, to amino acid biosynthesis inhibitor (AABI) herbicides, was compared with other resistant and sensitive plants in dose–response assays carried out in Petri dishes. Cuscuta campestris was found to be much more resistant to all AABI herbicides tested. The I50 value of C. campestris growth inhibition by glyphosate was eightfold higher than that of transgenic, glyphosate‐resistant cotton (RR‐cotton). The I50 value for C. campestris shoot growth inhibition by sulfometuron was above 500 μM, whereas that of sorghum roots was only 0.004 μM. Cuscuta campestris exposed to glyphosate gradually accumulated shikimate, confirming herbicide penetration into the parasite and interaction with an active form of the target enzyme of the herbicide, 5‐enolpyruvylshikimate‐3‐phosphate synthase. More than half of the C. campestris plants associated with transgenic, glyphosate‐resistant sugarbeet (RR‐sugarbeet) treated with glyphosate or with transgenic, sulfometuron‐resistant tomato (SuR‐tomato) treated with sulfometuron recovered and resumed regular growth 20–30 days after treatment. New healthy stems developed, followed by normal flowering and seed setting. The results of the current study demonstrate the unique capacity of C. campestris to tolerate high rates of AABI. The mechanism of this phenomenon is yet to be elucidated. 相似文献
78.
Eiji Tanaka Chihiro Tanaka Atsushi Ishihara Yasumasa Kuwahara Mitsuya Tsuda 《Journal of General Plant Pathology》2003,69(1):1-6
Aciculosporium take (Ascomycota; Clavicipitaceae) is a causal agent of witches' broom of
bamboo plants. The symptoms of this disease are believed to be induced by plant
hormones, particularly auxins. Indole-3-acetic acid (IAA) was identified in
cultures of this fungus in an l-tryptophan-supplemented liquid medium.
IAA production was confirmed on 30 isolates of A. take from various
hosts and locations at levels up to 1 mg/l. The biosynthetic pathway of
IAA in A. take culture was examined by analyzing intermediate products
and by feeding experiments. The results showed that the indole-3-pyruvic acid
pathway (l-tryptophan → indole-3-pyruvic acid → indole
acetaldehyde → IAA) was the dominant pathway in A. take.
Received: June 3, 2002 / Accepted: July 25, 2002 相似文献
79.
80.
通过取代苯氧异丁酸与12-(羟基亚氨基)十五内酯的反应,合成了取代苯氧异丁酰氧亚氨基十五内酯,并测定了其对苋菜的除草活性。所有化合物均经过1H NMR、13C NMR和元素分析确证。初步的生物活性测定结果表明,目标化合物 Ⅲa~Ⅲd 的EC50值分别为34.570、46.492、55.385、50.114 mg/L,其活性比对照药剂2,4-D(117.325 mg/L)高,而比苯磺隆(22.381 mg/L)低。 相似文献