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11.
不同生态型大白菜抽薹时内源激素含量比较 总被引:5,自引:0,他引:5
大白菜〔Brassicacampestrissubspeciespekinesis(Lour. )Olsson〕先期抽薹一直困扰着春大白菜和高纬度、高海拔地区的大白菜生产。为育成冬性较强不易抽薹的品种,大白菜晚抽薹特性及利用的研究逐渐成为新的热点。不同生态型的大白菜品种,在相同的环境条件下冬性越强越不易抽薹。国外对控制或减轻未熟抽薹的环境条件有较多报道〔1~3〕,本研究主要探讨了低温处理后不同生态型的大白菜品种抽薹时内源生长素类 (IAA、IPA)、赤霉素类(GA3、GA4 )、细胞分裂素类 (ZR、DHZR)和脱落酸(ABA)含量差异,以期为选育具有较强冬性的大白菜品… 相似文献
12.
不同化学物质打破葡萄、桃休眠的研究 总被引:7,自引:1,他引:7
以保护地栽培的葡萄、桃为试材,对氰氨类、细胞分裂素、赤霉酸和KNO3打破休眠的效果进行了研究。结果表明,1.5%单氰氨、11%石灰氮可明显促使葡萄提前萌芽,提早着色9-10d;50mg/LGA3和100mg/L6-BA对打破休眠基本无效。TDZ与单氰氨混用提高萌芽率的效果最好。在2个葡萄品种上,均没有观察到单氰氨或石灰氮处理对果穗或果实品质性状的不良影响。在华光油桃上,没有观察到化学物质对提早开花或成熟有明显的作用。对葡萄和桃上应用化学物质打破休眠的有关问题进行了讨论。 相似文献
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Comparison of morphology, viability, and function between blood and milk neutrophils from peak lactating goats 下载免费PDF全文
Sui Zhi Tian Chai Ju Chang Chih Chi Chiang Huo Cheng Peh Mu Chiou Huang Jai-Wei Lee Xin Zhao 《Canadian journal of veterinary research》2005,69(1):39-45
The morphological features of blood and milk neutrophils from peak lactating goats were compared using light microscopy, scanning electron microscopy and flow cytometry in order to investigate the cytological changes of neutrophils after migration into the mammary gland. The kinetics of reactive oxygen intermediates (ROI) generation and gelatinase release of blood and milk neutrophils, with or without stimulation of phorbol 12-myristate, 13-acetate ester (PMA), were used to characterize their responses to inflammatory stimuli. Neutrophils isolated from goat milk were highly segmented and contained multi-lobed nuclei. Ultrastructurally, milk neutrophils were more ruffled on the surface compared to blood neutrophils. Approximately 30% of milk neutrophils were undergoing cell death, either necrosis or apoptosis, in contrast to 8% of blood neutrophils. The ROI production of activated milk neutrophils peaked earlier than blood neutrophils, but the duration and the intensity were much less. Neutrophils from both sources augmented the release of gelatinase in response to PMA (1 ng/mL). However, the amount of gelatinase released from milk neutrophils was lower (P < 0.05) than that of blood neutrophils. In summary, more neutrophils become apoptotic and necrotic in the mammary gland, presumably due to spontaneous aging, the process of diapedesis, and the interaction with milk components. Milk neutrophils have impaired functionalities in comparison with blood neutrophils. The information is relevant when studying mammary gland immunity and related diseases, such as mastitis. 相似文献
15.
袋鼠花的组织培养 总被引:8,自引:0,他引:8
对袋鼠花( Anigozanthos) 组织培养研究表明: 外植体消毒以0. 1 %升汞溶液浸泡, 7~8 min 为宜; 不同浓度激素对其愈伤组织形成、分化以及根的形成有不同的影响, 随着62BA 浓度的增加, 愈伤组织的诱导率有增加的趋势; 生长素与分裂素的比例决定着愈伤组织的分化; 小苗在1/ 2 MS 培养基上生根最好, 6-BA 对其生根有抑制作用。各培养阶段最适培养基: (1) 愈伤, MS + 6-BA 1 mg/L + NAA 0. 1 mg/L +3 %活性炭; (2) 芽诱导, MS + 6-BA 0. 5 mg/L + NAA 0. 5 mg/L ; (3) 生根, 1/ 2 MS + IBA 0. 2 mg/L。 相似文献
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芽孢杆菌BC98-Ⅰ抗真菌物质的初步分离及特性 总被引:1,自引:0,他引:1
BC98-Ⅰ是一株分离自沤肥浸渍液的蜡状芽孢杆菌,对蔬菜、瓜类、花卉枯萎病具良好的防治效果。它分泌产生的抗真菌物质的粗提物对黄瓜、西瓜、青椒枯萎菌有很强的拮抗作用,当浓度为10mg/mL时,抑菌圈直径分别达到20.33、20.22和22.77mm。该粗提物对高温高压、紫外光和蛋白酶均不敏感。同时,它在中性偏碱(pH8~9)的条件下活性最高;在极性溶剂如水、甲醇、乙醇中溶解度大,抑菌活性高。粗提液经Sephadex G100层析后,得到了两个洗脱峰,活性物质存在于第一峰中。抑菌机制试验表明:它可造成孢子萌发率降低、菌丝生长形态异常、分支加剧并产生大量泡囊。 相似文献
18.
AIM: The goal of this study was to compare different methods for tumor antigen preparation, to observe the induction of tumor-specific cytotoxic T lymphocytes in rats by dendritic cells (DCs) pulsed with different tumor antigens. METHODS: The precursors of dendritic cells were isolated from bone marrow of rats, stimulated in vitro with recombinent rat granulocyte-macrophage colony-stimulating factor (rrGM-CSF) and interleukin-4 (rrIL-4). Then rat DCs were pulsed with C6 tumor cell antigens prepared with different methods: freeze-thaw, boiling or total protein extracted from ultrasonic crushed tumor cell. Subsequently primed DCs were cocultured with T lymphocytes isolated from spleen to induce CTL. Lymphocyte chemoattractant factor from DCs and cytokine IFN-γ release were determined by ELISA, the cytotoxicity of CTL was assayed by JAM test. RESULTS: DCs pulsed with boiled tumor cell in vitro induced an enhanced ability of T-cell proliferation and cytotoxic T lymphocyte activity.CONCLUSION: Our results demonstrated that DCs primed with boiled tumor cell may represent a method for inducing immune responses against the entire repertoire of tumor antigens of malignancies. 相似文献
19.
ZHANG Qian CHENG Jiang-tao WANG Shu-chun QIAO Peng WANG Yi-ling WU Jing-lan WANG Yu-ruo 《园艺学报》2004,20(10):1874-1877
AIM: To explore the change and the possible role of MAPKs in rat hippocampus neuron after sleep deprivation. METHODS: The morphology of hippocampus neuron after sleep derivation was observed by TUNEL and HE staining, the activity of ERK was assayed by β-liquid scintillation counting and the expression of JNK was detected by Western blot. RESULTS: In paradoxical sleep deprivation (PSD) group, the number of apoptotic cells in hippocampus was increased. The scores of ERK activity were 1 764.00±941.56. Compared with control groups, the ERK activity was obviously decreased (P<0.05). The JNK expression was 87.5%, which was higher than that in control group. CONCLUSION: These results provide some important evidences that the sleep deprivation could cause changes in MAPKs activity, which may be related to the mechanism of hippocampus neuron apoptosis. 相似文献
20.
肉鸡和蛋鸡心肌易颤性的比较研究 总被引:1,自引:0,他引:1
以常规饲养的肉鸡和蛋鸡作为试验动物,通过电刺激诱颤阈和输钾诱颤阈的测定以及进行冷加压试验,对同体重肉鸡和蛋鸡的心肌易颤性进行了比较研究。结果表明:(1)同体重肉鸡和蛋鸡相比,电刺激诱颤阈和输钾诱颤阈肉鸡均极显著低于蛋鸡(P<0.01);(2)在电刺激诱发室颤的过程中,开胸时室颤的发生率肉鸡(14%)显著高于蛋鸡(0%)(P<0.05);(3)冷加压试验:冷加压5min内,心率和PT波宽出现了显著的变化,而且变化幅度肉鸡均明显大于蛋鸡。上述试验结果从不同方面均表明肉鸡心肌易颤性高于蛋鸡。 相似文献