河北小五台山国家级自然保护区野生观赏植物资源概况及保育策略

根据多年的野外调查和查阅相关文献,发现河北小五台山国家级自然保护区可开发利用的野生观赏植物资源占其资源总量的20％以上,即270余种具有引种驯化意义,其中很多种类具有重要的栽培价值。通过多次野外普查并结合多年的引种驯化经验,总结了各种植物的生态习性、抗性及其观赏用途等。此外,在野生植物资源保育策略方面提出设想和建议,以期为今后保护区的科学发展提供参考。     

花皮高产西瓜新品种安业8号的选育

安业8号是山东省邹平县安业农作物研究所选育的中熟、花皮、大果型一代杂交西瓜新品种。全生育期约100d,果实发育期33d;具有果个大、花皮韧、易坐果、品质优、抗性强、适应范围较广等突出特点。     

Mcl-1 involves in G2/M arrest of HL-60 cells induced by diallyl disulfide

AIM: To investigate the role of Mcl-1 in the G₂/M arrest induced by diallyl disulfide (DADS) in leukemic HL-60 cells.METHODS: The inhibitory effect of DADS on human leukemic HL-60 cells was detected by CCK-8 method in vitro. Flow cytometry analysis was employed to observe the cycle arrest in HL-60 cells and the effect of DADS-induced G₂/M arrest on HL-60 cells with Mcl-1 gene knockdown by RNAi silencing. The expression of Mcl-1, PCNA and CDK1 in HL-60 cells treated with DADS was determined by Western blotting. The binding of Mcl-1 with PCNA and CDK1 was detected by coimmuno-precipitation. RESULTS: HL-60 cells were treated with DADS at concentration of 15, 30, 60, 120 or 240 μmol/L for 48 h. The inhibition rates of HL-60 cell proliferation were 31.15%, 55.88%, 66.14%, 75.29% and 80.35%, respectively, and gradually enhanced with the increase in the concentration of DADS (P<0.05). Flow cytometry analysis revealed that the proliferation of HL-60 cells was blocked by DADS in the G₂/M phase. Treatment with DADS for 24 h and 48 h at concentrations of 60 μmol/L and 120 μmol/L, the percentage of G₂/M phase cells increased as compared to the untreated cells (P<0.05). DADS induced arrest of HL-60 cells in G₂/M phase in a time- and dose- dependent manner (P<0.05). The results of Western blot analysis indicated that Mcl-1, PCNA and CDK1 in HL-60 cells were significantly reduced after treated with DADS (P<0.05). HL-60 cell cycle progression delayed by silencing Mcl-1 gene with siRNA technique, suggesting that silence of Mcl-1 gene led to G₂/M arrest. Compared to the cells treated with DADS only, the percentage of G₂/M cells raised in the cells with Mcl-1 gene silencing and treated with DADS (P<0.05), indicating that Mcl-1 gene silencing enhanced the effect of DADS-induced G₂/M arrest in HL-60 cells. The binding of Mcl-1 with PCNA and CDK1 was detected by coimmuno-precipitation and the formation of heterodimers was observed, which was decreased after treated with DADS for 4 h.CONCLUSION: DADS inhibits the proliferation of HL-60 cells and induces its G₂/M phase arrest. The decreased expression of PCNA is related to inhibiting the proliferation of leukemic cells. Knockdown of Mcl-1 gene enhances the effect of DADS-induced G₂/M arrest.     

金黄色葡萄球菌及其肠毒素等指标在发酵牛肉加工过程中变化规律的研究

作者对自然状态发酵牛肉、接种金黄色葡萄球菌的发酵牛肉和接种发酵剂(植物乳杆菌、戊糖片球菌)与金黄色葡萄球菌的发酵牛肉中金黄色葡萄球菌及其肠毒素等指标在加工过程中的变化规律做了研究。研究结果表明,自然发酵牛肉中没有金黄色葡萄球菌及其肠毒素;接种发酵剂和金黄色葡萄球菌的发酵牛肉中金黄色葡萄球菌先是上升然后快速下降,且金黄色葡萄球菌肠毒素为阴性;接种金黄色葡萄球菌的发酵牛肉中金黄色葡萄球菌及其肠毒素都显著高于接种发酵剂的发酵牛肉(P＜0.05)。由试验结果可知,发酵剂植物乳杆菌和戊糖片球菌对金黄色葡萄球菌有很强的抑制作用。     

木兰科植物主要病害及其防治研究

报道了木兰科植物主要病害的种类、病原及发病规律,并提出综合防治措施。     

抗氧化剂在公猪精液冷冻保存中的应用

近几年来,在公猪精液冷冻稀释液中添加抗氧化剂以提高冷冻精液质量的研究受到广泛的关注。添加谷胱甘肽、超氧化物歧化酶和过氧化物酶、维生素E、L-半胱氨酸和L-谷氨酰胺、中草药成分等抗氧化剂可以有效地防止氧化损伤,提高解冻后精子活率、精子成活力、质膜与顶体完整性等,进而提高冷冻保存精液的受精能力。作者综述了抗氧化剂的抗精子冷冻损伤的作用机制及不同抗氧化剂的应用效果,并对其在公猪精液冷冻保存中的应用前景进行了展望。     

玉米田杂草马唐的生长特性研究

在田间和室内条件下研究了马唐的生长特性。结果表明 ,马唐种子具有短期休眠 ,其出苗的适宜土壤深度为 0 .5～ 4 .0cm ;随着密度的增加和出苗时间的推迟 ,马唐的单株生长量逐渐下降。