跨区域产学研合作可以促进农作物育种科技创新收敛吗?——基于创新链视角的研究

为促进我国种业科技创新能力的提升,本研究运用全国31个省(市、自治区) 1999-2020年的面板数据(统计数据未含港澳台地区,下同),基于创新链视角,将农作物育种科技创新划分为基础研究、应用研究及试验发展阶段,采用社会网络分析方法和Dagum基尼系数分别对跨区域产学研合作的发展特征及育种科技创新的地区差异进行分析、运用β收敛模型检验跨区域产学研合作对农作物育种科技创新收敛的影响。研究表明：1)跨区域产学研合作呈现增长趋势,但合作中创新资源传递的效率降低。2)农作物育种科技创新产出存在较大的地区差异,但差异逐渐缩小,地区间差异是造成地区总体差异的主要原因。相对于试验发展阶段,基础研究和应用研究创新产出的地区差异较大、差异缩小的速度较慢。3)农作物育种科技创新存在收敛性发展特征,跨区域产学研合作加速了其创新收敛。从全国层面看,跨区域产学研合作对基础研究创新收敛的促进作用最强,对应用研究的促进作用最小。分区域看,跨区域产学研合作促进了东、中、西部地区的创新收敛,且对中、西部创新产出增长的促进作用更大。从时间演变看,由于合作中创新资源传递的效率降低,跨区域产学研合作对农作物育种科技创新收敛的...     

草坪在城市园林绿化中的作用及其发展研究

草坪在现代城市园林绿化中具有重要作用,如维持城市生态平衡、发展社会效益、美化环境等。本文在阐述草坪综合功能的同时,又从因地制宜地开发草坪资源,健全市场,应用新技术等方面就草坪业的发展进行了研讨。     

Do cover crops change the lability of phosphorus in a clayey subtropical soil under different phosphate fertilizers?

Plants have developed different mechanisms to absorb and solubilize phosphorus (P) in the soil, especially in environments with low P availability. This study evaluated the effects of different winter cover crops on soil P availability in a clayey subtropical (Hapludox) soil receiving soluble P fertilizer and a rock phosphate applied to the summer crop, under no‐tillage. The experiment was carried out over 3 yrs (2009–2011) with five different cover crop species: common vetch, fodder radish, ryegrass, black oat, white clover and fallow as control. The soil was sampled after the third year of cover crop cultivation and analysed for inorganic and organic P forms according to the well‐established Hedley fractionation procedure. Phosphate fertilizers promoted accumulation of both labile and nonlabile P pools in soil in the near surface layer, especially under rock phosphate. Fertilizer applications were not able to change P fractions in deeper layers, emphasizing that the Brazilian clayey soils are a sink of P from fertilizer and its mobility is almost nil. Although the cover crops recycled a great amount of P in tissue, in a short‐term evaluation (3 yrs) they only changed the content of moderately labile P in soil, indicating that long‐term studies are needed for more conclusive results.     

涪陵南沱茎瘤芥种植基地环境质量评价--土壤重金属

采用环境调查的方法研究了涪陵南沱镇茎瘤芥种植基地土壤重金属含量。结果表明,该区域土壤整体上重金属污染水平较低,基本没受到汞和铬污染,但已受到了铜、铅、镉污染,特别是镉污染已经相当严重。相关分析和回归预测分析均表明土壤养分对土壤重金属含量有较大影响。     

分层供水施磷对冬小麦磷效率及产量的影响

研究分层供水施磷对冬小麦磷效率及产量的影响,为指导旱地施磷提供一定理论和实践依据。试验设整体湿润(W1)和上干下湿(W2) 2 种水分处理,不施磷(CK)、表施(SP)、深施(DP)3 种施磷处理,供试品种选用水分敏感型（‘小偃22’）和抗旱型（‘长旱58’）。研究结果表明：磷肥施用深度对冬小麦磷根效率比、磷肥利用效率、磷肥偏生产力(PFPP)及产量的影响随土壤水分和品种而异。2 种水分条件下,‘小偃22’DP较SP处理磷肥利用率、PFPp均显著降低(P＜0.05),磷根效率比及产量则差异不显著;W1 处理下,‘长旱58’DP较SP处理除磷根效率比外其他指标均显著降低(P＜0.05),W2 处理下则相反,上述指标均显著增加(P＜0.05)。本试验结果表明,土壤水分供应不足时,磷肥深施有利于提高抗旱性较强冬小麦品种对磷素的吸收利用能力,从而提高磷肥利用率及产量。     

核酸疫苗SjCA/pc和SjMf1/pc在小鼠体内的表达

为了观察核酸疫苗SjCA／pc和SjMfl／pc在小鼠体内的表达，取昆明鼠，于其后腿外侧肌注免疫SjCA／pc和SjMfl／pc，2d后剖杀动物．取注射部位肌肉作石蜡切片，免疫组化分析，荧光显微镜下镜检。结果表明，SjCA／pc和SjMfl／pc在小鼠注射部位肌肉可见黄绿色荧光，而对照组无此现象。可见，SjCA／pc和SjMfl／pc可在小鼠体内表达。     

兔眼蓝莓组织培养过程中褐化与生根问题的探讨

以兔眼蓝莓茎尖和茎段形成的愈伤组织和长期继代培养的试管苗为材料,接种于改良的WPM和1/2WPM的培养基中,研究活性炭与Vc液对兔眼蓝莓外植体和愈伤组织形成中褐化的影响以及外源体、活性炭对无根苗瓶内生根的影响。结果表明,当培养基中加入Vc液并含100～200 mg·L-1的活性炭时,能有效防止外植体褐化的发生;当培养基中加入Vc液并含200～500 mg·L-1活性碳时,可有效防止愈伤组织褐化发生。蓝莓继代培养试管苗在1/2 WPM的培养基中添加0.2 mg·L-1IBA,并含100～200 mg·L-1活性炭时生根情况最为理想,经过7 d暗培养,30 d后生根率高达87.8%。     

Protective effect of vitamin C and lycopene on the in vitro fertilization capacity of sex-sorted bull sperm by inhibiting the oxidative stress

The fertilization capacity of sex-sorted sperms is seriously decreased, which inhibits its wide application. However, little information is still available about the effect of vitamin C (VC) and lycopene (Lyc) on the fertilization capacity of sex-sorted bull sperm. In this study, the washing medium and fertilization medium of sex-sorted sperm from three bull individuals were supplemented with different concentrations of VC (0, 1 × 10^–3, 1 × 10^–4, 1 × 10^–5, 1 × 10^–6 M) or Lyc (0, 1 × 10^–4, 1 × 10^–5, 1 × 10^–6, 1 × 10^–7). After washing twice and incubation for 1.5 hr, the malondialdehyde (MDA) level, phosphatidylserine (PS) translocation, membrane potential (Δψm) and IVF (in vitro fertilization) ability of sex-sorted sperm were investigated. For the sex-sorted sperm of bulls A, B and C, 1 × 10^–3 M VC or 1 × 10^–4 M Lyc treatment significantly decreased their MDA levels and PS translocation and increased their Δψm levels and cleavage rates after IVF. When blastocysts were concerned, 1 × 10^–4 M Lyc significantly improved the blastocyst rates and their IFN-tau expression of bulls A and C. In conclusion, supplementation of 1 × 10^–3 M VC or 1 × 10^–4 M Lyc in washing and fertilization medium contributed greatly to improving the fertilization capacity of sex-sorted bull sperm during IVF procedure.     

规模养蚕新技术的研究Ⅰ.大棚养蚕温湿度对蚕茧产质量的影响

试验调查了大棚养蚕春、夏大蚕期与蔟中的温湿度变化,以探索有利于大棚养蚕的饲养技术与小气候调节技术.棚内温湿度变化对蚕茧产质量的影响比较分析表明,春期5龄后期和上蔟初期,35～38.8℃的高温对蚕茧产质量有较大影响;夏蚕期棚内温度明显高于春蚕期,最高超过40℃,连续高温持续时间长,昼夜温差大.根据春、夏期不同的气候特点,春期大棚上蔟初期要重点进行降温排湿,夏期重点进行降温.     

牛烂蹄坏尾病致病弯角镰刀菌代谢产物分离鉴定

取金寨县耕牛烂蹄坏尾病致病弯角镰刀菌的玉米培养物，用丙酮提取，硅胶净化，制备型硅胶大板分离，得到无色针状结晶体，经质谱和红外光谱分析，并经相关谱图数据库联机检索、甄别，按其分子量、化学式及结构式确定为麦角甾醇，从而证实了致牛烂蹄坏尾病的弯角镰刀菌可产生麦角甾醇。