防御素基因在乌金猪与约大乌猪组织中的表达及东亚飞蝗抗菌活性物质对防御素基因表达的调节作用

本试验旨在检测β防御素-1(p BD-1)、β防御素-2(p BD-2)和β防御素-3(p BD-3)基因在乌金猪和具有乌金猪血缘的约大乌猪不同组织中的表达,并探讨东亚飞蝗抗菌活性物质(LAAS)对猪胎儿皮肤成纤维细胞(PFSF)免疫应激参数和防御素(p BDs)基因表达的调节作用。采用实时荧光定量PCR方法检测2月龄乌金猪与约大乌猪心脏、肝脏、肺脏、肾脏、空肠、回肠、十二指肠、皮肤、肌肉、胰腺、睾丸或卵巢这12种组织中p BD-1、p BD-2和p BD-3基因的表达差异;采用培养至第4~5代的PFSF,通过脂多糖(LPS)诱导建立免疫应激模型,在DMEM/F12培养液中添加不同浓度(0、75、150、300、600和1 200μg/m L)的LAAS,考察LAAS对PFSF免疫应激参数和p BD-1、p BD-2、p BD-3基因表达的影响。结果表明:1)乌金猪血清溶菌酶(LSZ)活性、免疫球蛋白G(Ig G)含量显著高于约大乌猪(P0.05),血清一氧化氮(NO)含量极显著低于约大乌猪(P0.01)。2)约大乌猪大多数组织中p BD-1、p BD-2和p BD-3基因的表达量高于乌金猪;2个品种猪的p BD-1和p BD-3基因均在皮肤和卵巢中表达量较高,p BD-2基因在肝脏和肾脏中表达量较高。3)300μg/m L LAAS极显著降低了培养液中乳酸脱氢酶(LDH)活性(P0.01);LAAS极显著增加了培养液中NO含量(除75μg/m L组正常细胞外)(P0.01),正常细胞和应激细胞均在LAAS浓度为600μg/m L时达到最高;LAAS浓度为0、75和150μg/m L时应激细胞一氧化氮合酶(NOS)活性显著或极显著高于正常细胞(P0.05或P0.01);添加1 200μg/m L LAAS可极显著降低培养液中的LSZ活性(P0.01),LAAS浓度为150、300、600和1 200μg/m L时应激细胞与正常细胞中LSZ活性差异显著或极显著(P0.05或P0.01)。4)应激细胞p BD-1、p BD-2和p BD-3基因的表达量均高于正常细胞;当LAAS浓度为150μg/m L时,p BD-1、p BD-2和p BD-3基因的表达量最高。结果提示,乌金猪和约大乌猪防御素基因的表达存在明显的品种差异性和组织特异性,适宜浓度的LAAS能够降低PFSF中LDH活性,提高NO含量及NOS、LSZ活性,上调应激细胞与正常细胞防御素的表达量。     

黄脊竹蝗监测预警技术指标的初步研究

提出了黄脊竹蝗界标准的危害程度。在饲养观察的基础上,初步确定了黄脊竹蝗的监测预警技术指标,并就发布各虫期(态)发生趋势预报的相关问题提出了建议。     

激素、通气和pH值对四倍体刺槐和二乔刺槐离体生长的影响

以四倍体刺槐和二乔刺槐的不定芽为试验材料,通过比较培养前后的芽伸长量、增殖率和生物量等指标,研究了激素、通气状况(封口材料)、培养基pH值对刺槐离体生长的影响.结果表明,在BA0.5mg/L、NAA0.1mg/L时,四倍体刺槐不定芽的生物量最大;在BA0.5mg/L、NAA0.5mg/L时,二乔刺槐不定芽的生物量最大.在湿度为35%±5%环境条件下,四倍体刺槐封口材料以耐高温塑料最好,二乔刺槐以棉塞最好;在湿度为55%±5%条件下,四倍体刺槐和二乔刺槐均以棉塞最好.在pH值为5.6、5.8和6.0时四倍体刺槐的增殖系数大,二乔刺槐在pH为6.4时的增殖系数大,而两品种在不同pH下的质量增量百分率差异不显著.     

不同退耕还林模式对土壤修复作用的研究——以甘肃省庆阳市为例

以甘肃省庆阳市为例,探讨了退耕还林对土壤理化性质的影响,结果表明:坡耕地退耕后,有机质和营养元素的含量渐趋恢复,土壤容重、pH值减小,土体中团聚体的数量增大,土壤结构不断得到改善。其中刺槐×沙棘混交林地速效养分丰富,粘粒和≥0.25mm水稳性团聚体的数量大;侧柏×沙棘混交林地则酸性强,容重低,≥50μm的微团粒含量较高。刺槐×沙棘混交林对土壤的修复作用明显强于侧柏×沙棘混交林。     

不同培养基对四倍体刺槐叶片不定芽诱导研究

以四倍体刺槐不同着生节位大田叶片为试材,接种于3种不同培养基进行培养,诱导不定芽,使其形成再生植株。结果表明:以尚未充分展开复叶为最佳外植体,MS Salt B5Vitamin 1.8 mg/L NAA 1.1mg/L6-BA培养基为最佳诱导培养基,愈伤组织诱导率、芽分化率、苗增值系数最高,分别为96.7%、93.1%、9.1倍。     

Soil moisture relations at the tree/crop interface in black locust alleys

A study was undertaken in Ohio to determine whether the presence of black locust hedgerows would increase water shortage on crop land. Water was applied to bare soil which had carried pure stand maize in the previous growing season, and to the previously established alley cropping plots, some of which had 100 cm deep below-ground fiberglass partitions to prevent root competition for soil moisture in the alleys. Direct soil evaporation was reduced by covering the soil with a black polyethylene sheet. Soil moisture remaining in the top 45 cm soil depth was monitored for 8 days. Soil 1 had a higher organic carbon content and contained more moisture than Soil 2, which had more gravel than Soil 1. In Soil 2 there was significantly less water in alleys without below-ground partitions than on bare soil. In alleys without below-ground partitions, the hedgerows reduced soil moisture content of the alleys without below-ground partitions, the hedgerows reduced soil moisture content of the alleys by about 8% on Soil 1 and 32% on Soil 2, after 8 days following water application. In the top 45 cm depth of Soil 1, the influence of the hedgerows in the same treatment was large within 76 cm of the hedgerows but declined farther inside the alleys. For Soil 2 which had more gravel in the lower soil layers, which prevented deep growth of black locust roots, the influence of the hedgerows was pronounced throughout the alleys but was also most marked within the 76 cm distance from the hedges.     

太行山刺槐花量与蜜源林经营

通过对大量标准地的调查研究表明，单株开花量主要受自身遗传因素的控制，单株在量为0－5．2kg／株，同一单株各年度的开花量也有较大变化。林分花量与林龄、林分平均胸径、林分平均高、林分优势木平均高、每公顷胸高断面积、每公顷蓄积、林分总生物量、林分干量、林分枝量、林分叶量、林分根量等林分因子均具有极显著的相关关系，通过逐步回归分析，筛选出影响林分花量的主要林分因子，并建立了林分花量的多元回归估测模型。林分花量生长动态符合生物增长的Logistic运动规律，其速生点为8a，速生期为4-12a，林分生长后期的花量动态与干、枝、叶、根等其它器官的生长动态存在显著差异，上述结论对蜜源林的经营具有重要意义。     

竹蝗林间防治试验

应用油烟雾剂、敌敌畏烟剂、林丹烟剂、药尿液等不同药剂进行林间防治竹蝗试验 ,结果表明油烟雾剂、敌敌畏烟剂对竹蝗的防治效果较好 ,药尿液也有良好的防治效果。同时 ,提出了竹蝗综合防治措施 ,在大发生初期采用油烟雾剂或烟剂防治 ,在一般发生年份应用药尿液诱杀防治     

Fine root biomass,distribution, and production in young pine-hardwood stands

Patterns of fine root biomass, production, and distribution were estimated for pure stands and mixtures of three-year-old loblolly pine (Pinus taeda L.) with red maple (Acer rubrum L.) or black locust (Robinia pseudoacacia L.) on the Virginia Piedmont to determine the role of fine roots in interference between pine and hardwood tree species. Estimates were based on amounts of live and dead fine roots separated from monthly core samples during the third growing season after planting. Live and dead fine root biomass and production varied by species, but mixtures of loblolly pine and black locust generally had greater fine root biomass and fine root production than pure stands or loblolly pine-red maple mixtures. Hardwood species had greater live fine root biomass per tree in mixtures with pine compared to pure stands. Greater live fine root biomass in pine-locust stands may be attributed to differential utilization of the soil volume by fine roots of these species. For all stands, approximately 50% of live five root biomass was located in the upper 10 cm of soil.     

杨树刺槐混交林下沙质土壤腐殖物质特性

研究了沙质土壤种植杨树、刺槐纯林和混交林后土壤腐殖物质特性变化的状况。研究结果表明：与无林地相比，沙地土壤种植树、刺槐纯林和混交林后土壤有机C和腐殖质C增加，土壤胡敏酸的光密度值增大，胡敏酸／富啡酸比值上升，E4和Ec值提高，色调系数（△logK）降低和相对色度（RF）升高，土壤松结合态腐殖物质（Ⅰ）和紧结合态腐殖物质（Ⅲ）以及松／紧（Ⅰ／Ⅲ）比值均有不同程度的增加，土壤稳结合态腐殖质（Ⅱ）的含C量占土壤全C的比例有不同程度的下降，表明土壤腐殖物质的聚合程度提高，腐殖物质的芳香核原子团增多，芳化度和芳化分子复杂程度以及腐殖化程度均得到提高，腐殖物质的品质变佳，土壤熟化度增大，土壤供肥保肥的能力增强，土壤肥力得以提高。培肥土壤的效果以种植杨树枣槐混交林为,其次为刺槐纯林，再次为杨树纯林。