白背飞虱羧酸酯酶与乙酰胆碱酯酶的体躯与亚细胞分布特征

白背飞虱Sogatella furcifera(Horváth)羧酸酯酶(CaE)和乙酰胆碱酯酶(AchE)的体躯及亚细胞分布特征研究结果表明，若虫头、胸、腹部中CaE活性分别占50.8%，26.0%和23.2%，雌成虫各占33.0%，23.5%和43.5%，雄成虫各占26.5%，23.2%和50.3%。若虫、雌雄成虫的AchE活性均主要分布于头部，各占总活性的87.7%，71.1%和74.7%。差速离心结果表明，该飞虱CaE主要位于胞质溶胶层中，其活性占57.0％～66.9%；AchE活性在胞质溶胶层中仅占5.8%～17.0%，而62.8%～76.9%的活性则分布于线粒体层、细胞核和细胞碎片层中。最后就上述两种酶在细胞中的存在形式作了讨论。     

基于改进生态足迹模型的保定市土地利用的生态安全评价

为保定市土地资源的合理开发利用提供依据,运用生态足迹模型及生态压力指数模型,研究了保定市土地利用的生态安全。结果表明:1)2002-2012年保定市土地利用生态安全水平呈下降趋势,生态压力指数年平均增长率为3.57%,2002-2003年土地利用生态系统的生态安全等级处于很不安全状态,2004年以后处于极不安全状态。经对2012年保定市区及22个县(市)安全等级进行分区,由西部山区到东部平原区的生态安全等级依次为较安全→很不安全→极不安全→较不安全。     

抗生素对不同基因型矮牵牛分化及再生的影响

以矮牵牛4个品种美声晨光、黄金肉红、珊瑚红、黄金紫罗兰星条为试材,分别以卡那霉素Kan和头孢霉素Cef为选择抗生素和抑菌剂,研究不同浓度抗生素对叶片不定芽再生和试管苗生根的影响,分别筛选出适宜的抗生素浓度。结果表明：30mg/L Kan可以抑制叶片不定芽再生,50mg/L Kan条件下,无不定芽再生。低浓度Kan即可抑制试管苗不定根再生,30mg/L Kan条件下试管苗不再生根。550mg/L Cef条件下,叶片不定芽再生受到抑制,而试管苗生根的适宜Cef浓度是400mg/L Cef。     

New records of endoparasitoidBassus fabricius, 1804 (Hymenoptera: Braconidae: Agathidinae) species from Turkey

SixBassus species were recorded for the first time in Turkey:B. calculator (Fabricius, 1798),B. cingulipes (Nees, 1814),B. conspicuus (Wesmael, 1837),B. graecus Achterberg, 1992,B. rugulosus (Needs, 1834) andB. zaykovi (Nixon, 1986). By adding these new records, the number ofBassus species in Turkey has been raısed from seven to 13. Distribution and known hosts are given.     

宝珠梨疫腐病病原菌研究

 宝珠梨疫腐病是云南省的一种新记录病害,其病原菌为恶疫霉Phytophthora cactorum (Lebert et Cohn) Schrot.适宜恶疫霉分离培养的培养基是番茄汁培养基、V8汁培养基和PDA培养基。适宜恶疫霉生长的pH值范围在3～10之间,最适pH值为5～6,适宜生长的温度范围为在10～30℃之间,最适生长的温度为20～25℃. 恶疫霉对果糖、麦芽糖、蔗糖等碳源的利用好于其它碳源,对酵母膏、天门冬酰胺、牛肉膏等氮源的利用好于其它氮源。     

2008―2021年新疆审定长绒棉品种主要性状演变分析

为全面了解近年新疆育成长绒棉品种的特征特性,对2008―2021年新疆维吾尔自治区主要农作物品种审定委员会审定的43个早中熟长绒棉品种和4个当前待审品种的主要性状演变情况进行分析.结果表明:2012年以来审定品种的铃重较之前明显增加,普遍在3.40 g以上;衣分总体表现较为平稳,皮棉产量受气候环境等因素影响波动较大;纤...     

Spatial continuity and local conditions determine spatial pattern of dried soil layers on the Chinese Loess Plateau

Purpose

Many efforts of restoring vegetation have ignored the feedbacks between biotic and abiotic factors that have developed in water-limited ecosystem. Dried soil layers (DSLs) have formed extensively on the Chinese Loess Plateau (CLP). The objective of this study was to identify the primary factors controlling spatial pattern of DSLs on the CLP.

Materials and methods

Two DSL indices (DSL thickness (DSLT) and soil water content in a DSL (DSL-SWC)) were estimated by measuring SWC to a depth of 5 m at 86 sites along a south-north transect on the CLP in 2013. The correlation between the spatial pattern of DSLs and environmental factors was determined with redundancy analysis (RDA).

Results and discussion

DSLs had formed at most of the sites (66 of the 86 sites) along the transect. The sites without DSLs were primarily in an irrigated agricultural zone. DSLT was >400 cm and generally increased from south to north, and DSL-SWC was 2.54% (v/v) in the semi-arid zone of the transect. The connected features of DSLs between connected neighboring sampling units exhibited a much wider extent. A total of nine environmental variables were the primary contributors to the spatial pattern of the DSLs, explaining approximately 47.3% of the variability. Local conditions were responsible for the higher proportion of explained variability than climatic factors. In addition, field capacity was the most important factor in all environmental factors, which may have influenced water-holding capacity.

Conclusions

This study concludes that spatial continuity and local conditions determine the spatial pattern of DSLs at a regional scale. Understanding the characteristic of DSLs is useful for efficiency of vegetation restoration and soil water management.

     

有机肥质量分数对土壤导水率稳定性的影响

饱和导水率是水循环和土壤侵蚀模型中的重要参数,也是土壤结构改善的重要指标.通过室内土柱模拟实验研究有机肥添加量对风沙土和壤土导水率的影响.土壤添加有机肥的比例设置为0％、5％、10％、15％、20％、25％、30％7个水平,土壤密度设3个水平,各处理5个重复.结果表明：1）土壤饱和导水率随有机肥质量分数的增加呈降低趋势,风沙土的饱和导水率随有机肥质量分数的增加呈直线下降趋势,而壤土饱和导水率的降低趋势随有机肥质量分数的增加减缓;2）有机肥质量分数的增加对土壤密度的降低作用可以抵消有机肥增加导致的饱和导水率的降低;3）低土壤密度下土壤导水率随时间变化不稳定,土壤密度增大后随时间变化稳定.随着有机肥质量分数的增加,土壤导水率的测定过程趋于稳定,但是测定时间延长.