荸荠新品种桂蹄2号与芳林荸荠种植比较试验

将荸荠新品种桂蹄2号和传统主栽品种芳林荸荠进行种植比较,结果显示,2个品种的植株生长期和外部生长特性基本一致,特征差异主要在花穗、产量和大果率3个方面.桂蹄2号的叶状花茎比芳林荸荠多且花穗长度相对较长,花穗平均长度为39.8 mm,最长花穗达58.4 mm;桂蹄2号产量为3208 kg/667 m2,大果率71.1%,与芳林荸荠相比均有大幅提高.桂蹄2号是一个产量高、商品价值率高的优良新品种.     

不同基质配方对章姬草莓移栽苗的影响

探讨了不同基质配方和栽培环境移栽草莓的效果,分析了草莓大田苗移栽效果的有关影响因素。试验结果表明,草莓苗基质栽培中,基质种类、混合比例和湿度条件等因素对移栽效果的影响均表现明显;其中,采用草炭∶菇渣∶珍珠岩∶河砂=3∶2∶1∶1的栽培基质,并配合移栽后的10 d内保持相对湿度80%～90%的条件下,草莓苗的移栽缓苗良好,移栽成活率达100%,且幼苗生长发育状况良好。     

Are laboratory derived toxicity results informative for field situations? Case study on earthworm populations contaminated with heavy metals

The relevance of laboratory tests on toxicants for field situations is often disputed given that laboratory tests are conducted under, next to the toxicant stress, optimal conditions which are not expected in field situations. In this paper we confront the results of laboratory tests on growth, reproduction and survival of earthworms, in a polluted and a reference field soil with a field inventory of earthworms. The field inventory includes population density, biomass and demographic composition in life stages measured monthly over a period of one year. The field inventory showed that density and biomass was higher at the polluted field site, a result in conflict with the extrapolation of the laboratory tests that showed a decrease in population growth rate by 23% at this site compared to the reference. The field inventory and laboratory derived results agreed in the demographic composition of the population with more individuals in the younger age class at the polluted site compared to the reference. Abiotic and biotic conditions that differ between sites and could possibly explain the lower earthworm biomass and density at the reference site are discussed. We suggest that predation by the two to five times higher densities of meadow birds in spring may have caused the lower density and biomass of earthworms at the reference site.     

Impacts of earthworms and arbuscular mycorrhizal fungi (Glomus intraradices) on plant performance are not interrelated

Earthworms and arbuscular mycorrhizal fungi (AMF) might interactively impact plant productivity; however, previous studies reported inconsistent results. We set up a three-factorial greenhouse experiment to study the effects of earthworms (Aporrectodea caliginosa Savigny and Lumbricus terrestris L.) and AMF (Glomus intraradices N.C. Schenck & G.S. Sm.) on the performance (productivity and shoot nutrient content) of plant species (Lolium perenne L., Trifolium pratense L. and Plantago lanceolata L.) belonging to the three functional groups grasses, legumes and herbs, respectively. Further, we investigated earthworm performance and plant root mycorrhization as affected by the treatments. Our results accentuate the importance of root derived resources for earthworm performance since earthworm weight (A. caliginosa and L. terrestris) and survival (L. terrestris) were significantly lower in microcosms containing P. lanceolata than in those containing T. pratense. However, earthworm performance was not affected by AMF, and plant root mycorrhization was not modified by earthworms. Although AMF effectively competed with T. pratense for soil N (as indicated by δ¹⁵N analysis), AMF enhanced the productivity of T. pratense considerably by improving P availability. Remarkably, we found no evidence for interactive effects of earthworms and AMF on the performance of the plant species studied. This suggests that interactions between earthworms and AMF likely are of minor importance.     

恩施烟区土壤氮素和烤烟烟碱含量的分布特点及关系分析

以恩施烟区有代表性的宣恩县和咸丰县为试验地点, 采用野外调查与室内分析相结合的方法, 分析了土壤氮素和烤烟烟碱含量的分布状况及其相互关系, 结果表明: 恩施烟区土壤全氮含量适宜, 速效氮含量明显偏高, 依据土壤氮素含量, 可把129个供试土壤样品聚成高、中、低3类, 其中低氮类样本所占比例(60.47%)最大.烤烟烟碱含量变幅为8.18～42.25 g·kg-1, 平均为22.80 g·kg-1, 变异系数为36.42%; 烟碱含量在15～35 g·kg-1的样本占总样本数的66.94%; 烟碱含量在不同品种间、等级间和海拔高度间均存在显著变异, 品种间烟碱含量表现为"K326">"云烟85">"云烟87", 不同等级间表现为B2F>C3F>X2F, 不同海拔间表现为低海拔>中海拔>高海拔.建立了土壤速效氮含量对烤烟烟碱含量的回归方程, 经F测验未达到显著水平.     

生物学野外教学实习的问题分析与改革思路

结合生物学学科的特点,分析了生物学野外教学实习过程中存在的定位较为简单、内容单一、经费不足、考核评价环节较少、条件简陋等问题,由此提出改革思路,强调调整野外实习理念、整合实习内容、开展问题驱动的研究型实习,并尝试与乔治亚州立大学合作。提出生物学野外教学改革的具体实施操作,建议制订较为详细的生物学野外教学实习计划,采取分段实习,并建立及实施多元化的课程评价体系。目的在于提高西南交通大学生物学野外实习的质量,培养高素质的复合型人才。     

不同剂型吡虫啉的杀蚜活性比较

拟明确吡虫啉剂型与生物活性的关系,以期获得高效、安全环保及应用范围广的制剂产品,进而为其正确合理使用提供依据。以吡虫啉5种剂型制剂为供试药剂,萝卜蚜、苹果黄蚜、烟蚜和麦长管蚜等4种不同属蚜虫为试虫,分别采用浸虫浸叶和常量喷雾进行室内与田间生物活性比较。室内试验表明,乳油、微乳剂、可溶性液剂、悬浮剂及可湿性粉剂24h的LC50分别为6.15~17.54、7.38~18.44、8.71~20.59、8.62~20.72和20.97~29.49mg/L;田间试验表明,有效成分为30g/hm2时,乳油、微乳剂、悬浮剂及可溶性液剂对苹果黄蚜速效性好、持效期长、防效相当,7d仍在94%以上,而可湿性粉剂防效较差,药后7d为84.01%。可见,悬浮剂与乳油、微乳剂及可溶性液剂的生物活性基本相当,而可湿性粉剂活性最低。然而,从安全、环保及生产成本等综合考虑,推荐在生产应用中应以吡虫啉悬浮剂为主。     

甘农1号小黑麦的田间抗旱性研究

以‘甘农1号'小黑麦(Triticale wittmack)为试验材料,‘石大1号'(CK1)和‘中饲1048'(CK2)为对照,通过测定不同干旱胁迫天数的土壤水分含量和生理生化指标,以研究‘甘农1号'小黑麦的田间抗旱性,为其在西北干旱半干旱雨养农业区种植提供参考。于小黑麦分蘖期采用遮雨棚控水法进行干旱胁迫处理,分别在干旱胁迫第7,14,21,28,35和42 d测定土壤含水量,并采集叶片测定其可溶性糖含量、脯氨酸含量和丙二醛含量等生理生化指标,直到小黑麦地上部分萎蔫至死亡。结果表明:除品种间和品种×干旱胁迫天数交互作用间丙二醛含量无显著差异外,品种间、干旱胁迫天数间和品种×天数互作间可溶性糖、脯氨酸、POD、SOD、CAT含量均存在极显著差异(P0.01)。3个小黑麦品种的抗旱能力强弱依次为:‘甘农1号'CK2CK1,‘甘农1号'属于中抗旱型,CK1和CK2为干旱较敏感型。     

Validating the effectiveness and sensitivity of two soil quality indices based on natural forest soils under Mediterranean conditions

Soils from natural ecosystems have specific physical, chemical and biochemical properties determined by the conditions in which these soils have developed. These soils that develop without external disturbance reach a balance amongst their properties. Thus, the creation of a model that represents the established balance of different soil properties from stable ecosystems can be used as a soil quality index, thus any perturbation must lead to modifications in this natural balance. Two regression models with soils from undisturbed forest regions in eastern Spain were previously developed, representing the balance between organic carbon and some physical, chemical and biochemical properties. For undisturbed forest soils, the prediction of soil organic carbon (SOCc) with the calibrated models should be similar to the actual value of this variable (SOCa) (SOCc ≈ SOCa). Consequently, the residuals (SOCc − SOCa) should be around 0. On the contrary, disturbance practices cause a disruption in the balance defined between the different properties and SOC. As a consequence, residuals must be < or >0. Furthermore, the more the degree of degradation increases, the more the values of SOCc must differ from the values of SOCa. According to this, two soil quality indices (SQI) were defined, one for each model, by the calculation of the model residuals (SQI = SOCc − SOCa). The SQIs have been applied to different undisturbed forest soils to evaluate their validity. In addition, they have also been applied to severely altered soils, like agricultural soils, and abandoned agricultural fields, to assess the sensibility of this index to perturbations. After applying the soil quality indices to eleven undisturbed forest soils, it has been verified that a balance exists between organic matter content and different physical, chemical and biochemical properties in forest soils from SE Spain, and the proposed calibrated models are capable of reflecting that balance (SQI ≈ 0). Our results confirm that our models are sensitive to soil perturbation, because agricultural and abandoned agricultural soils have shown an imbalance between organic carbon content and the physical, chemical and biochemical properties (SQI > 0). Moreover, soils from abandoned fields showed lower deviation in the natural equilibrium, indicating a recovery of soil quality.     

面包专用小麦高产栽培技术

WANG Jin-hua(Shanghai Guangming Qianjin Farm Co.,Ltd.,Shanghai 202179)