枸杞红瘿蚊入土、出土及其在土壤中活动规律

枸杞红瘿蚊主要集中在3 cm土层,9 cm土层内只有少量分布,在土中活动方向上没有差异。幼虫入土初期的灌水可促使幼虫下潜;化蛹羽化时幼虫上迁至土表,此时灌水可使上迁变得困难。枸杞红瘿蚊在土中移动水平距离是12.5 cm。     

山羊人工感染日本血吸虫血清酶活性的变化

山梨醇脱氢酶活性在牛羊四氯化碳中毒显著升高,γ-谷氨酰转肽酶活性在牛羊肝片形吸虫病显著升高,而山羊日本血吸虫病,这些酶活性都无变化,只有鸟氨酸氨基甲酰转移酶活性显著升高.由此可知,肝特异酶活性,在不同肝病中可出现不同的变化,这对诊断上具有重大意义.     

Microbial diversity and activity of disturbed soil in the northern Chihuahuan Desert

 The effects of intense grazing, seasonal drought, and fire on soil microbial diversity (substrate utilization) and activity in a northern Chihuahuan Desert grassland were measured in summer 1997, winter 1998, and spring 1998. Intense livestock grazing was initiated in winter 1995, burning occurred in August 1994, and drought stresses were imposed from October 1994 to June 1997. Microbial diversity was inferred from the carbon substrate utilization patterns in both gram (+) and gram (–) Biolog plates. Microbial activity was estimated by the activity of selected enzymes. Neither microbial diversity nor activity was affected by grazing. The interaction of intense grazing and stress sub-treatments only occurred in spring for one set of diversity measurements. The maximum microbial diversity and activity occurred in the winter-drought-stress sub-plots in summer and spring. Burning reduced microbial diversity and most enzyme activities as compared to the control in summer and spring. Microbial diversity was also lower in summer-drought-stress sub-plots than in the control in summer and spring. Microbial diversity was highest in summer, intermediate in winter, and lowest in spring. Microbial activity was generally higher in summer and lower in winter. It was concluded that substrate availability was the most important factor affecting the diversity and activity of soil microorganisms within a season. Soil moisture was not the factor causing differences in microbial diversity and activity among the stress treatments, but it was a predictor for some microbial responses under a particular stress. Received: 12 August 1999     

烟田施用菜子饼肥对土壤酶活性及烟叶质量的影响

试验结果表明,植烟土壤施用油菜子饼肥后,增加了土壤蔗糖酶、尿酶、过氧化氢酶的活性,促进了烟株的生长发育,增加了烤烟的经济效益;水稻田土壤中的酶活性高于山地土壤,且烟株长势较强,经济指标也高于山地烟;田烟氮化合物含量高,化学成分协调性稍差;烟叶感官评吸质量以施用油菜子饼肥的山地烟最高,未施用油枯的山地烟最低。     

甜瓜种子活力的初步研究

以相同年份相同地点收获的5个甜瓜品种种子为材料,采用幼苗生长测定、电导率测定、加速老化试验、抗冷测定、模拟田间出苗率测定以及POD、CAT、SOD、ADH、Apase等酶活性测定和MDA含量测定等10种方法测定种子活力,并进行活力指标间的相关分析。结果表明:不同品种间种子活力水平为:红城脆>八里香>灰鼠子>龙甜>白沙蜜;加速老化试验发芽率和POD活性均与模拟田间出苗率呈显著正相关,幼苗生长测定的活力指数和SOD活性均与模拟田间出苗率呈极显著正相关。该研究初步认为幼苗生长测定、加速老化试验、POD和SOD活性测定,可作为甜瓜种子活力测定较好的方法。     

小麦脯氨酸脱氢酶活性染色方法研究

以小麦(Triticum aestivum L.)为研究材料,建立了小麦叶片脯氨酸脱氢酶活性染色方法。结果表明,小麦叶片脯氨酸脱氢酶活性染色的最佳反应pH值是10,而且脯氨酸脱氢酶谱带的大小与酶浓度呈正比。该染色方法是在脯氨酸脱氢酶活性测定的基础上建立起来的,克服了酶活力测定过程中由于异硫氰酸甲酯在水溶液中的颜色变化而造成的酶活力测定误差大,平行性差的缺点,具有简单直观的优点。     

7种菜用豆中凝集素活性的比较

菜用豆中的豆科凝集素主要存在于豆粒中,加工不当易引起食用者中毒。通过血凝试验对7种菜用豆中凝集素的活性进行了测定和比较,确定了凝集素提取液中的凝集素最适检测浓度。结果表明,7种菜用豆中凝集素的活性各不相同,刀豆样品中凝集素活性最强,凝集效价为27,蚕豆样品最弱,为23。     

BR对小麦种子萌发和幼苗生长的影响

试验以小麦品种豫麦10号为材料,研究了0.1ug ml~(-1)BR浸种对小麦种子萌发和土培条件下小麦苗体生长状况的影响。结果表明,无论在蒸馏水中或是在0.2M甘露醇溶液中BR处理发芽率分别比对照提高7.2％和9.0％,胚根条数分别比对照增加0.8条和O.9条。土培条件下,BR处理明显地促进根系发育,根干重比对照增加18.2％(40d)和11.5％(60d),根苗比比对照提高33.0％(40d)和21.8％(60d)。显而易见,BR改变了植株体内干物质的分配,为小麦苗体安全越冬和正常生长准备了物质基础。     

Dh菌株胞外蛋白酶及几丁质酶的活性测定

对Dh菌株的胞外蛋白酶及几丁质酶的活性进行了测定，发现该菌的胞外蛋白酶足以碱性蛋白酶为主，兼含中性和酸忡蛋白酶组成的复合酶系，其中中性蛋白酶对酸碱和温度的稳定性较好，最适作用温度为45C；该茼胞外蛋白酶在虫尸培养基和明胶培养基上均可活跃地产生，不同温度下在明胶-琼脂平板培养基上培养3d后用15％HgCl处理后菌落周围显示出清晰透明的环状，产酶量在33C时达到最大值，随后减少；几丁质酶产酶高峰出现在4～5d。     

TrxS基因的表达及其对大麦种子淀粉酶活性的影响

 【目的】分析TrxS基因对大麦种子发芽及淀粉酶活性的影响,为TrxS基因对大麦种子代谢的调控提供了理论依据。【方法】以转TrxS基因啤酒大麦株系为材料，从分子水平和生理指标进行分析。【结果】实时荧光RT-PCR检测证明TrxS基因在RNA水平上能够表达；转基因大麦籽粒α-淀粉酶和β-淀粉酶活性明显提高，发芽1-5d转基因大麦种子α-淀粉酶活性比对照分别增加5.86%、75.24%、118.51%、71.02%和22.99%，β-淀粉酶活性分别比对照增加19.29%、14.68%、35.47%、23.62%和2.67%；种子的发芽能力提高。【结论】TrxS基因能够促进种子发芽。