未来中高排放情景下松嫩平原农业气候资源变化分析

基于松嫩平原地区基准时段（1961−1990年）的观测数据,应用统计方法对模型模拟的未来30a(2021−2050年)温度、降水、辐射的逐日数据进行偏差订正,同时采用五日滑动平均法计算≥10℃积温,分析研究区域相对于基准时段,未来30a农业气候资源指标的时空变化特征。结果表明：在RCP4.5和RCP8.5两种排放情景下,未来30a松嫩平原大部分地区平均温度在4～8℃,较基准时段升高2.5～2.8℃,且北部地区的增温幅度大于南部地区;此外,大部分地区≥10℃积温介于3000～3700℃·d,两种情景下分别增加500～550℃·d和600～670℃·d,其中南部部分地区增幅超过670℃·d;大部分地区年降水量在460～580mm,增量为50～90mm不等,降水增量在空间分布上表现为南多北少,其中南部地区增量超过90mm,而北部地区年增量则不足50mm,两种情景在相同区域的降水增量表现为RCP4.5多于RCP8.5;相较于基准时段,年辐射量减少85～100MJ·m−2,生长季内辐射量减少10～40MJ·m−2,变化趋势均不明显。综上所述,未来松嫩平原地区农业气候资源表现为整体提升趋势,农作物可种植期相对延长,因此,应适当种植生育期更长的作物,避免因未来气温升高,造成现有作物生育期缩短,导致产量降低的情况发生;同时研究结果对调整种植结构、改变种植措施和选育作物品种等具有指导意义,有利于充分利用气候资源,提高作物产量。     

农杆菌介导抗根结线虫Bt cry6A基因转化茄子的研究

本试验以茄子下胚轴和子叶为外植体,通过对抗生素选择压筛选、不同抗生素抑菌效果比较、农杆菌侵染时间、预培养时间、共培养时间等条件优化,建立了适用于茄子的遗传转化体系,并利用农杆菌介导法将抗根结线虫Bt cry6A基因导入茄子中,以期获得抗线虫的茄子材料,探索新的抗线虫育种途径,为利用茄子转基因技术培育和改良茄子品质提供理论依据.结果表明,75mg· L-1的卡那霉素可以有效地抑制愈伤组织的产生;200mg· L-1特美汀能够完全抑制农杆菌的生长;最佳侵染外植体为子叶,在预培养4d,侵染10min,共培养1d时转化率最高;获得的56株Kan抗性植株中有15株具有GUS活性;经过PCR、RT-PCR验证,初步确认Bt cry6A基因已整合至茄子基因组中,并在转录水平上正常表达;根结线虫幼虫接种鉴定表明,转Bt cry6A基因茄子再生植株对南方根结线虫抗性明显提高.     

采伐干扰对东北温带次生林土壤碳矿化和活性有机碳的影响

在黑龙江东部的张广才岭选择典型次生杂木林进行不同采伐处理,一个生长季后测定了土壤潜在碳矿化速率和活性有机碳含量.结果表明:在28℃条件下经过90d的培养,土壤潜在碳矿化速率和碳矿化总量在所测定的土层中(0-10 cm,10-20 cm,20-30 cm)均表现为:50%强度采伐>皆伐后农作>25%强度采伐≌对照>皆伐后造林的变化趋势,但各处理间差异不显著.土壤易氧化碳含量在3个土层50%强度采伐均显著高于对照.土壤微生物碳含量在0-10 cm和10-20 cm土层,50%强度采伐显著高于对照.在0-10 cm土层,皆伐后造林显著低于对照.水溶性有机碳含量在0-10 cm和10-20 cm土层,50%强度采伐显著高于对照,在20-30cm土层,皆伐后造林显著低于对照,这说明在东北温带次生林中,较大强度的择伐短期内可增加土壤活性有机碳含量.而皆伐后造林可导致土壤活性有机碳出现下降趋势.     

美国豆芋花总皂苷制备及其α-葡萄糖苷酶抑制活性

为高效利用美国豆芋花皂苷类化合物,以皂苷得率和纯度为指标,研究美国豆芋花总皂苷的提取工艺及大孔树脂纯化工艺,并对制备的美国豆芋花总皂苷的抗氧化及α-葡萄糖苷酶活性抑制能力进行研究。结果表明,美国豆芋花总皂苷的提取工艺为提取溶剂90%乙醇,料液比1∶20,温度70℃,提取时间2 h。得到的提取物石油醚脱脂后用水饱和正丁醇萃取,D-101大孔树脂吸附柱纯化的工艺为上样皂苷质量浓度1 mg·m L~(-1),上样量40 m L·g~(-1)树脂,洗脱剂为80%乙醇(pH值6),洗脱剂用量4 BV(树脂柱体积)。制备的美国豆芋花总皂苷样得率4.24%,纯度达65.35%,比粗提物(纯度15.27%)提高了约3倍;抗氧化性能(清除DPPH和ABTS自由基IC50值分别为51.08、29.24μg·m L~(-1))和α-葡萄糖苷酶活性抑制能力(IC50值为83.62μg·m L~(-1))也均优于粗提物(清除DPPH、ABTS自由基IC50值分别为286.51、69.92μg·m L~(-1),α-葡萄糖苷酶的抑制浓度(IC50)值为1 043.57μg·m L~(-1)),表明该工艺可用于高活性美国豆芋花总皂苷的富集和纯化。此外,美国豆芋花总皂苷抑制α-葡萄糖苷酶活性的抑制类型为竞争型抑制,抑制常数为49.68μg·m L~(-1)。本研究结果为开发具有降血糖功能的医药中间体或功能性食品提供了新资源和实践基础。     

不同液土比和温度条件下塿土铵离子吸附

Effects of NH₄⁺ concentration, solution/soil ratio and temperature on NH₄⁺ adsorption were studied in a Eum-Orthic Anthrosol. The slopes of the soil NH₄⁺ adsorption isotherms and the fitted n, the coefficient for the adsorption intensity, and k, the coefficient related to adsorption capacity, of the Freundlich equation increased with increasing solution/soil ratio (SSR) and with decreasing temperature (T). For the range of experimental conditions, the value of ∂q/∂c, the rate of change of the amount of NH₄⁺ adsorbed in the soil solid phase (q) with respect to the equilibrium concentration of NH₄⁺ in soil solution (c), was 0.840, indicating that q increased with increasing c. From 2 to 45 ℃, ∂q/∂SSR, the rate of change of q with respect to SSR, decreased from 2.598 to 1.996, showing that q increased with increasing SSR, while its increasing rate decreased with temperature. From SSR 1:1 to 20:1, ∂q/∂T, the rate of change of q with respect to T, decreased from -0.095 to -0.361, indicating that q decreased with increasing temperature, and at the same time the negative effect of temperature became larger as SSR increased. Thus under the experimental conditions the order of importance in determining the amount of NH₄⁺ adsorbed in the soil solid phase was ∂q/∂SSR > ∂q/∂c > |∂q/∂T|, indicating that the greatest effect on the amount of NH₄⁺ adsorbed was with the solution/soil ratio; the equilibrium concentration of NH₄⁺ had a lesser effect; and temperature had the least effect.     

基于长江三角洲地表水典型土壤铜、锌环境容量探究

我国水污染日益严重,Ⅰ类地表水地区较少,目前可供饮用的Ⅲ类水成为研究土壤地表水体系污染状况的热点。选取具有代表性的长江三角洲地区4种母质（河相、湖相、海相沉积物和沟沟堆积物）发育而成的土壤,通过加入不同量的外源铜、锌金属培育污染土样,使其分别达到国家土壤环境质量三级标准的0.25、0.5、1.0、1.5、2.0、2.5倍。在此基础上研究雨水和模拟酸雨条件下,对模拟污染的土样进行解吸,并对解吸曲线进行拟合,在基于地表水Ⅲ类水质标准的铜、锌环境容量的基础上,计算了4种土壤在不同情况下的土壤环境容量,并通过探讨国家土壤标准的吻合性,提出针对不同母质的土壤,对其重金属的土壤污染临界值进行适当的调整,以达到Ⅲ类水标准,保障人类的安全与健康。结果表明,在模拟雨水情况下,基于地表水Ⅲ类标准的4种土壤的环境容量分别为：SEBC-06：铜10002mg·kg^-1,锌848.1mg·kg^-1;SEBC-19：铜1162mg·kg^-1,锌612.9mg·kg^-1;SEBC-20：铜9796mg·kg^-1,锌1047mg·kg^-1;SEBC-25：铜720mg·kg^-1,锌180.2mg·kg^-1。     

嫁接对番茄连作土壤环境及土壤酶活性消减的影响

连作障碍是我国番茄集约化生产的瓶颈,为了探索适宜连作的栽培模式,试验以易感青枯病番茄品种‘梅赛德斯’实生苗及以抗病品种‘爱好’为砧木,‘梅赛德斯’为接穗的嫁接苗为试材,通过分析检测连作3年下根际土壤养分和土壤酶活性指标的变化,结合土传病害发生情况,分析嫁接对番茄连作障碍下土壤环境消减的影响。结果表明：连作3年内,嫁接苗青枯病的发病率都极显著低于实生苗,说明嫁接苗较实生苗极显著降低了土传病害发生率;嫁接有利于缓解番茄根际土壤中碱解氮含量的升高及连作导致的土壤酸化问题;同时,嫁接有利于缓解番茄根际土壤多酚氧化酶活性、尿酶活性和蔗糖酶活性的下降;另外,连作对嫁接苗种植土壤有机质含量的影响相对不显著,而实生苗在连作1年后显著降低了土壤有机质含量;嫁接对番茄速效钾、有效磷含量的影响无明显规律性。综上所述,嫁接对改善番茄根际土壤化学性质和土壤酶活性有积极作用。     

微波技术对大豆蛋白功能特性的影响

研究了微波辐照对大豆功能蛋白（FSP）溶解性、乳化性与起泡性的影响。结果表明，微波辐照能改善FSP溶解度、乳化活性、起泡能力与泡沫稳定性。试验中FSP溶解度可提高343．7％，乳化活性可提高2392．7％，起泡能力可提高196．9％，泡沫稳定性可提高82．76％。     

Farrerol inhibits nicotine-induced proliferation of pulmonary vascular smooth muscle cells by enhancing Kv1.5 and Kv2.1 expression

AIM:To study the effect of farrerol (Far) on nicotine-induced proliferation of rat pulmonary smooth muscle cells (PASMCs), and further to explore its relationship with voltage-dependent potassium channels (Kv) 1.5 and Kv2.1. METHODS:Firstly, the effect of nicotine on the proliferation of PASMCs was detected by cell counting method, and the optimal concentration of nicotine was selected. Primary cultured PASMCs were randomly divided into 5 groups:normal control group, nicotine (1 μmol/L)group, nicotine (1 μmol/L) + Far (10^-6 mol/L, 10^-5 mol/L and 10^-4 mol/L) Far group. The activity of caspase-3 was measured by apoptosis kit, the cell viability was measured by CCK-8 assay, the apoptotic rate was analyzed by flow cytometry. The expression of Kv1.5 and Kv2.1, and apoptosis-related factors Bcl-2 and Bax at mRNA and protein levels was determined by RT-qPCR and Western blot respectively. RESULTS:Nicotine at 1 μmol/L increased the number of PASMCs to the maximum extent (P<0.01). Nicotine at 1 μmol/L significantly reduced the caspase-3 activity and enhanced the cell viability of the PASMCs (P<0.01). Farrerol at 10^-6~10^-4 mol/L eliminated the effect of PASMCs induced by nicotine in a concentration dependent manner. Compared with control group, nicotine at 1 μmol/L significantly increased the proliferation and inhibited the apoptotic rate of rat PASMCs (P<0.01). The apoptotic rate of PASMCs in farrerol intervention group was significantly higher than that in nicotine group (P<0.01). Nicotine at 1 μmol/L significantly inhibited the expression of Kv1.5, Kv2.1 and Bax but increased the expression of Bcl-2 in PASMCs (P<0.01). Farrerol at 10^-5 mol/L obviously inhibited the effect of PASMCs induced by nicotine. CONCLUSION:Farrerol eliminates nicotine-induced inhibition of caspase-3 and Bax, and enhancement of Bcl-2 in PASMCs by enhancing Kv1.5 and Kv2.1 expression.     

Soil chronosequence and biosequence on old lake sediments of the Burdur Lake in Turkey

The Burdur Lake is located in the southwest of Turkey, and its area has decreased by 40% from 211 km² in 1975 to 126 km² in 2019. In this study, we investigated how the soil has changed in the lacustrine material. Three soil profiles were sampled from the former lakebed (chronosequence profiles: P1, 2007; P2, 1994; and P3, 1975), and three soil profiles under different land use types (biosequence profiles: P4, native forest vegetation; P5, agriculture; and P6, lakebed) were sampled. The chronosequence and biosequence soil profiles represented various distances from the Burdur Lake and showed different stages of lacustrine evolution. Soil electrical conductivity (EC; 18.1 to 0.4 dS m_-1), exchangeable Na⁺ (34.7 to 1.4 cmol kg^-1) and K⁺ (0.61 to 0.56 cmol kg^-1), and water-soluble Cl^- (70.3 to 2.1 cmol L^-1) and SO₄^2- (275.9 to 25.0 cmol L^-1) decreased with increasing distance from the Burdur Lake, whereas the A horizon thickness (10 to 48 cm), structure formation (0 to 48 cm), gleization-oxidation depth (0 to 79 cm), and montmorillonite and organic matter (OM; 25.9 to 46.0 g kg^-1) contents increased in the chronosequence soil profiles. The formation of P3 in the chronosequence and P5 in the biosequence soil profiles increased due to longer exposure to pedogenic processes (time, land use, vegetation, etc.). Changes in EC, exchangeable cation (Na⁺ and K⁺) and water-soluble anion (Cl^- and SO₄^2-) concentrations of the salt-enriched horizon, OM, gleization-oxidation depth, A horizon thickness, and structure formation of the chronosequence and biosequence soil profiles (especially the topsoil horizon) were highly related to the distance from the Burdur Lake, time, and land use.