人参黑斑病流行发生期及参籽产量预测模型的研究

 根据1982-1983年在左家地区调查人参黑斑病情、孢子捕捉量,结合有关的气象数据,通过偏相关分析,明确了病情指数与孢子捕捉量之间存在高度正相关R=0.8722;通过逐步回归筛选出5月下旬至6月上旬平均气温X₁及5月下旬至6月上旬连续降雨天数X₆建立预测当年初发病时间Y₁的模型为:Y₁=-26.68+2.07X₁-0.25X₆±0.0745;依据初发病时间XⅡ₁及7月至8月上旬均湿度XⅡ₄建立预测当年病害出现高峰时间Y₂模型为:Y₂=9.0495+0.336XⅡ₁-0.0359XⅡ4±0.0089:另据初发时间XⅡ₄及7月至8月总降雨量XⅡ₂建立的预测模型:Y₃=5.514+0.4575XⅡ₁-0.0013XⅡ₂±0.0586。上述模型数学检验合理,经实测数据证明模型有较高的可靠程度。参籽产量Y与病情指数相互间的曲线回归:Y=25.54e^-0.4060x     

不同盐度施氮水平下盐地碱蓬幼苗生长及光合色素含量分析

以盐生植物盐地碱蓬为试验材料,以NaCl模拟不同盐度环境,采用盆栽试验方法研究了不同盐度施氮水平下,盐地碱蓬幼苗生长及光合色素含量的变化。结果表明：① 轻度、中度及重度盐环境下施适量氮（0.3 g·kg^-1、0.6 g·kg^-1、1.2 g·kg^-1）可以促进盐生植物盐地碱蓬幼苗的生长,在高盐高氮条件下,施氮对盐地碱蓬幼苗生长的影响与盐度有关;② 不同盐度环境下施氮所能达到的最高干物质产量及最高施氮限量也不同,表现为轻度盐环境（含NaCl 2.5 g·kg^-1）＞中度盐环境（含NaCl 5 g·kg^-1）＞重度盐环境（含NaCl 7.5 g·kg^-1）,随着施氮量的增加氮素生产力均表现出下降的趋势;③ 同一施氮水平下,随着盐度的增加盐地碱蓬幼苗叶片渗透势显著下降,并且同一盐度环境下,随着施氮量的增加叶片渗透势也呈现出下降趋势,渗透调节能力增大;④ 3个盐度环境下,施氮均可增加盐地碱蓬幼苗叶片光合色素含量,从而提高光合效率,增强幼苗对盐渍环境的适应能力。     

NaCl胁迫下不同葡萄砧木耐盐性与其离子吸收、光合特性的关系

为筛选耐盐葡萄砧木并探究其耐盐机制，以13种1 a生葡萄砧木为试材，研究100 mM NaCl浇灌处理下葡萄砧木的生长量、光合特性及植株体内Na⁺、Cl^-、K⁺、Mg²⁺、Ca²⁺的差异性变化。盐害指数结果表明：110R和101-14盐害指数较小，为高抗盐砧木，Dogridge、5BB和香槟尼为抗盐品种；5C、贝达和B.R.No.2为中抗盐砧木，Valiant和山河2号为盐敏感品种，188-08、3309C和140R盐害指数最大耐盐性最弱，为盐高敏感砧木。生理指标测定结果发现：NaCl胁迫下，砧木5BB、101-14、Valiant、山河2号、Dogridge、5C其茎粗增加量、新梢增加量与对照相比均存在显著性差异；各葡萄砧木净光合速率(P_n)、气孔导度、蒸腾速率(T_r)均显著低于对照组，盐胁迫后期，140R和188-08叶片P_n分别为0.38μmol·m^-2·S^-1和...     

长春地区大菜粉蝶生物学特性观察

大菜粉蝶Pieris brassicae是十字花科蔬菜上的重要害虫之一。本文通过田间观察结合室内饲养,系统描述了该虫各发育阶段的形态特征,记录了发育历期、生活史及其生活习性。大菜粉蝶在长春地区1年发生3代,以蛹越冬。成虫多产卵于叶背面,每块卵10～207粒。幼虫5个龄期,群集为害,随着幼虫龄期的增长,头壳宽度与体长逐渐增加,各龄期头壳宽度和体长生长模型为：y_W=1.727e^0.557x(R²=0.998)和y_L=0.031x²+0.339x-0.013(R²=0.994)。取食白菜、油菜、甘蓝和萝卜4种寄主的幼虫发育历期存在显著差异,取食白菜发育最快,取食油菜的蛹最重,白菜和油菜更适宜其生长发育。本研究描述了大菜粉蝶各发育阶段的形态特征,明确了其主要生物学特性,为该害虫的识别监测和综合防控提供了理论基础。     

一个与稻瘟病菌无毒基因AVR-Pik~m连锁的SCAR标记的分离

 本研究将以前在稻瘟病菌菌株S1522获得的与决定对水稻品种梅雨明无毒性的基因(AVR-Pik^m)相连锁的1个RAPD标记OPO12₁₀₀₀进行了克隆和鉴定。核苷酸序列测定与分析结果表明:OPO12₁₀₀₀的大小为946个碱基,不含有与已报道的稻瘟病菌Mg-SINE、Fosburry、Magyy、Grasshopper、Pot2以及Pot3等同源的重复序列。根据OPO12₁₀₀₀的核苷酸序列,设计了1对24个核苷酸的特异引物,对无毒表型亲本S1522和毒性表型亲本S159、无毒表型群体基因池、毒性表型基因池以及有性杂交后代108个菌株进行了PCR扩增,所有无毒表型的菌株均能特异性地扩增出1条与OPO12₁₀₀₀大小相同的DNA条带,而毒性表型的菌株除5个重组个体外,均不能扩增出这条特异带。此结果表明,与稻瘟病菌无毒基因AVR-Pik^m连锁的RAPD标记OPO12₁₀₀₀被成功地转化为SCAR标记,为进一步通过染色体步移克隆该无毒基因奠定了基础。     

分离土壤棉花黄萎病菌选择性培养基的筛选

 采用土壤检测稀释法、水筛法和不同土样接种量,对5种土壤浸提液改良培养基进行了比较研究。结果表明,土壤水筛法对土壤棉花黄萎病菌的检测效果优于稀释法,其菌落检测数增加4~10倍。培养基每皿0.25 g土样接种量的检测效果高于0.5 g和1g。5种测试培养基中,培养基D对分离土壤棉花黄萎病菌的选择性表现最好,其土壤接种体检测回收率达63.5%~83.3%.培养基D的组份为:土壤浸提液25 ml,KH₂PO₄ 1.5 g,K₂HPO₄ 4 g,尿酸钠0.2 g,半乳糖醛酸钠(果胶)1g,山梨糖1g,Dox盐2 ml,Tergitol NP-101ml,PCNB0.1g,琼脂17g,蒸馏水1000 ml,pH6.4~6.7。每1000ml融化培养基倒皿前加抗菌素液50 ml (含氯霉素0.05 g,链霉素0.05 g,青霉素-G盐0.05 g)。     

稻瘟菌无毒基因AVR-Pikm的定位

 无毒基因是病原物中决定寄主抗病性表达与否的功能基因,其功能的丧失导致毒性小种的产生。在先前的研究中,本研究小组从稻瘟病菌中分离了与无毒基因AVR-Pik^m连锁的2个SCAR标记SCO12₉₄₆和SCE12₁₄₀₆。在本研究中,作者首先通过TAC克隆末端核苷酸序列的测定及其与70-15全基因组序列的比较,将这2个标记定位到稻瘟菌第1号染色体上;然后,利用稻瘟菌70-15全基因组草图序列和SSR技术,又分离了与无毒基因AVR-Pik^m连锁的4个SSR标记:SSR47T34、SSR50CA24、SSR52TAGG18和SSR56A28。进一步分析表明:上述4个SSR标记位于与SCO12₉₄₆和SCE12₁₄₀₆相反的一侧,与AVR-Pik^m位点的遗传距离分别为4.90、7.01、19.12和21.94cM,无毒基因AVR-Pik^m位于SCE12₁₄₀₆和SSRA7T34之间。本研究获得的稻瘟菌无毒基因AVR-Pik^m的精细定位为通过染色体步移克隆该基因奠定了基础。     

一个新的与稻瘟病菌无毒基因AVR-Pikm紧密连锁的SCAR标记

 无毒基因是病原物中决定寄主抗病性表达的功能基因,其功能的丧失导致毒性小种的产生。本研究利用随机引物扩增DNA多态性技术,从稻瘟病菌菌株S1522中新筛选到1个与无毒基因AVR-Pik^m紧密连锁的DNA标记OPE12₁₄₀₀。根据OPE12₁₄₀₀的核苷酸序列,设计了1对含有17个核苷酸的特异性SCAR引物,并利用该引物对无毒表型亲本S1522和毒性表型亲本S159及其有性杂交后代的108个菌株进行了PCR扩增。结果表明:所有无毒表型的菌株均能特异性扩增出1条与OPE12₁₄₀₀大小相近的DNA片段,而毒性表型的菌株除2个重组体外,均不能扩增出此片段。根据计算,这一SCAR标记与目标无毒基因AVR-Pik^m之间的遗传距离为1.89 cM,与本研究小组先前报道的另一个标记OPO12₁₀₀₀位于目标基因的同一侧,但与OPO12₁₀₀₀相比,距目标基因近了2.86 cM。本标记的获得将有助于确定AVR-Pik^m在染色体上的位置,有助于确定用于进一步筛选位于相反一侧的连锁标记的重叠群区域。     

赤霉素和磷肥配合施用对胡麻光合酶活性及其产量形成的影响

为探究赤霉素和磷肥配合施用对胡麻叶片光合酶活性以及籽粒产量的影响,以‘轮选2号’为材料,采用田间二因素裂区试验设计,研究了不同磷肥用量水平(P₀:0 kg·hm^-2 P₂O₅,P₁:67.5 kg·hm^-2 P₂O₅,P₂:135 kg·hm^-2 P₂O₅)和赤霉素(Gibberellin acid, GA₃)喷施浓度(G₀:0 mg L^-1,G₁:15 mg·L^-1,G₂:30 mg·L^-1)对胡麻光合同化酶活性、干物质积累量及籽粒产量的影响。结果表明：施磷和喷施赤霉素均显著提高了胡麻叶片RuBP(Ribulose-1,5-bisphosphate)、PEP(Phospho...     

窟野河水-气界面CO2交换通量变化特征及其影响因素分析

近年来内陆水体CO₂释放受到广泛关注,为揭示黄土高原地区内陆水体CO₂的释放特征,于2018年7月和10月及2019年3月和6月利用LI-7000 CO₂分析仪对窟野河及代表性水库开展了高频次的水体CO₂分压(pCO₂)和水-气界面CO₂交换通量(FCO₂)观测,并分析其时空变化规律。结果表明:窟野河水体pCO₂和FCO₂(分别为996μatm和94.5 mmol·m^-2·d^-1)均高于水库(分别为752μatm和10.3 mmol·m^-2·d^-1)。FCO₂季节性差异明显:对于河流而言,表现为秋季最高(165.7 mmol·m^-2·d^-1),春季最低(42.9 mmol·m^-2·d^-1);对于水库而言,变化趋势则完全相反,表现为春季最高(16.6 mmol·m^-2·d^-1),秋季最低(-5.4 mmol·m^-2·d^-1)。生物地球化学活性更强的支流FCO₂(107.4 mmol·m^-2·d^-1)高出干流(66.5 mmol·m^-2·d^-1)约50%;同时,位于中下游黄土丘陵区的水库FCO₂(16.4 mmol·m^-2·d^-1)显著高于位于上游呼鄂丘陵区的水库FCO₂(1.2 mmol·m^-2·d^-1)。整体来看,流域水体pCO₂受碳酸盐体系影响最大,有机碳分解作用次之;流速是控制水-气界面气体交换速率的关键因素。在年尺度上,窟野河的河流与水库水体均为大气持续碳源。窟野河平均CO₂释放量与我国长江及国外温带河流相近,但低于黄河中游的其他支流。     

Variation of soil physical-chemical characteristics in salt-affected soil in the Qarhan Salt Lake,Qaidam Basin

Soil salinization has adverse effects on the soil physical-chemical characteristics.However,little is known about the changes in soil salt ion concentrations and other soil physical-chemical characteristics within the Qarhan Salt Lake and at different soil depths in the surrounding areas.Here,we selected five sampling sites(S1,S2,S3,S4,and S5)alongside the Qarhan Salt Lake and in the Xidatan segment of the Kunlun Mountains to investigate the relationship among soil salt ion concentrations,soil physical-chemical characteristics,and environmental variables in April 2019.The results indicated that most sites had strongly saline and very strongly saline conditions.The main salt ions present in the soil were Na⁺,K⁺,and Cl^-.Soil nutrients and soil microbial biomass(SMB)were significantly affected by the salinity(P<0.05).Moreover,soil salt ions(Na⁺,K⁺,Ca2+,Mg²⁺,Cl^-,CO₃^2-,SO₄^2-,and HCO₃^-)were positively correlated with electrical conductivity(EC)and soil water content(SWC),but negatively related to altitude and soil depth.Unlike soil salt ions,soil nutrients and SMB were positively correlated with altitude,but negatively related to EC and SWC.Moreover,soil nutrients and SMB were negatively correlated with soil salt ions.In conclusion,soil nutrients and SMB were mainly influenced by salinity,and were related to altitude,soil depth,and SWC in the areas from the Qarhan Salt Lake to the Xidatan segment.These results imply that the soil quality(mainly evaluated by soil physical-chemical characteristics)is mainly influenced by soil salt ions in the areas surrounding the Qarhan Salt Lake.Our results provide an accurate prediction of how the soil salt ions,soil nutrients,and SMB respond to the changes along a salt gradient.The underlying mechanisms controlling the soil salt ion distribution,soil nutrients,and SMB in an extremely arid desert climate playa should be studied in greater detail in the future.     

Soil microbial activity and community structure as affected by exposure to chloride and chloride-sulfate salts

Mixed or chloride salty ions dominate in saline soils, and exert wide-ranging adversely affect on soil biological processes and soil functions. The objectives of this study were to(1) explore the impacts of mixed(0, 3, 6, 10, 20 and 40 g Cl~–/SO_4~(2–)salt/kg dry soil) and chloride(0, 1.5, 3, 5, 8 and 15 g Cl~– salt/kg dry soil) salts on soil enzyme activities, soil physiological functional(Biolog) profiles and microbial community structure by using soil enzymatic, Biolog-Eco microplates as well as denaturing gradient gel electrophoresis(DEEG) methods, and(2) determine the threshold concentration of soil electronic conductivity(EC_(1:5)) on maintaining the functional and structural diversity of soil microbial community. The addition of either Cl~– or mixed Cl~–/SO_4~(2–)salt obviously increased soil EC, but adversely affected soil biological activities including soil invertase activity, soil microbial biomass carbon(MBC) and substrate-induced respiration(SIR). Cl~– salt showed a greater deleterious influence than mixed Cl~–/SO_4~(2–)salt on soil enzymes and MBC, e.g., the higher soil MBC consistently appeared with Cl~–/SO_4~(2–)instead of Cl– treated soil. Meanwhile, we found that SIR was more reliable than soil basal respiration(SBR) on explaining the changes of soil biological activity responsive to salt disturbance. In addition, microbial community structures of the soil bacteria, fungi, and Bacillus were obviously affected by both salt types and soil EC levels, and its diversity increased with increasing of mixed Cl~–/SO_4~(2–)salt rates, and then sharply declined down after it reached critical point. Moreover, the diversity of fungal community was more sensitive to the mixed salt addition than other groups. The response of soil physiological profiles(Biolog) followed a dose-response pattern with Cl~–(R~2=0.83) or mixed Cl~–/SO_4~(2–)(R~2=0.89) salt. The critical threshold concentrations of salts for soil physiological function were 0.45 d S/m for Cl~– and 1.26 d S/m for Cl~–/SO_4~(2–), and those for soil microbial community structural diversity were 0.70 d S/m for Cl~– and 1.75 d S/m for Cl~–/SO_4~(2–).     

Dielectric properties of saline soil based on a modified Dobson dielectric model

Soil salinization is a major concern for agricultural development in arid areas. In this paper, a modified Dobson dielectric model was applied to simulate the dielectric constant of saline soil in the Ugan-Kuqa river delta oasis of Xinjiang Uygur autonomous region, northwestern China. The model performance was examined through analyzing the influences of its parameters on the soil dielectric constant and the relationship between radar backscattering coefficient and the dielectric constant of saline soil. The results of the study indicate that:(1) The real part of the soil dielectric constant is affected by soil water content at low radar frequencies; the imaginary part is closely related with both the soil water content and soil salt content.(2) The soil water and salt contents are related with the coefficient of dialectical loss, which is consistent with the natural conditions of saline soil in arid areas and provides valuable references for the study of soil dielectric properties.(3) The changes of soil water content and soil salt content have instant influences on the dielectric constant of saline soil. Subsequently, the radar backscattering coefficient is affected to respond to the dielectric constant of saline soil. The radar backscattering coefficient is most responsible to the radar's cross polarization pattern with a correlation coefficient of R2=0.75. This study provides a potential method to monitor soil salinization and soil water content by using a soil dielectric model and radar techniques.     

新疆盐碱地生物改良的必要性与可行性

盐碱地资源的利用、盐渍化耕地的改良 ,在有盐碱地的地区 ,是农业生产发展的重要环节之一。新疆盐碱地总面积 2 181.4× 10 4 hm2 ,占全国盐碱土 (9913× 10 4 hm2 )面积的 2 2 .0 1% ;在 40 7.84× 10 4 hm2 耕地面积中 ,受不同程度盐化危害的面积占 30 .12 %。生物改良盐碱地 ,指利用耐盐植物直接种植 ,通过常规灌溉 ,不需要任何附加条件和设施 ,将土壤盐分控制在植物根系土层以下的土体中。新疆漫灌式种植生产有利于这种生物改良。生物改良盐碱地 ,灌溉水利用率高 ,又利于生态环境的良性循环和永久性建设。种植根系较多、较深的耐盐植物 ,土壤盐分在灌水条件 ,向下移动较深。     

甘肃沿黄灌区土壤盐渍化特征及其成因

沿黄灌区在甘肃经济发展中占有举足轻重的地位,但盐碱荒地的开发利用、次生盐渍化防治和水资源的不合理利用一直是制约农业发展的关键因素之一。通过对甘肃沿黄灌区耕地土壤盐分含量、离子组成与分布、土壤pH及地下水矿化度等特征,及盐碱地形成的气候、地形、土壤母质、人为因素进行系统分析。在此基础上,提出了5条改良措施与建议：① 实行盐碱地分区治理;② 调整农业产业结构;③ 强化盐碱地生物治理;④ 建全节水农业体系;⑤ 加强水盐运移动态监测,建立预警评价体系。     

Comparing phreatic evaporation at zero water table depth with water surface evaporation

Salt-affected soils are mostly found in irrigated areas within arid and semi-arid regions where the groundwater table is shallow. Soils of this type have become an increasingly severe problem because they threaten both the environment and the sustainable development of irrigated agriculture. A tool to estimate phreatic evaporation is therefore urgently required to minimize the salinization potential of salt-affected areas. In this context, phreatic evaporation at zero water table depth (E₀) is a key parameter for establishing a model for calculating phreatic evaporation. The aim of this study was to explore the law of phreatic evaporation and to develop structurally rational empirical models for calculating phreatic evaporation, based on E₀ data of six types of soil (i.e., gravel, fine sand, sandy loam, light loam, medium loam, and heavy loam) observed using the non-weighing lysimeter and water surface evaporation (E₆₀₁) data observed using a E601 evaporator of same evaporation area with a lysimeter-tube at the groundwater balance station of the Weigan River Management Office in Xinjiang Uygur Autonomous Region, China, during the non-freezing period (April to October) between 1990 and 1994. The relationship between E₀ and E₆₀₁ was analyzed, the relationship between the ratio of E₀ to E₆₀₁ and the mechanical compositions of different soils was presented, and the factors influencing E₀ were discussed. The results of this study reveal that E₀ is not equal to E₆₀₁. In fact, only values of the former for fine sand are close to those of the latter. Data also show that E₀ values are related to soil texture as well as to potential atmospheric evaporation, the ratio of E₀ to E₆₀₁ and the silt-clay particle content (grain diameter less than 0.02 mm) is negatively exponentially correlated, and that soil thermal capacity plays a key role in phreatic evaporation at E₀. The results of this analysis therefore imply that the treatment of zero phreatic depth is an essential requirement when constructing groundwater balance stations to study the law of phreatic evaporation.     

玛纳斯河流域绿洲农田土壤盐分反演及空间分布特征

土壤盐分的准确监测是干旱、半干旱地区农业可持续发展的前提,气候变化、不合理灌溉等因素使土壤盐渍化问题逐渐显现。文中以新疆玛纳斯河流域为例,采用多光谱遥感影像和野外实测土壤盐分数据相结合的方法,选取对土壤盐渍化影响较大的归一化差异水体指数及其它具有代表性的多光谱遥感指数与土壤盐分构建反演模型,探讨研究区内土壤盐渍化的空间分布特征。结果表明:与土壤盐分相关性最高且具有代表性的多光谱遥感指数是NDWI、NDVI和DVI,相关系数分别为0.841、-0.787、-0.768,达到极显著水平(P<0.01),均可以用于构建土壤盐分反演模型。最优光谱参数与土壤盐分构建的模型建模精度均在80%以上,达到极显著水平,可以较为准确的预测出研究区内盐渍化状况。在玛纳斯河流域绿洲区土壤盐渍化以中度、重度盐渍化为主,其中石河子灌区盐渍化程度最为严重,莫索湾灌区盐渍化程度较轻,与实地调查结果一致。基于多光谱影像提取的土壤归一化差异水体指数作为构建土壤盐分反演模型的基础,可以获得较好的土壤盐分空间分布。土壤盐渍化遥感反演为新疆玛纳斯河流域土壤盐渍化治理和土地资源可持续利用提供理论依据。     

开都河流域下游绿洲盐渍化土壤特征研究

通过野外调查、实地测点以及土壤采样分析,以新疆开都河流域下游绿洲为典型区,利用SPSS、Excel等软件对土壤盐分离子含量、电导率、土壤水溶液中总溶解固体（TDS）与土壤含盐量和电导率的关系以及盐分离子间相关性进行了分析。结果表明：土壤pH值的平均值大于8.0,属于碱性土壤;土壤含盐量较高,0～10 cm土层中的含盐量...     

微咸水膜下滴灌对土壤盐分及棉花产量的影响

合理利用微咸水资源灌溉对于缓解新疆南部地区淡水资源短缺的问题有着至关重要的意义。本文以库尔勒31团棉田为供试对象,淡水作为对照,利用排碱渠咸水与淡水不同比例混合,设置6种梯度配比,研究微咸水及咸水对棉田土壤盐分分布及产量的影响。结果表明:①随着矿化度的增加,各处理土壤盐分呈现不同程度的增加,其中处理5(全咸)增加程度最大,积盐率为131.03%。②在垂直方向上,随着土层深度的增加,各处理土壤盐分在20~40 cm处达到峰值;在水平方向上,盐分累积程度的大小为:膜间>宽行>窄行。③随着矿化度的增加,棉花的产量逐渐下降,棉花产量下降的主要因素是单株结铃数,而单铃重对棉花产量无明显影响。由膜下滴灌土壤盐分对棉花生长和产量的影响得出,当灌溉水的矿化度在淡咸水比为4∶1(矿化度2.36~3.39 g·L^-1)时对棉花生长的抑制作用较小,较对照处理相比,产量减少11.85%。