生物有机肥对马铃薯根际土壤生物活性 及根系活力的影响

针对大量化肥长期施用对马铃薯田土壤造成的生物活性降低等问题，利用根际益生菌（PGPR）制成生物有机肥，通过盆栽试验，研究了不施肥（对照，CK）以及分别施化肥（CF）、普通有机肥（OF）和5种生物有机肥（BOF1，BOF2，BOF3，BOF4和BOF5）对马铃薯根际土壤生物活性和根系活力的影响。结果表明，在马铃薯的成熟期，5种生物有机肥处理的可培养细菌数量平均比CF及OF高52%和37%，微生物量碳比CF和OF处理平均增加了30%，其中以BOF3效果最明显,比其它生物有机肥处理的可培养细菌数量和微生物量碳增加达3%～7%和2%～7%；且土壤脲酶、蔗糖酶和磷酸酶活性显著提高(P<0.05)，相比CF和OF，5种生物有机肥处理土壤酶活性的增幅为11%～114%；根系活力分别增加了265%和224%，块茎产量分别增加了16%和21%，根系活力和块茎产量的提高也以BOF3效果最明显，其根系活力比BOF5高出166%，其块茎产量比其它生物有机肥处理的增幅为5%～9%。说明生物有机肥有助于提高土壤的生物活性，改善马铃薯的根际环境，进而提高了马铃薯的根系活力，增加了马铃薯的块茎产量。     

旧膜及秸秆覆盖对西北旱地马铃薯 产量及土壤水热的影响

为了探究旧膜二茬及秸秆带状覆盖条件下，马铃薯田的土壤水热特征及增产机制，设置旧膜直播(T1)、秸秆带状覆盖种植带不旋耕（T2）、秸秆带状覆盖种植带旋耕（T3）、新覆膜（T4）和露地平作（CK）5个处理进行田间试验。结果表明：各覆盖处理较CK提高产量14.24%~56.33%、商品薯率1.21%~22.60%及水分利用效率8.28%~55.39%（P<0.05）;产量与块茎形成期的单株薯干重正相关（r=0.744），覆盖处理在块茎形成期较CK提高单株薯干重118.0%~720.0%（P<0.05），以T4最高;覆盖处理对马铃薯水热特征有显著影响（P<0.05），T1、T2的降温效应显著小于T3，T3的蓄水保墒效应与T4差异不显著，但显著大于T1、T2及CK。可见，在本试验条件下，秸秆带状覆盖种植带旋耕的产量高于旧膜直播、略低于新覆膜，但蓄水保墒效应与新覆膜相近，同时秸秆带状覆盖种植带旋耕较其余覆盖处理具有较明显的降温增墒效应，有利于促进马铃薯块茎的形成及膨大。     

马铃薯抗旱栽培土壤含水量及产量效益研究

于2014年在宣威市农业技术示范基地开展了玉米间作马铃薯集雨保墒抗旱栽培复合技术试验研究。试验处理包括：T₁：玉米+开沟覆膜‖马铃薯;T₂：玉米+打塘覆膜‖马铃薯;T₃：玉米+平作覆膜‖马铃薯;T₄：玉米平作覆膜单作;T₅：马铃薯单作。结果表明,T₁和T₂处理玉米土壤含水量均高于其它处理,T₁、T₂处理0～7.6 cm土层玉米平均土壤含水量比T₄处理最多增加28.32%,0～20 cm土层最多增加28.12%;间作处理马铃薯的土壤含水量均高于马铃薯单作,T₁、T₂处理马铃薯平均土壤含水量在0～7.6 cm和0～20 cm两个土层分别比T₅处理最多增加23.52%和12.78%;T₁、T₂处理玉米产量、复合产量和土地当量比（LER）均高于T₃处理,其中,T₂处理的土地当量比最大（LER=1.20）,比T₃处理增加10.52%,产量效益明显。     

不同复种油菜-轮作模式对马铃薯耗水特征及产量的影响

为探讨马铃薯不同轮作系统复种饲用油菜对马铃薯耗水特征及产量的影响,2017年在长期大田定位试验基础上选取4个处理,即马铃薯连作（CK）、马铃薯-小麦复种油菜-马铃薯（WPRP）、马铃薯-豌豆复种油菜-马铃薯（PPRP）、小麦-豌豆复种油菜-马铃薯（WPPR）,研究不同复种轮作模式对马铃薯耗水特性、水分利用效率和产量的影响。结果表明：马铃薯块茎增长期到收获期,CK 160~200 cm土壤水分含量和播前无差异,而WPRP、PPRP、WPPR 0~200 cm土壤各层含水量均大于播前,其中,块茎增长期到淀粉积累期,各层土壤平均含水量分别提高了43.02%、38.58%、24.63%,淀粉积累期到收获期,分别提高36.47%、33.63%和21.43%; 120~200 cm土壤各层含水量表现为：WPRP＞PPRP＞WPPR＞CK。WPRP、PPRP、WPPR耗水深度和贮水量均大于CK,其中,块茎增长期到淀粉积累期,耗水深度较CK分别增加42.86%、42.86%、42.86%,土壤贮水量较CK分别增加10.36%、12.91%和8.49%;淀粉积累期到收获期,耗水深度较CK分别增加了25.00%、12.50%、12.50%,土壤贮水量分别增加了12.56%、6.78%和2.95%,且WPRP贮水量较CK显著提高12.56%。块茎形成期、块茎增长期和淀粉积累期,WPRP耗水量较CK分别减少了16.2%、25.2%和5.1%。WPRP、PPRP、WPPR较CK产量分别增加33.51%、40.05%、14.47%,WUE分别提高54.83%、52.32%、19.78%。综上,马铃薯轮作系统复种油菜增加了降雨入渗深度、土壤贮水量和耗水深度,降低了阶段性耗水量,提高了马铃薯产量和WUE。且马铃薯-小麦复种油菜-马铃薯为该地区较佳的轮作模式。     

干旱胁迫对马铃薯移栽组培苗内源激素含量的影响

为深入了解马铃薯抗旱机制，选用马铃薯品种夏坡蒂和根优2号，研究了干旱胁迫对移栽马铃薯组培苗（移栽苗）块茎形成及其内源激素含量的影响。结果表明：基质相对含水量为50%对移栽苗的生长及块茎形成产生抑制作用，其单株薯数、薯重、结薯植株率和整株干物质量均显著低于65%处理，但其地下部干物质分配比例较65%处理高31.75%~36.42%（移栽后55 d）；块茎形成过程中，匍匐茎GA含量、GA/IAA、ZR/IAA、GA/(IAA+ZR)值均为50%处理下明显低于65%处理，分别降低7.45%、26.67%、26.67%和23.08%；而茎与匍匐茎IAA含量则在50%处理下较高。各器官IAA含量随着块茎形成表现为先降后升，但GA/IAA、ZR/IAA和GA/(IAA+ZR)值则先增加后降低。块茎形成进程中，干旱胁迫在植株内部建立新的激素平衡，这可能是激素介导干旱信号影响马铃薯块茎形成的内因之一。     

灌溉量对马铃薯生理特性及 块茎产量品质的影响

以 “大西洋”马铃薯品种为试验材料，在甘肃省中部沿黄高扬程灌区的白银市景泰县条山农场马铃薯种植基地设置小区试验，在各发育阶段分别设置5个水分梯度（原灌溉量的50%、75%、100%、125%和150%，其中原灌溉量，即100%灌溉量，为当地常用的、维持试验地25.8%左右土壤含水率的灌溉量），探讨马铃薯各发育阶段灌溉量对其生理特性及块茎产量、品质的影响。结果表明，在马铃薯的各发育阶段，随着灌溉量的增加马铃薯叶片净光合速率 (P_n)和蒸腾速率(T_r)分别先增加到最大值30.19 μmol·m^-2·s^-1、12.50 mmol·m^-2·s^-1，而后减小。当灌溉量为50%和150%时叶片P_n较100%灌溉量分别降低35.06%和19.59%。在不同发育阶段马铃薯叶片的生理活性对灌溉量表现出敏感响应。幼苗期75%灌溉量马铃薯叶片叶绿素含量、P_n和水分利用效率（WUE）分别为0.86 mg·g^-1、21.88 μmol·m^-2·s^-1、2.29 μmol·mmol^-1，较100%灌溉量分别提高了14.15%、0.31%、3.80%，而MDA含量、SOD活性及CAT活性最低，较100%灌溉量分别降低了8.40%、11.69%、8.23%；发棵期100%灌溉量处理下P_n和WUE最高，较50%灌溉量处理分别提高了53.99%、24.85%，此时脯氨酸含量、可溶性糖含量、POD活性最低，分别为89.06 μg·g^-1、143.45 μmol·g^-1、438.14 U·g^-1，同时超氧阴离子产生速率较50%灌溉量也降低了26.07%；结薯期125%灌溉量处理的P_n和WUE最高，较100%灌溉量分别提高了19.16%、6.76%，而SOD、POD活性较100%灌溉量分别降低了0.93%、6.23%；成熟期75%灌溉量马铃薯叶片P_n最高，较其余各灌溉量处理的P_n分别提高了38.64%、13.81%、14.16%、21.27%，而MDA含量、超氧阴离子产生速率分别为21.107 μmol·g^-1、6.07 nmol·min^-1·g^-1，较100%灌溉量分别降低了19.35%、2.26%。同一生育期低灌溉量（50%灌溉量）块茎中淀粉含量较低。在幼苗期75%灌溉量处理使得块茎的可溶性蛋白含量较100%灌溉量处理提高6.20%。发棵期100%灌溉量块茎中淀粉含量达到最高（15.14%），而结薯期125%灌溉量处理的块茎可溶性蛋白含量处于最高水平，较100%灌溉量下提高4.61%。成熟期75%灌溉量块茎淀粉含量处于最高水平，较100%灌溉量提高12.77%。结合块茎的总鲜重、商品薯率、淀粉含量、维生素C含量、可溶性蛋白含量、还原糖含量等指标，可知在幼苗期、发棵期、结薯期、成熟期灌溉量分别为原灌溉量的75%、100%、125%、75%时马铃薯块茎品质最优而且产量最高，分别为654.30、650.60、773.00、703.53 g·株^-1。     

水肥供应对马铃薯根层养分及产量的影响

以陕北地区普遍种植的马铃薯品种荷兰15号为供试材料，设置灌水水平和施肥量两因素，研究水肥供应对马铃薯根层养分及产量的影响。以100%ET₀（W1）和当地推荐施肥量（F1，N-P₂O₅-K₂O为240-120-300 kg·hm^-2）为基础，3个灌水量处理分别为W1，W2（80%ET₀）和W3（60%ET₀），3个施肥水平分别为F1，F2（75%F1）和F3（50%F1），以60%ET₀灌水水平和不施肥处理为对照组（CK），共10个处理。结果表明：不同水肥供应对马铃薯各生长阶段耗水量及水分利用效率有显著的影响，随着灌水量增加，土壤水分逐渐向下层迁移；在马铃薯整个生育期，W3F2处理水分利用效率最高，为44.69 kg·hm^-2·mm^-1，其次为W2F2(44.41 kg·hm^-2·mm^-1),比CK分别高39.64%和38.75%;W3F1处理在10~60 cm土层硝态氮含量平均值最高，比CK高166.1%，W2F2在10~60 cm土层铵态氮含量平均值最高，比CK高61%，W3F3在10~60 cm土层电导率平均值最高，比CK增高48.44%。W2F2处理的土壤养分含量较高，主要集中在10~30 cm土层；W2F2处理的产量最高，为12 539.33 kg·hm^-2，比CK处理的产量高55.65%，且变异系数小。因此，该地区推荐的灌水量为80%ET₀，施肥量N-P₂O₅-K₂O为180-90-225 kg·hm^-2。     

土壤水分胁迫对马铃薯块茎淀粉合成关键酶基因表达及酶活性的影响

为探讨马铃薯块茎淀粉合成对土壤水分胁迫的响应机制，以马铃薯品种‘青薯9号’和‘闽薯1号’为材料，采用盆栽试验，设置3个水分胁迫处理：正常供水（保持土壤田间持水量的75%）、中度水分胁迫（保持土壤田间持水量的50%）、重度水分胁迫（保持土壤田间持水量的25%），研究了土壤水分胁迫对马铃薯块茎淀粉合成关键酶基因表达及酶活性的影响。结果表明：在块茎形成过程中，土壤水分胁迫显著提高了马铃薯块茎AGPase、GBSSI、SBEI、SBEII、SSII、SSIII基因表达量，随土壤水分胁迫程度的提高，马铃薯块茎SBEI、SBEII、SSII基因表达量上调；土壤水分胁迫显著降低了马铃薯块茎AGPase、GBSS、SBE、SSS酶活性，其中GBSS、SBE酶活性下调；而AGPase、GBSSI、SSIII基因表达量及AGPase、SSS酶活性在马铃薯青薯9号、闽薯1号品种间表现出相反的上、下调趋势。     

AMMI模型在马铃薯产量及农艺性状分析中的应用

使用AMMI模型对2010-2011年贵州省马铃薯区域试验结果中的产量及其农艺性状，包括株高、单株块茎数、单株主茎数、生育期、单株块茎重量进行了分析。分析结果表明，AMMI模型中的主成分轴能够解释产量、 单株主茎数、单株块茎数、生育期、单株块茎质量等性状90.64%,90%,86%,82%,81%交互作用平方和，在参加贵 州省马铃薯区试的11个品种中，W04-36,0402-2，米拉等品种稳定性、适应性与丰产性表现良好，W04-36可作为 大面积推广种植品种,0402-7，宣薯2号,2005-1，盘薯1号，丽薯200202，威薯001号，B01-41-4产量表现一般， 黑美人产量表现差。参加区试的5个试点中，通过对其鉴别力参数D_i，进行计算可知，毕节和安顺地区D_i值大，鉴 别力高，对品种具有较强选择性，六盘水地区的鉴别力最低，对品种选择性弱，适合多品种种植。     

旱地燕麦间作对土壤酶活性、微生物含量及产量的影响

本文通过研究内蒙古旱作区禾本科、豆科及茄科间作对土壤生物性状的影响，旨在揭示燕麦（Avena sativa Linn）与不同作物间作及其单作在土壤酶活性、微生物量及土地当量比（LER）等方面的优势机理。本试验设置燕麦、黑豆（Glycinemax（L.）merr）、苜蓿（Medicago sativa）、马铃薯（Solanum tuberosum L）单作和黑豆间作燕麦、苜蓿间作燕麦、马铃薯间作燕麦共7个处理，探讨各处理对上述各指标的影响。结果表明：燕麦间作黑豆土地当量比最高，2015年和2016年分别为1.62和1.65。燕麦间作黑豆土壤脲酶活性和蔗糖酶活性较苜蓿间作燕麦、马铃薯间作燕麦显著提高了5.00%~51.61%和5.73%~52.29%。2015年和2016年播种后75 d苜蓿间作燕麦土壤过氧化氢酶活性显著高于黑豆间作燕麦，分别提高了29.47%和40.56%。黑豆间作燕麦对比其他两间作处理土壤微生物的生物量碳、氮含量分别显著提高了2.70%~17.89%和11.36%~26.47%，土壤脲酶活性提高了1.51%~55.22%，蔗糖酶活性提高了5.73%~52.29%，是该地区最优的间作模式。     

黄腐酸对雾培马铃薯幼苗抗旱性的影响

试验以马铃薯(Solanum tuberosum)幼苗为研究对象,采用雾培装置进行不同黄腐酸用量和干旱胁迫处理(分别为CK,不加黄腐酸和PEG; 10％ PEG;0.01％ FA+ 10％ PEG;0.03％ FA+ 10％ PEG;0.05％ FA+ 10％ PEG和0.10％ FA+ 10％ PEG),分析其对马铃薯生长发育及抗性生理的影响。结果表明,在干旱胁迫下,雾培马铃薯幼苗的成活率、叶绿素含量、膜稳定指数、根系活力、匍匐茎数、结薯率和产量呈下降趋势,而丙二醛(MDA)、过氧化氢(H₂O₂)、脯氨酸、可溶性糖含量和过氧化氢酶(CAT)活性及超氧阴离子(O^-₂)产生速率呈上升趋势,过氧化物歧化酶(SOD)和过氧化物酶(POD)活性先增加后下降,说明雾培马铃薯幼苗在干旱胁迫下生长发育受到显著抑制,正在遭受逆境胁迫。经黄腐酸处理后,幼苗的成活率、匍匐茎数、结薯率和产量则得到了提高,而叶绿素含量、膜稳定指数和根系活力仍呈下降趋势,但较单一干旱胁迫的下降趋势缓慢,而MDA含量、SOD和POD活性及产生速率呈先升高后下降的趋势,脯氨酸、可溶性糖、H₂O₂含量及CAT活性呈上升趋势,其中H₂O₂含量上升趋势较单一干旱胁迫缓慢,说明黄腐酸处理后使干旱胁迫下雾培马铃薯幼苗的生长发育得到了促进,减轻了干旱胁迫对幼苗造成的伤害,提高了植株的整体抗旱性,而这种抗性与黄腐酸浓度呈明显相关性,0.05％ FA对植株的的保护效应最显著,而0.10％ FA则协同PEG加剧了对幼苗的伤害作用。     

Root infection of potato by Spongospora subterranea: knowledge review and evidence for decreased plant productivity

Information is reviewed on root infection of potato by the plasmodiophorid Spongospora subterranea f. sp. subterranea. This pathogen has long been recognized as the cause of root galls (hyperplasia) and the economically important disease powdery scab on tubers (modified stolons). The significance for plant productivity of the zoosporangium stages of the pathogen in potato roots has only recently begun to be documented. Two experiments are described that assessed effects of S. subterranea root infection on potato plant root function and productivity. A greenhouse experiment measured root function and plant parameters for eight potato cultivars with markedly different susceptibilities to tuber powdery scab. Water uptake and plant growth were reduced by S. subterranea inoculation in all eight cultivars. The magnitudes of these negative effects, and intensities of root hyperplasia, differed among the cultivars, but were not related to respective susceptibilities to tuber powdery scab. A field trial assessed root function and plant productivity for a cultivar (Iwa) that is very susceptible to Spongospora tuber and root diseases. Soil water content beneath uninoculated plants was consistently less than for inoculated plants, indicating that inoculation reduced water uptake (root function). Inoculation reduced shoot and root dry weights, and reduced weight of tubers per plant by 42%. Spongospora subterranea causes three diseases of potato: root membrane dysfunction, root hyperplasia and tuber powdery scab. The root diseases caused by the pathogen are likely to be important both for powdery scab management and for deleterious effects on potato crop yields.     

粉垄耕作对宁南旱地马铃薯生理特性及产量的影响

设置传统耕作(CK)、深耕(DT)、粉垄30 cm(F30)和粉垄50 cm(F50) 4种耕作措施进行试验,分析了粉垄耕作对马铃薯生理特性、叶片淀粉合成关键酶活性、土壤水分含量及马铃薯产量的影响。结果表明:粉垄耕作显著提高了土壤含水量,其中F50处理土壤含水量最高,分别在0～20 cm和20～40 cm土层较处理F30、DT、CK高出0.66%～1.12%、0.74%～2.22%、1.26%～1.41%;相关分析表明,土壤含水量与丙二醛(MDA)、脯氨酸(Pro)和可溶性糖含量呈负相关关系,与超氧化物歧化酶(SOD)、过氧化氢酶(CAT)呈正相关关系;粉垄耕作降低了丙二醛(MDA)、脯氨酸(Pro)和可溶性糖的含量,不同生育时期F50和F30分别较CK降低了13.19%～20.35%、25.19%～41.11%、13.75%～33.33%和12.75%～22.88%、38.35%～86.39%、14.29%～36.36%;粉垄耕作提高了超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、淀粉合成酶(GBSS)、淀粉磷酸合成酶(SSS)和淀粉分支酶(SBE)活性,不同生育时期F50和F30分别较CK提高了8.73%～14.94%、17.24%～31.07%、14.94%～39.76%、42.5%～81.23%、35.43%～61.26%和8.56%～14.61%、19.56%～36.32%、14.86%～36.16%、36.54%～75.73%、26.17%～53.27%;粉垄耕作显著提高了马铃薯产量,与CK相比,F50和F30分别显著提高32.09%、24.60%;通过灰色关联度分析得出,粉垄耕作处理F30表现较优,除苗期外等权关联度和加权关联度位次都为第一。在生产中建议推广的耕作措施为粉垄30 cm(F30)。     

Modifications in the potato rhizosphere during infestations of <Emphasis Type="Italic">Globodera rostochiensis</Emphasis> and subsequent effects on the growth of <Emphasis Type="Italic">Rhizoctonia solani</Emphasis>

Two controlled environment experiments were conducted to explore the hypothesis that invasion and damage caused to potato roots by the potato cyst nematode Globodera rostochiensis might result in quantitative or qualitative changes in the release of root exudates to subsequently affect the growth of Rhizoctonia solani (AG3) in the potato rhizosphere. The growth of five R. solani isolates was compared on media amended either with root exudates from G. rostochiensis-infested or uninfested potato (cv. Désirée) plants at different time intervals after the introduction of the nematodes. In Experiment 1, the growth of R. solani was higher on medium amended with potato root exudates from G. rostochiensis-infested compared to uninfested plants, collected 4, 6, 8 and 12 days after the G. rostochiensis treatments were administered. Similarly, in Experiment 2, R. solani isolates grew faster on medium amended with potato root exudates from G. rostochiensis-infested than uninfested plants. This trend was particularly pronounced at the 12-day collection. At this time, 49% of the G. rostochiensis juveniles in roots were found to belong to the juvenile moults J2 and J3, indicating that root exudates were modified during the earlier stages of juvenile invasion. Carbohydrate analysis of root exudates indicated significantly higher levels of sucrose in root exudates from G. rostochiensis-infested than uninfested plants, whereas no significant differences were found in total nitrogen content. The results are discussed to help elucidate the mechanism behind the disease complex found between G. rostochiensis and R. solani in previous field research.     

Direct infection of potato tubers by the root parasite Orobanche aegyptiaca

Parasitic plants of the Orobanchaceae are known as obligate root parasites that develop haustoria that connect to roots of various host plants. This article describes, for the first time, a case where the root parasite successfully connected to potato tubers, i.e. to the swollen portion of an underground stem rather than to a root. The rhizosphere of Orobanche aegyptiaca and of its host Solanum tuberosum (potato) was carefully examined. In anatomical studies, the adventitious roots were directly connected to potato tubers. Numerous secondary haustoria, which developed along the adventitious roots in close vicinity to the potato tuber, penetrated the tuber epidermis and the perimedullary tuber parenchyma and developed xylem strands that are presumably connected to the minor xylem strands within the tuber cortex. These findings indicate that parasites of the Orobanchaceae that normally attack host roots may also parasitise underground stem tubers.     

不同降水年型下秸秆带状覆盖对西北旱地马铃薯品质和产量的影响

为探明不同覆盖方式对马铃薯品质和产量的影响，于2019—2021年在西北半干旱雨养农业区设置秸秆带状覆盖(SM)、地膜覆盖(PM)、无覆盖露地(CK)3个处理，通过测定马铃薯块茎维生素C、淀粉、直链淀粉、还原糖、粗蛋白含量及产量指标，研究不同覆盖方式对马铃薯品质和产量的影响。结果表明：不同降水年型下秸秆带状覆盖和地膜覆盖均可以显著改善马铃薯的品质，丰水年(2019年和2020年),与CK相比，SM处理显著提高了块茎淀粉、直链淀粉的含量，增幅分别为15.2%和31.9%,PM处理显著提高了粗蛋白含量，增幅为26.6%;平水年(2021年),与CK相比，SM处理维生素C、还原糖含量分别显著提高20.4%和5.1%,PM处理维生素C、还原糖、粗蛋白含量分别显著提高35.2%、8.3%、14.6%;覆盖方式对马铃薯品质的影响整体表现为SM>PM。主成分分析和灰色关联度分析表明，SM和PM处理均可提高马铃薯品质，且SM处理马铃薯品质与产量关联度高于PM处理，SM处理下淀粉、直链淀粉含量与产量的关联度最高。覆盖栽培方式均显著提高了马铃薯鲜薯产量，SM、PM分别较CK提高13.7%～19.5%...     

绿洲膜下滴灌调亏马铃薯水分生产函数及灌溉制度优化

通过田间试验研究了绿洲膜下滴灌调亏马铃薯各生育期耗水规律及其影响因素,建立了以Jensen模型为基础的水分生产函数并对马铃薯灌溉制度进行了优化。结果表明:块茎膨大期马铃薯水分敏感指数最大,块茎形成期次之,苗期和淀粉积累期较小;块茎形成期轻度调亏对马铃薯产量无显著影响(P0.05),而块茎形成期中度调亏、块茎膨大期轻度和中度调亏对其产量均有显著影响(P0.05);块茎形成期轻度调亏的水分利用效率比块茎形成期中度调亏、块茎膨大期轻度调亏和全生育期充分灌水分别提高了6.2%、8.3%和6.7%;膜下滴灌调亏马铃薯产量随耗水量增加而增加,水分利用效率随之降低,全生育期充分灌水比块茎膨大期中度水分调亏耗水量增加22.4%,产量增加20.4%,水分利用效率降低14.0%。采用遗传算法并结合水分生产函数进行灌溉制度优化,结果表明:河西绿洲区膜下滴灌马铃薯全生育期灌溉定额为225 mm时,产量最高,为43.86 t·hm-2,灌溉水利用效率为19.5 kg·m-2;灌溉制度为苗期灌水20~30 mm,块茎形成期灌水70~75 mm,块茎膨大期灌水100~115mm,淀粉积累期灌水20~25 mm,灌水间隔为7 d。因此,膜下滴灌调亏在降低马铃薯耗水量的同时,提高了水分利用效率,在块茎形成期轻度水分调亏不影响产量,可达到节水增产的目的。     

Detection of the root lesion nematode Pratylenchus penetrans in potato tubers

The root lesion nematode Pratylenchus penetrans parasitizes a wide range of economically important crops, including potato (Solanum tuberosum). Damage by P. penetrans impacts not only the potato yield but can also reduce the tuber quality. Detailed information on tuber infection by P. penetrans is scarce for most cultivars and molecular detection of nematodes from infected tubers is needed. The objective of this study was to assess tuber symptomatology due to P. penetrans infection in 10 potato cultivars and to provide an accurate molecular methodology for nematode detection using tuber peels. Sprouts of certified potato seed from cultivars Agata, Agria, Camel, Désirée, Dirosso, Kennebec, Laura, Picasso, Royata, and Stemster were planted in 2 L pots, and soil was inoculated with 4 P. penetrans/g of soil. Sixty days after inoculation, tubers were harvested, inspected for lesions, and the number of nematodes/g of potato peel assessed. Observations of tubers with symptoms showed the presence of P. penetrans in superficial layers of peels around the lenticels and injured necrotic tissue. Different nematode stages were detected in tubers of all inoculated cultivars, varying from 4 to 46 nematodes/g of potato peel. Species-specific primers showed suitable sensitivity and reproducibility for the detection of P. penetrans in tuber potato peel samples. The molecular detection of P. penetrans directly from tuber peels can facilitate routine nematode inspections of potato seed tubers or cull potatoes for nematode detection, and prevent further dissemination of this species.     

Dynamics of the root/soil pathogens and antagonists in organic and integrated production of potato

Microbial communities in the root, rhizoplane, and rhizosphere and non-rhizosphere soil in potato, in organic and integrated production systems, were compared at the emergence and flowering phases of plant development. Microorganisms were identified on the basis of their morphology. The dominant groups included Clonostachys + Gliocladium + Trichoderma, Fusarium + Gibberella + Haematonectria + Neonectria, Paecilomyces, Penicillium and Phoma. Microbial density at the flowering phase was often significantly greater in roots and non-rhizosphere soil than in the rhizoplane and rhizosphere. Diversity of the communities often remained stable or was greater at the emergence phase. The density of bacteria changed with time. The density of Pseudomonas often decreased while Streptomyces significantly increased with time. Changes in densities of pathogens and antagonists decreased the suppressiveness of the habitat towards soil-borne potato pathogens at the flowering phase. The study contributes information that will help to: (a) understand the epidemiology of some potato diseases, (b) make decisions on the economic and ecological aspects of chemical control in potato, (c) develop strategies for manipulation of the soil microbial environment as a viable crop management technique, and (d) develop prognosis models for potato diseases in central Europe.