基于热红外图像的小麦品种抗旱性鉴定与评价

【目的】分析不同基因型小麦冠层的温度参数相关信息,探寻快速高效筛选冬小麦抗旱品种的指标和方法,给冬小麦抗旱品种筛选提供参考依据。【方法】本研究以小麦为研究对象,获取干旱胁迫下10个抗旱性存在差异的小麦品种冠层热红外图像,采用温度频率直方图等分析方法提取冠层温度特征参数,明确温度特征参数与抗旱指数之间定量关系,分析冠层温度特征参数对筛选冬小麦抗旱品种的有效性。【结果】基于产量抗旱指数（DRI）的分级标准将测定小麦品种分为4种抗旱类别,其抗旱性越强,最大光化学效率（F_v/F_m）,植株含水量（PWC）,气孔导度（G_s）,蒸腾速率（T_r）和籽粒产量越稳定。基于热红外图像提取冠层温度特征参数,小麦抗旱性越强,冠层温度的差异性越小,冠层温度的离散程度也较小。产量抗旱指数（DRI）与拔节期、孕穗期和开花期的作物冠层温度与环境温度的偏差（CTD）均呈现极显著的正相关关系,相关系数r为0.79—0.84,而与冠层温度标准差（CTSD）、变异系数(CTCV)、水分胁迫指数（CWSI）和冠层相对温差（CRTD）呈显著负相关（r=-0.56—-0.78）。基于单一生育时期冠层温度特征参数建立了产量抗旱指数（DRI）回归模型,估算精度为r²=0.73—0.87,其中以拔节期预测模型精度最高。而基于3个生育时期的相关冠层温度参数CTD、CTCV、CTSD CWSI组合构建产量抗旱指数（DRI）预测模型,较基于单一生育时期预测精度显著提升（r²=0.95）。【结论】利用热红外图像可进行小麦品种抗旱性的早期鉴定与快速评价,这对促进作物高效节水生产具有重要意义。     

玉米不同基因型的抗旱性鉴定及遗传分析

研究结果表明,武105的抗旱性最强;水分胁迫对植物产量性状、形态发育指标及生理性状的影响随着基因型及胁迫强度的不同而不同,单株籽粒产量对水分亏缺的反应最为敏感;抗旱系数、Eberhat-Russell稳定性参数(bi)及变异系数均能对供试材料的抗旱性做出客观地评价;从直观指标看,叶片窄长,雌雄发育协调,植棘体内水分含量及叶绿素含量高的基因型较抗旱;抗旱自交系在缺水条件下,一般配合力效应有所堤高,不抗旱自交系有所下降;抗旱自交系抗旱系数的一般配合力效应高,严重水分胁迫条件下抗旱系数的遗传主要受加性效应控制;控制产量与控制抗旱性的基因或基因系列不同,二者可独立进行选择.     

干旱胁迫下春玉米冠层吐丝动态及籽粒数模拟研究

【目的】为实现干旱胁迫下玉米冠层吐丝动态的模拟,建立开花—吐丝间隔(anthesis-silking interval,ASI)和吐丝百分率与单位面积籽粒数的关系,改善干旱胁迫条件下玉米籽粒数的模拟效果。【方法】本研究基于锦州农业气象试验站干旱胁迫控制试验,测定了不同水分处理下玉米开花前后植株平均生长速率(PGR)、玉米冠层逐日吐丝百分率动态、ASI、开花后果穗生物量累积和株籽粒数等指标,利用上述数据确定了玉米冠层吐丝动态模型参数;进行了模拟吐丝百分率对植株生长速率平均值(PGR_AVE)和标准差(PGR_SD)两个输入参数的敏感性分析;基于果穗生物量累积过程,考虑干旱胁迫条件下冠层内植株个体间PGR的差异,开展开花前后不同干旱胁迫条件下冠层吐丝动态过程模拟;建立ASI与株结实率(株籽粒数占株最大潜在籽粒数的百分比)的定量关系;基于冠层吐丝动态模型模拟的开花后吐丝植株百分率、单株最大潜在籽粒数和株结实率,构建了基于冠层吐丝动态的籽粒数模型,进行了干旱胁迫下的籽粒数模拟与检验。【结果】冠层吐丝动态模型对PGR_AVE和PGR     

穗期干旱胁迫对玉米单交种产量影响的研究

2004～2005年在黑龙江省农科院嫩江农科所抗旱大棚内,选用6个玉米单交种作为试材,在穗期设置正常供水、轻度干早胁迫和中度干早胁迫3个水分处理,研究不同水分处理条件下,不同玉米品种穗部生长发育的变化与产量的关系.试验结果表明:穗粗、行粒数、轴粗、百粒重、出籽率和轴重等6个指标与产量的相关性达到了显著或极显著水平,但不同供水条件下,穗部性状差异的显著性因品种而不同.     

水分胁迫对玉米萌芽期和苗期生长的影响

[目的]为了研究水分胁迫对玉米萌芽期和苗期生长的影响。[方法]用PEG高渗溶液模拟干旱条件,以抗旱性不同的玉米自交系为材料,研究了玉米萌芽期和苗期水分胁迫对其生长的影响及生理指标的变化与抗旱性的关系。[结果]各玉米自交系发芽率、叶片鲜干比明显下降,抗旱性强的自交系下降的幅度较小;根冠比、MDA含量和CAT、SOD酶活性均有一定程度升高,抗旱性强的自交系升高的幅度较大。萌芽期发芽率、苗期叶片鲜干比、根冠比、失水率、MDA含量及SOD和CAT酶活性与玉米抗旱性都有明显的相关性,可作为玉米抗旱性的鉴定指标。[结论]该研究为玉米早期抗旱育种提供了参考。     

玉米质膜内在蛋白ZmPIP2;6响应渗透、盐和干旱胁迫的功能鉴定

【目的】质膜内在蛋白(plasma membrane intrinsic proteins,PIPs)广泛存在于植物细胞的膜系统上,在植物体内水分运输和水分平衡的过程中至关重要。对ZmPIP2;6在植物水分胁迫耐性中的功能进行探究,为玉米培育抗旱耐盐新品种提供优秀基因资源。【方法】分析并比对ZmPIP2;6与其他物种中报道参与水分胁迫的PIPs的氨基酸序列,构建ZmPIP2;6-GFP载体并通过PEG介导转化玉米原生质体,对ZmPIP2;6进行亚细胞定位。采集玉米的不同组织样品,包括根、茎、叶、未成熟雄穗、未成熟雌穗、胚和胚乳;对玉米进行PEG或NaCl处理,在处理的不同时间点采集玉米的根和叶样品。提取总RNA并通过qRT-PCR调查ZmPIP2;6在玉米不同组织以及在水分胁迫下的表达模式。构建ZmPIP2;6超表达载体,发展并鉴定ZmPIP2;6超表达拟南芥材料,观察转基因植株对渗透、盐及干旱胁迫的耐性生理表型,并测量其根长、叶片水分散失率等性状。检测在干旱或盐胁迫条件下,拟南芥胁迫信号通路上的相关基因在ZmPIP2;6超表达植株中的表达。【结果】氨基酸序列分析比对结果显示ZmPIP...     

水分胁迫对玉米叶片光合作用的影响

试验在盆栽人工控制水分的条件下,选用耐旱性不同的玉米杂交种沈单10、掖单13号和丹玉13号为试验材料,比较了不同水分胁迫强度对不同耐旱性玉米杂交种叶片光合作用的影响。结果表明,水分胁迫下玉米叶片光合速率随胁迫增强而下降,而在重度胁迫下光合速率显著下降。     

Spectral indices sensitively discriminating wheat genotypes of different canopy architectures

A field experiment of 18 wheat cultivars of erectophile, planophile and horizontal canopy architectures was conducted during the 2004–2005 growing seasons in Beijing (40°10.6′ N, 116°26.3′ E), China. Canopy reflectance (350–2500 nm) at different growth stages was measured and leaf area index (LAI) and leaf chlorophyll concentration (Chl) were determined at booting. The main objective of the study was to evaluate the ability of various vegetative indices (VIs) to detect canopy architectures in wheat genotypes. The chlorophyll-sensitive spectral indices, the modified chlorophyll absorption reflectance index (MCARI) and the transformed chlorophyll absorption reflectance index (TCARI), were very sensitive to canopy architectures in the wheat plants. The MCARI values were significantly (p < 0.05) larger for the horizontal genotypes than for the planophile ones, and also larger for the planophile genotypes than for the erectophile ones for the six growth stages. The TCARI had a similar power to MCARI for discriminating between different wheat canopy architectures. At booting, both MCARI and TCARI were only weakly related to Chl in the upper, middle and lower leaves. The results emphasized the difficulties of determining crop Chl from canopy reflectance. The mechanisms that cause the differences in MCARI and TCARI among the canopy architectures are discussed.     

Foliage temperature extraction from thermal imagery for crop water stress determination

Crop water stress determination methods from canopy temperatures, derived from the surface energy balance equations, treat the canopy temperature under the assumption that the canopy behaves as a virtual “big-leaf”, covering the ground surface. Introduction of very high-resolution thermal imagery, 0.01–0.3-m pixel size, acquired from low altitude platforms, enabled finely detailed observation of the whole canopy, raising the question how to select the relevant canopy temperatures. One approach is to select the sunlit leaves confirming to the “big leaf” energy balance paradigm. However, thermal imagery alone is incomplete and needs additional marking or synchronized visible imagery for interpretation, which makes the process complicated and expensive. The other approach, used in reference surface based water stress evaluation, is to use full frame pixel statistics without pattern recognition by selecting the mean temperature of the cold fraction from the pixel histogram. That greatly simplifies processing for large-scale aerial thermography. Here are presented the results of experiments conducted in cotton and vine grapes, where both approaches were evaluated simultaneously. Ground referenced thermal and visible images were overlapped, and sunlit, shaded and whole canopy leaves were selected for crop temperature evaluation. The pixel histograms of the same images were analyzed in a two-step method, after discarding soil pixels where their temperature was 7 °C higher than air temperature at step one, and calculation of the mean temperatures of the lowest 33 and 100 % of the remaining pixels for step two. Several crop water stress indices were compared with leaf and stem water potentials and stomatal conductance. Good agreement was found between both image segmentation and histogram analysis methods, demonstrating the suitability of both methods in canopy temperature evaluation for crop water stress evaluation.     

干旱胁迫对玉米雄穗发育特征及产量的影响

【目的】探究干旱胁迫对玉米雄穗发育特征及产量的影响,以期为中国东北地区玉米种植抗旱保产提供一定理论基础。【方法】采用盆栽试验,设置原土处理和添加土壤改良剂处理,并于玉米大喇叭口期至吐丝期进行不同程度的干旱胁迫：正常供水、轻度干旱胁迫、中度干旱胁迫和重度干旱胁迫,研究不同程度干旱胁迫对玉米的抽雄吐丝间隔、雄穗形态特征、生理指标以及产量的影响。【结果】干旱胁迫导致玉米雌穗吐丝时间延后,雌、雄穗开花吐丝不同步,且在重度干旱胁迫时达到最大值,其中原土处理较CK延长了6.33 d,添加土壤改良剂处理延长了4.67 d;不同程度干旱胁迫会导致玉米雄穗变小、主轴缩短,轻度干旱胁迫有利于雄穗积累干物质,原土处理和添加土壤改良剂处理的雄穗干物质分别比CK增加了5.18%和14.87%;干旱胁迫会促使雄穗分泌抗氧化系统酶以及渗透调节物质抵御逆境伤害,但重度干旱胁迫时雄穗内部产生过多丙二醛(MDA)以及有害物质,会导致抗氧化系统酶活性有所降低;干旱胁迫会造成玉米产量严重下降,重度干旱胁迫时原土处理的产量与CK相比下降了62.39%,添加土壤改良剂处理的产量则下降了57.77%。【结论】干旱胁迫会对玉米雄穗发...     

Study and evaluation of drought resistance of different genotype maize inbred lines

Using cultivating experiments in fields under drought stress, yields and characteristics in morphology, growth and development of different genotype maize inbred lines were studied systematically. We evaluated and classified the drought resistance of these materials based on the needed indexes, including subordinate function values of drought resistance (SV), drought coefficient (DC) and drought index (DI) of yield by fuzzy function method and cluster analysis. We also analyzed the correlations between parameters and tested values of traits. The effective parameters and indexes of comprehensive evaluation for drought resistance were selected with principal component analysis. The results showed that under drought stress, the yield of maize inbred lines obviously decreased. The anthesis and silking interval (ASI) was prolonged compared with the control, with a smaller leaf area, thinner stalk, shorter and smaller ears, lengthened barren ear tip, a decline in plant height and ear position, reduced grain number per ear and grain weight, which led to a yield decline. Effects of drought treatment on different maize inbred lines were significantly different. 79-1E, Jiao51, Su1-1 and 18599 were found to be highly resistant to drought, while 1125 and 5311 performed the worst. DI and SV were significantly correlated with drought resistance. Our results indicated that DI, SV, yield and leaf area could be used as parameters and indexes to effectively evaluate the drought resistance of maize. Meanwhile, DC, plant height, ASI, grain number per ear or row, ear length and diameter could be taken as auxiliary parameters and indexes. An applied scientific method for the comprehensive evaluation of drought resistance was offered in this paper. __________ Translated from Journal of Maize Science, 2007, 15(5): 6–11 [译自: 玉米科学]     

不同玉米杂交种对水分和氮胁迫的响应及其抗逆性

 【目的】研究玉米对水分胁迫和低氮条件的响应及其所受的影响，明确不同杂交种的抗旱耐瘠性表现，为干旱、半干旱和土壤贫瘠地区选用玉米品种提供依据。【方法】选择17个杂交种，设置不同水分和施氮处理的田间肥水耦合试验，研究水分和低氮胁迫对不同杂交种生长发育、形态和产量性状的影响，以产量抗逆指数对其抗旱耐瘠性进行综合评价，并选择抗逆性密切相关的8个指标对不同品种进行聚类。【结果】不同水分和低氮胁迫下玉米籽粒产量较对照明显降低，粒数减少，粒重下降，果穗变短小，秃尖增多，散粉至吐丝期间隔延迟。水分胁迫与低氮条件下受影响最大，其次是低氮胁迫。水分胁迫下增施氮肥或低氮条件下增加供水均能明显提高产量。水分与氮肥间有极显著的互作效应，这种交互作用也表现一定的复杂性，与品种密切相关。供水与不供水或施氮与不施氮以及不同品种间产量差异也均呈极显著。各胁迫处理的产量、行粒数、千粒重、秃尖长、穗粗、穗长、ASI与产量抗逆指数之间有较密切关系，平均ARI与胁迫下的产量也均呈极显著正相关，以此为评价依据并结合聚类分析表明：抗旱耐瘠性表现最好的是黔2599、黔玉3号和中单2号，其次是兴黄单89-2、黔2411、遵玉3号、贵毕302和贵毕303；而安单136表现最差，其次是黔玉1号和黔兴4号。【结论】玉米对低氮胁迫的响应要高于对水分胁迫的响应，而不同品种因抗逆性差异，对水分和低氮胁迫响应的敏感性明显不同。水分与氮肥之间有明显的协同作用。以产量抗逆指数对不同杂交种的抗逆性进行综合评价是合理的。     

不同耐旱基因型玉米根系生理性状研究

为了研究玉米根系生理性状与耐旱性的关系,以生长于田间的玉米掖单13(耐旱)和丹玉13(不耐旱)为试验材料,分别于苗期、拔节期、孕穗期和灌浆期测定其根系分布、保水力、吸收面积、氧化力、硝酸还原酶活性以及总糖和还原糖含量等项指标.结果表明:耐旱基因型玉米在21 cm以下土层中的根干重以及根系氧化力极显著高于不耐旱基因型玉米根系(P＜0.01);根系保水力、可溶性糖含量、还原糖含量以及硝酸还原酶活性显著高于不耐旱基因型玉米根系(P＜0.05);根系总吸收面积和活跃吸收面积在两基因型玉米根系之间差异不显著(P＞0.05).这些结果表明,根系所具有的吸水、保水能力和生物节水能力对玉米耐旱能力的发挥起着重要作用.     

水分胁迫对不同抗旱性玉米幼苗叶片蛋白质的影响

在水分胁迫及复水条件下，选用抗旱性较弱的丹玉13号和抗旱性较强的掖单13号玉米品种幼苗为试村，研究了玉米叶片蛋白质的变化规律和抗旱性的关系。结果表明，可溶性蛋白含量随水分胁迫加强而下降。水分胁迫可引起蛋白质合成的变化并产生干早诱导蛋白，抗旱性弱的品种诱导蛋白产生早于抗旱性强的品种。     

基于冠层温度的夏玉米旱情指数理论模型和经验模型的比较

对水分胁迫指数(CWSI)的经验模型和理论模型在华北平原夏玉米中的应用进行了对比,分析了2种模型与土壤含水量以及叶水势之间的关系,对比了2种模型得到的CWSI的日际变化.结果表明,经验模型经常性地溢出0～1的范围,理论模型则很少出现溢出0～1的范围,经验模型的日际变化较理论模型大,理论模型1 d中得到的CWSI变化很小;2种CWSI模型与土壤含水量均显著相关,可用于指导作物灌溉时间;CWSI理论模型与夏玉米叶水势的相关性较好,更能反映作物本身的水分状况.     

水分胁迫对玉米杂交种叶绿素含量的影响

 叶绿素含量是反映植物抗旱性的一个重要指标。为了研究玉米杂交种的抗旱性,筛选出抗旱性较强的玉米杂交种用于生产,本研究选用7个玉米杂交种,在遮雨棚中进行盆栽试验,通过控制浇水,研究水分胁迫对玉米杂交种叶绿素含量及抗旱性的影响。结果表明,花期干旱处理的叶绿素a,总叶绿素含量以及叶绿素a/b分别为5.464 mg/L,7.853 mg/L和2.286,均高于苗期干旱处理（分别为2.373 mg/L,4.769 mg/L和0.990）。在不同干旱处理进程中,苗期干旱有利于叶绿素b含量的提高,而在花期干旱中,随着干旱处理时间以及玉米的逐渐成熟,叶绿素含量显著下降。在不同杂交种间,无论是苗期干旱处理,还是花期干旱处理,长城706的叶绿素含量最高,苗期干旱处理下,其叶绿素a,叶绿素b以及总叶绿素含量分别为8.831,3.705,12.533 mg/L,花期干旱处理下,三者分别为12.608,4.277,16.881 mg/L;长城799,农单5号、北玉16号、海禾1号次之;而路单8号和会单4号的叶绿素含量最低。而叶绿素a/b在苗期干旱处理、花期干旱处理进程中,以及在不同品种间均无明显变化。由于叶绿素含量的高低可以反映不同玉米品种对水分胁迫的敏感程度,因此,从干旱处理中的叶绿素含量变化可以看出,长城706的抗旱性最强,长城799,农单5号、北玉16号、海禾1号的抗旱性较强,而路单8号和会单4号的抗旱性较差。叶绿素含量可以作为筛选玉米品种抗旱性的指标之一。     

水分胁迫对玉米生长发育和产量的影响

为增进玉米对干旱响应与适应的了解并制定应对策略,利用锦州市农业生态站大型活动遮雨棚及池栽,在全生育期控水条件下,研究不同水分胁迫程度对玉米生长发育和产量的影响。结果表明,玉米受干旱胁迫的影响程度因受旱轻重、持续时间以及生育进程的不同而不同,受旱越重,持续时间越长,影响越大。拔节期前,玉米株高和生物产量受有限供水或轻度干旱影响较小,但从拔节期后,至抽雄和灌浆期,干旱胁迫对株高和产量产生较大的不良影响,进而引起果穗性状恶化,穗粒数和百粒重减小,最终导致经济产量大幅下降。     

干旱胁迫下两个玉米自交系雄穗花器官分化期的转录组分析

【目的】 运用现代分子生物学及高通量测序技术,在全基因组水平鉴定耐旱相关的基因,研究玉米雄穗花器官分化期对干旱胁迫的响应机理, 为抗旱育种将提供新的理论基础。【方法】 以干旱胁迫15 d和正常浇水的耐旱自交系“PHBA6”和干旱敏感自交系“吉63” 花器官分化期的雄穗进行Illumina HiSeq 2000高通量测序分析,将测序得到的Unigene与玉米参考基因组进行比对,利用 RPKM 来衡量样本间的基因表达丰度, 以|log₂foldchange|≥1,P<0.05,FDR≤0.001筛选出样本间的差异表达基因, 并通过 Gene Onto 1ogy (GO ) 数据库、 KEGG pathway 数据库对筛选出的差异表达基因的功能和参与的调控路径进行分析。【结果】 与正常水分处理相比,耐旱自交“PHBA6”和干旱敏感自交系“吉63”在干旱胁迫下分别有1 394个和1 300个显著差异表达基因,其中共有差异表达基因831个,包括上下调表达趋势是一致的822个基因和9个具有相反的表达模式基因。除这些基因外,各自分别还有563个和469个基因型特异的干旱响应基因,这些特异的干旱响应基因的G0 富集分析的条目并不完全相同,除共同富集在刺激响应,细胞壁改变外,耐旱自交“PHBA6”还富集在激素合成调控,机氮化合物代谢、蛋白结合上,特异的干旱响应基因的KEGG 显著性富集分析在2个自交系中也不完全相同,耐旱自交“PHBA6”还有部分差异基因富集在生物素代谢通路上,另外,筛选出耐旱自交“PHBA6”中在干旱胁迫下差异表达的3个脱水素基因和3个特有差异表达的bZIP、MYB和ERF转录因子。【结论】 胁迫相关基因的特异性响应可能是材料间耐旱性存在差异的主要原因,耐旱自交“PHBA6”中的3个脱水素基因和3个特有差异表达的bZIP、MYB和ERF转录因子基因在玉米耐旱育种中可能有重要的利用价值。     

Aromatic constituents in fresh leaves of Lingtou Dancong tea induced by drought stress

The effect of different degrees of drought stress on the aromatic constituents and their relative contents in fresh leaves of Lingtou Dancong tea plants was studied in this paper. The results showed that drought stress could evidently increase the kinds of aromatic components in the fresh leaves. The largest number of kinds (58) of the aromatic constituents was detected when soil relative water content was 53.90% among all the designed treatments, while the lowest number was found under a soil relative water content of 99.75%. The total amount of relative contents of 17 kinds of aromatic components such as linalool etc., increased with drought stress, whereas 12 kinds of aromatic components such as tetradecanoic acid etc., decreased with drought stress. Linalool, linalool oxide, tetradecane, 10-methylnonadecane, and dodecanal showed high contents under the soil relative water content of 53.90%; Cyclohexane, 1-hexadecene, and 1-tricosanolonly were induced in the soil relative water content of 53.90% and 29.25%; while drought stress could inhibit the synthesis of constituents of 7 kinds such as nonanedioic acid monomethyl ester, etc. Different degrees of drought stress could induce various kinds of aromatic constituents, and the number of aromatic constituents induced in fresh leaves increased with the strengthening of drought stress. __________ Translated from Journal of South China Agricultural University, 2006, 27(1): 17–20 [译自: 华南农业大学学报]