水分胁迫对甜玉米主要农艺性状及产量的影响

在大棚内采用人工供水的方法,研究不同水分胁迫下甜玉米品种主要农艺性状与产量的关系。结果表明,轻度干旱胁迫下可用株高、茎粗、散粉至吐丝间隔期(ASI)、穗粗、每穗粒数、千粒重等6个性状耐旱系数作为品种耐旱性鉴定的指标,而中度干旱胁迫下可用穗位叶面积、散粉至吐丝间隔期(ASI)、穗粗、每穗粒数、出籽率、千粒重这6个性状耐旱系数预测品种产量的耐旱系数。在不同程度水分胁迫下,散粉至吐丝间隔期(ASI)、穗粗、每穗粒数、千粒重等4个性状耐旱系数是不同品种耐旱性鉴定的重要指标,除此之外,株高、茎粗、穗位叶面积等决定植株形态的性状指标也对甜玉米耐旱性起一定作用。     

37个玉米新品种（组合）耐旱性评价

为评价37个玉米新品种（组合）的耐旱性潜力,采用4种控水处理对玉米植株性状和产量性状进行了分析评价。结果表明,水分胁迫对穗长、秃尖长、行粒数、百粒重、ASI和单株产量6个性状有显著或极显著影响。水分胁迫使玉米品种抽丝散粉间隔期延长,秃尖变长,结实率降低,行粒数减少,籽粒变小,百粒重下降,单株产量降低。应用模糊数学隶属函数法综合评价分析,‘帮豪玉509’、‘忠玉9号’、D36、BH0310和D30综合耐旱性较强,D23、D3、D26和BH3404综合耐旱性较差。     

水分胁迫下玉米杂交种光合抗旱指数与抗旱性评价研究

通过筛选抗旱玉米品种和抗旱评价指标,进而对其进行生理生化研究,最终实现干旱半干旱地区玉米抗旱节水,是研究玉米高产高效的重要课题。采用盆栽试验方法,选用辽宁省近几年最新选育的12个玉米杂交种,在水分胁迫条件下,对苗期、抽雄吐丝期和灌浆期玉米形态和光合生理等性状特征进行了研究和分析,找出了不同时期水分胁迫下光合抗旱指数与产量抗旱指数的相关性,筛选出了抗旱性较强的玉米品种。结果如下：苗期水分胁迫缩短了58％供试品种抽雄至散粉期时间,延长了83％供试品种的ASI,而铁研120在水分胁迫处理后ASI比对照短,且和其他品种相比,该品种苗期叶片叶绿素含量较高。相关分析表明,灌浆期水分胁迫处理,光合抗旱指数与产量均呈正相关关系,其中,蒸腾速率抗旱指数与产量抗旱指数相关性较强。不同水分胁迫时期的产量抗旱等级划分结果显示,铁研120和铁研58综合抗旱性较强,在苗期、抽雄吐丝期和灌浆期受到水分胁迫,在籽粒成熟期均能获得较高产量。     

玉米品种耐旱性评价及相关鉴定指标的研究

耐旱性鉴定和评价是培育优良耐旱玉米杂交种品种的基础。本研究通过对一组杂交种进行耐旱性指标评价分析发现,产量仍是衡量耐旱性强弱最重要的指标,而开花吐丝间隔期、株高等农艺指标在评价品种耐旱性时也具有重要的参考价值。产量指标中,种质耐旱指数（DTIg）也可用于评价品种耐旱性。根据DTIg对参试品种进行了五级耐旱性评价。     

37个玉米品种耐低氮能力潜势分析

为明确37个玉米品种耐低氮潜势,于2013年通过大田试验研究了施氮量对玉米品种植株性状、产量及其组成性状的影响。结果表明：施氮量对玉米的穗上叶叶面积、穗下叶叶面积、穗位叶叶面积、叶绿素含量、有效功能叶片数、散粉至吐丝间隔期（ ASI）、穗长、穗粗、秃尖长、行粒数、百粒质量和籽粒产量影响显著或极显著,对株高、穗位高和穗行数影响不显著;不同施氮水平下37个品种各性状的变异系数除穗下叶叶面积ASI和秃尖长外,其余性状均为45 kg／hm2施氮量的变异系数最大,该施氮量可能是玉米品种耐低氮鉴定的适宜施氮量。低氮胁迫对玉米各性状具有不利影响。低氮胁迫下玉米籽粒产量与穗位叶叶绿素含量、有效功能叶片数、穗长、穗粗、行粒数显著或极显著正相关,可作为耐低氮性筛选指标。不同玉米品种耐低氮能力存在基因型差异,采用模糊数学隶属函数分析方法筛选出三峡玉3号、三峡玉5号、三峡玉9号、忠玉9号、先玉508、M8（ XZ071-4×渝561）、M15（11 Y2×08 HC-7）、BH1421（281H ×S99）共8个高产耐低氮玉米品种。     

灰色关联度分析和主成分分析在油菜抗旱育种中的应用

以12份芥菜型春油菜品种为材料,利用灰色关联度和主成分分析法,分析大田干旱处理和正常灌溉下17个性状指标的变化,筛选和鉴定油菜耐旱性产量指标和耐旱性状指标。灰色关联度分析结果表明,旱胁迫下与单株产量关联度最为密切的是与产量相关的因子,最不紧密的是气孔导度;正常灌溉下单株产量与胞间CO_2浓度(0.636)关联紧密;主成分分析将干旱胁迫下17个性状的耐旱系数综合成为5个互相独立的综合指标。因此,在选育耐旱品种时,应重点观察与单株产量关联密切的产量因子、植株形态因子和光合生长因子。     

不同耐旱性玉米品种对干旱的生理生化反应

马秀芳等以耐旱性不同的3个玉米品种为试材，通过两年的盆栽试验研究了抽雄期水分胁迫下玉米的一系列生理生化指标的变化，探讨了这些指标与玉米耐旱性之间的关系。结果表明，水分胁迫下，相对含水量、SOD、CAT和POD活性下降，相对电导率、丙二醛、脯氨酸和可溶性糖含量升高。3个品种中，相对含水量与穗粒数呈显著或极显著正相关，其余各指标与产量构成因素之间的相关程度依品种而异。这些指标在确定品种耐旱方面可以作为参考。     

常用玉米自交系抗旱性及抗旱性鉴定指标研究

采用人工水分胁迫处理,通过植物生理学方法,对10个常用玉米自交系进行了抗旱性研究。结果表明,不同玉米自交系存在明显差异,沈136、齐319、丹598和沈137耐旱性较好,可以作为玉米耐旱育种的基础材料。干旱胁迫下,玉米植株叶片相对含水量、丙二醛含量、电导率和ASI与玉米子粒产量极显著相关,能够比较准确地评价玉米自交系抗旱性的强弱,和抗旱系数、抗旱指数一样可以作为玉米育种耐旱自交系筛选的鉴定指标。     

马铃薯冠气温差变化特性与耐旱性的关系

冠气温差能够反映植物在干旱胁迫下的生理适应性。本研究以耐旱型马铃薯品种冀张薯8号和陇薯10号; 干旱敏感型品种大西洋和夏波蒂, 以及从秘鲁国际马铃薯中心引进的10份具有不同耐旱性的种质资源为材料, 在半干旱和半湿润2种环境下对其植株表型性状(株高、叶面积、叶鲜重、植被覆盖指数)、光合生理指标(光合速率、气孔导度、蒸腾速率、叶绿素)以及冠气温差进行测定和耐旱性评价。结果表明, 所测性状指标中, 冠气温差、蒸腾速率和气孔导度对干旱胁迫最敏感; 冠气温差在不同供试马铃薯材料之间及干湿两种环境之间均表现出极显著差异性; 冠气温差的耐旱系数与植株表型性状及光合生理指标的耐旱系数均呈极显著正相关; 利用红外热成像技术监测冠气温差, 是进行马铃薯耐旱性评价的有效手段, 可为马铃薯耐旱育种研究提供理论依据。     

不同种质杂交玉米品种间的耐旱性研究

选用3个不同种质的玉米品种迪卡007、桂单22号和农大108为试材,通过盆栽试验研究苗期水分胁迫下玉米的一系列生理生化指标的变化,并探讨了这些指标与玉米耐旱性之间的关系。结果表明,水分胁迫下,株高、叶绿素和光合作用速率下降,相对电导率、丙二醛(MDA)含量、SOD和POD活性升高,生物产量、穗粒数、百粒重随着干旱胁迫程度的加重而降低。这些指标在3个品种间的表现差异显著,在确定品种耐旱方面可以作为参考。     

Evaluation of grain yield and its components in wheat cultivars and landraces under near optimal and drought conditions

In a 2-years experiment, 30 wheat cultivars and 21 landraces from different countries were tested under near optimum and drought stress conditions. Plant height, number of sterile spikelets per spike, spikelets per spike, number of kernels per spike, kernel weight per spike, 1000 kernel weight and grain yield were evaluated. The number of kernels per spike, 1000 kernel weight and especially yield were more sensitive to drought stress in the cultivars than plant height and number of spikelets per spike, while in the landraces these traits did not differ under drought stress compared to near optimum conditions. The average yield of cultivars was significantly better than the average yield of landraces under near optimum as well as drought stress conditions. Path coefficient analysis showed that for cultivars under near optimum conditions there was no significant direct association of any of the analysed characters with yield, while under drought stress conditions, number of kernels per spike had a significant positive direct effect. Under drought stress conditions, the number of sterile spikelets displayed a negative direct effect, while kernel weight per spike had a positive direct effect on yield. Hierarchical cluster analysis was used as a tool to classify cultivars and landraces according to their yield ability under near optimum and drought stress conditions. Among the cultivars, two groups out of five and among one of three in the landraces were characterised by high yields in both near optimum as well as under drought stress conditions. These genotypes may serve as sources of germplasm for breeding for drought tolerance. This revised version was published online in August 2006 with corrections to the Cover Date.     

The Effect of Late-terminal Drought Stress on Yield Components of Four Barley Cultivars

Barley (Hordeum vulgare L.) is an important winter cereal crop grown in the semiarid Mediterranean, where late‐terminal drought stress during grain filling has recently become more common. The objectives of this study were to investigate the growth performance and grain yield of four barley cultivars under late‐terminal drought stress under both glasshouse and field conditions. At grain filling, four barley cultivars (Rum, ACSAD176, Athroh and Yarmouk) were exposed to three watering treatments: (1) well‐watered [soil maintained at 75 % field capacity (FC)], (2) mild drought stress at 50 % FC, (3) severe drought stress at 25 % FC in the glasshouse experiment and (1) well‐watered (irrigated once a week), (2) mild drought (irrigated once every 2 weeks), (3) severe drought (non‐irrigated; rainfed) in the field. As drought stress severity increased, gross photosynthetic rate, water potential, plant height, grain filling duration, spike number per plant, grain number per spike, 1000‐grain weight, straw yield, grain yield and harvest index decreased. In the glasshouse experiment, the six‐row barley cultivars (Rum, ACSAD176, and Athroh) had higher grain yield than the two‐row barley cultivar (Yarmouk), but the difference was not significant among the six‐row cultivars under all treatments. In the field experiment, Rum had the highest grain yield among all cultivars under the mild drought stress treatment. The two‐row cultivar (Yarmouk) had the lowest grain yield. In general, the traditional cultivar Rum had either similar or higher grain yield than the other three cultivars under all treatments. However, the yield response to drought differed between the cultivars. Those, Rum and ACSAD176, that were capable of maintaining a higher proportion of their spikes and grains per spike during drought also maintained a higher proportion of their yield compared with those in well‐watered treatment. In conclusion, cultivar differences in grain yield were related to spike number per plant and grain number per spike, but not days to heading or grain filling duration.     

不同高产玉米品种抗旱性的比较研究

为了有效筛选出适合鲁东半干旱区应用的夏玉米品种,以山东省目前主推的9个玉米品种为试材,通过2010-2011年连续2年防雨棚控水干旱试验,以抗旱隶属度、抗旱指数为评价参数,对各品种进行抗旱性综合评价。结果表明,干旱胁迫导致各品种玉米株高、穗位高、穗长、穗粒重均不同程度地降低,茎秆变细,秃尖变长,产量降低。年份间比较,2011年夏玉米植株性状、穗部性状、地上部干物重、产量均显著高于2010年。以茎秆性状、穗部性状、地上部干物重及产量指标隶属度的平均值为综合评价标准,‘登海701’为典型抗旱性品种;‘莱农14’、‘农大108’、‘金海5号’为抗旱性较强的品种;‘登海662’、‘郑单958’、‘中科11’、‘浚单20’为抗旱性弱的品种;‘青农105’在2年内的隶属度值差异较大,其抗旱性有待进一步研究。     

我国主要玉米自交系开花期耐旱性差异及改良

通过对37份我国主要玉米自交系两年的开花期耐旱性鉴定, 筛选出耐旱系12份(K22、 SH15、 X178、 P138、中自01、中自451、金黄96B、齐319、旱23、东91、临京11、 CA156). 在干旱胁迫下, 果穗吐丝延迟, 雌雄开花间隔增大, 结穗率下降, 籽粒产量严重降低; 雌雄开花间隔天数和结穗率与籽粒产量均呈极显著相关, 是可供耐旱性选择     

Assessment of soybean yield with altered water-related genetic improvement traits under climate change in Southern Brazil

Water deficit is a major factor responsible for soybean yield gap in Southern Brazil and tends to increase under climate change. An alternative to reduce such gap is to identify soybean cultivars with traits associated to drought tolerance. Thus, the aim of this study was to assess soybean adaptive traits to water deficit that can improve yield under current and future climates, providing guidelines for soybean cultivar breeding in Southern Brazil. The following soybean traits were manipulated in the CSM-CROPGRO-Soybean crop model: deeper root depth in the soil profile; maximum fraction of shoot dry matter diverted to root growth under water stress; early reduction of transpiration under mild stress; transpiration limited as a function of vapor pressure deficit; N₂ fixation drought tolerance; and sensitivity of grain filling period to water deficit. The yields were predicted for standard and altered traits using climate data for the current (1961–2014) and future (middle-century) scenarios. The traits with greater improvement in soybean yield were deeper rooting profile, with yield gains of ≈300 kg ha⁻¹, followed by transpiration limited as a function of vapor pressure deficit and less drought-induced shortening of the grain filling period. The maximum fraction of shoot dry matter diverted to root and N₂ fixation drought tolerance increased yield by less than 75 kg ha⁻¹, while early reduction of transpiration resulted in a small area of country showing gains. When these traits were combined, the simulations resulted in higher yield gains than using any single trait. These results show that traits associated with deeper and greater root profile in the soil, reducing transpiration under water deficit more than photosynthesis, creating tolerance of nitrogen fixation to drought, and reducing sensitivity of grain filling period to water deficit should be included in new soybean cultivars to improve soybean drought tolerance in Southern Brazil.     

Effects of Zinc Deficiency and Drought on Grain Yield of Field-grown Wheat Cultivars in Central Anatolia

Drought stress and zinc (Zn) deficiency are serious abiotic stress factors limiting crop production in Turkey, especially in Central Anatolia. In this study, the effects of Zn deficiency and drought stress on grain yield of 20 wheat cultivars (16 bread wheat, Triticum aestivum; four durum wheat, Triticum durum cultivars) were investigated over 2 years under rainfed and irrigated conditions in Central Anatolia where drought and Zn deficiency cause substantial yield reductions. Plants were treated with (+Zn: 23 kg Zn ha⁻¹, as ZnSO₄·7H₂O) and without (−Zn) Zn under rainfed and irrigated conditions. Both Zn deficiency and rainfed treatments resulted in substantial decreases in grain yield. Significant differences were determined between both bread wheat and durum wheat cultivars in terms of drought stress tolerance. Considering drought sensitivity indices over 2 years, the bread wheat cultivars Yayla‐305, Gerek‐79, Dagdas‐94 and Bolal‐2973 were found to be more drought‐tolerant than the other cultivars under both −Zn and +Zn treatments. Especially the durum wheat cultivars Cakmak 79 and Selcuklu 97 showed much greater drought susceptibility under Zn deficiency, and irrigation alone was not sufficient to obtain satisfying grain yield without Zn application. The results indicate that sensitivity to Zn deficiency stress became more pronounced when plants were drought‐stressed. The effect of irrigation on grain yield was maximized when Zn was adequately supplied, leading to the suggestion that efficient water use in Central Anatolia seems to be highly dependent on the Zn nutritional status of plants.     

The effect of drought stress on the leaf relative water content and tuber yield of a half-sib family of ‘Katahdin’-derived potato cultivars

Drought tolerance in plants is a complex trait involving morphological, physiological, and biochemical mechanisms. Hundreds of genes underlie the response of plants to the stress. For crops, selecting cultivars that can produce economically significant yields under drought is a priority. Potato (Solanum tuberosum L.) is considered as drought sensitive crop, although cultivar-dependent differences in tolerance have been described. Cultivar ‘Katahdin’ possesses many appropriate characteristics and is widely used for breeding purposes worldwide; it also has enhanced tolerance to drought stress. In this study, we evaluated cv. ‘Katahdin’ and a half-sib family of 17 Katahdin-derived cultivars for leaf relative water content (RWC) and tuber yield under drought stress. The yields of cultivars ‘Wauseon’, ‘Katahdin’, ‘Magura’, ‘Calrose’, and ‘Cayuga’ did not significantly decline under drought stress. Among these five, Wauseon exhibited the lowest reduction in both tuber yield and relative water content under water shortage. The data showed that ‘Wauseon’ is the most attractive cultivar for studies of molecular and physiological processes under drought and for potato breeding due to low yield losses that correspond with high RWC values. This cultivar can serve as a reservoir of potentially useful genes to develop cultivars with enhanced tolerance to this abiotic stress.     

Application of natural plant extracts improves the tolerance against combined terminal heat and drought stresses in bread wheat

Drought and heat are among the main abiotic stresses causing severe damage to the cereal productivity when occur at reproductive stages. In this study, ten wheat cultivars were screened for combined heat and drought tolerance imposed at booting, heading, anthesis and post‐anthesis stages, and role of the foliage applied plant extracts was evaluated in improving the performance of differentially responding wheat cultivars under terminal heat and drought stresses. During both years, wheat crop was raised under ambient temperature and 70% water holding capacity (WHC) till leaf boot stage. The plant extracts (3% each) of sorghum, brassica, sunflower and moringa were foliage applied at booting, anthesis and post‐anthesis stage; and after one week of application of these plant extracts, combined heat and drought was imposed at each respective stage. Heat and drought stresses were imposed at each respective stage by placing pots in glass canopies with temperature of 4 ± 2°C above than the ambient temperature in combination with drought stress (35% WHC) until maturity. Combination of drought and heat stresses significantly reduced the performance of tested wheat cultivars; however, stress at the booting and heading stages was more damaging than the anthesis and post‐anthesis stages. Cultivars Mairaj‐2008 and Chakwal‐50 remained green with extended duration for grain filling, resulting in the maintenance of number of grains per spike and 100‐grain weight under stress conditions and thus had better grain yield and water‐use efficiency. However, in cultivars Fsd‐2008, and Shafaq‐2006, the combined imposition of drought and heat accelerated the grain filling rate with decrease in grain filling duration, grain weight and grain yield. Foliar application of all the plant extracts improved the wheat performance under terminal heat and drought stress; however, brassica extract was the most effective. This improvement in grain yield, water‐use efficiency and transpiration efficiency due to foliage applied plant extracts, under terminal heat and drought stress, was owing to better stay‐green character and accumulation of more soluble phenolics, which imparted stress tolerance as indicated by relatively stable grain weight and grain number. In crux, growing of stay‐green wheat cultivars with better grain filling and foliage application of plant extracts may help improving the performance of bread wheat under combined heat and drought stresses.