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1.
樟子松幼苗水力结构参数和生长特征对模拟降水梯度的响应 总被引：1，自引：0，他引：1
水分是影响樟子松生长和存活的关键因素,为弄清樟子松幼苗对水分胁迫的响应过程,采用人工控制降水处理方法 (105%年均降水量：500 mm,无干旱; 74%年均降水量: 350 mm,轻度干旱;42%年均降水量: 200 mm,干旱),监测了2 a生樟子松幼苗水力结构和生长特征对降水处理的响应。结果表明：随着降水量减少,幼苗水分饱和亏缺没有发生显著变化;轻度干旱下幼苗组织密度显著增加,干旱下幼苗失水系数显著降低;表明樟子松幼苗的保水、抗旱能力随干旱胁迫程度增强而增加。干旱胁迫显著降低了株高、基径和各器官生物量的增加量,轻度干旱胁迫下幼苗根重比和根冠比显著增加,表明轻度干旱胁迫改变了生物量分配格局,促使幼苗向有利于水分维持方向的发展策略;与轻度干旱相比,干旱胁迫下幼苗生物量分配策略并没有发生明显变化。樟子松幼苗可以通过改变水力结构特征和生物量分配策略来适应轻度干旱;而在干旱下幼苗仅改变水力结构特征,不利于其在干旱环境下生存。 相似文献
2.
水分胁迫对文冠果幼苗生长及生理特性的影响 总被引：1，自引：0，他引：1
《干旱区资源与环境》2018,(1):128-132
以1年生文冠果(Xanthoceras sorbifolia Bunge)幼苗为试材,通过盆栽控水试验设置3个水分处理:对照、干旱胁迫和水涝胁迫,研究了不同程度水分处理对文冠果幼苗生长和生理特性的影响。结果表明:1)水分胁迫下文冠果幼苗地上生物量、根生物量和总生物量显著下降,根冠比显著增大(P<0.05)。2)与对照相比,干旱胁迫下文冠果叶片SOD活性、MDA含量、脯氨酸含量和相对电导率显著升高,分别比对照上升了43.4%、4.1%,86.8%和12.3%;而CAT活性显著下降,比对照下降了37.2%。3)与对照相比,水涝胁迫下文冠果叶片MDA含量、脯氨酸含量和相对电导率显著升高,分别比对照上升了19.8%、50.2%和20.5%;SOD活性、CAT活性显著下降,分别比对照下降了13.9%、55.8%。综合指标分析认为,文冠果对水分胁迫具有较强的忍耐力。 相似文献
3.
《干旱区资源与环境》2017,(7):162-166
以2年生柠条幼苗为材料,研究了不同强度火烧和基部覆土保护对柠条幼苗存活与生长的影响。结果表明:不论基部是否覆土保护,柠条幼苗遭受火烧后存活率都显著降低(P<0.01),火烧幼苗的主根长、侧根数、萌条高、总生物量和萌条生物量显著减小(P<0.05),但幼苗的萌条数和根冠比均显著增大(P<0.05);与轻度火烧相比,重度火烧幼苗的存活率、萌条数、总生物量、萌条生物量和生物量补偿指数均不同程度减小,但幼苗的侧根数、萌条高和萌条基径均表现出增大趋势;火烧幼苗的根冠比均显著大于对照(P<0.05),不同强度火烧处理间差异不显著。基部覆土保护可缓解火烧对幼苗的负面影响,即对幼苗具有一定的保护作用;基部覆土保护幼苗遭受火烧后存活率提高,且侧根数、萌条高、萌条基径、萌条生物量和总生物量均不同程度增大,生物量补偿指数显著增大(P<0.05),但基部覆土保护幼苗的根冠比在不同火烧处理均显著减小(P<0.05)。 相似文献
4.
不同气候条件下柠条锦鸡儿水力结构特征比较 总被引：1，自引：0，他引：1
以生长在内蒙古高原荒漠区的柠条锦鸡儿为研究对象,通过观测一年生枝条在不同气候条件下的水力结构特征日变化,结合气候因子,分析旱生植物如何通过调整水分传输来适应变化着的环境条件。结果表明:不管是晴天还是阴天,柠条锦鸡儿的水力结构参数与气温呈显著线性负相关,与相对湿度呈显著线性正相关;晴天柠条锦鸡儿的导水率、比导率和叶比导率明显比阴天低。这说明柠条锦鸡儿能根据环境胁迫的变化及时调整水分运输策略,在满足枝端叶片不同需水要求的前提下,尽量减少水分丧失,达到节水的目的。 相似文献
5.
土壤干旱对冬小麦幼苗生长和叶片生理特性的影响 总被引：8，自引：1，他引：7
采用盆栽试验对不同土壤干旱下冬小麦幼苗生长和生理特性进行了初步研究。结果表明,幼苗株高、叶面积、叶干重、茎干重、根干重、总生物量、叶水势、叶片相对含水率均随土壤水分的减少而呈降低趋势;根冠比、叶片水分饱和亏、可溶性糖含量、脯氨酸含量、质膜透性、MDA含量以及叶片SOD、POD活性均呈增加趋势。这说明,在干旱胁迫下,冬小麦幼苗一方面通过改变生物量分配策略,较多地提高根比重,以利于根系吸水增加抗旱性;另一方面,通过改变叶片的生理特性以提高抗旱性。 相似文献
6.
通过对沿年均降水量减少的兰州、白银、景泰和临泽4个试验点不同科属植物进行野外调查与室内分析,试图明确干旱区降水量梯度下植物叶、茎属性〔比叶重(LMA)、单位面积氮含量(Narea)和单位面积叶绿素含量(Chlarea)〕的变化并探讨其对渐进干旱胁迫的适应规律。结果表明:降雨量梯度下叶、茎利用不同属性特征应对干旱胁迫,LMA和Narea含量随干旱胁迫的加剧而增大,Chlarea含量随干旱胁迫的加剧而降低,这在一定程度上体现了研究区域植物对干旱胁迫加强的适应规律。另外随年均降水量的减少,临泽、景泰、白银、兰州其物种的绿色茎枝/叶生物量比依次减小。即随干旱胁迫的加剧,干旱区植物绿色茎枝与叶片生物量的比例逐渐增大。 相似文献
7.
黑果枸杞幼苗对干旱胁迫的生理响应 总被引：7，自引：0，他引：7
以黑果枸杞（Lycium ruthenicum Murr.）幼苗为试验材料,采用称重控水的方法,设置4个水分处理水平（对照CK、轻度胁迫D1、中度胁迫D2、重度胁迫D3）,研究黑果枸杞幼苗对不同程度干旱胁迫的生理生化响应。结果显示：① 随着干旱胁迫的加剧,黑果枸杞幼苗株高、基径生长量、生物量积累和叶重比在轻度胁迫下升高,中、重度胁迫下降低;根重比、根冠比在轻、中度胁迫下升高,重度胁迫下降低。② 随着胁迫时间的延长,各处理组脯氨酸（Pro）、可溶性糖含量逐渐升高,可溶性蛋白含量先降后升;丙二醛（MDA）含量先增后减再逐渐增加。③ 随胁迫时间的延长,各处理组超氧化物歧化酶（SOD）活性逐渐升高,过氧化物酶（POD）、过氧化氢酶（CAT）活性呈先升后降的趋势。综合分析认为,干旱胁迫下,黑果枸杞幼苗通过调整生长和生物量分配,减少地上部分水分散失,增加根系物质的积累,以吸收更多的水分,利用渗透调节物的积累来改变细胞渗透势,以便减少胞内水分流失。同时,通过提高保护酶活性来减弱膜脂过氧化对自身的伤害,表现出较强的耐旱性。 相似文献
8.
干旱、盐胁迫条件下两种盐生植物生物量分配对策的研究 总被引：10，自引：5，他引：5
以2种一年生盐生草本植物钠猪毛菜、盐生草为试验对象,研究干旱和盐分胁迫对2种盐生植物生长和生物量分配的影响。结果表明:不同程度干旱和盐分胁迫显著影响了2种盐生植物的生长、生物量积累和生物量的分割。生长分析表明:2种盐生植物在生长率、根冠比、叶面积比方面皆存在明显可塑性,且根冠比、叶面积比的变化均受到个体发育漂变的影响;在整个营养生长期的不同处理组中,根冠比、叶面积比总体上呈逐渐降低趋势。不同干旱胁迫处理下2种盐生植物的根冠比和叶面积比的变化与最优理论和模型的预测相一致;随干旱胁迫的加重,根冠比增大而叶面积比减小。但在盐分胁迫条件下,2种盐生植物并未出现基于最优分配理论来调节生物量分配模式,且2种盐生植物根冠比和叶面积比的响应表现出明显的种间差异。此外,不同处理组间植物生物量分配特征(根冠比、叶面积比)的差异,往往只存在于生活史的某一时期,在整个营养生长期间,并不自始至终保持一致。 相似文献
9.
干旱胁迫下砂生槐、锦鸡儿的生理生化特性与抗旱性 总被引：4，自引：1，他引：3
以西藏半干旱区的两种豆科灌木为研究对象,采用盆栽控水干旱胁迫手段,比较和分析了砂生槐、矮锦鸡儿在持续水分胁迫条件下的生理响应。结果表明：随着干旱胁迫时间推移,土壤含水量不断下降,2种灌木体内水分饱和亏缺值均呈上升趋势,从上升速率和变化情况来看,砂生槐的叶片保水能力优于矮锦鸡儿;叶绿素a＋b值和叶绿素a/b值综合比较结果... 相似文献
10.
高寒沙地不同林龄中间锦鸡儿的水分利用策略 总被引：3，自引：0，他引：3
中间锦鸡儿是青海共和盆地高寒沙地的主要造林灌木树种之一。文中利用稳定同位素技术,测定共和盆地不同林龄(5a,9a,25a)中间锦鸡儿枝条木质部和土壤各层(10,20,30,50,100,150,200cm)水分的δD值、δ18O值,分析它们是否随林龄变化而选择性地利用不同深度的土壤水分;并通过测定不同林龄中间锦鸡儿叶片的δ13C值,分析比较它们的长期水分利用效率。结果表明:5a,9a和25a中间锦鸡儿均主要利用源自降雨的土壤浅层10-50cm的水分。3个林龄中间锦鸡儿的水分利用效率差异显著(P<0.05),5a中间锦鸡儿明显高于9a和25a中间锦鸡儿,9a和25a中间锦鸡儿水分利用效率类似。水分利用策略的分析结果表明,中间锦鸡儿在发育低龄期,采取提高水分利用效率的方法来应对干旱胁迫。25a中间锦鸡儿未发生明显退化。 相似文献
11.
以天然生长于祁连山自然保护区隆畅河自然保护站的濒危植物蒙古扁桃(Prunus mongolica)去内果皮的种子为材料,以不同渗透势PEG-6000溶液模拟干旱条件,研究了种子萌发和幼苗生长对干旱胁迫的响应特征。结果表明,随着干旱胁迫程度的加剧,蒙古扁桃种子吸胀速率、萌发率、萌发指数、活力指数、苗高和根长、组织饱和含水量等指标均表现出明显降低的趋势,而幼苗初生芽干重、根干重和根冠比均呈先升后降的趋势。蒙古扁桃种子对水势变化既敏感又抗旱,种子能够萌发的最低渗透势阈值为-0.65 MPa。干旱胁迫未能萌发的种子复水后萌发率较高。分析认为,蒙古扁桃种子萌发和幼苗生长对干旱胁迫的响应特征对种的延续具有重要意义,但在人工栽培时保证
土壤墒情应是保障建植成功的关键措施。 相似文献
12.
山东省部分小麦材料的抗旱特性分析 总被引：1，自引：0，他引：1
以山东地区21个小麦品系为材料,用聚乙二醇-6000(PEG-6000)模拟干旱胁迫,以小麦萌发期的发芽率、胚根数、主根长、胚芽鞘长为实验指标研究不同品系冬小麦在水分胁迫下萌发期的抗旱特性;用幼苗反复干旱鉴定方法,比较不同品系冬小麦在水分胁迫下苗期的抗旱特性;在旱棚内人工控制水分模拟干旱胁迫,以小麦开花期及灌浆期的株高、穗下第一节间长、叶片相对含水量、叶片POD活性,成熟期的产量为实验指标,研究不同品系冬小麦在水分胁迫下中后期的抗旱特性。结果表明:品系11、17、12、4、6、15、14全生育期抗旱性强;品系13全生育期不抗旱;品系20、9、2、19、18萌发期、苗期抗旱性强;品系10、5萌发期、中后期抗旱性强;品系7、1、8苗期抗旱性强;品系16、3苗期、中后期抗旱性强。通过对21份小麦品系萌发期的综合抗旱系数、苗期的综合抗旱系数、中后期的综合抗旱系数进行相关分析,结果表明小麦各生育期抗旱相关性不强,其中苗期综合抗旱系数与中后期综合抗旱系数相关系数最高为0.465。 相似文献
13.
JAVAD Mirzaei 《干旱区科学》2017,9(3):368-378
This study assesses the effects of vegetation patterns and environmental factors on the abundance of natural tree and shrub regeneration in semi-arid forests of the Zagros Mountains, western Iran. We sampled 120 releves at different topographic positions in a protected area of the studied region. Floristic composition, slope, elevation and soil properties were recorded at each releve, and woody seedling density was measured. We have first discerned five floristic groups using two-way indicator species analysis(TWINSPAN), detrended correspondence analysis(DCA), and canonical correspondence analysis(CCA) and then explored the relationships among the floristic group compositions, environmental factors and seedling densities. The indicator species of the five groups were Quercus brantii, Acer monspessulanum, Cerasus microcarpa, Rhamnus arvensis and Astragalus licyoides. Our results indicated that these groups were significantly affected by elevation and soil properties and the soil properties refer to: EC(electrical conductivity), N(nitrogen), K(potassium), OM(organic matter), and bulk density. Woody regeneration was composed of Q. brantii, A. monspessulanum, C. microcarpa, Amygdalus scoparia and Crataegus pontica seedlings. The highest density of seedlings was found for Q. brantii(97.14(±48.00) plants/hm~2) and the lowest for A. scoparia(2.28(±1.50) plants/hm~2). Quercus brantii was the dominant species and the seedling density was positively correlated with soil p H and P(phosphorus) values. Amygdalus scoparia regeneration was negatively correlated with elevation, and the seedling density peaked in C. microcarpa group. There was no significant variation in distribution of C. pontica seedlings among the groups, but the seedling density of this species was positively correlated with slope and K. Cerasus microcarpa seedlings were more abundant in the Q. brantii group than in other groups. This study showed that the regeneration of tree and shrub species was unequally distributed in different floristic groups for some species(A. scoparia and C. microcarpa) but not for other(Q. brantii and C. pontica) and was generally correlated with some environmental factors, particularly elevation, slope and soil nutrients(P and K). These results are a first step to implement future management and restoration strategies for promoting forest regeneration. 相似文献
14.
研究不周浓度盐溶液(NaCl、MgSO4、盐渍土壤)和PEG模拟干旱胁迫对沙米种子吸胀、萌发和幼苗生长的影响,并观察胁迫解除后种子的反应.结果表明:随着NaCl、MgSO4和PEG浓度的升高,沙米种子吸胀率先升后降,种子萌发率呈现不同程度降低,盐渍土壤溶液对萌发率没有显著影响;对沙米种子萌发和幼苗生长的胁迫效应是NaC... 相似文献
15.
B. A. AULD 《Weed Research》1976,16(5):323-330
The native perennial shrub, Bassia birchii. occurs as a weed over large areas of semi-arid eastern Australia. Its germination requirements and seedling growth were investigated and related to field observations and to possible means of control. Seeds cannot germinate until the woody fruit has broken down. Laboratory experiments showed that seeds would germinate throughout the year with most germinating at autumn and spring temperatures. Seedling deaths in the field are attributed to poor root growth, before the effects of water stress occurs. The spasmodic appearance of Bassia birchii infestations, particularly after droughts, is related to the dependence on the death of mature plants to provide propagules and fruit breakdown for germination. The unpredictable infestation pattern and the early development of spined fruits and basal buds on seedlings hinder control. Short period rotational or strategic grazing are suggested as possible means of control of seedlings in areas where perennial pastures can be established. 相似文献
16.
MAMUT Jannathan 《干旱区科学》2019,11(5):774-784
For a plant species to complete its life cycle in arid and saline environments, each stage of the life cycle must be tolerant to the harsh environmental conditions. The aim of the study was to determine the effects of water stress (water potentials of -0.05, -0.16, -0.33, -0.56, -0.85 and -1.21 MPa) and NaCl stress (50, 100, 200, 300, 400, 500 and 600 mmol/L NaCl) on seed germination percentage, seedling survival and growth, juvenile growth and plant reproduction of Lachnoloma lehmannii Bunge (Brassicaceae), an cold desert annual that grows in the Junggar Basin of Xinjiang, China in 2010. Results indicated that low water stress (-0.05 and -0.16 MPa) had no significant effect on seed germination percentage. With a decrease in water potential, germination percentage decreased, and no seeds germinated at -0.85 and -1.21 MPa water stresses. Germination percentage of seeds was significantly affected by NaCl stress, and higher germination percentages were observed under non-saline than saline conditions. An increase in NaCl concentrations progressively inhibited seed germination percentage, and no seeds germinated at ≥400 mmol/L NaCl concentration. Non-germinated seeds were transferred from both PEG (polyethylene glycol-6000) and NaCl solutions to distilled water for seed germination recovery. The number of surviving seedlings and their heights and root lengths significantly decreased as NaCl stress increased. About 30% of the plants survived and produced fruits/seeds at 200 mmol/L NaCl concentration. Thus, seed germination, seedling establishment and reproductive stage in the life cycle of L. lehmannii are water- and salt-tolerant, with seedlings being the least tolerant. These tolerances help explain why this species can survive and produce seeds in arid and saline habitats. 相似文献
17.
内陆石羊河灌区灌溉和施氮对夏玉米苗期生长及生理特性的影响 总被引：1，自引：0，他引：1
以夏玉米为材料,设4个灌水水平:337.5、6751、012.5、1 350 m3/hm2;4个施氮水平:75、150、225、300 kg N/hm2,研究限量灌溉和施氮对夏玉米苗期生长及生理指标的影响。结果表明:严重干旱会抑制玉米的生长。在玉米苗期,充分供水和高氮对玉米的生长不利,轻度亏缺与中氮组合使玉米苗期处于最佳生长状态,水氮共同作用对玉米的光合速率有促进作用;玉米苗期适度经受水分亏缺,有利于根系的生长;在同一施氮水平下,不同程度水分亏缺处理的根冠比(R/S)大于充分供水的处理。玉米苗期叶水势随灌水量的增大而增大,在灌水量相同时,叶水势随施氮量的增加而逐渐变大;干旱会使玉米光合速率下降,但适量增施氮肥可增加玉米的光合速率。 相似文献
18.
YuanRun ZHENG LianHe JIANG Yong GAO Xi CHEN GePing LUO XianWei FENG YunJiang YU Ping AN Yi YU Hideyuki SHIMIZU 《干旱区科学》2013,5(3):331-339
Clarifying the persistence time of seedlings of dominant species under continual drought will help us understand responses of ecosystems to global climate change and improve revegetation efforts.Drought tolerance of four dominant psammophytic shrub species occurring in different environments was studied in the semi-arid areas of Inner Mongolian grasslands.Seedlings of Hedysarum laeve,Caragana korshinskii,Artemisia sphaerocephala and Artemisia ordosica were grown under four air temperature regimes(night/day:12.5/22.5℃,15/25℃,17.5/27.5℃ and 20/30℃)within climate(air temperature and humidity)controlled,naturally lit glasshouses with a night/day relative humidity of 70%/50%.Pots were watered to field capacity for each temperature treatment.Soil water condition was monitored by weighting each pot every day using an electronic balance.Date of seedling death for each treatment was recorded and the dead plants were harvested.Plant dry weights were determined after oven drying at 80℃ for 3 days.Two Artemisia species had higher growth rates than H.laeve and C.korshinskii,and the growth of all four species increased with increasing temperatures.The two Artemisia species had the highest leaf biomass increment,followed by C.korshinskii,and then H.laeve.Shoot biomass increment was higher for A.ordosica and C.korshinskii,intermediate for A.sphaerocephala and lowest for H.laeve.C.korshinskii had the highest root biomass increment.The final soil water content at death for all four species varied from 1% to 2%.C.korshinskii,A.sphaerocephala,H.laeve and A.ordosica survived for 25-43,24-41,26-41,and 24-37 days without watering,respectively.C.korshinskii,A.sphaerocephala,H.Laeve,and A.ordosica seedlings survived longer at the lowest temperatures(12.5/22.5℃)than at the highest temperatures(20/30℃)by 18,17,15 and 13 days,respectively.Increased climatic temperatures induce the death of seedlings in years with long intervals between rainfall events.The adaptation of seedlings to droughts should be emphasized in revegetation efforts in the Ordos Plateau,Inner Mongolia. 相似文献
19.
2014年浑善达克沙地黄柳生长季水分来源同位素示踪研究 总被引：2，自引：0，他引：2
黄柳是我国内蒙古东部和辽宁西部沙丘上广泛分布的多年生灌木,是极佳的固沙树种.通过利用氢同位素示踪方法,测定了2014年浑善达克沙地黄柳生长季茎干水与潜在水源(降水、土壤水、地下水)氢同位素比率δD值,并利用多源线性混合模型IsoSource,计算了黄柳对各潜在水源的利用比例.结果表明:在5月黄柳80％以上利用120 ～ 160 cm土壤水和地下水;6月主要吸收0～40 cm土壤水;7月主要吸收120～160 cm土壤水;8月以地下水为主要水源,利用率为82％.这表明生长在不同季节的黄柳对于各潜在水源的利用有特定的适应结果,同时也说明荒漠灌木可以通过自身的调节朝着最优的方向发展,实现最大限度的水分利用. 相似文献
20.
甜瓜种质资源苗期抗旱性生理鉴定指标测定 总被引：3，自引：1，他引：2
以6个甜瓜品种为试材,测定其株高胁迫指数(PHSI)、干物质胁迫指数(DMSI)、叶片水分饱和亏(WSD)、相对含水量(RWC)、束缚水含量、组织水含量、自由水含量、电解质渗出率、干旱处理伤害率、离体叶片抗脱水能力等指标,并对各指标进行显著性测验,评价各品种的抗旱性。结果表明:鉴定甜瓜品种抗旱性,苗期可应用株高胁迫指数(PHSI)、干物质胁迫指数(DMSI)、叶片水分饱和亏、电解质渗出率、干旱处理伤害率等指标。 相似文献