Physiological Responses of Brazil Banana Seedlings to Drought Stress Simulated by PEG-6000

[Objective] The aim was to explore physiological responses of Brazil banana seedlings to drought stress simulated by PEG-6000.[Method] Brazil banana （Musa AAA Cavendish subgroup cv.Brazil） was taken as test materials to explore changes of physiological indices of banana seedlings under drought stresses simulated by PEG-6000,including three stress levels （5％,10％ and 15％） and time periods （24,48 and 72 h）.[Result] Relative water content and chlorophyll content both declined under different stress levels and in different times.The content of proline （Pro） in seedling leaves from high to low was PEG15％,PEG10％ and PEG5％; the content of treatment of 5％ stress in 24 h was of insignificant differences with that of the control and the contents in rest treatments were all remarkably higher compared with the control.POD activities of seedling leaves from high to low were as follows：PEG15％＞PEG10％＞PEG5％,and POD activity was of significant differences among treatments; POD activity achieved the peak in treatment group with 5％ of stress,and POD activities of different groups were all higher compared with the control.The activity of root system in treatment groups with PEG at different concentrations was as follows：PEG10％＞PEG15％＞PEG5％ and the activity increased remarkably in the group with PEG at 5％ within 24,48 and 72 h,though the activity dropped significantly within 72 h and slowly in 24 and 48 h.[Conclusion] It can be concluded that relative water content,chlorophyll content,Pro content and activity and root activity can be references of banana resistance to drought.

Responses of the Anthocyanin and Osmolyte Contents of the Capsicum annuum Cultivars Planted in Wenshan Prefecture of Yunnan Province to the Drought Stress Simulated by PEG-6000

[Objective] The aim of this study was to compare the drought resistance difference of the main Capsicum annuum cultivars planted in Wenshan Prefecture of Yunnan Province. [Method] The total anthocyanin, soluble sugar, soluble protein and free proline contents of the leaves of the five main C. annuum cultivars planted in Wenshan Prefecture, i.e., ZSZ75-1, ZSZ49-1-1, 12WS-18-1, 12ZH01 and ZS130, under the drought stress simulated by PEG-6000 were studied by using spectrophotometry, and the total osmoregulation abilities of the leaves were evaluated by using subordinate function. [Result] Under the drought stress simulated by PEG-6000, the total anthocyanin contents of the veins, mesophylls and whole leaves of the five cultivars were all as： ZSZ75-1〉ZSZ49-1-1〉12WS-18-1〉12ZH01〉ZS130, the soluble sugar contents as： 12ZH01 〉12WS-18-1 〉ZS130〉ZSZ49-1-1 〉ZSZ75-1, the soluble protein contents as： ZSZ75-1〉12ZH01〉ZSZ49-1-1〉12WS-18-1〉ZS130, and the free proline contents as： ZS130〉ZSZ75-1 〉12WS-18-1 〉ZSZ49-1-1 〉12ZH01. Furthermore, the differences among the total anthocyanin contents of the veins, mesophylls and whole leaves of the five cultivars all reached the extremely significant levels, whereas the differences among the contents of the soluble sugar, soluble protein and free proline did not reach the significant levels, the correlation degrees among the contents of the total anthocyanin, soluble sugar, soluble protein and free proline of different cultivars were also inconsistent, and the total osmoregulation abilities of the five cultivar leaves were as： ZSZ75-1 〉7SZ49-1-1 〉12WS-18-1 〉ZS130〉12ZH01. [Conclusion] The anthocyanin accumulation in the specific organs of the five C. annuum cultivars in Wenshan Prefecture is beneficial to the strengthening of the leaf osmoregulation abilities under drought stress, favoring the drought tolerance of the cultivars.

Study on Effect of Drought Stress with PEG-6000 on Physiological and Biochemical Indicators in Kadsura coccinea

[Objective] The aim was to research drought resistance and adaptation mechanisms of Kaclsura coccinea under different drought stresses. [Method] The seedlings of Kadsura coccinea growing one year were taken as materials in order to investigate and analyze leaf SPAD value, relative water content （RWC）, malonaldehyde （MAD）, cell membrane permeability （RP）, proline （PRO） and superoxide dismutase activity （SOD）. [Result] As drought stress improved, leaf SPAD value and RWC were both diminishing and RWC fell remarkably; MAD, Pro, RP and SOD activity were increasing; MAD and RP grew significantly. [Conclusion] Kadsura coccinea is much sensitive to drought stress and will be affected if water loss is too much high.

PEG-6000模拟干旱对水稻幼苗期根系的影响

试验研究了不同PEG-6000浓度(0g·L-1、50g·L-1、125g·L-1和200g·L-1)对"湘丰早119"(耐旱)和"爱华5号"(干旱敏感)2个水稻品种的根体积、根粗、最长根长、侧根长、不定根长、根总长度、根数量、根系质膜相对透性和POD活性的影响。结果表明:耐旱水稻品种和敏感水稻品种根部的形态指标除根数量外都受严重干旱(200g·L-1PEG-6000)抑制,敏感品种更为明显;形态指标在各浓度PEG-6000处理下随着处理时间的延长而增大,且这些指标一般在不同浓度PEG处理3～4d后产生明显差异;根系POD活性随处理浓度升高而增大,随处理时间延长,耐旱品种POD活性的上升速度大于敏感品种;根系质膜相对透性随处理浓度升高而增加,随处理时间延长而增大,敏感品种的质膜相对透性高于耐旱品种;耐旱品种的根系较敏感品种更粗、更长,根系茁壮程度优于敏感品种。根数量和根系质膜相对透性不应作为耐旱选择指标。

PEG-6000模拟干旱胁迫对甘薯近缘野生种Ipomoea trifida (Kunth) G.Don幼苗生理生化指标的影响

Ipomoea trifida(Kunth)G.Don(2n=2x=30)是甘薯祖先种之一,具有较强的抗旱性,其抗旱生理机制尚无报道。本文采用营养液水培法,以30%浓度的PEG6000模拟干旱,研究干旱胁迫对甘薯近缘野生种幼苗叶片生理生化指标的影响。结果表明:随着PEG6000干旱胁迫时间的延长,叶片中丙二醛(MDA)、游离脯氨酸(Pro)含量逐渐增加。过氧化物酶(POD)和过氧化氢酶(CAT)及谷胱甘肽还原酶(GR)活性在PEG处理后活性均增强,揭示了甘薯近缘野生种MDA和Pro含量和氧化酶类的活性在短时间急性胁迫情况下的不同变化规律,可为抗旱品种的筛选和下一步抗旱相关基因的挖掘提供一定的参考。

PEG-6000模拟干旱及NaCl和温度胁迫对不结球白菜种子活力的影响

以不结球白菜品种矮脚黄种子为材料,研究聚乙二醇(PEG-6000)模拟干旱胁迫、NaCl胁迫和温度胁迫下,种子萌发和内部抗氧化相关特性及其渗透调节物质的变化。结果表明:不结球白菜种子的发芽势、发芽率、发芽指数和活力指数随3种胁迫的加重而显著下降,不正常苗率显著上升;随着3种胁迫的加重,SOD和POD活性均下降,CAT活性先有上升的趋势,胁迫加重时降低,活性氧产生速率加快,H_2O_2积累,造成生物膜破坏,相对电导率上升;逆境胁迫下,渗透调节物质可溶性糖、可溶性蛋白和脯氨酸含量显著增加。综上说明,不结球白菜种子在PEG-6000模拟干旱胁迫、NaCl胁迫和温度胁迫下,其种子抗氧化系统代谢失去协调作用的能力,并造成活性氧积累伤害,渗透调节紊乱,从而降低了种子活力直至种子死亡。

PEG-6000模拟干旱胁迫对广丰药薯试管苗生理特性的影响

目的:对PEG-6000处理广丰药薯试管苗的生理特性进行研究,为广丰药薯的大田移栽提供理论基础。方法:采用分光光度计的方法,测定PEG-6000处理下广丰药薯试管苗的总叶绿素、可溶总糖、可溶性蛋白和脯氨酸含量以及SOD、CAT和POD的活性。结果:在PEG-6000模拟干旱胁迫中,随干旱胁迫的加重和胁迫时间的延长,广丰药薯试管苗的总叶绿素含量持续下降,可溶性总糖、脯氨酸和MDA含量显著增加,可溶性蛋白含量以及CAT、POD和SOD活性则呈先升后降的趋势。结论:本研究揭示了广丰药薯试管苗在PEG-6000模拟干旱胁迫下生理指标的变化,表明广丰药薯具有一定的耐旱性。

PEG-6000模拟干旱胁迫对青稞种子萌发的影响

为探究干旱对青稞萌发的影响,以20个青稞种质为研究材料,采用17%PEG-6000模拟干旱胁迫,测定其萌发指标(发芽势、发芽率、芽长、根长、芽干重和根干重等),利用相关性分析、主成分分析、综合评价方法以及聚类分析对供试材料抗旱性进行鉴定。结果表明,与对照处理比较,17%PEG胁迫下,所有材料的萌发指标均受到抑制,但不同材料之间存在差异性。

The Influence of Induced Drought Stress on Germination of Cenchrus ciliaris L.and Cenchrus setigerus Vahl.:Implications for Rangeland Restoration in the Arid Desert Environment of Kuwait

Drought impacts in arid desert ecosystems can result in decreased ecosystem productivity and biodiversity.Imple­mentation of restoration projects in arid desert environments is largely dependent on water availability and soil mois­ture condition.This study investigated the influence of induced drought stress by using polyethylene glycol(PEG-6000)solution on germination viz.Cenchrus ciliaris and Cenchrus setigerus as the important rangeland species.The water stress potential treatments were 0(control),-0.5 MPa,-1.0 MPa,-1.5 MPa,and-2.0 MPa.The extent of seed germi­nation was severely affected by decreased water stress potential.As drought increased,the percentage of germination decreased in both Cenchrus’species.The water deficit at-0.5 MPa showed a significant(P<0.001)reduction in the final germination percentage in the case of C.setigerus and C.ciliaris by 65%and 42.5%,respectively.At-1.0 MPa to-1.5 MPa,changes in intermediate germination were observed in C.ciliaris(from 35%to 17.5%,respectively)and C.setigerus(from 22.5%to 11.25%respectively).Higher levels of water stress(-2.0 MPa)prevented the survival of both species.Understanding the germination strategies of native desert plant species associated with drought stress and identifying favorable conditions during the germination process can be useful for restoration practices and rangeland management actions to improve desert ecosystems and maintain biodiversity.

不同大豆品种(系)萌发期抗旱性综合评价

为确定大豆萌发期模拟干旱最适PEG-6000溶液浓度,筛选出抗旱种质资源,选用4份抗旱性不同的大豆品种,设置3个浓度PEG-6000溶液(12%、16%、20%)进行萌发期模拟干旱处理。利用浓度为16%PEG-6000溶液对70份大豆种质资源进行干旱胁迫,以相对发芽率、相对胚根长、相对胚根鲜质量为鉴定指标,利用隶属函数法对抗旱性进行评价。结果表明:16%PEG-6000溶液模拟干旱效果最好,胁迫组发芽率、胚根长、胚根鲜质量的平均值均显著小于对照组(P<0.05),胚根鲜质量的抑制程度最高;相对发芽率、相对胚根长、相对胚根鲜质量3个鉴定指标均与平均隶属函数值极显著正相关(P<0.01),相对胚根长与平均隶属函数值相关系数最大(R=-0.979);利用隶属函数法将70份大豆种质资源分为5个等级,其中抗旱型大豆品种3份,较抗旱型8份。本研究确定了PEG-6000溶液模拟干旱胁迫的最适浓度,筛选出11个抗旱和较抗旱型品种,为大豆抗旱品种筛选提供方法参考,也为抗旱品种的应用提供理论依据。

吸湿回干法提高冬凌草种子抗旱性的研究

目的:采用PEG-6000溶液模拟干旱条件处理经过吸湿回干法锻炼的冬凌草种子,筛选出提高冬凌草种子抗旱性的方法。方法:用PEG-6000溶液模拟干旱条件;用吸湿回干法对种子进行干旱锻炼;并分别采用考马斯亮蓝G-250染色法、愈创木酚法、硫代巴比妥法测其生理指标可溶性蛋白含量、过氧化物酶(POD)活性、丙二醛(MDA)活性。结果:吸湿4 h干旱锻炼1次处理项的POD含量最高,吸湿1 h干旱锻炼2次次之,吸湿2 h干旱锻炼4次最低,并且吸湿1 h干旱锻炼2次、吸湿4 h干旱锻炼1次处理项的MDA含量均低于对照组,说明经过这两项的处理种子的生活力增强,即抗旱性增强。结论:吸湿回干法可以提高冬凌草种子的发芽率,最好的处理项是吸湿4 h干旱锻炼1次。

The Effects of Temperature, Light and Moisture on the Seed Germination of Siphonostegia chinensis Benth

To explore the optimum temperature,light intensityand water conditions for seed germination of Siphonostegia chinensis Benth.,seed germination experiment were carried out under different temperatures(5/15,10/20,15/25,20/30℃),different light intensity(14h light/10h darkness,complete darkness)and different concentrations(0%,5%,10%,15%,20%)of PEG-6000 solution.In terms of concentration,5%PEG was regarded as the low level,10%and 15%as the medium level,and 20%as the high level.The results showed that(1)Germination rate,germination potential,and germination index were increased with the rise of temperature.In addition,seed germination was significantly higher under the dark conditions than that with the 14h light/10h darkness.(2)No seed germination occurred when the temperature was below 10/20 C at 14h light/10h darkness.(3)Under 14h light/10h darkness,the germination rate,germination potential and germination index first increased and then decreased with the increase of PEG concentration.The low concentration was more beneficial to the seed germination.(4)Under the condition of complete darkness,the germination rate,germination potential and germination index decline with fluctuation with the increase of PEG concentration.Seed germination of Siphonostegia chinensis Benth.was inhibited in high concentration of PEG.

外源SA对干旱胁迫下金莲花种子萌发及幼苗生长的影响

为提高金莲花种子萌发和幼苗生长阶段的抗旱性,试验选用采自河北小五台山国家级自然保护区的金莲花种子,利用PEG-6000模拟干旱,探讨了外源SA对干旱胁迫下金莲花种子萌发和幼苗生长的影响,并探索了减轻干旱胁迫危害的最适SA浓度及各个生长指标、生理指标的变化规律。结果表明:通过对不同处理及对照的发芽率、发芽势、发芽指数、根冠比、相对含水量、叶片叶绿素含量以及叶片相对电导率进行测定比较,外源SA的最佳缓解浓度为1.0 mmol/L。该结论为促进其规范化栽培和扩大其在干旱半干旱地区的种植范围提供了科学依据。