水稻外源DNA导入系的分子检测及耐旱性评价

耐旱种质创新对农业节水和培育水稻新品种具有重要意义。本研究以SSR标记检测了以空心莲子草DNA溶液浸胚处理获得的10个农艺性状稳定遗传的水稻变异体,结果表明,10个水稻变异体均整合了供体空心莲子草DNA的不同片段。在此基础上,以8个导入空心莲子草DNA的水稻导入系及2个对照为试验材料,采用二因素裂区设计,并以主成分分析、逐步回归分析等多种统计方法分析了导入系的耐旱性。结果表明,以综合评价指标与耐旱指数相结合的复合评价体系,可增强水稻耐旱评价的可靠性。导入系H8最耐旱,H6和H7较耐旱,均优于巴西陆稻。本研究结果对水稻的耐旱性评价与耐旱品种选育具有重要意义。     

空心莲子草DNA溶液浸胚处理水稻的变异系分子检测及耐旱性评价

通过SSR标记检测了以空心莲子草DNA溶液浸胚处理获得的10个农艺性状稳定遗传的水稻变异系,结果表明,10个水稻变异系均整合了供体空心莲子草DNA的部分片段。在此基础上,以8个水稻变异系及2个对照为试验材料,采用二因素裂区设计,并以主成分分析、逐步回归分析等多种统计方法分析了变异系的耐旱性。结果表明,以综合评价指标与耐旱指数相结合的复合评价体系,可增强水稻耐旱评价的可靠性。导入系H8最耐旱,H6和H7较耐旱,均优于巴西陆稻。本研究结果对水稻的耐旱性评价与耐旱品种选育具有重要意义。     

Na2CO3胁迫对黄瓜幼苗生长及生理指标的影响

以‘津优一号’和‘春四’黄瓜为实验材料,采用砂培法研究了Na2CO3胁迫对黄瓜幼苗生长及生理指标的影响。结果显示,随着Na2CO3浓度的增大,两个黄瓜品种的幼苗根冠比逐渐下降,叶绿素含量先上升后下降,可溶性糖含量、脯氨酸含量、SOD活性逐渐上升;‘津优一号’的相对电导率和丙二醛含量随Na2CO3浓度的增大逐渐增加,而‘春四’的相对电导率和丙二醛含量在20 mmol.L-1时最低,此后逐渐上升。主成分分析结果显示,丙二醛含量、SOD活性、可溶性糖含量、脯氨酸含量、叶绿素b,这5项指标在评价黄瓜幼苗的Na2CO3耐性方面是比较重要的。结合这5项指标综合分析,发现‘津优一号’较‘春四’有较强的耐碱性。     

新疆野核桃种质对低温胁迫的生理响应

以新疆巩留野核桃林37份新疆野核桃种质资源的1年生枝条为材料,6份核桃楸为对照,利用人工气候箱模拟春季低温,分别于-20 ℃和4 ℃处理12 h,测定其相对电导率、游离脯氨酸、可溶性糖、丙二醛含量、过氧化物酶活性等生理生化指标,并进行相关分析。采用隶属函数和主成分分析综合评价核桃种质对低温的生理响应。结果表明: 低温胁迫下,新疆野核桃相对电导率、游离脯氨酸含量、可溶性糖含量、丙二醛含量和过氧化物酶活性均呈上升趋势。综合评价其低温抗性与生境相关:巩留野核桃林中沟>东沟>西沟>主沟。新疆野核桃表现出比核桃楸更为耐低温的特性。本研究从37份新疆野核桃种质中筛选出7份耐低温种质,为改良核桃品种和提高核桃耐倒春寒等生长期的突然天气变化的能力提供科学参考。     

不同相思树种单株抗寒性综合评价

选择赤云相思(Acacia mangium×A. auriculiformis (Chiyun))、杂交相思(A. mangium×A. auriculiformis)和马占相思(A. mangium) 3个品种的8个单株,对其扦插繁殖幼苗进行12、9、6、3、0℃的低温处理,以25℃为对照,测定幼苗叶片相对电导率、丙二醛、可溶性糖、游离脯氨酸、可溶性蛋白和超氧化物歧化酶含量等6个生理指标,应用隶属函数法综合各项生理指标进行抗寒性评价,筛选高度抗寒品种单株,为相思选育提供优质材料。结果表明:在低温胁迫下,幼苗叶片相对电导率升高,游离脯氨酸、可溶性蛋白和可溶性糖含量增加,且这4个指标可作为相思树种抗寒性评价的参考指标;结合生理指标的变化情况,相思发生寒害的温度主要是0～6℃;依据平均隶属函数值,综合筛选出抗寒性较强的品种单株依次是杂交相思1、杂交相思4和赤云相思,抗寒性最弱的是马占相思11。     

东北中部地区水稻不同生育时期低温处理下生理变化及耐冷性比较

摘要：研究水稻不同生育时期低温条件下各种生理指标的变化,选育耐低温水稻新品种,对于东北地区的水稻生产具有重要意义。以东北中部地区目前主要栽培的15个主要栽培水稻品种为实验材料,利用人工气候箱进行低温处理,分析苗期、孕穗期、抽穗期和灌浆期4个不同生育时期各个品种过氧化物酶（POD）、丙二醛（MDA）、脯氨酸和叶绿素4种生理指标含量变化与耐低温系数之间的关系。同时利用不同生理指标隶属函数的加权平均值（D值）对不同水稻品种的抗冷性进行分类划分。结果表明,每个生育时期的低温处理下,过氧化物酶（POD）、脯氨酸、叶绿素均呈下降趋势,丙二醛（MDA）则呈上升趋势,并且4种指标的变化幅度与水稻耐低温系数之间呈极显著相关性（P＜0.01）,各种指标的加权平均值（D值）与抗低温系数之间相关系数达到极显著,并且高于每一个单一指标。因此,D值可以更有效的对水稻进行抗低温评价和分级。     

水稻转导外源总DNA变异后代盐胁迫下株高及生理指标分析

通过田间筛选的G系列水稻耐盐新品系生理生化指标和形态学指标的测定,进一步鉴定筛选的耐盐水稻的耐盐性.采用沙培法培养水稻幼苗,在水稻幼芽期和两叶一心期进行盐处理,设清水、0.3％ NaCl、0.6％ NaCl、0.9％ NaCl 4个浓度盐溶液浇灌植株.前者,待两叶一心期,测定丙二醛(MDA)含量、脯氨酸(Pro)含量、超氧化物歧化酶(SOD)活性和株高;后者,从浇盐水当天开始算起,分别测定第3天和第6天水稻的上述4个指标.结果显示,G16、G20这两个新品系在两个处理下都是随着盐浓度的增加,MDA含量逐渐降低,但在同一浇灌条件下均低于对照G6;Pro含量逐渐升高,但在同一浇灌条件下均高于对照G6;SOD活性先增强后减弱,但在同一浇灌条件下均高于对照G6;随着盐浓度的增加株高逐渐减小,但在同一浇灌条件下均高于对照G6.通过MDA含量、PRO含量、SOD活性和株高的显著变化,由此得出田间筛选出的水稻G16、G20的耐盐性都强于对照G6,从生理角度和形态学角度证实了田间筛选耐盐水稻结果的正确性,也证实了丙二醛含量、脯氨酸含量、SOD活性和株高可以做为水稻耐盐性鉴定的生理生化指标和形态学指标.     

NaCl胁迫对5种绿化植物幼苗生长和生理指标的影响及耐盐性综合评价

采用分次浇灌的方法,对2、4、6、8和10 mg·g-1 NaCl胁迫条件下光叶决明(Cassiafloribunda Cav.)、紫穗槐(Amorpha fruticosa L.)、海滨木槿(Hibiscus hamabo Sieb.et Zucc.)、决明[Senna tora(L.)Roxb.]和田菁[Sesbania cannabina(Retz.)Poir.]幼苗的3个生长指标和6个生理指标的变化进行了测定和分析,采用相关性分析、主成分分析(PCA)与隶属函数法相结合的方法对5种植物对NaCl的耐性进行了鉴定和综合评价,并利用回归分析确定了5种植物的生长临界NaCl浓度(C50).结果表明:在2～10 mg·g-1 NaCl胁迫条件下,5种植物幼苗的株高生长量和全株干质量总体上小于对照,且总体上随着NaCl质量浓度的提高而降低.随NaCl质量浓度的提高,5种植物幼苗的相对电导率、叶绿素含量、丙二醛含量、脯氨酸含量、可溶性糖含量和SOD活性均受到不同程度的影响,说明5种植物对NaCl胁迫的响应不同.除MDA含量外,5种植物的生长和生理指标间大多存在显著或极显著的相关性.通过主成分分析和隶属函数法获得的5种植物的综合评价值D及C50均表明田菁和海滨木槿对NaCl的耐性较强,其次为紫穗槐和决明,光叶决明对NaCl的耐性最差.     

水稻BCAT4基因突变株幼苗对PEG模拟干旱胁迫的响应

以水稻野生型‘日本晴’(NIP)及其BCAT4基因突变体BCAT4 1为材料,在苗期进行PEG 6000模拟干旱处理,分析其对幼苗形态、生长和抗逆生理指标的影响,以探究BCAT4基因在水稻响应干旱胁迫中的作用。结果表明：(1)20% PEG处理后野生型NIP幼苗叶片中BCAT4表达量显著高于对照(处理0 d),复水后幼苗存活率显著高于突变体BCAT4 1。(2)20% PEG处理后,两水稻材料幼苗叶片的相对叶绿素含量下降,脯氨酸和可溶性糖含量上升,抗氧化酶活性先上升后下降,且突变体BCAT4 1中上述各指标均显著低于同期NIP。(3)两材料幼苗叶片中丙二醛和过氧化氢含量及相对电导率随胁迫处理天数增加而上升,且BCAT4 1均显著高于同期NIP。(4)在20% PEG处理后,两水稻材料间根系各形态、生长和生理指标的差异均小于相应叶片。研究发现,BCAT4基因突变加剧了干旱胁迫下水稻幼苗叶片叶绿素含量的下降,抑制了地上部渗透调节物质的积累及抗氧化酶活性上升的幅度,促进了丙二醛和过氧化氢积累以及相对电导率增加,从而降低了水稻的耐旱性。     

二倍体马铃薯耐盐品种鉴定的生理指标测定

以不同耐盐性的二倍体马铃薯富利亚（Solanum phureja, PHU） 和窄刀薯假stenotomum,STN）杂种（PHU．STN）无性系为材料,在离体条件下用0（对照）、10、20、30mmol·L^-1NaCl进行胁迫处理,测定试管苗叶的电导率、丙二醛和脯氨酸含量,结果表明,随着盐浓度的升高,这3个生理指标的相对值均逐渐升高,耐盐性不同的二倍体马铃薯差异极显著。表明电导率、丙二醛和脯氨酸含量可以作为二倍体马铃薯耐盐性鉴定的生理指标。     

Identification of a Drought Tolerant Introgression Line Derived from Dongxiang Common Wild Rice (O. rufipogon Griff.)

Construction of introgression lines using cultivated rice as recipient and wild rice is a novel approach to explore primitive and broad genetic resources in rice breeding. We recently generated a set of 159 introgression lines via a backcrossing program using an elite Indica cultivar rice Guichao 2 (O. sativa L. ssp. indica) as recipient and a common wild rice Dongxiang accession (O. rufipogon Griff.) as donor. In this study, we have evaluated the previously constructed 159 introgression lines for drought-tolerance. A total of 12 quantitative trait loci (QTLs) related to drought tolerance were mapped. Furthermore, a drought tolerant introgression line, IL23, was identified and characterized. Genotype analysis of IL23 demonstrated that IL23 contained two QTLs associated with drought tolerance, qSDT2-1 and qSDT12-2, which were located on chromosome 2 and 12 within the two introgressed segments derived from the common wild rice, respectively. Physiological characterization, including measurement of water loss, osmotic potential, electrolytical leakage, MDA content, soluble sugars content and the leaf temperature, revealed that IL23 showed the characteristics associated with drought tolerance. Identification and characterization of IL23 would provide a useful basis for isolation of novel genes associated with drought tolerance and for molecular breeding of drought tolerant rice. Furthermore, the results in this study indicated that construction of introgression lines from common wild rice should be an appropriate approach to obtain favorable genetic materials.     

QTLs affecting morph-physiological traits related to drought tolerance detected in overlapping introgression lines of rice (Oryza sativa L.)

Plant photosynthetic traits such as net photosynthetic rate (P_n), stomata conductance (g_s), transpiration rate (T_r), and intercellular CO₂ concentration (C_i), are known to relate to drought tolerance in plants, but the genetic basis of these traits remains largely uncharacterized because of the difficulty in phenotyping physiological traits in a large mapping population. In this study, a set of 55 overlapping introgression lines (ILs) in the Teqing (indica) background were used to genetically dissect several morph-physiological traits and their relationship with grain yield under water stress and non-stress conditions. These traits included specific leaf weight (SLW), chlorophyll content (CC), leaf stomata frequency (SF), P_n, g_s, T_r, and C_i. A total of 40 QTLs affecting the measured traits were identified and mapped to 21 genomic regions in the rice genome. Clustered QTLs affecting P_n, g_s, T_r, and C_i in the same genomic regions suggest common genetic bases for the physiological traits. Low or no phenotypic correlations between leaf morphological traits and photosynthetic traits and between morph-physiological traits and grain yield (GY) appeared to be due to inconsistence in QTL effect for clustered QTLs, unlinked QTLs affecting different traits, and to possible epistasis that could not be adequately addressed in this study. Our results indicate that improving drought tolerant (DT) of rice by selecting any single secondary traits is not expected to be effective and the identified QTLs for GY and related morph-physiological traits should be carefully confirmed before to be used for improving DT in rice by MAS.     

Effects of Selenium on Wheat Seedlings Under Drought Stress

The paper reports the effects of selenium (Se) supply on growth and some physiological traits of wheat (Triticum aestivum L. cv Shijiazhuang NO. 8) seedlings exposed to drought stress. The growth and physiological responses of seedlings were different depending on the Se concentration. The higher (3.0 mg Se kg⁻¹) and lower amount used (0.5 mg Se kg⁻¹) did not significantly affect on biomass accumulation. Treatments with 1.0 and 2.0 mg Se kg⁻¹ promoted biomass accumulation of wheat seedlings. Treatments at 1.0, 2.0, and 3.0 mg Se kg⁻¹ significantly increased root activity, proline content, peroxidase (POD), and catalase (CAT) activities, carotenoids (Car) content, chlorophyll content, and reduced malondialdehyde (MDA) content of wheat seedlings. Lower Se treatment did not significantly effect on chlorophyll content and MDA content, although it also increased some antioxidant index (proline and Car content, POD and CAT activities) in wheat seedlings. These results suggest that optimal Se supply is favorable for growth of wheat seedlings during drought condition.     

几种盐生植物抗盐生理指标的研究

研究对几种盐生植物进行了相关抗盐生理指标测定,抗盐生理指标测定结果表明：盐生植物组的功能叶中ＭＤＡ含量平均值高于非盐生植物对照组,而膜透性平均值低于对照组;盐生植物组Ｃ１＾－离子含量平均值高于对照组,可溶性糖含量平均值低于对照组,脯氨酸含量在所测３种渗透调节剂中所占比例最高,而且盐生植物组平均值高于对照组;无机渗透剂与有机渗透剂之间似有互补关系;Ｃ１＾－离子含量与肉质性存在一定正相关;盐生植物组和     

山杜英和黧蒴幼苗对干旱胁迫(PEG)的生理响应

以山杜英(Elaeocarpus sylvestris)和黧蒴(Castanopsis fissa)幼苗为试验材料,利用聚乙二醇6000(PEG-6000)人工模拟水分胁迫环境,设置三个胁迫强度处理(轻度、中度、重度)、三个胁迫持续时间处理(12h、24h、36h),以不加PEG-6000的1/2Hoagland营养液中的苗木作为对照,对2个树种幼苗的叶片相对含水量、相对电导率、脯氨酸含量、叶绿素含量、超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量和可溶性糖含量进行了测定,研究了水分胁迫对这2种幼苗的影响。结果表明:随着水分胁迫强度的加深及持续时间的延长,2种幼苗叶片相对含水量出现下降趋势,黧蒴的含水量下降更为显著;2种树种幼苗叶片内相对电导率呈波动性上升,黧蒴在轻度胁迫时相对电导率有大幅增加;2种幼苗的脯氨酸含量显著增加,叶绿素含量呈小幅波动,SOD活性先升后降,可溶性糖含量呈现波动性上升;山杜英叶片的MDA含量增加较缓慢,而黧蒴叶片的MDA含量大幅度增加。研究表明幼苗山杜英比黧蒴抗旱性强,叶片相对含水量、相对电导率和MDA含量可作为评价这2种苗木抗旱性的依据。     

Using QTL mapping to investigate the relationships between abiotic stress tolerance (drought and salinity) and agronomic and physiological traits

Background

Drought and salinity are two major abiotic stresses that severely limit barley production worldwide. Physiological and genetic complexity of these tolerance traits has significantly slowed the progress of developing stress-tolerant cultivars. Marker-assisted selection (MAS) may potentially overcome this problem. In the current research, seventy two double haploid (DH) lines from a cross between TX9425 (a Chinese landrace variety with superior drought and salinity tolerance) and a sensitive variety, Franklin were used to identify quantitative trait loci (QTL) for drought and salinity tolerance, based on a range of developmental and physiological traits.

Results

Two QTL for drought tolerance (leaf wilting under drought stress) and one QTL for salinity tolerance (plant survival under salt stress) were identified from this population. The QTL on 2H for drought tolerance determined 42% of phenotypic variation, based on three independent experiments. This QTL was closely linked with a gene controlling ear emergency. The QTL on 5H for drought tolerance was less affected by agronomic traits and can be effectively used in breeding programs. A candidate gene for this QTL on 5H was identified based on the draft barley genome sequence. The QTL for proline accumulation, under both drought and salinity stresses, were located on different positions to those for drought and salinity tolerance, indicating no relationship with plant tolerance to either of these stresses.

Conclusions

Using QTL mapping, the relationships between QTL for agronomic and physiological traits and plant drought and salinity tolerance were studied. A new QTL for drought tolerance which was not linked to any of the studied traits was identified. This QTL can be effectively used in breeding programs. It was also shown that proline accumulation under stresses was not necessarily linked with drought or salinity tolerance based on methods of phenotyping used in this experiment. The use of proline content in breeding programs can also be limited by the accuracy of phenotyping.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1243-8) contains supplementary material, which is available to authorized users.     

不同西瓜基因型对干旱胁迫的生理响应及其抗旱性评价

以来源于不同地区的12个西瓜基因型为试材,采用盆栽控水的方式进行持续干旱处理,研究干旱胁迫对西瓜幼苗株高、根长、鲜质量及干物质积累等生长状况的影响,比较不同基因型材料对干旱胁迫的生理响应差异,同时依据旱害指数对其抗旱性进行直接评价,并采用隶属函数法进一步验证和综合评价.结果表明: 干旱处理下,12个西瓜基因型对干旱胁迫的耐受能力存在明显差异,各基因型开始出现旱害症状的时间和发生旱害的程度各不相同.干旱胁迫降低了西瓜幼苗的株高、地上、地下鲜质量和地上干物质积累量,普遍提高了根冠比,而对根长和地下干质量存在正向和负向两种不同的影响.干旱处理后,西瓜叶片的相对含水量和叶绿素含量均不同程度降低,丙二醛、过氧化氢和超氧阴离子含量增加,脯氨酸大量积累,而可溶性蛋白含量以及抗氧化酶活性则因基因型的不同而表现出不同的结果.分析认为,3个野生型材料M20、KY-3和Y-2为抗旱性强的西瓜种质,Y34、金美人和04-1-2为敏感种质,而其余基因型为中抗种质.