[目的]探究盐和干旱胁迫对沙葱种子萌发的影响,为沙葱人工栽培和抗逆性研究提供参考依据.[方法]以沙葱种子为试验材料,采用不同浓度NaCl、Na2SO4混合的中性盐溶液和PEG-6000溶液分别模拟盐和干旱胁迫,测定其发芽率、发芽势、发芽指数和活力指数,并通过相对发芽率与各处理浓度建立的函数方程确定其种子的耐受性.[结果]随着盐和干旱胁迫的增强,沙葱种子的萌发指标均逐渐下降,初始萌发时间延迟.当盐浓度为75 mmol/L和150 mmol/L时,种子萌发时间分别延迟至第3天和第5天,其发芽率分别下降到23.33％和12.66％;当PEG-6000浓度为15％和20％时,种子萌发时间分别延迟至第3天和第4天,其发芽率分别下降到38.66％和25.33％.沙葱种子耐盐和耐旱半致死渗透势分别为-0.20 MPa和-3.80 MPa,耐盐和耐旱极限渗透势分别为-0.60 MPa和-7.38 MPa.[结论]轻度干旱环境并未明显抑制沙葱种子的萌发,其耐旱极限渗透势为-7.38 MPa;低渗盐溶液显著抑制沙葱种子的萌发,其耐盐极限渗透势为-0.60 MPa.

“沙珍F J-1号”斧形沙芥是采用单株-混合选择法培育而成的常规栽培种.该品种叶色深绿、叶基部紫色,营养生长生育期为125 d,生殖生长期为130 d,属中晚熟品种,营养品质好、抗病能力强,产量18 023.6 kg·hm-2,适合在内蒙古等西北地区种植.

为了寻找对白菜种子萌发产生抑制作用的化学物质,进而研究沙芥化感作用,通过生物检测方法研究了沙芥果皮浸提液中的甲醇、乙酸乙酯、乙醚、石油醚萃取相及剩余水相对白菜种子萌发及幼苗生长的影响,并利用GC-MS技术鉴定其化学组成.结果表明:不同浓度沙芥果皮各分离相萃取液对白菜种子萌发及幼苗生长呈现化感抑制作用,且浓度越高,抑制作用越强,其化感综合效应介于-0.01～-0.49.相同浓度处理下,沙芥果皮各分离相萃取液对白菜种子萌发与幼苗生长的抑制程度为乙醚相>乙酸乙酯相>甲醇相>剩余水相>石油醚相,乙醚相为优势分离相.从沙芥果皮各分离相萃取液中鉴定出的主要化合物为酚酸类、有机酸类、醇醚类、芳香烃类物质,其中邻苯二甲酸和15-冠醚-5为各分离相共有的物质.各分离相萃取液浓度高于0.75 g/mL对白菜种子发芽、幼苗苗高和根长均具有较强的抑制作用.

Cynanchum thesioides are upright, xerophytic shrubs that are widely distributed in arid and semi-arid areas of China, North Korea, Mongolia and Siberia. To date, little is known about the molecular mechanisms of drought resistance in C. thesioides. To better understand drought resistance, we used transcriptome analysis and Illumina sequencing technology on C. thesioides, to identify drought-responsive genes. Using de novo assembly 55,268 unigenes were identified from 207.58 Gb of clean data. Amongst these, 36,265 were annotated with gene descriptions, conserved domains, gene ontology terms and metabolic pathways. The sequencing results showed that genes that were differentially expressed (DEGs) under drought stress were enriched in pathways such as carbon metabolism, starch and sucrose metabolism, amino acid biosynthesis, phenylpropanoid biosynthesis and plant hormone signal transduction. Moreover, many functional genes were up-regulated under severe drought stress to enhance tolerance. Weighted gene co-expression network analysis showed that there were key hub genes related to drought stress. Hundreds of candidate genes were identified under severe drought stress, including transcriptional factors such as MYB, G2-like, ERF, C2H2, NAC, NF-X1, GRF, HD-ZIP, HB-other, HSF, C3H, GRAS, WRKY, bHLH and Trihelix. These data are a valuable resource for further investigation into the molecular mechanism for drought stress in C. thesioides and will facilitate exploration of drought resistance genes.

以人工老化和Ce3+浸种后再人工老化的沙葱种子为试材,对种子活力 、电导率 、呼吸速率 、活性氧和超微弱发光等指标进行了研究,探讨Ce3+浸种对沙葱老化种子活性氧与超微弱发光的影响.结果表明,Ce3+1处理下,沙葱种子的发芽率 、活力指数和胚根长分别比ck1高4％ 、0.042和1.64 cm,表明Ce3+有助于提高种子活力及促进胚根的伸长;在老化程度较低的情况下,Ce3+前处理对沙葱种子电解质外渗有一定缓解作用;活性氧在老化15 h前,Ce3+处理的超氧阴离子产生速率低于ck;Ce3+比ck的超微弱发光强度高,Ce3+1和Ce3+0的超微弱发光强度差异不显著,Ce3+0显著高于Ce3+2、Ce3+3和Ce3+4的超微弱发光强度.超微弱发光与胚根长 、超氧阴离子产生速率和过氧化氢含量呈极显著正相关,表明超微弱发光强度随活性氧的变化而变化.在种子的加速老化过程中,Ce3+处理可调控活性氧的增加,减缓老化对细胞损伤,维持细胞功能稳定性.

Kochia prostrata is a good forage plant, which has important economic and ecological value in arid and semi-arid regions of China. Drought is one of the main factors affecting its productivity. At present, there are few studies on the mechanism of drought resistance. In order to reveal the changes of physiological and biochemical indexes, stomatal structure and gene expression profiles of Kochia prostrata under drought treatment, the classical determination method and high-throughput Illumina Hiseq sequencing platform were applied to the control group (CK) and drought treatment group of Kochia prostrata. The results showed that under the condition of moderate to mild drought stress, the SOD activity reached the maximum value of 350.68 U/g min on the 5th day of stress, and under the condition of severe drought stress, the SOD activity reached the maximum on the 2nd day of stress. The accumulation of Proline remained at a high level on the 5th day of stress, and there was at least one epidermal cell interval between the two adult stomatal of the leaf epidermis, so that the evaporation shell of each stomatal did not overlap, it ensures the efficient gas exchange of the stomatal, indicating that the Kochia prostrata has strong drought resistance. A total of 1,177.46 M reads were obtained by sequencing, with a total of 352.25 Gbp data and Q30 of 85%. In the differential gene annotation to the biological process (BP), a total of 261 GO terms were enriched in the up-regulated genes, and a total of 231 GO terms were enriched in the down-regulated genes. The differentially expressed genes (DEGs) were obtained in 27 KEGG metabolic pathways, which laid a foundation for revealing the molecular mechanism of drought tolerance.

以沙芥属植物沙芥和斧形沙芥幼苗为试材,采用盆栽控水干旱方法,分析其在不同干旱胁迫强度下根和叶的活性氧水平、抗氧化酶活性和抗氧化剂含量的变化,并利用隶属函数法和抗旱系数法综合评价沙芥和斧形沙芥的抗旱性.结果表明:(1)随着干旱胁迫程度的加剧,沙芥和斧形沙芥的根和叶中O2·产生速率及·OH、H2O2、MDA含量总体呈逐渐升高的趋势,且干旱胁迫下沙芥比斧形沙芥产生了更多的ROS和MDA.(2)随着干旱胁迫程度的加剧,沙芥和斧形沙芥的根和叶中POD、APX、GST活性及叶中GR活性均先升高后降低,叶中的SOD活性以及根中GR、GPX活性均先降低后升高,根和叶中的CAT活性、叶中的GPX活性和根中SOD活性均逐渐升高;但根和叶中的SOD、POD、CAT活性在各干旱处理下均表现为斧形沙芥高于沙芥.(3)沙芥和斧形沙芥的根和叶中AsA含量随着干旱胁迫程度的加剧而先升高后降低,GSH含量逐渐升高,CAR含量逐渐降低,而VE含量在叶中逐渐升高,在根中却逐渐降低;但斧形沙芥比沙芥合成更多的AsA和GSH,其植物体内AsA-GSH循环系统能清除更多的ROS.(4)沙芥和斧形沙芥的根和叶中总抗氧化能力(T-AOC)均随着干旱加剧逐渐增强,且斧形沙芥的总抗氧化能力强于沙芥;活性氧清除系统的平均隶属度和综合抗旱系数显示,轻度干旱胁迫下沙芥抗旱性强于斧形沙芥,中度和重度干旱胁迫下斧形沙芥的抗旱性强于沙芥.研究认为,在干旱胁迫条件下,斧形沙芥根叶中ROS和MDA含量明显低于沙芥,而其大部分抗氧化酶活性和抗氧化剂含量高于沙芥,斧形沙芥植株体内抗氧化系统表现出更强的活性氧清除能力,从而表现出更强的抗旱性.

以蒙古高原野韭种子为试材,模拟盐度和碱度各不相同的复杂盐碱条件,研究了混合盐碱胁迫对野韭种子萌发及幼苗生长的影响.结果表明:野韭种子萌发对低盐低碱具有一定适应性;但是随着盐碱胁迫的增强,野韭种子的发芽率、发芽势、发芽指数与对照相比均显著性下降,其中碱性盐所占的比例越大,下降程度越大;各胁迫处理均显著影响了胚轴的生长;将未萌发的种子转移至蒸馏水中复水后,高盐浓度和高pH最终发芽率是对照的44％,说明高盐高碱延缓了种子的萌发,也抑制了一些低活力种子的萌发;综合分析各胁迫处理种子萌发的各项指标,盐浓度、pH及其相互作用对野韭种子萌发有抑制作用,其中盐浓度是决定性的主导因素,pH的影响次之.

以沙芥和斧形沙芥为试材,采用盆栽控水干旱法,研究不同干旱胁迫强度对其根和叶的抗坏血酸含量及其代谢相关酶活性的影响,探讨沙芥属植物抗坏血酸代谢对干旱胁迫的响应机制,揭示沙芥属植物抗坏血酸代谢方面的抗旱机理,评价沙芥和斧形沙芥抗旱性强弱.实验结果表明:随着干旱胁迫强度的加剧,沙芥和斧形沙芥的根和叶中抗坏血酸(ASA)、总抗坏血酸(T-ASA)含量均先增加后减少,脱氢抗坏血酸(DHA)、谷胱甘肽(GSH)、氧化型谷胱甘肽(GSSG)以及总谷胱甘肽(T-GSH)含量逐渐增加,ASA/DHA、GSH/GSSG比值逐渐降低;ASA合成途径的L-半乳糖脱氢酶(GalDH)和L-半乳糖-1,4-内酯脱氢酶(GalLDH)以及再生途径的脱氢抗坏血酸还原酶(DHAR)、单脱氢抗坏血酸还原酶(MDHAR)、抗坏血酸氧化酶(AAO)、抗坏血酸过氧化物酶(APX)活性均先升高后降低.不同干旱胁迫下斧形沙芥根和叶中ASA含量、GalLDH、MDHAR活性以及叶中GSH含量、GalDH、GR活性和根中DHAR活性均高于沙芥,根中GSH含量、GalDH、AAO、GR活性和叶中DHAR、AAO活性均与沙芥相近,说明干旱胁迫下斧形沙芥能够维持较高的ASA合成和再生能力,其抗坏血酸代谢能清除更多的活性氧物质,抗旱性强于沙芥.

为了进一步开发利用饲用植物,笔者以内蒙古地区的斧形沙芥、沙芥、沙葱、地梢瓜、蒲公英、苦菜和苋菜为试验材料,定量分析其叶片主要营养成分含量,并采用模糊数学隶属函数法对其营养价值进行综合评价.结果表明:7种饲用植物中斧形沙芥的粗蛋白含量(24.78％)和可溶性糖含量(21.13 mg/g)最高,沙芥的维生素C含量(126.53 mg/100 g)最高,沙葱的含水量(91.49％)和粗脂肪含量(5.60％)最高,地梢瓜的中性洗涤纤维含量(47.78％)、酸性洗涤纤维含量(31.19％)和可溶性蛋白质含量(7.86％)最高.说明7种饲用植物中蒲公英营养价值最高,其次是沙芥,地梢瓜的营养价值最低.

Air-drying,vacuum drying and blasting drying with different temperature(40,60 and 80 ℃)were compared on the quality of dried and rehydrated leaves of Pugionium cornutum (L.) Gaertn.and the physical characteristic and nutrition component were investigated.The results showed that obvious differences of physical properties and nutrient contents were found between treated leaves with different drying methods and fresh leaves.In the aspect of physical properties,the rehydration rate of leaves in vacuum drying was significantly higher than that of other treatments (p ＜ 0.05).In terms of nutrients,the amino acid,Vc and soluble protein content of dried and rehydrated leaves products in vacuum drying were higher than other drying methods (p ＜ 0.05).In a word,the vacuum drying did the least harm to the nutrients of leaves and had better reconstituability.It was the better method which had better quality and shorter times for processing.

The effects of drought stress on the growth and antioxidant system of Pugionium cornutum and P. dolabratum seedings were studied by pot-culture method in greenhouse. The results showed that with the in-crease of drought stress, the changes in growth indexes of P. cornutum and P. dolabratum seedlings were in-creased firstly and then decreased, and the biomass of the P. cornutum began to decline earlier than that of the P. dolabratum, and the reduction rate was also greater. The superoxide dismutase (SOD) activity in leaves of P. cornutum seeding decreased firstly and then increased under drought stress, and peroxidase (POD) and catalase (CAT) activities increased firstly and then decreased, while SOD and POD activities in P. dolabratum seeding increased firstly and then decreased, and CAT activity increased continually. The leaf relative plasma membrane permeability (PMP), and malondialdehyde (MDA), ascorbic acid (AsA) and proline (Pro) contents of P. cornu-tum and P. dolabratum seedings were increased under drought stress, but soluble protein (SP) content was de-creased. By comparing growth indexes, antioxidant system, comprehensive drought-resistance coefficients and average subordinate function coefficients of all indexes in response to drought stress of two Pugionium species, P. dolabratum seeding exhibited higher drought tolerance than P. cornutum.

Study on the effect of light on Germination and antioxidant metabolism of Allium mongolicum seed.The results showed that 12 h and 24 h light seed germination rate of Allium mongolicum were 20.8％ and 8.8％,showed that the Allium mongolicum seed for dark seed,and exist light dormancy phenomenon;in the 12 h and 24 h light treatment,germination of early SOD and POD activity and Vc content in high level,MDA and CAT was lower than that of control,and in late SOD,seed germination decreased,the activity of POD,MDA and CAT content increase,this illustrates that in light stress,membrane lipid peroxidation of Allium mongolicum seed germination stage enhanced.

综述了沙芥属植物种子的形态结构、化学成分、物理特性、形成发育及成熟、休眠与萌发、贮藏与寿命、抗逆性等方面的研究进展,并指出了研究中存在的问题,展望了今后研究的重点,以期为沙芥属植物种子的开发利用和深入研究提供参考.

地梢瓜Cynanchum thesiodes (Freyn) K.Schum],为萝藦科鹅绒藤属的直立半灌木,是一种具有多功能的沙生蔬菜.在地梢瓜的驯化栽培中经过母系单株—混合选择法选育出地梢瓜新品种,2016年经内蒙古自治区包头农作物品种推荐小组办公室登记,命名沙珍DG-1号,该品种具有优质、高产、稳产、耐性强以及适应性广等特点.这一新品种的选育填补了国内外沙生蔬菜——地梢瓜的驯化、选育与大面积栽培的空白,丰富了蔬菜栽培品种.

The germination indexes and main storage material of seed in P .cornutum (L .) Gaertn .and P .dolabratum Maxim .storage for 1 to 10 years were investigated ,and discussing the seed longevity and the change of storage material .The results showed that :The seed germination rate of P .cornutum (L .) Gaertn .The seeds germination rate ,germination force ,germination index and vigor index in-creased at first and kept for 2 years then decreased with the extension of time .The content of soluble sugar and starch increase at first and then decreased with the extension of time .The content of reduc-ing sugar and soluble protein reduced gradually .The content of crude fat of P .cornutum (L .) Gaertn . also declined ,but there was no obvious change in the P .dolabratum Maxim .The seed average longevi-ty of P .cornutum (L .) Gaertn .was 4 -5 years ,while the seed average longevity of P .dolabratum Maxim .was 6 -7 years ,both of them belong to medium longevity ,the workable lifetime was 2 -4 years in the agricultural production .

The effects of different temperature (5-45 ℃) and NaCl (0-300 mmol·L-1) on seed germination index and antioxidant enzyme activities of Cynanchum thesioides(Freyn).K.Schum were studied.The results showed that: (1) with the increase of temperature, germination index of seed all increased first and then decreased.The low or high temperature inhibited significantly seed germination.The optimum temperature for germination was 25 ℃, and its recovery germination ratio was over 95% at 5 ℃ and 35 ℃.(2) As NaCl concentration went up, the germination ratio, germination potentiality, vigor index of seed decreased, but relative salt injury rate increased and germination was completely inhibited at 300 mmol·L-1.The root vigor of seed was inhibited significantly only at high NaCl concentration(>150 mmol·L-1), the seed could recover germination after the salt stress was relieved, but it was still inhibited by salt stress.The higher salt concentration, the more prohibitive, and the appropriate content of salt-tolerant was 65.25 mmol·L-1(the salt content is 0.38%).(3) Under salt stress, the germination ratio was positively correlated with POD and APX, but negatively correlated with O-·2 generation rate and MDA, the vigor index was negatively correlated with CAT.Therefore, the seed germination was significantly inhibited by salt stress, protective enzymes POD and APX played a major antioxidant role during seed germination under salt stress, Cynanchum thesioides(Freyn).K.Schum was suitable for germination in moderate saline soil.

采用室内培养皿生物测定的方法,研究了不同浓度的沙芥叶、果皮、枝条水浸提液的自毒作用.结果表明:沙芥自毒效应的总体趋势为水浸提液浓度越高,抑制作用越强;高于0.15g/mL的浓度处理,均显著降低了沙芥种子发芽率、发芽指数、苗高、根长、幼苗鲜重及干重.在0～0.10g/mL的浓度范围内,水浸提液对沙芥种子萌发及幼苗生长抑制作用不明显.随着水浸提液浓度升高,SOD与POD酶活性降低,而CAT酶活性呈先升后降的趋势,丙二醛(MDA)含量则持续增加.不同部位水浸提液的自毒作用强弱表现为叶＞果皮＞枝条.沙芥不同部位自毒作用是沙芥连作障碍的重要因素.

This study was to observe the nutritional value of high and low in different kinds of dandeli-on,as the dandelion of forage value provides the theory basis for the development and utilization. The main nutrition of 5 kinds of dandelion were measured with the method of quantitative analysis, and the nutritional value were evaluated with the fuzzy membership function method and the grey correlation method, which will provide the theory basis for it's development and utilization. The results show that 5 kinds of dandelion leaves, the content of crude fat (4.78%)、crude protein (20.27%) and soluble sug-ar (24.91 mg/g) of Taraxacum variegatum Kitag is the highest in the 5 kinds of dandelion; The content of soluble protein (8.17 mg/g) and amino acid (24.67 mg/100 g) of Taraxcum erythropodium Kitag is the highest; The content of acid washing fiber (30.66%)、vitamin C (47.96 mg/100 g) and water content (74.16%) of Taraxacum centrasiaticum D. T. Zhai is the highest; The content of neutral deter-gent fiber content (46.88%) of Taraxacum pseud-oroseum Schischk is higher. The results of nutri-tional value with membership function method and the grey correlation method analysis show that nutritional value of Taraxcum erythropodi-um Kitag is highest in 5 kinds of dandelion, and the second is the Taraxacum altaicum Schischk,but the nutritional value of Taraxacum centrasiaticum D.T.Zhai is the least. The neutral detergent fiber is highest in 8 kinds of nutri-ents, followed by amino acids, the worst is crude protein in nutri-tional value. Taraxcum erythropodium Kitag has the highest nutri-tional value,the next is Taraxacum altaicum Schischk, Taraxacum pseudoroseum Schischk, Taraxacum variegatum Kitag and Taraxa-cum centrasiaticum D.T.Zhai.

Taking P.cornutum a special species in China and P.dolabratumlisted an endangered species in 1992 as materials,the effect of water supplying and sand burial on seedling emergence of P.cornutumand P.dolabratum were studied,a set of experiments were conducted under six depths of sand burial and four kinds of continual water supply.The results showed that the buried depth was closely correlated with water supply.When the water supply was 22.5mm that would be 50%of the average rainfall of Mu Us Sandy Land in June,the seeds couldnu0027t emerge.When the water supply was 50mm(the average rainfall in June),the seeds could germinate on the superficial layer of P.cornutum(1-4cm)and P.dolabratum(1-2cm).When the water supply was 100mm(the average rainfall in July),a few seeds could emerge well in 1-4cm of P.cornutumand 0-6cm of P.dolabratum.When the water supply was 150mm(50%of water supply of the average rainfall in July),the seeds could emerge in 1-8cm of P.cornutumand 0-8cm of P.dolabratum.The emergence rate of P.cornutum would be increase with water supply increasing.For P.cornutum,there was the fastest emergence rate in 135 mL in all sand burial,and 2cm in all the buried depth.For P.dolabratum,90 mL was faster than 135 mL in the water supply of the seedling emergence,and 1cm was the fastest seedling emergence in all sand burial depth.Based on our experiment results and precipitation characteristics of the Mu Us sandy land,there would be the important conditions for P.cornutum and P.dolabratumin 1.0-2.0cm buried depth and 100 mm average rainfall.