3个玉米品种苗期耐寒性鉴定

为鉴定不同玉米品种的耐寒性,筛选抗寒性强的品种,以玉米品种青农8号、郑单958和农大108为材料,在10、4℃下进行苗期低温胁迫试验,研究低温处理对超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性以及丙二醛(MDA)和可溶性蛋白(SP)含量等耐寒性鉴定指标的影响。结果表明,SOD活性及其变化率、CAT活性变化率、POD活性及其变化率、MDA含量变化率和SP含量等7个指标的结果均表明青农8号耐寒性最强;CAT活性、MDA含量和SP含量变化率等3个指标的结果表明青农8号耐寒性居第2位。农大108和郑单958耐寒性强弱在不同生理指标下得到的结论不尽相同,SOD活性及其变化率、POD活性及其变化率、MDA含量和SP含量等6个指标的结果表明农大108耐寒性优于郑单958;CAT活性及其变化率、MDA含量变化率和SP含量变化率等指标的结果表明郑单958耐寒性优于农大108。本研究结果为玉米新品种青农8号的推广以及抗寒性品种的选育提供了一定的理论依据。     

牡丹不同品种耐涝性综合评价

为发掘耐涝牡丹品种,建立牡丹的耐涝评价体系,以9个3年生牡丹品种为研究对象,采用模拟涝害的方式对其进行涝害胁迫,通过测定相对电导率、叶绿素、可溶性蛋白、丙二醛(MDA)含量,超氧化物歧化酶(SOD)、过氧化物酶(CAT)和过氧化氢酶(POD)活性等指标的变化研究胁迫下牡丹生理生化变化情况,并以各项指标的耐涝系数为衡量指标进行主成分分析。结果表明,涝害胁迫后,不同牡丹品种的相对电导率、MDA含量均增加;叶绿素和可溶性蛋白含量均降低;SOD活性在大部分品种中呈现增加变化趋势,但在百园红霞、银红娇艳和菱花普中呈现降低的变化趋势;POD和CAT活性在不同品种中呈现升高或降低的变化趋势。主成分分析将7个单项指标综合成3个独立指标,隶属函数分析将9个牡丹品种划分为3类:洛阳红、香玉、银红娇艳强耐涝,白雪塔、肉芙蓉、俊艳红中等耐涝,百园红霞、明星、菱花普不耐涝,分析结果与外部形态特征观察基本一致。本研究结果为丰富江南牡丹品种提供了理论依据。     

磷胁迫对粉带扦插苗生长和生理特征的影响

以粉带(Scaevola albida)扦插苗为材料,研究磷胁迫对其外观形态、生根率、叶绿素、可溶性蛋白、MDA含量和SOD、APA活性的影响.结果表明:在磷浓度0 g/kg处理下,无植株死亡,但生长状况(指标包括株高、叶片宽度、颜色和数量)在各处理中最差,生根率显著低于对照,叶绿素和可溶性蛋白含量均略低于对照,MDA含量、SOD和APA活性均显著高于对照;在磷浓度0.02 g/kg处理下,生长状况、叶绿素含量和SOD、APA活性与对照基本相同,生根率显著高于对照,达到100%,可溶性蛋白含量略高于对照,MDA含量略低于对照;在磷浓度0.04,0.06,0.08 g/kg处理下,植株存活率、生根率、叶绿素含量和APA活性均开始显著下降,可溶性蛋白、MDA含量和SOD活性均显著上升.根据在各磷浓度处理下粉带扦插苗生长和生理指标的变化,磷浓度0.02 g/kg处理最适于粉带扦插苗的生长.     

铅胁迫对杨梅生理特性的影响

通过水培试验,研究了不同浓度的铅胁迫对杨梅（Myrica rubra Sieb. et Zucc.）叶片的叶绿素含量、可溶性蛋白质含量、可溶性糖含量、超氧化物歧化酶（SOD）活性、过氧化物酶（POD）活性、丙二醛（MDA）含量以及根系活力的影响。结果表明,在2 mmol·L^-1低铅条件下,杨梅叶片叶绿素含量和可溶性蛋白质含量在30 d内与对照相比无显著性差异;叶片可溶性糖和MDA含量在2 mmol·L^-1低铅处理第10 d即比对照显著增加;根系活力在2 mmol·L^-1低铅胁迫处理20 d后比对照显著降低;叶片SOD和POD活性在2 mmol·L^-1低铅胁迫下活性随着处理时间的延长而呈先升后降的变化趋势,在低铅处理第20 d SOD 和POD活性达到最大。在6 mmol·L^-1高铅胁迫下,杨梅叶片的叶绿素含量、可溶性蛋白质含量、SOD活性、POD活性、MDA含量以及根系活力均随着处理时间的延长而不断降低;而叶片可溶性糖含量在高铅处理30 d时比对照有所增加。综上所述,杨梅在低铅条件下可诱导活性氧清除系统以及叶片可溶性糖含量增加以减少由于铅胁迫带来的活性氧代谢失衡和缺水对植株的伤害。     

常压室温等离子体对NaCl胁迫下胡麻种子萌发及幼苗生理特性的影响

为探究常压室温等离子体(ARTP)照射处理对胡麻耐盐性的影响,以2个胡麻品种天亚10号和陇亚13号为材料,利用ARTP对胡麻种子进行不同时长(0、10、20、30 min)照射,测定不同Na Cl浓度(0、85、170 mmol·L-1)胁迫下胡麻的发芽指标、幼苗生长指标、叶绿素(Chl)和类胡萝卜素含量、叶片质膜相对透性、叶片丙二醛(MDA)含量、可溶性蛋白含量及超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性,分析ARTP处理对Na Cl胁迫下胡麻种子萌发及幼苗生长的影响。结果表明,ARTP处理对2个胡麻品种的影响存在差异,ARTP处理可以促进天亚10号在Na Cl胁迫下种子萌发和幼苗生长,降低质膜相对透性、叶绿素含量、类胡萝卜素含量、MDA含量,提高POD活性及可溶性蛋白含量;在170 mmol·L-1Na Cl胁迫下ARTP处理10 min,天亚10号发芽率可以提高90.27%;但抑制了陇亚13号在Na Cl胁迫下种子萌发和幼苗生长,增加了质膜相对透性、叶绿素含量、类胡萝卜素含量、MDA含量,降低了POD活性及可溶性蛋白含量,在170 mmol·L-1Na Cl胁迫下ARTP处理30 min,陇亚13号的发芽率下降了17.60%。本研究结果为胡麻育种及盐碱地人工栽培提供了一定的理论参考。     

干旱胁迫及复水对大豆关键生育时期叶片生理特性的影响

以“辽豆15”为试材，在开花期和鼓粒期设置轻度干旱（土壤相对湿度65%±5%）和重度干旱（土壤相对湿度50%±5%）以及对照（土壤相对湿度80%±5%）处理，开展大豆干旱及复水控制试验。干旱处理持续7d、14d和21d，并在胁迫结束后进行复水，复水水平与对照处理一致。达到胁迫时间当日和复水后第7天取大豆倒三叶叶片，测定叶片可溶性蛋白和丙二醛（MDA）含量以及超氧化物歧化酶（SOD）和过氧化物酶（POD）活性，研究干旱胁迫对以上生理指标的影响以及复水后补偿效应。结果表明：开花期，轻度干旱和重度干旱胁迫均使叶片可溶性蛋白和MDA含量以及POD活性显著升高，轻度干旱胁迫使SOD活性显著升高。鼓粒期，大豆受干旱胁迫影响后，叶片可溶性蛋白含量、MDA含量、SOD活性显著升高，但POD活性显著降低。复水对大豆叶片可溶性蛋白含量、MDA含量和SOD活性均出现补偿效应，但对POD补偿效应不明显。由此可见，干旱会对大豆叶片造成过氧化伤害，主要表现在抗氧化酶和渗透调节物质含量的提高，同时复水可使大豆叶片由干旱造成的过氧化伤害得到缓解，表现出不同程度的补偿效应。     

高温干旱共胁迫下外源甜菜碱和CaCl2对烟草生理响应的影响

以烤烟品种云烟85为材料,采用盆栽试验研究了对高温干旱共胁迫的反应,以及外源甜菜碱（GB）和CaCl2对烟草抗高温干旱共胁迫方面的作用。结果表明,叶面喷施GB和CaCl2能显著提高烟草植株生物量。在高温干旱共胁迫下,叶面喷施GB较蒸馏水处理能极显著提高烟草叶片叶绿素含量、SOD和POD活性,维持较高的脯氨酸含量及较低的丙二醛（MDA）含量和质膜相对透性;叶面喷施CaCl2较蒸馏水处理能极显著提高烟草叶片叶绿素含量、SOD和POD活性,极显著降低质膜相对透性,显著降低丙二醛（MDA）含量,维持较高的脯氨酸含量。高温干旱共胁迫恢复生长后,GB、CaCl2和蒸馏水处理的烟草其叶绿素含量、SOD和POD活性均有不同程度回升,丙二醛含量、脯氨酸含量、细胞质膜透性都有所下降。因此,GB和CaCl2对有效减轻双逆境胁迫引起的伤害,提高烟草的抗高温干旱胁迫能力具有积极的作用。     

低磷胁迫对不同磷效率基因型烟草苗期生长及生理特征的影响

为揭示不同磷效率烟草对低磷胁迫的响应机理,以磷高效且耐低磷基因型K326和云烟105及磷低效且低磷敏感基因型G28和中烟101为试验材料,设置低磷(0.01 mmol·L^-1,LP)和正常磷(1.00 mmol·L^-1,NP)2个处理,研究不同磷效率基因型烟草苗期主要农艺性状及生理指标对低磷处理的反应。结果表明,磷高效基因型的农艺指标(株高、地上部干重、根系干重等)在2种处理中均显著高于磷低效基因型,表明磷高效基因型在LP和NP水平下均能较好生长,对磷素具有较高的吸收或利用效率;在LP下,磷高效基因型的主根长增幅较大,干重、株高等降幅较小,即磷高效品种的生长受低磷影响较小,耐低磷性较强。在生理指标方面,LP条件下磷高效基因型的3种保护酶[过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、过氧化物酶(POD)]和酸性磷酸酶(ACP)活性及可溶性糖和游离脯氨酸含量的增幅较磷低效基因型大,丙二醛(MDA)含量的增幅较小,可溶性蛋白含量、根系活力的降幅较小,水培营养液的pH值降幅较大;磷高效基因型的农艺性状及生理指标的耐低磷指数均高于磷低效基因型。综上,在低磷胁迫中,磷高效基因型烟草具有较强的活性氧清除能力,可累积较多渗透调节物质以维持细胞渗透势,较好地保护细胞,增强体内ACP活性,提高对磷素的吸收利用效率,维持自身的正常生长与代谢。本研究结果为烟草磷素高效吸收利用提供了一定的理论依据。     

弱光胁迫及光恢复对玉米幼苗活性氧代谢的影响

以耐弱光品种郑单958和不耐弱光品种豫玉22为材料,研究了50%遮荫处理及恢复光照过程中玉米苗期植株地上部生物量、活性氧代谢和抗氧化酶活性的动态变化.结果表明,与正常光照相比,遮荫处理后2品种的地上部生物量和可溶性蛋白含量降低,超氧化物歧化酶(SOD)和过氧化物酶(POD)活性升高,MDA含量、过氧化氢(H2O2)含量...     

湿地匍灯藓（Plagiomnium acutum）的防御机制对镉胁迫的响应

采用浸没培养实验研究不同浓度镉溶液（0、2、5、50mg·L-1）对湿地匍灯藓（Plagiomnium acutum）的膜系统、光合系统的损伤情况及其抗氧化酶系统的影响。结果表明：湿地匍灯藓外表伤害症状随Cd胁迫浓度增加而加重;湿地匍灯藓对Cd有较强的生物富集能力,且藓体Cd累积量与溶液Cd浓度显著正相关（P〈0.05）;湿地匍灯藓的总叶绿素含量随Cd浓度增加显著降低,其含量与可溶性蛋白含量显著正相关（P〈0.05）;Cd胁迫引起湿地匍灯藓的丙二醛（MDA）积累,同时伴随可溶性糖和游离脯氨酸含量显著增加,其中可溶性糖含量与MDA含量显著正相关（P〈0.05）;可溶性蛋白含量和过氧化氢酶（CAT）活性随Cd浓度增加均持续下降,而超氧化物歧化酶（SOD）和过氧化物酶（POD）的活性却随Cd浓度增加而呈现逐渐上升趋势,其中可溶性蛋白和CAT活性均与MDA含量显著负相关（P〈0.05）,SOD活性则与MDA含量显著正相关（P〈0.05）,POD活性与MDA含量极显著正相关（P〈0.01）。Cd胁迫抑制或降解光合作用相关酶类、细胞膜质过氧化和蛋白质代谢紊乱可能是湿地匍灯藓遭受Cd毒害的主要原因;湿地匍灯藓通过增加可溶性糖含量、SOD和POD活性来抵御Cd的毒害,但由于CAT活性丧失,使湿地匍灯藓的防御系统崩溃,最终导致了湿地匍灯藓细胞的凋亡。可溶性糖、SOD和POD可以作为湿地匍灯藓防御Cd毒害的指标。     

Hydroponic experiment for identification of tolerance traits developed by rice Nagina 22 mutants to low-phosphorus in field condition

Development of phosphate (P)-deficiency tolerant rice cultivars is constrained by lack of suitable, reproducible, and consistent seedling stage screening methods in breeding programs. This study reports the screening and characterization of M5 mutants derived from an ethyl methane sulfonate treated population of rice cv. Nagina 22 (N22) in low-P field (soil Olsen P 1.94–2.01 mg kg^?1; alkaline Vertisol; pH 7.94) for high yield. The present study showed that seedling growth responses such as increase in root weight, root length, root/shoot weight, and dry weight in P-deficient medium can be taken as indices of low-P tolerance in mature plants in field. Total phosphorus content in seedlings showed an inverse relationship with total phosphorus content and low-P tolerance in mature plants in the field. But, phosphorus content in seeds and acid phosphatase activity in the seedling stage were positively correlated with survival and seed set in low-P field. In low-P field, plant height correlated most with yield per plant, and the number of productive tillers in mature plants was highly correlated with tiller number at vegetative stage. These mutants (NH776, NH710, and NH719) have agronomic importance because of their ability to grow and give higher yield than N22 in P-deficient field.     

低磷胁迫对水稻地上部氮、钾吸收和积累的影响

在盆栽土培条件下,采用耐低磷水稻基因型508T、580T、99011T和99112T及低磷敏感基因型99012S和99056S为材料,研究了不同生育时期,低磷胁迫对水稻氮、钾吸收和积累的影响。结果表明,在分蘖期,低磷处理对水稻体内氮、钾含量的影响较小,但低磷敏感基因型水稻受影响较大;孕穗期,除508T的氮含量变化不明显外,其它基因型体内氮、钾含量均显著增加。在这两个时期,低磷敏感基因型99012S氮、钾含量的变化幅度在所有基因型中最高,而另一个低磷敏感基因型99056S则相反。至成熟期,由于受吸收效率和转运效率的共同影响,不同基因型水稻体内氮、钾含量的变化趋势明显比生育前期复杂,耐低磷基因型水稻茎叶的氮、钾含量与低磷敏感基因型没有明显的差异。在生育前期,耐低磷基因的氮、钾积累量显著高于低磷敏感基因型;生育后期,耐低磷基因型的绝对积累量优势消失,但相对积累量优势变大。     

酸性磷酸酶活性与大豆耐低磷能力的相关研究

在水培条件下研究了11个南方春大豆地方品种和育成品种对低磷胁迫反应的差异及其与酸性磷酸酶活性（APA）的相关关系。结果表明，不同大豆品种的地上部干重、根干重、植株全磷和全氮积累量差异极显著（P＜0.01），表现出品种间耐低磷的差异性。大豆品种地上部干重、根干重、植株全磷和全氮量与APA的相关性均达到显著或极显著水平。APA是大豆品种磷效率的一种机制，它可作为耐低磷品种筛选的一个生化指标。     

大豆品种耐低磷和对磷肥效应的遗传差异

大豆不同品种对低磷胁迫和磷肥效应有显著的遗传差异。低磷胁迫下,苗期植株叶片酸性磷酸酶活性（APA）和叶面积与品种的子粒产量呈极显著相关;APA、叶面积、干物质量和氮积累量与生物学产量呈显著或极显著相关。但在施磷条件下,它们之间则无相关关系。这表明APA、叶面积、干物质量和氨积累量可作为耐低磷基因型的筛选指标。试验表明,耐低磷能力弱的品种对磷肥反应更为敏感。在低磷和施磷条件下产量均较高的品种也是存在的,它们对不同的磷素营养环境有着广泛的适应性,进一步挖掘这类基因型很有意义。     

Identification of Phosphorous Efficient Germplasm in Oilseed Rape

ABSTRACT

Plant species and genotypes within one species may significantly differ in phosphorus (P) uptake and utilization when they suffer from P starvation. The objective of this research was to screen P-efficient germplasm of oilseed rape (Brassica napus L.) and analyze the possible mechanism responsible for P efficiency by two-steps screening experiments and validation of P efficiency. Phosphorus efficiency coefficient at seedling stage, namely, ratio of shoot dry weight under low P to that under adequate P (PECS) of 194 oilseed rape cultivars varied from 0.050 to 0.62 and was significantly related with shoot dry weight under low P level (r = 0.859??, P < 0.01). Oilseed rape cultivar ‘Eyou Changjia’ presented the highest P efficiency coefficient in each growth stage and had the highest seed yield at low P, whereas oilseed rape cultivar ‘B104-2’ was the most sensitive to low P stress among the 12 candidate cultivars obtained from the two-steps screening experiments. Under low P condition in validation experiments of soil and solution cultures, ‘Eyou Changjia’ could produce much more dry matter and acquire more P than ‘B104-2.’ Moreover, P efficient coefficient obtained from the pot experiment was comparable to those from the field experiment. This might be attributed to high P uptake efficiency for ‘Eyou Changjia’ when it suffered from low-P stress. Comparison of results from the hydroponics with those from the pot and field experiments led to the conclusion that the P uptake efficiency in the hydroponics is highly related to that in soil culture conditions. These results show that there are large genotypic differences in response to phosphorus deficiency in oilseed rape germplasm (Brassica napus L.) and ‘Eyou Changjia’ is P-efficient and ‘B104-2’ is P-inefficient. By comparing these results further, the mechanism responsible for P efficiency was suggested to be mainly due to high P uptake efficiency by forming larger root system, and improving the ability of mobilizing and acquiring soil P in P-efficient oilseed rape under the condition of P starvation.     

耐低磷水稻筛选与鉴定

对2472个来自不同核心种质资源库的代表性水稻品种进行了苗期耐低磷初选和复筛,并通过全生育期鉴定,研究了耐低磷水稻种质资源筛选的基本条件和指标。结果表明,采用两步筛选法,即苗期初筛和复筛,并通过全生育期产量验证,既可以获得典型耐低磷和低磷敏感水稻品种,又提高效率,吻合度达67%;在供试土壤有效磷含量小于5.mg/kg时,筛选密度为4株/600g土,设低磷水平为50.mg/kg(外加);分蘖数及其耐低磷指数(相对分蘖数)综合性较强,作为苗期筛选指标比较适宜;对于少数特殊的品种,它们在高磷和低磷处理时都没有分蘖,此时用干重耐低磷指数(相对干重)来衡量它们的耐低磷能力比较合适;全生育期验证以经济产量及其耐低磷指数(相对经济产量)为鉴定指标,其中有效穗对经济产量影响最大。     

不同耐低磷玉米自交系生长发育特征研究

采用盆栽和田间试验方法研究了低磷胁迫对不同耐低磷玉米基因型全生育期生长发育的影响。结果表明,不同自交系在生长发育过程中对低磷胁迫的反应存在明显差异,在苗期耐低磷自交系植株干重和缺磷症状的相对值显著高于敏感自交系;到拔节始期,耐低磷自交系仍无缺磷症状,而敏感自交系症状加剧;进入生殖生长期后,耐低磷自交系孕穗期上部叶干重、茎干重受低磷影响的程度显著低于敏感自交系;至吐丝期,不同自交系间的耐低磷差异除了表现在植株干重上外,穗位高、雄花分枝数、功能叶面积也出现显著差异,低磷胁迫下耐低磷自交系这几个性状的相对值均显著高于敏感自交系;在成熟期,低磷胁迫下耐低磷自交系的相对产量较大,敏感自交系的相对产量较小。受低磷影响,敏感自交系的抽雄期、抽穗期、吐丝期和散粉期都显著延迟,而耐低磷自交系受影响较小或几乎不受影响。     

Effects of phosphorus and water stress levels on growth and phosphorus uptake of bean and sorghum cultivars

Primary determinants of crop production in arid/semiarid regions are lack of moisture and infertility, especially phosphorus (P) deficiency or unavailability. The effects of P and water stress (WS) levels on shoot and root dry matter (DM), leaf area, root volume, total root length, and shoot and root P concentrations and contents were determined in two bean [Phaseolus acutifolius Gray, cv ‘Tepary #21’ ("drought‐resistant") and P. vulgaris L., cv “Emerson’ ("drought‐sensitive")] and two sorghum [Sorghum bicolor (L.) Moench, cv SA7078 ("drought‐resistant") and ‘Redlan’ ("drought‐sensitive")] cultivars grown in nutrient solution. Plants were grown with different levels of P (20 and 100 μM for bean and 20, 80, and 160 μM for sorghum) when seedlings were transferred to nutrient solution, and WS levels of 0, 13.8, and 1 6.4% polyethylene glycol (PEG‐8000) introduced after plants had grown in solution 23 days (bean) and 31 days (sorghum). All growth traits were lower when bean and sorghum plants were grown with WS and low P. Growth traits were higher in cultivars grown with high compared to low P regardless of WS. Root P concentration and content and shoot content, but not shoot P concentration, were lower when bean plants were grown with WS compared to without WS. Tepary #21 bean had higher shoot DM, leaf area, total root length, and shoot P concentration than Emerson when plants were grown with WS at each level of P. Sorghum shoot and root P concentrations were higher as P level increased regardless of WS, and WS had little effect on shoot P concentration, but root P concentration was higher. Contents of P were similar for SA7078 and Redlan regardless of P or WS treatment, but SA7078 had greater P contents than Redlan over all P and WS treatments. “Drought‐resistant”; cultivars generally had better growth traits, especially total and specific root lengths, than “drought‐sensitive”; cultivars.     

Seedling vigor and nitrogen use efficiency of Moroccan wheat as influenced by level of soil nitrogen

Abstract

One of the characteristics that can help wheat (Triticum aestivum L.) plants escape late season drought in the semiarid areas of Morocco is early stand establishment and adequate vigor. Little is known about the effect of nitrogen (N) on early seedling vigor in wheat. The objective of this study was to determine how N supply affects early root and shoot growth, N partitioning between the two parts and N use efficiency of seedlings. To reach this objective, three spring wheat cultivars were grown in pots in a growth chamber under N conditions which were low, adequate and high. Data showed that optimum N rates increased shoot and root growth but high N concentrations reduced their dry matter accumulation and inhibited root elongation. The cultivars tested behaved differently. ‘Nesma’, an older cultivar, produced 60% more dry matter and accumulated 93% more N in the shoot and root than the newer cultivars ‘Merchouch 8’ and ‘Saada’. Because of its high N uptake, ‘Nesma’ probably reduced soil N concentration at the root zone and avoided the negative effect of high N concentration on root growth. Although, ‘Nesma’ performed better and produced more dry matter, it used N less efficiently than the other two cultivars.

From this study, we can conclude that use of optimum N rates at time of seeing will result in quicker establishment and higher vigor of wheat seedlings. However, excessive N supply may retard seedling growth. The cultivars that produce more seedling dry matter with greater N accumulation are not necessarily the ones that use N more efficiently.