Na+K+Cl-对碱蓬营养和毒性的比较研究

用NaCl、KCl、NaNO3和KNO3四种盐处理盐生植物碱蓬(Suaeda salsa)幼苗，比较Na^ 、K^ 、和Cl的营养性和毒性。低浓度时，Na、K和Cl对碱蓬的生长都有促进作用，其中K元素的促进作用明显。高浓度处理时，Na、K和Cl的效应有差异，NaCl和NaNO3处理时，Na和Cl没有表现出明显的毒性，KCl和KNO3处理时，K和Cl表现出毒害现象，叶片的叶绿素含量降低和脯氨酸含量明显的升高，植株干枯或黄化。     

外源脯氨酸对缓解红砂干旱胁迫的机理研究

红砂属于干旱半干旱荒漠区生态系统中重要的超抗旱树种,对维护荒漠区植物群落的稳定性具有重要的作用。近年来由于极端干旱气候的频发,导致以红砂为建群种的荒漠植物群落出现大面积死亡以及退化的趋势。因此,采用人工措施提高干旱荒漠区植物的抗旱能力显得尤为重要。通过对干旱胁迫中的红砂苗木喷施外源脯氨酸（Pro）以减缓干旱胁迫对其造成的伤害。研究设置5个Pro浓度,分别为50,100,150,200,250 mg·L^-1,对红砂植株进行喷施处理,于处理前第0天（CK）,处理后第1,3, 6和9天对叶片抗氧化酶系统、代谢调节系统、光合色素、光合性能进行测定,第9天对生长状况进行测定,以期揭示干旱胁迫下Pro的作用机理。结果表明,外源Pro处理红砂植株后,对其抗氧化酶系统、代谢调节系统、光合色素、光合性能以及生长状况均有显著影响。除叶绿素a/b（Chl a/b）在处理年份间差异不显著,可溶性糖含量在处理浓度间差异不显著外,其他指标在处理年份之间、处理浓度之间、处理后作用时间之间以及处理浓度与处理后作用时间交互作用之间均差异显著,其中以100 mg·L^-1 Pro处理效果最佳。100 mg·L^-1 Pro处理后第9天和CK相比,可溶性蛋白（SP）、脯氨酸（Pro）、过氧化氢酶（CAT）、过氧化物酶（POD）分别提高了4.48%、131.07%、30.66%、12.30%,可溶性糖（SS）、超氧化物歧化酶（SOD）分别下降了6.42%、1.95%;总叶绿素含量Chl（a+b）、叶绿素a含量（Chla）、叶绿素b含量（Chlb）分别较CK降低了5.81%、1.47%和22.22%;净光合速率（P_n）、气孔导度（G_S）、蒸腾速率（T_r）、胞间二氧化碳浓度（C_i）以及水分利用效率（WUE）分别比CK降低了16.07%、10.00%、6.44%、7.68%和9.92%;红砂苗木的生长特性在处理后第9天,株高净生长量为2.48 cm,侧芽萌发数量为3.67个,侧芽净生长量为1.87 cm,地径净生长量为0.27 mm,比处理效果最差的250 mg·L^-1处理分别高出0.68 cm,0.34个,0.32 cm,0.07 mm。因此,100 mg·L^-1 Pro处理干旱胁迫中的红砂植株,能显著提高其抗旱性。     

脯氨酸及KCl替代食盐对海鲈鱼品质影响的研究

为研究脯氨酸及KCl对海鲈鱼品质的影响,本试验用不同腌制组分(NaCl、NaCl+脯氨酸、NaCl+KCl、NaCl+KCl+脯氨酸)在4℃条件下干腌海鲈鱼,分别在腌制18 h、腌制36 h(结束)、风干3 h、风干6 h取样,测定海鲈鱼的pH值、色差、水分含量、含盐量、硫代巴比妥酸(TBA)值,同时进行质构、微观结构和感官评价。结果表明,随着处理时间的延长,不同处理腌制海鲈鱼pH值均呈现先下降后上升的趋势,含水量始终呈下降趋势,而含盐量则呈现上升趋势,用NaCl+脯氨酸腌制海鲈鱼后测得的TBA值最低,为1.415 7mg·kg^-1。通过透射电镜观察,添加脯氨酸使鱼肉组织更紧密,能更好地溶解肌球蛋白。使用NaCl+KCl+脯氨酸的减盐配方结合干腌法对海鲈鱼进行腌制,制得的海鲈鱼硬度和咀嚼性较高,并且能够有效抑制脂肪氧化,使肌球蛋白更好的凝集,得到风味及品质更好的产品。本研究结果为海鲈鱼的工业化腌制生产提供了技术支撑。     

Drought and Salt Stress Mitigation by Seed Priming with KNO3 and Urea in Various Maize Hybrids: An Experimental Approach Based on Enhancing Antioxidant Responses

Priming offers an effective means for counteracting different stresses induced oxidative injury and raising seed performance in many crop species. The present study was carried out to investigate the ability of potassium nitrate (KNO₃) and urea to promote the tolerance of different maize hybrids to drought and salt stresses to identify some biochemical parameters associated with KNO₃ and urea induced resistance in maize seedlings. An experiment was conducted in a controlled environment of the laboratory at the college of agriculture, Shiraz University, Shiraz Iran, during 2010. The first factor was stress type and intensity at five levels; moderate drought, severe drought, moderate salt, severe salt, and control (without stress). Seed priming was the second factor; water as control, KNO₃, and urea, and maize hybrids, including Maxima, SC704, Zola, and 304 were the third factor. Results indicated that the highest chlorophyll a (Ch a), chlorophyll b (Ch b), total chlorophyll (Ch T) contents, and carotenoids (Car) were found in no stress treatments and the most proline, protein contents, superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities in severe drought treatment. Also, results revealed that generally, drought and salinity stresses decreased the amount of Ch a and the lowest Ch a was recorded for severe salinity stress (4.29 mg g^?1). Stresses caused decrease in Ch b, but the effect of sever salinity level was higher than the others. Priming of KNO₃ had significantly higher proline content than water and urea priming. The SC704 and 304 hybrids showed higher proline content than the other ones. Finally, the maize seed KNO₃ and urea priming lead to high activities of antioxidant defensive enzymes and increase the tolerance level to abiotic stresses such as salt and drought.     

水分逆境对果树脯氨酸和叶绿素含量变化的影响

以盆栽二年生富士苹果、玉杏、肥城桃和巨峰葡萄为试材,研究了水分逆境对果树脯氨酸和叶绿素含量的影响。在干旱和多水处理初期,杏、桃脯氨酸含量急剧上升,然后下降;而苹果在水分逆境下脯氨酸含量变化不大。认为逆境下脯氨酸累积仅是一种受害反应特征,树种间反应各异。干旱和水涝均使果树长枝中部成熟叶片的叶绿素含量下降,水涝使正在成熟(长枝上部)的叶片叶绿素含量明显下降。三种果树抗涝性的顺序是:苹果>桃>杏。可以把叶绿素含量下降看作是水分胁迫发展中由功能性影响到器质性伤害的一个中间过程。     

盐碱胁迫对刺槐和绒毛白蜡叶片叶绿素含量的影响

用不同浓度的中性盐(NaCl)和碱性盐(NaCl、NaHCO3、Na2SO4、Na2CO3)溶液处理1 a生刺槐和绒毛白蜡,研究了两树种叶片中叶绿素a、叶绿素b和总叶绿素含量的动态变化以及叶绿素和丙二醛、脯氨酸的相关性。结果表明:在中性盐的胁迫下,刺槐和绒毛白蜡总叶绿素和叶绿素a的含量随盐胁迫程度的增加而降低,叶绿素b的变化较小,叶绿素a/b并不呈现单一的变化趋势;在碱性盐的胁迫下,刺槐总叶绿素和叶绿素a的含量随胁迫程度的增加呈现先升高后降低再升高的趋势,绒毛白蜡总叶绿素和叶绿素a的含量随胁迫程度的增加而上升,叶绿素b的变化较小,叶绿素a/b都呈现上升的趋势。相关分析表明,两树种在中性盐和碱性盐胁迫下,总叶绿素含量与膜脂过氧化产物丙二醛含量呈负相关;中性盐胁迫下,刺槐和绒毛白蜡都与脯氨酸呈正相关,在碱性盐胁迫下则呈负相     

含苯甲酸和磷酸二氢钾的保鲜剂对非洲菊切花衰老的影响

研究含苯甲酸和磷酸二氢钾的保鲜剂对非洲菊切花衰老的影响,以期探索出一种适宜的保鲜剂,解决非洲菊花茎的弯颈问题。结果表明:含适宜浓度的苯甲酸和磷酸二氢钾的保鲜剂明显延长切花保鲜时间,维持切花鲜重,增强水分平衡,降低脯氨酸含量,延缓第二呼吸高峰的到来,解决了非洲菊鲜切花的弯颈问题;其中保鲜剂Ⅳ、Ⅴ(30g·L-1蔗糖 200mg·L-18-羟基喹啉柠檬酸盐 75mg·L-1磷酸二氢钾 40～60 mg·L-1苯甲酸)保鲜效果最好。     

核果类果树砧木耐盐性差异的研究

采用盆栽试验结合田间观察,对山桃(Prunusdavidiana)、毛桃(P.persica)、山杏(Ameniacasibirica)、山樱桃(P.serrulata)、毛樱桃(P.tomentosa)5种核果类果树砧木的耐盐性进行了研究。盆栽砧木苗用不同浓度的NaCl溶液处理后,对砧木苗相对生长量、盐害指数、植株受害率及叶片中游离脯氨酸含量等指标进行了测定。通过各项指标的分析并结合田间观察结果,发现这5种砧木在耐盐性方面表现出较大差异,其耐盐性由强到弱的顺序依次为山桃>毛桃>山杏>山樱桃>毛樱桃。     

Comparative study of enzymes related to proline metabolism in tepary bean (Phaseolus acutifolius) and common bean (Phaseolus vulgaris) under drought and irrigated conditions,and various urea concentrations

There are several mechanisms used by plants for survival in adverse environments such as drought, high temperature and salinity. The objective of this study was to evaluate the drought tolerance of tepary bean as a function of biochemical processes linked to isozyme synthesis and changes in enzymatic activity related to proline metabolism. Mature seeds of common beans var. flor de mayo, Phaseolus vulgaris and tepary beans Phaseolus acutifolius were grown under two water conditions (irrigation and drought), and four levels of urea. Vertical electrophoresis and spectrophotometric techniques were used to evaluate protein patterns, glutamate dehydrogenase (GDH), proline oxidase (PO) and pyrroline-5-carboxylate reductase (P5C reductase) enzyme activities. These enzymes were studied because they are directly related to protein synthesis. Electrophoretic patterns showed more proteins in tepary beans than in common beans with limited irrigation. GDH showed only one isozyme, with a molecular weight between 240 to 270 kDa. A decrease in PO activity was observed in common beans under drought stress with a value of 237 mol/min, in comparison to irrigation conditions of 580 mol/min. GDH and P5C reductase enzymes have had higher activity in common beans than in tepary beans under water stress. There was a significant difference only in glutamate dehydrogenase enzyme with respect to urea level. The results suggest that drought tolerance of tepary beans is due to biochemical processes related to proline metabolic enzymes.     

The effect of water salinity on potatoes (Solanum tuberosum L.): Physiological indices and yielding capacity

Summary The response of several potato cultivars to salinity levels of 20.5, 34.2 and 51.3 mM NaCl was investigated. Salinity tended to lower the water and the osmotic potentials of leaves and tubers while increasing the content of total soluble solids and of proline; it also increased the content of dry matter in the tubers and reduced tuber yields. Susceptibility to salinity was described by the relative loss of tuber dry weight. ‘Blanka’ tolerated the lowest NaCl level (20.5 mM) and exhibited moderate tolerance to higher levels when exposed to salinity stress for 37 days.before harvest, but was susceptible when exposed to the higher levels for 63 days. Cv. Alpha showed moderate tolerance, loosing up to 15% of tuber dry weight when exposed to salinity levels of 20.5 and 34.2 mM NaCl. Mechnisms involved in the adaptation of potatoes to salinity stress are discussed. Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel. No. 2206-E, 1987 series.