坏损外担菌培养液对烤烟幼苗生长及主要生理特性的影响

为探明坏损外担菌培养液对烤烟幼苗生长和生理特性的影响,研究了坏损外担菌培养液不同浓度（原液、1/10原液、1/50原液和1/100原液）对烤烟幼苗叶片、茎和根系生长及叶片叶绿体色素、NR活性和根系活力等的影响。结果表明,处理5 d时,1/50原液最大叶长和根系鲜质量最大,与原液达到显著差异,1/50原液茎高、地上部鲜质量和叶绿素b最大,显著高于其他处理和对照。处理10 d时,1/50原液最大叶长、最大叶宽、叶面积、茎高、茎围、叶绿素a和类胡萝卜素含量最高,且显著高于原液、1/100原液和对照,1/50原液NR活性和根系活力最高,且与原液和对照达到显著水平。处理15 d时,1/50原液最大叶长、最大叶宽、叶面积、茎高、地上部鲜质量、NR活性和根系活力最大,显著大于其他各处理和对照,而茎围、根鲜质量和叶绿素a含量显著大于原液、1/100原液和对照。坏损外担菌培养液不同浓度对烤烟幼苗生长和生理代谢影响不同,1/50原液烟苗生长最好。     

萝卜苗中异硫氰酸盐的动态变化及体外抗氧化活性

测定不同生长时期的6种萝卜苗(长春白萝卜苗、盛丰白萝卜苗、象牙白萝卜苗、德国特白萝卜苗、抚顺红萝卜苗及满堂红萝卜苗)正己烷提取物的总异硫氰酸盐和4-methylthio-3-butenyl isothiocyanate (MTBITC)含量,分别用FRAP法、ABTS法、抗超氧阴离子自由基(O2－ ·)和抗羟自由基( ·OH)能力4种方法测定提取物的体外抗氧化性能。结果显示：萝卜苗中MTBITC含量占总异硫氰酸盐的80%以上;5～10d的萝卜苗中含有较高的MTBITC含量;同生长期的苗中,长春白萝卜苗、盛丰白萝卜苗、象牙白萝卜苗、德国特白萝卜苗的MTBITC含量比抚顺红萝卜苗和满堂红萝卜苗高。长春白萝卜苗、盛丰白萝卜苗、象牙白萝卜苗、德国特白萝卜苗4种萝卜苗的抗氧化性能与MTBITC含量呈正相关。而满堂红和抚顺红萝卜苗中MTBITC含量较低,但却表现出较强的抗氧化性能。     

沼液对烟苗生长及生理特征的影响

在有机烟叶生产中,为替代化学肥料,提高有机肥源在烤烟育苗中的利用效率,以烤烟育苗专用肥为对照(CK), 研究沼液营养液氮浓度分别为50、150、250 mg/L 对烟苗生长及生理特性的影响。结果表明,与CK 相比,氮浓度为50 mg/L 的处理烟苗矮小,营养液中的养分难于满足烟苗生长的需要;氮浓度为150 mg/L 的处理烟苗长势较好,能显著增加烟苗根系的干、鲜质量,同时,总根长、根表面积、体积、根系活力均有不同的程度的增加。而叶片中光合色素含量、光合特性、 生理特性各指标与CK 相比差异不大。综合来看,氮浓度为150 mg/L 的处理能够达到使用漂浮育苗专用营养液的效果,可用于有机烟草育苗生产。     

膜下小苗移栽最适地膜透光率优选研究

为确定攀西烟区膜下小苗移栽最适宜的地膜透光率,在凉山州会理县以白膜为对照,进行了不同黑膜透光率研究。试验为单因子4水平3重复随机区组设计,处理水平为白膜和3种透光率（36.39%、14.36%和2.10%）的黑膜覆盖。结果表明,白膜覆盖的处理穴内最高气温可达40.7℃,小苗成活率受到严重影响;而黑膜覆盖的穴内最高气温为35.7℃,移栽后15 d内小苗成活率均在98%以上。透光率越高,烟株更易早生快发,根冠比更高,株高、茎围、最大叶长和叶宽更长;透光率越低,烟叶外观质量、化学成分含量和协调性越好。综合来看,在当地生态条件下,使用透光率为14.36%的黑膜进行覆盖比较合适。     

小麦幼苗质膜Mg2+-ATP酶活性与低温损伤及其恢复的关系

采用氯化铈(CeCl3)沉淀的电镜细胞化学方法观测了小麦(Triticum aestivum L.)幼叶细胞质膜三磷酸腺苷酶活性在低温胁迫后、恢复过程中以及恢复后的变化.所得主要结果如下 :(1)在正常温度(20℃)下生长的小麦幼苗,其幼叶细胞内的三磷酸腺苷酶主要定位于质膜、细胞壁和细胞间隙等处,其中以质膜上的酶活性最强.(2)小麦幼苗在-2℃处理16h后未经恢复生长即固定,此时质膜上的ATPase活性明显降低或失活,细胞的超微结构也受到破坏.(3)小麦幼苗经-2℃低温胁迫16h后,并经过24h的恢复生长,此时质膜的ATP酶活性有了很大程度的恢复;小麦幼苗在-2℃低温下处理16h后,经150mmol/L CaCl2溶液处理,并经24h的恢复生长,此时质膜上的ATP酶活性比未用CaCl2处理时增强;小麦幼苗经-2℃低温处理16h后,经100mmol/L Na3VO4(钒酸钠)处理,也经过24h的恢复生长,此时质膜上观察不到ATPase的活性反应,同时细胞的超微结构受到严重破坏.(4)小麦幼苗在-2℃处理16h后,经过72h的恢复生长,质膜上的ATPase活性基本恢复到正常水平,同时小麦幼苗也基本恢复正常生长.     

Inhibition of cucumber leaf expansion by ferulic acid in split-root experiments

Experiments were conducted to determine how the proportion of a root system in contact with an allelopathic compound may affect seedling responses. Cucumber seedlings grown in a split-root nutrient culture system were given either single (1 mM) or multiple applications (0.5 mM) of ferulic acid. Seedlings receiving single applications were left in the treatment solutions for two days and then harvested, while seedlings receiving multiple applications had their solutions changed every other day for a total of three changes. Leaf areas were determined daily starting with the initial ferulic acid treatment. Mean absolute and mean relative rates of leaf expansion were inversely related to the proportion of the root system in ferulic acid solution. Leaf expansion was inhibited primarily during the first 24 hr after each treatment. A partial recovery of growth occurred during the second 24-hr period following each treatment. Root length was reduced by ferulic acid. These results suggest that information on root and allelochemical distribution in soils is important when assessing the potential of allelopathic interactions between plants.Paper No. 11940 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, North Carolina 27695-7643. The use of trade names in this publication does not imply endorsement by the North Carolina Agricultural Research Service of products named, nor criticism of similar ones not mentioned.     

模拟酸雨对油菜幼苗生物量及其生理指标的影响

采用土培的方法研究了不同pH值的模拟酸雨（acidrain,AR）对油菜幼苗生长的影响。结果表明,pH≥4.0的酸雨刺激幼苗生长,生物量和色素含量维持在与对照（pH6.0）相当或更高的水平;抗氧化酶（超氧化物歧化酶SOD、过氧化物酶POD和过氧化氢酶CAT）活性和非酶抗氧化剂（抗坏血酸AsA和谷胱甘肽GSH）含量与对照相比无显著差异。随着酸雨酸度的进一步增强（pH≤4.0）,油菜幼苗的生物量、色素含量、抗氧化酶活性和非酶抗氧化剂含量逐渐下降,且下降速度越来越快;膜脂发生过氧化,丙二醛含量和相对电导率显著增加。当pH≤2.5时,幼苗叶片可观察到不同程度的伤斑。     

Biodegradation in vivo and in vitro of chlorogenic acid by a sunflower-seedling (Helianthus annuus) like-polyphenoloxidase enzyme

Sunflower seeds contain a high amount of chlorogenic acid (3–4% in weight) and a specific polyphenoloxidase that oxidize it. In this research, the activity of a sunflower seed enzymatic solution was investigated in vivo and in vitro on endogenous and exogenous chlorogenic acid. Phenol degradation was monitored by spectrophotometric analysis at 325 and 420 nm or by HPLC analysis. It was ascertained that during the germination, sunflower seeds synthesized an enzyme like-polyphenoloxidase after 24 h that got dark the seedlings ground and degraded endogenous chlorogenic acid. Sunflower-seedling like-polyphenoloxidase enzyme could be easily isolated in active form. Enzymatic extract catalysed in vitro the degradation of chlorogenic and also caffeic acid. In comparison to original value, after 60 min of incubation under environment temperature and pH 7, chlorogenic and caffeic acid have been reduced by 64 and the 90%, respectively. A high linear correlation was verified between enzymatic activity and original concentration of chlorogenic acid in a range from 0.01 to 0.1 mM. This linear correlation suggested a possible use of like-polyphenoloxidase enzyme for analytical application and other biotechnological uses in the treatment of medium containing natural phenols.     

Effect of Rare Earths on Plant under Supplementary Ultraviolet-B Radiation: Ⅰ Effect of Cerium on Growth and Photosynthesis in Rape Seedlings Exposed to Supplementary Ultraviolet-B Radiation

Theapplicationofrareearth(RE)inagriculture initiallyoriginatedfromChina.Itdeservesexclusive intellectualpropertyright,whichstandsforadvancedtechnologyinthefield.Ithasalreadybeenprovedthat REplaysanimportantroleinimprovingproduction andqualityofcropsandall…     

地乐胺（dibutralin）对大豆幼苗根腐病,核酸和蛋白质的影响

地乐胺（dibutralin）可降低大豆幼苗根腐病的发病率和严重度，可使大豆幼苗的RNA含量和叶部蛋白质含量增加，RNA酶活性提高，对蛋白酶的活性无影响，这说明地乐胺可诱发某些应激蛋白的产生。另外DNA含量和根部蛋白质含量略减少，幼苗体内IAA,GA,Z，ABA4种激素的含量有不同程度的变化。这些变化都对大豆根腐病的发生有不同程度的影响。