SCAR标记技术鉴别榆黄蘑品种

为了建立一套基于DNA分子标记技术快速鉴定榆黄蘑菌株的有效方法,本研究通过对生产上常用的16个榆黄蘑菌株进行SRAP多态性分析,从榆黄蘑2号菌株中扩增获得了一个片段长为537bp的特异片段,将其克隆、测序并设计引物,成功转化为稳定的SCAR标记。试验结果表明,利用该特异SCAR标记,能在1d时间内准确鉴定出榆黄蘑2号菌株。由此可见,SCAR分子标记是一种快速、稳定、准确鉴定榆黄蘑菌株的新方法。     

万州区高山林下茶园榆黄蘑间种技术及效益分析

从榆黄蘑的菌包制作、栽培、出菇管理、采收及加工等方面介绍了采用返生态栽培方式在高山林下茶园间种榆黄蘑的栽培技术,并分析间种的经济效益、生态效益和社会效益。结果表明:1)榆黄蘑种植沟深19～20 cm,最深不超过25 cm,菌包入沟后覆盖茶园土2～3 cm。2)出菇管理过程中,温度在15～28℃、空气湿度90%～95%为宜。3)采摘后的榆黄蘑宜保存在3～8℃的冷库中或采用分段梯式温度干燥方式进行初加工,干燥温度以35～60℃为宜。4)通过在林下茶园间种榆黄蘑,重庆市万州区茶园每667 m~2可增加产值2 800元左右,并解决了农闲时茶叶基地大量剩余劳动力的务工问题,促进了万州区茶叶产业的可持续健康发展。     

玉黄蘑半地下式驯化栽培技术

玉黄蘑属担子菌纲、伞菌目、侧耳科、侧耳属的一种木腐菌,又名榆黄蘑、金顶侧耳、金顶蘑.因常见腐生于榆树枯枝上而得名榆黄蘑,群众取其吉祥谐音称为玉黄蘑.其子实体呈覆瓦状丛生,菌盖基部下凹为喇叭状,边缘平展呈波浪状,许多菌盖层叠簇生在一起,宛如一束金色花朵,色彩绚丽.玉黄蘑富含蛋白质、脂肪、碳水化合物以及多种维生素等营养成分,营养丰富,口感细嫩鲜美,气味清香.此外,玉黄蘑还可入药,有滋补健身、化痰定喘、平肝健胃、降压减脂等疗效.     

三氯乙烯和三氯苯在水-玉米-空气系统中的传输过程研究

采用水培实验及光照培养箱培养方法,通过测量玉米木质部伤流液及露珠中三氯乙烯（TCE）和1,2,3-三氯苯（TCB）两种有机污染物的浓度,对比探讨了两种有机污染物在水-玉米-空气系统中的传输过程和机制。结果表明,露珠中TCE与TCB均主要来源于随水蒸气的叶面挥发过程;水培条件下TCB在玉米木质部伤流液中的浓度与根外部水溶液中TCB浓度呈正相关,而露珠中TCB浓度与外部水溶液浓度呈负相关,蒸腾流浓缩系数（TSCF）值由暴露时间决定。实验条件下,根外部溶液浓度较低时,露珠中TCB浓度远大于木质部伤流液中TCB浓度;而高浓度时,木质部伤流液中TCB浓度远大于露珠中浓度。露珠中TCE浓度远大于木质部伤流液中TCE浓度,且与根外部水溶液浓度呈正相关;而木质部伤流液中TCE浓度随营养液中TCE浓度增加而减小。     

有棱丝瓜主要农艺性状的相关及通径分析

对有棱丝瓜10个品种的10个主要农艺性状进行了相关及通径分析。相关分析表明。瓜长、单瓜质量等2个性状与产量呈极显著正相关，前期产量、瓜形指数与产量呈显著正相关，始收期与产量呈极显著负相关，第一坐瓜节位与产量呈显著负相关；通径分析表明，结果数和单瓜质量2个性状对产量形成的直接作用最大。且对产量的决定系数总和达0．9812。因此，可以作为有棱丝瓜高产育种的主要选择性状。     

不同硼效率棉花品种根系参数和伤流液组分的差异

溶液培养条件下研究硼对不同硼效率棉花品种根系参数、伤流量及伤流液组分的影响。结果表明,缺硼抑制棉花根系生长,根重、根体积、根长、活跃吸收面积、总吸收面积、活跃吸收面积占总吸收面积的比例以及伤流量均显著降低,高效品种降低幅度比低效品种小;缺硼还使高效品种根系比表面积升高,而低效品种无显著变化。缺硼显著影响不同棉花品种伤流液各组分含量,与低效品种相比,高效品种伤流液中有较多的NO3-、K+、无机磷、可溶性糖和游离氨基酸。说明缺硼条件下高效品种根系比低效品种具有更强的吸收、代谢活力,可能是其硼效率较高的主要原因之一。     

不同浓度氯化钙对鸢尾切叶瓶插寿命的影响

以3个浓度氯化钙(500、1 000、1 500 mg·L~(-1))为保鲜液对4种鸢尾(Iris lactea var.chinensis Pall、Iris sanguinea、Iris pseudacorus、Iris halophila)做切叶进行瓶插保鲜,研究其衰老过程。结果表明:1)氯化钙能提高瓶插中的鸢尾叶片叶绿素含量,优化观赏效果。2)1 500 mg·L~(-1)的氯化钙溶液可普遍提高鸢尾叶片的瓶插寿命。3)马蔺叶片的瓶插保鲜效果最佳,其次为溪荪和喜盐鸢尾,黄菖蒲叶片作为切叶在瓶插过程中,叶片变黄衰老的最快。     

不同保鲜剂对散枝香石竹保鲜效果的初探

通过由蔗糖、杀藻铵、柠檬酸、叠氮化钠组成的保鲜剂和蔗糖、明矾、尿素、氯化钾和氯化钠组成的保鲜剂以及经过硝酸银预处理后再用以上两种保鲜剂对香石竹进行了保鲜试验,并与自来水进行对照。结果表明,经过预处理后两种保鲜液的保鲜效果明显增强,由硝酸银预处理10min后再用明矾、尿素、氯化钾和氯化钠组成的保鲜液的效果更为显著。     

江门地区夏秋丝瓜品种比较试验

为了筛选出适合江门地区栽培的优良丝瓜品种,江门市农业科学研究所对2014年夏秋季引进的2个有棱丝瓜品种在江门地区的生长表现进行了比较试验,结果表明‘华绿宝丰’与‘绿源3号’总产量都比对照‘雅绿6号’优胜,均适合在江门地区夏秋季推广种植;而‘绿源3号’比较早熟,前期产量比较高,在夏秋淡季抢早上市能获得更高的经济价值。     

根际通气对基质气体、肥力及黄瓜伤流液的影响

为改善根际气体环境,试验采用基质通气栽培方式,研究不同通气方式对基质气体、肥力及黄瓜伤流液的影响。结果表明,基质底部通气和基质上部通气均显著改善根际二氧化碳和氧气体积分数,二氧化碳体积分数比对照降低33.31%～98.02%,氧气体积分数比对照提高2.13%～12.22%。通气处理显著提高基质速效养分质量分数,碱解氮比对照提高12.95%～28.87%,速效磷比对照提高12.02%～20.46%。基质上部通气处理的伤流液流量、电导率值和伤流液氨基酸含量均最高,表明基质上部通气处理根系代谢旺盛,是较理想的基质通气方式。     

外源稀土对水稻伤流组分的影响

应用微区试验和伤流测定法研究了外源稀土对水稻根系合成氨基酸和激素的效应,以及对伤流中无机营养离子的影响。结果表明,在本试验条件下,土施低浓度稀土能促进根系合成,显著增加氨基酸总量和激素在伤流中的含量,提高营养离子的吸收;但高浓度稀土却有着明显的抑制效应。应用数学模拟的方法计算出稀土抑制氨基酸合成的半效应值(或50值)约为350～500mg/kg。稀土提高了伤流液中钙的含量,而对磷、钾的含量起抑制效应。     

~(60)Co辐照对白灵菇采后低温贮藏的影响

以0.8、1.2、1.6和2.0kGy60Coγ射线辐照白灵菇,在4℃下贮藏保鲜。结果表明,经过1.2kGy辐照处理的白灵菇维持了最高的可溶性蛋白质含量和最大的硬度,贮藏保鲜时间最长。白灵菇在贮藏期间的硬度越大,其可溶性蛋白的含量也越高,且二者之间存在显著的相关性。辐照会加大白灵菇的细胞膜透性,破坏细胞膜结构,剂量过大反而会加速营养成分降解和腐烂。     

水 、氮供应对玉米伤流及其养分含量的影响

以玉米为供试作物, 在遮雨棚内进行了微区田间试验, 研究了不同水、氮供应玉米的伤流量, 伤流液中的硝态 氮、铵态氮、游离氨基酸及磷、钾含量, 以及对植株氮、磷、钾等养分含量和吸收量的影响。 结果表明, 供水明显增加 伤流量和伤流液中硝态氮、铵态氮、游离氨基酸及磷、钾含量。 水分充足或水分胁迫较轻时, 伤流量及其养分含量 随施氮增加而增加;水分胁迫严重时, 则减少。 在不同水、氮供应条件下, 植株氮、磷、钾养分含量及吸收量具有相 同的变化趋势。     

Nitrogenous constituents of bleeding sap from taro plants grown in nitrate nutrition under a potassium deficiency

The previous work (1) with bleeding sap from taro plants grown in solution culture at varying ammonium sulphate application under aerobic condition revealed that a potassium deficiency led to a contradictory relationship of the variation in amino-N content in bleeding sap to the exudation rhythm; in the earlier period of bleeding experiment a deficient K-application decreased the amino-N content but accelerated the exudation rate. In this connection, there are good reasons for believing that the passage of water and salts into the xylem ducts is largely controlled by the metabolic conditions in adjacent living cells, especially their rate of aerobic respiration (2). Therefore, the effects of potassium nutrition on the exudation phenomenon were reexamined with taro plants grown in solution culture under nitrate nutrition and correlated with information about the effect of aeration through culture medium during bleeding experiment on the rate of exudation and contents of nitrogenous constituents of bleeding sap. Arsenite- or DNP-treatment was also carried out in vivo with the roots in order to elucidate a possible relationship between the respiration in roots and the exudation process of xylem sap.     

生物保鲜剂对海鲈鱼冰藏保鲜效果的影响

为延长冰藏海鲈鱼肉的保鲜期,以新鲜海鲈鱼为材料,研究冰藏条件下竹叶抗氧化物(AOB)、茶多酚(TP)、乳酸链球菌素(Nisin)对海鲈鱼肉的保鲜效果;通过单因素和正交试验,以感官评分结合海鲈鱼肉的挥发性盐基氮(TVB-N)值、pH值和菌落总数(TBC)等指标表征其新鲜度,确定复合保鲜剂的最佳配比。结果表明,单一竹叶抗氧化物、茶多酚和Nisin的最佳保鲜浓度分别为0.3、0.4、0.7 g·L~(-1);海鲈鱼复合生物保鲜剂的最佳复配比为竹叶抗氧化物0.3 g·L~(-1)、茶多酚0.4 g·L~(-1)、Nisin 0.7 g·L~(-1),经此复合生物保鲜剂处理,海鲈鱼肉分别在冰藏第13、第19和第23天超出TVB-N一级、二级和三级鲜度范围,比未进行保鲜处理的空白组分别延长了6、4和6 d。该复合生物保鲜剂对海鲈鱼肉有较好的保鲜效果,为海鲈鱼肉的生物保鲜提供了一定的科学依据。     

自然条件下乳化茶树油在香蕉保鲜中的应用

为拓展茶树油的应用范围,开发新型天然保鲜剂,试验由“Span80+Tween80”乳化剂制备得到乳化茶树油,通过检测分析病情指数、可溶性固形物含量、硬度、呼吸强度等指标, 探讨了自然条件下乳化茶树油在香蕉保鲜中的应用效果,并与常用的香蕉保鲜复合农药进行比较。结果表明：乳化茶树油可在不同程度上对香蕉起到保鲜作用,且浓度越大效果越好,但高于1000 mg/L时随着浓度增大,保鲜效果增加不显著。1000 mg/L乳化茶树油可显著延长香蕉货架期,其抑制香蕉采后还原糖转化及可溶性固形物含量上升的效果稍逊于复合农药,延缓香蕉硬度下降的效果与复合农药相当,抑制香蕉呼吸的效果明显好于复合农药。     

罗汉果砧木研究

用葫芦科不同植物种类作砧木嫁接罗汉果，试验结果表明：栝楼与罗汉果的亲和性明显优于苦瓜、南瓜、丝瓜和葫芦，嫁接成活率最高，达60％；插接具有简单易行、嫁接速度快等优点，劈接和合接的成活率差异不显著；低位嫁接和发枝素处理效果好．嫁接成活率明显高于高位嫁接和糖液处理；接种内生菌根(VA)有利于提高嫁接成活率，以地表VA菌根接种的成活率最高，达72．5％。     

Evaluation of antioxidant activity and inhibitory effect on nitric oxide production of some common vegetables

The objectives of this study were to study the antioxidant activities and nitric oxide (NO) scavenging effects of vegetables in vitro systems and to study the inhibitory effects of vegetables on the NO production and NO-induced DNA damage in RAW 264.7 macrophage. The results indicated that water extracts from Indian lotus, Jew's ear, shiitake, eggplant, and winter mushroom showed stronger antioxidant activity and free-radical-scavenging ability than that of other vegetable extracts. The scavenging effects of vegetable extracts on NO derived from sodium nitroprusside (SNP) were in decreasing order of water spinach > Indian lotus > eggplant and garland chrysanthemum. In the macrophage model system, the water extracts from fresh daylily flower, sponge gourd, pea sprout, and eggplant exhibited over 80% inhibition on NO generation stimulated by lipopolysaccharide. The extract from fresh daylily flower that expressed the strongest inhibition on NO production was attributed to the ability to reduce the inducible nitric oxide synthase (iNOS) induction. However, the extracts from pea sprout and eggplant suppressed the NO production by scavenging on NO and inactivating toward iNOS enzyme. In addition, the water extracts from fresh daylily flower, sponge gourd, pea sprout, and eggplant also showed over 40% inhibitory effect on DNA damage induced by SNP in RAW 264.7 macrophage. The data also indicated that eggplant and pea sprout extracts contained higher total phenolic compounds, anthocyanins, and ascorbic acids and appeared to be responsible for their antioxidant activities and scavenging effects on NO derived from SNP.     

Effect Of Mineral Nutrition on Metabolic Change Induced in Crop Plant Roots (I)

Attempts have long been made to study the effect of mineral nutrition on the metabolic substances in excised roots from a numcer of plant species, but very little attention has teen given to an approach to the problem by using the bleeding sap from crop plants. Recently, however, an increasing number of reports about the occurrence of organic substances in bleeding sap from crop plants has completely revised an old view that xylem sap was essentially a rather dilute aqueous solution of inorganic salts. Evidence has already been obtained which suggests a significant role for the root system as a centre of metabolism and an upward transport of metabolites from the root via the xylem to the leaf. Although analyses of the nitrogenous compounds present in bleeding sap from herbaceous plants have shown glutamine and asparagine to be the most important constituents, in some species of plants nitrate nitrogen may be a predominant nitrogenous compound. Besides ami des and nitrate, the presence of amino acids in bleeding sap has ceen shown by Kulayeva, Silina, and Kursanov ¹⁾ for pumpkins, Wieringa and Bakhuis ²¹ for Lupins, and DIE³⁾ for cucumbers and tomatoes.     

Silicon nutrition of tomato and bitter gourd with special emphasis on silicon distribution in root fractions

Two plant species, tomato (Lycopersicon esculentum Mill.) and bitter gourd (Momordica charantia), were used for in‐depth studies on the dynamics of silicon (Si) uptake and translocation to the shoots and compartmentation of Si in the roots. The experiments were conducted under controlled environmental conditions in nutrient solutions, which were partly amended with 1 mM Si in the form of silicic acid. At harvest, xylem exudates were collected, and Si concentrations and biomass of roots and shoots were determined. Mass flow of Si was calculated based on the Si concentration of the nutrient solution and transpiration determined in a parallel experiment. Plant roots were subjected to a fractionated Si analysis, allowing attributing Si to different root compartments. Silicon concentrations in the roots compared to the shoots were higher in tomato but lower in bitter gourd. A more ready translocation from the roots to the shoots in bitter gourd was in agreement with Si concentrations in the xylem exudates which were higher than in the external solution. In tomato, the xylem‐sap Si concentration was lower than in the nutrient solution. Calculated Si mass flow to the root exceeded Si uptake in tomato, which was consistent with the measured accumulation of Si in the root water‐free space (WFS). In contrast, Si concentration in the root WFS was lower than in the nutrient solution in bitter gourd, reflecting the calculated Si depletion at the root surface based on the comparison of Si mass flow and Si uptake. Within the roots, more than 80% of the total Si was located in the cell wall and less than 10% in the cytoplasmic fractions in tomato. In bitter gourd, between 60% and 70% of the total root Si was attributed to the cell‐wall fraction whereas the proportion of the cytoplasmic fraction reached more than 30%. Our results clearly confirm that tomato belongs to the Si excluders and bitter gourd to the Si‐accumulator plant species for which high Si concentrations in the cytoplasmic root fraction appear to be characteristic.