硅化物处理对甜瓜白粉病的抑制效果

以玉金香甜瓜幼苗为材料研究不同硅化物对白粉病的抑制作用,结果表明:硅化物处理浓度较高时,对甜瓜幼苗叶片有一定的药物伤害,相同浓度条件下,硅酸钠伤害最大;其次为正硅酸;纳米氧化硅伤害最小。硅酸钠、正硅酸和纳米氧化硅能显著降低白粉菌初生芽管的萌发,并能显著提高甜瓜对白粉病的抑病率。3种硅化物处理可显著降低甜瓜白粉病的严重度,提高对白粉病的防效,其中硅酸钠防效最高;其次为正硅酸;纳米氧化硅防效最低。硅酸钠处理可显著提高过氧化物酶(POD)和β-1,3葡聚糖酶(GLU)的活性,起到诱导抗性作用;纳米氧化硅处理对POD活性没有影响,不具有诱导抗性作用。     

生长环境对刺五加生理生化及光合作用的影响

比较了全光、林缘和林下生长环境下栽培刺五加对其丙二醛(MDA)、可溶性糖、叶绿素的含量,过氧化物酶(POD)的活性及光合速率的影响。结果表明:全光照过氧化物酶的活性和可溶性糖含量显著高于林缘和林下,而丙二醛含量各组间无差异;过氧化物酶的活性和可溶性糖季节含量变化与丙二醛含量呈明显的负相关。在移栽后保证水分的条件下,全光照不会对刺五加造成损害。     

甜瓜蔓枯病抗性与SOD、CAT和POD活性变化的关系

为了明确甜瓜蔓枯病抗性与SOD、CAT和POD活性变化的关系,采用甜瓜蔓枯病菌孢子悬浮液对抗病材料PI196477和感病材料绿宝石进行接种,并于接种后测定叶片内SOD、CAT和POD的活性变化。结果表明:甜瓜植株受蔓枯病菌侵染后,抗病材料的SOD、CAT活性均高于感病材料;抗病材料的POD活性上升慢,活性相对较弱,感病材料的POD活性上升快,活性强,且抗病材料的POD活性增加幅度明显低于感病材料。POD活性变化与甜瓜蔓枯病抗性有密切关系,可作为早期筛选抗性种质的辅助指标。     

Antioxidative activity associated with chilling injury tolerance of muskmelon (Cucumis melo L.) rind

‘Galia’ melon (Cucumis melo L. var. reticulatus) is a climacteric fruit with a short storage life. To prevent over-ripening, fruits are stored at 4–6 °C, which also results in chilling injury (CI) that appears as numerous brown spots on the surface of the fruit. It has been suggested that exposure of ‘Galia’ fruits to high growth temperatures in the field renders them sensitive to low storage temperatures. Activity profile of the antioxidative enzymes catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX) and glutathione reductase (GR) was monitored in the rind of ‘Galia’ fruits during low-temperature storage, to associate each enzyme's activity with CI incidence. Experiments were performed with low-temperature-sensitive and tolerant varieties, 5080^S and 1537^T respectively, and included a pre-storage treatment of hot-water wash of 5080^S fruits.     

盐胁迫对早开堇菜生长及生理指标的影响

采用盆栽试验法,对早开堇菜进行不同浓度NaC1溶液盐胁迫处理,测定盐胁迫下早开堇菜的生长及叶片中丙二醛(MDA)含量、超氧化物歧化酶(SOD)和过氧化物酶(POD)活性等指标,以探讨其耐盐能力.结果表明:随盐浓度和盐胁迫时间的增加叶片萎蔫程度、黄化程度加剧;叶片中MDA含量和POD活性基本呈上升趋势,其中MDA缓慢上升;POD活性先缓慢上升、后大幅上升;SOD活性呈现先上升后下降趋势.综合各观测指标认为,早开堇菜有较强的耐盐性,可在含盐量4 mg/g以下的土壤中正常生长.     

三种瓜类子房发育初期可溶性糖、Pr及POD活性的变化

 黄瓜、西瓜、西葫芦经授粉或外源激素处理的子房和黄瓜未经处理的子房的可溶性糖和可溶性蛋白质(Pr) 含量, 花后4 d 比开花当天分别增加约1/ 2 和1 倍以上, 西瓜和西葫芦未处理子房则分别下降1/ 2 和3/ 4。子房POD 活性与子房发育呈明显负相关, POD 活性高时子房不膨大, 反之则子房发育迅速。     

Induction of resistance in Yali pear (Pyrus bretschneideri Rehd.) fruit against postharvest diseases by acibenzolar-S-methyl sprays on trees during fruit growth

The objective of this work was to evaluate how disease resistance in harvested fruit of Yali pears (Pyrus bretschneideri Rehd.) may be affected by acibenzolar-S-methyl (ASM) sprays on trees. Results showed that disease incidence and lesion diameter in mature pears from trees sprayed with ASM for three times during growth and inoculated with Penicillium expansum or Alternaria alternata after harvest were 27.9 and 42.7%, or 29.1 and 23.4% lower, respectively, than in control fruit 17 days after inoculation. Mature fruit from ASM-treated trees exhibited higher activities of defense enzymes including phenylalanine ammonia-lyase (PAL), chitinase and β-1,3-glucanase than in control at harvest. In young pears, activities of peroxidase, polyphenoloxidase, PAL, chitinase and β-1,3-glucanase were significantly enhanced by ASM after first spray on trees. The ASM spray also significantly increased H₂O₂ level and glutathione reductase activity, but reduced activities of catalase and ascorbate peroxidase in young pears. The study indicated that enhancement of disease resistance in harvested Yali pear fruit could be the result of multiple effects of several factors related to plant defenses induced by ASM sprays on trees during fruit growth. Application of ASM in the field holds great promise for controlling postharvest diseases of the fruit.     

红叶石楠生根培养与根系活力的研究

 以红叶石楠继代组培苗为试材, 研究了不同生长素( IAA、NAA和IBA) 、间苯三酚、暗培养、多效唑(MET) 以及培养基支持体对红叶石楠生根过程的影响。结果表明: NAA 015 mg·L ^{- 1}和暗培养7 d促进红叶石楠的生根; 培养基1/2MS +NAA 0.5 mg·L ^{- 1} + IBA 0.3 mg·L ^{- 1} +MET 0.5 mg·L ^{- 1}的处理使平均每株生根数达615条, 生根率达到90%; 以琼脂、蛭石、珍珠岩为培养基支持体诱导生根, 其中以珍珠岩为培养基支持体诱导效果最佳, 平均每株生根数达2318条, 生根率达96.6% , 移栽成活率达95.9% , 根系活力高达576.159μg·g^{- 1} ·h^{- 1} , 过氧化物酶( POD) 活性达到27.08 △A₄₇₀ ·min^{- 1} ·g^{- 1}。     

抗锈小麦新品系与感病品种甘麦8号的水杨酸含量和相关酶类活性的变化

抗锈小麦新品系89144接种锈菌后SA含量升高,同时CAT活性降低,H2O2含量升高,SOD活性升高,在不抗锈品种甘麦8号接种锈菌后SA含量也有升高,但并不伴随有CAT活性下降和SOD活性升高以及H2O2含量的升高.推测SA为CAT过氧化活性提供一个电子的过程中SA的量必须达到一定的阈值,并且与CAT的时序调节相配合.据SA结合态和游离态含量的变化     

西芹鲜根浸提液对黄瓜叶片内POD和CAT活性的影响

分别用乙醚、乙醇和水提取西芹鲜根内的化感物质,后于黄瓜幼苗第2片真叶展开且横宽4cm时,及其后第3d、第5d 3次处理(灌根)黄瓜幼苗,以3种空白溶液为对照,处理前2d和最后1次处理后第3d、第6d、第9d和第12d对黄瓜叶片内的过氧化物酶(POD)和过氧化氢酶(CAT)活性进行测定,试验结果表明:除乙醚浸提液处理后对黄瓜叶片内的POD活性与CK没有显著差异外,浓度为0.05g/ml和0.025g/ml的乙醇和水漫提液处理后黄瓜叶片内的POD和CAT活性都高于CK且差异均表现为极显著和显著水平,而蒸馏水、乙醇、乙醚浓度为0.0125g/ml的浸提液处理后黄瓜叶片内的POD和CAT与CK差异不显著.在浸提液浓度为0.025g/ml-0.05g/ml的范围内,黄瓜叶片内POD和CAT活性较对照差异最大.