改良剂对柴油污染土壤中黑麦草生理代谢的调节

开展了土壤柴油污染的单因素盆栽实验和柴油污染盐渍化土壤中添加锯末-硝酸铵-磷酸二氢钾的三因素正交盆栽实验,对黑麦草幼苗抗氧化酶活性和叶绿素含量进行了分析,探究了柴油污染土壤中黑麦草幼苗的生理变化与调节。结果表明,土壤柴油污染显著减小了黑麦草幼苗生物量,与对照相比,叶SOD活性在柴油浓度0.3%和0.9%时显著降低,POD和CAT活性在0.6%和0.9%柴油浓度下显著降低;根SOD活性在0.9%柴油浓度下显著增大,POD活性在0.6%和0.9%柴油浓度下显著下降。受柴油污染的盐渍化土壤,施加锯末体积分数为10%时,黑麦草幼苗叶POD和CAT活性显著增强,叶绿素a和叶绿素b含量显著增加;施氮量为0.3 g·kg^-1土时,黑麦草幼苗叶绿素a和叶绿素b含量显著增加。可见,土壤受柴油污染时,添加锯末和硝酸铵可有效调节黑麦草幼苗的生理代谢。     

炭疽叶枯病菌诱导的不同苹果种质中防御酶活性及丙二醛含量比较

以苹果品种‘秦冠’、‘富士’及二者的杂交种‘QF-2’为试材,室内接种炭疽叶枯病菌,发现前者表现为感病,后二者均表现为抗病.接种后的0~4 d内,寄主叶片内的SOD、POD、CAT活性均出现先升高后降低的趋势,在接种1 d后出现峰值,且在抗病种质上明显高于感病种质.PPO活性在接种后也是呈现先上升后下降的趋势,但感病种质'秦冠'的上升速度较快,峰值出现较早.对三份种质来说,受病原菌的诱导,MDA含量均在接种1 d后达到高峰,然后缓慢下降,但其含量变化与种质间的抗性水平差异没有明显的相关性.     

Alleviation of Salt Stress in Durum Wheat (Triticum durum L.) Seedlings Through the Application of Liquid Seaweed Extracts of Fucus spiralis

Many research studies have shown the importance of seaweed extract (SWE) in alleviating stress damage to plants. In this study, we examined the effect of liquid SWEs made from brown seaweed, Fucus spiralis, on germination, growth, antioxidant enzymes and some biochemical attributes of durum wheat under different levels of NaCl concentrations. Application of SWE at different concentrations (5, 10, 25, and 50%) significantly enhanced seed germination and growth parameters under salt stress, especially with 25% of seaweed liquid extract. Results show that the activity of antioxidant enzymes increased with increasing the algal extract concentration to 50%. Therefore, algal treatment is proved to be an effective technique to improve the growth of wheat seedlings under salt stress conditions. This study provides important information on the identification and utilization of seaweed resources for agriculture and it is the first study to report on the uses of this macroalgae as biostimulants in agriculture.

Abbreviations TG: total germination (%); SL: shoot length (cm); SFW: seedling fresh weight (g); SDW: seedling dry weight (g); TC: total carotenoids (mg/g.FW); TSP: total soluble proteins (mg/g.FW); SSC: soluble sugars content (mg/g.FW); TPC: (µg equivalent AG/mg DW); CAT: catalase (U mg^?1 protein); SOD: superoxide dismutase (U mg^?1 protein); APX: ascorbate peroxydase (U mg^?1 protein).     

Identification of Minimum Data Set Under Balanced Fertilization for Sustainable Rice Production and Maintaining Soil Quality in Alluvial Soils of Eastern India

The scarcity of non-renewable fertilizers resources and the consequences of climate change can dramatically influence the food security of future generation. Introduction of high yielding varieties, intensive cropping sequence and increasing demand of food grains day-by-day, application of recommended dose of fertilizers could not fulfill our targets due to outdated fertilizers recommendations are yet in practice. It not only alters soil quality, nutrient balance, microbial and enzymatic ecology but also affected productivity and sustainability of rice in Gangetic alluvial soils of India. The effect of fertilizers application based on “fertilizing the soil versus fertilizing the crop” which insure real balance between the applied and available soil nutrient is urgently needed. Hence, the present study was conducted during three consecutive crop seasons (2010, 2011, and 2012) to assess the effect of imbalance and balance fertilization based on initial soil test values and targeted yields, and to determine the effect of farmyard manure (FYM) when superimposed with balanced fertilizers on identification of minimum data set for the development soil quality, nutrient acquisition, and grain yield of rice. The six fertilizer treatments were laid out in a randomized block design with three replications. The treatments were: T₁-control (no fertilization), T₂-farmyard manure @ 5 t ha^?1, T₃-farmers practice (60:30:30 kg N:P₂O₅:K₂O ha^?1), T₄-precise application of mineral fertilizers based on initial soil test values (77:24:46 kg N:P₂O₅:K₂O ha^?1) for targeted grain yield of 4.0 t ha^?1, T₅-precise application of mineral fertilizers based on initial soil test values (74:23:43 kg N:P₂O₅:K₂O ha^?1) plus FYM (5 t ha^?1) for targeted grain yield of 4.0 t ha^?1 and T₆-precise application of mineral fertilizers based on initial soil test values (135:34:65 kg N:P₂O₅:K₂O ha^?1) for targeted rice grain yield of 5.0 t ha^?1. Result revealed that the targeted rice grain yield of 4.0 and 5.0 t ha^?1 was achieved in T₄ and T₆ treatments with 1.59% (4.06 t ha^?1) and –3.40% (4.83 t ha^?1) deviations, respectively. T₄, T_5, and T₆ significantly increased crop growth, nutrient uptake, available P (P_a) and K (K_a) and augmented rice grain yield by 10.6, 20.2 and 31.6%, respectively, over T₃. Microbial biomass carbon, soil respiration and enzymatic activity were enhanced significantly in T₅ as compared to T₆. Highest soil quality index was found in T₅ (0.95) followed by T₆ (0.90) and, lowest was in T₁ (0.63). The contribution of minimum data set (MDS) toward the SQI was in the descending order of ALP (30.6%) > SOC (21.5%) > K_a (11.3%) > PSM (9.68%) > N_a (8.51%). Overall, rice yield and soil quality was improved by using balance fertilization based on fertilizing the crop Vs fertilizing the soil in alluvial soils of India.     

DEHP对土壤蚯蚓氧化胁迫及DNA损伤的研究

土壤环境中的酞酸酯污染日益严重,为了探讨和分析典型酞酸酯邻苯二甲酸二(2-乙基己基)酯(Di(2-ethylhexyl)phthalate,DEHP)对土壤动物的生态毒理效应,以赤子爱胜蚓为指示生物,暴露于DEHP浓度为CK、0.1、1、10、50 mg kg~(-1)人工土壤中,并于染毒后的7、14、21、28d取样测定。通过蚯蚓体内的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物(POD)、谷胱甘肽转移酶(GST)等指标反映DEHP对蚯蚓的氧化激活程度,通过活性氧自由基(ROS)的含量反映DEHP对蚯蚓的细胞毒性,通过丙二醛(MDA)含量和Olive尾矩反映DEHP对蚯蚓的遗传毒性,从多个角度评价DEHP对蚯蚓的生态毒理效应。结果表明:(1)在DEHP的刺激下,各浓度组蚯蚓的SOD、CAT、POD、GST活性均呈激活状态,表明DEHP对蚯蚓的抗氧化酶有诱导作用;(2)DEHP影响蚯蚓的ROS含量,各染毒处理组与对照组相比均升高且差异性明显,表现出明显的剂量—效应关系;(3)对比各染毒处理组之间的数据,DEHP对蚯蚓MDA含量的影响无明显规律;(4)DEHP可使蚯蚓GST呈激活状态,表明中高浓度的DEHP对蚯蚓GST具有诱导作用;(5)DEHP能够引起蚯蚓体腔细胞DNA的损伤,且随着浓度的增加,Olive尾矩值随之增加,说明DNA损伤程度与DEHP浓度之间具有剂量-效应关系。从实验结果可以看出,DEHP可以对蚯蚓机体和DNA造成一定程度的损伤,表现出较强的生态毒理效应。     

Evaluation of sunflower (Helianthus annuus L.) single cross hybrids under heat stress condition

Sunflower is an important oilseed crop, which shows susceptibility to heat stress. In this study, 63 single cross hybrids were evaluated under heat stress condition for 2 years and compared with the two commercial hybrids. Genotype and genotype × environment (GGE) was used to differentiate single cross hybrids on the basis of multiple traits. GGE biplot showed that several single cross hybrids had higher seed yield potential than standard check. Moreover, seed yield per plant (SYP) was related to pollen viability percentage, showing that achene yield was the product of high gametophytic fertility under heat stress. Hybrids having high seed yield potential under heat stress had lower cell membrane injury. GGE biplot for SYP and its components showed that single cross hybrids were characterized into two major groups. Group I was further characterized into two sub group. Group Ia included hybrids with high 100-SW, while group Ib had the hybrids with high number of seeds per head and head diameter. Group II had the hybrids with high kernel weight and kernel to seed ratio. The hybrids could be recommended according to their potential utilization in the seed industry.     

壳聚糖和抗坏血酸复合处理提高台湾青枣采后保鲜效果

为了延长台湾青枣(Ziziphus mauritiana Lam.)的采后保鲜时间,基于抗坏血酸(ascorbic acid,As A)可提高果实抗氧化能力,壳聚糖涂膜处理能防止果实失水和微生物侵染,该文探讨抗坏血酸、壳聚糖涂膜及抗坏血酸和壳聚糖复合处理对台湾青枣(Ziziphus mauritiana Lam.)采后保鲜效果的影响.果实采收后当天,分别用30.0mmol/L抗坏血酸浸泡处理、8g/L壳聚糖涂膜以及30.0mmol/L抗坏血酸浸泡后并用8g/L壳聚糖涂膜复合处理,以双蒸水浸泡处理为对照,处理结束后,置于(25±1)℃和90%~95%相对湿度下贮藏,定期测定果实相关生理参数,扫描电镜观察果皮果实组织结构.结果表明,与对照相比,抗坏血酸或壳聚糖单独处理虽然对台湾青枣保鲜有一定效果,但复合处理后保鲜效果更好.表现为显著减少果实失水率和相对电导率(P<0.05),抑制果皮叶绿素降解及果实果胶酶和多聚半乳糖醛酸酶活性增加,降低原果胶分解成可溶性果胶的速率(P<0.05),使果实硬度和细胞完整性得以维持;延缓果实超氧化物歧化酶(superoxide dismutase,SOD)和过氧化氢酶(catalase,CAT)活性下降,降低膜脂氧化速率,果实过氧化氢和膜脂过氧化产物丙二醛含量显著下降(P<0.05);维持果实较高的可溶性固形物(total soluble solids,SS)、可溶性总糖(total soluble sugar,TSS)、可滴定酸(titratable acidity,TA)、谷胱甘肽(glutathione,GSH)及抗坏血酸含量.研究结果说明,抗坏血酸和壳聚糖复合处理可提高台湾青枣贮藏过程中的抗氧化能力,降低氧化伤害;降低果实失水率,减缓果皮叶绿素降解速率,延缓细胞降解和软化速率,维持果实细胞完整性,降低果实的腐烂率,从而达到延长采后果实保鲜的效果.     

Morpho-physiological and biochemical response of maize (Zea mays L.) plants fertilized with nano-iron (Fe3O4) micronutrient

Nano-sized formulations of micronutrient iron (Fe) were found to substantially alter the growth and metabolism of maize plants. Plants fertilized with the optimal recommended dose of Fe in the nano-form (54 μM) registered an enhancement in morphological features, viz. plant height, biomass (shoot and root), and diminution in antioxidant enzyme activities than the plants fertilized with the sub-optimal dose of Fe in the macroform (salts). However, half of the recommended dosage of Fe (27 μM) in the nano-form positively influenced leaf area and proline content of plants too. This indicated that there is a possibility of reducing the dose of Fe supplement for plants in the nano-form to increase the nutrient use efficiency in a major cereal crop like maize. This may open a new era in plant nutrient management with a scope for improvement in nutrient use efficiency using nano-nutrient formulations.     

微生物砂浆防护粉土坡面的强度与抗侵蚀性影响因素分析

微生物砂浆表面防护处理是处理粉土边坡扬尘与水流侵蚀问题的新技术。采用微生物砂浆层对粉土表面进行防护处理试验,通过微型贯入试验、水稳定性试验以及模拟降雨冲刷试验,分析了微生物砂浆防护层厚度、CaCl_2和尿素混合胶结溶液浓度、喷洒处理遍数等参数变化对微生物砂浆表面防护层的强度、水稳定性和土壤剥蚀率等性能的影响规律。结果表明,微型贯入仪可用于微生物砂浆表面防护层的强度测定,防护层的强度、水稳定性随胶结溶液浓度和喷洒处理遍数的增长而提高,最小有效厚度为5 mm。采用浓度为0.50 mol/L胶结溶液喷洒4遍,厚5 mm的防护层能够达到贯入阻力310 kPa,防护强度比77.5,崩解率2.3%,浸水强度损失率5.4%,具备较高的强度和较好的抗崩解性与强度水稳定性。粉土边坡在微生物砂浆防护前后,土壤剥蚀率能够从大于29.6降至6.8 g/(m~2·s)以下。该研究表明,微生物砂浆层用于粉土表面防护具有较好的抗冲刷性;微生物诱导结晶的方解石形成包裹砂颗粒的胶结微结构,能够使表面防护砂浆层具备良好的抗水流侵蚀性。     

Increased iron level in phytase-supplemented diets reduces performance and nutrient utilisation in broiler chickens

1. The effect of different levels of dietary iron on phytase activity and its subsequent effect on broiler performance were investigated in a 3 × 2 factorial arrangement. A total of 360 day-old Ross 308 male broiler chicks were distributed to 6 experimental diets, formulated with three levels of Fe (60, 80 and 100 mg/kg) and two levels of phytase (0 and 500 FTU/kg).

2. Phytase supplemented to mid-Fe diets increased feed consumption more than the non-supplemented diet at d 24. From hatch to d 35, Fe × phytase interaction significantly influenced the feed intake (FI), body weight gain (BWG) and feed conversion ratio (FCR). The high-Fe diet supplemented with phytase significantly reduced FI and BWG of broilers than those supplemented with low- or mid-Fe diets. The overall FCR was significantly better in birds fed on the mid-Fe diets with phytase supplementation.

3. A significant improvement in ileal digestibility of N, P, Mg and Fe was observed in birds feed diets containing 60 mg Fe/kg, with significant interaction between Fe and phytase.

4. Phytase improved the bone breaking strength when supplemented to low- or mid-Fe diets, compared to the non-supplemented diets. There was a significant Fe × phytase interaction effect. Tibia Fe content was higher in birds fed on phytase-free diets with high Fe but the reverse was the case when phytase was added and their interaction was significant. High dietary Fe significantly increased the accumulation of Fe in liver.

5. Phytase improved Ca-Mg-ATPase, Ca-ATPase and Mg-ATPase activities in jejunum when supplemented to the diet containing 80 mg Fe/kg.

6. This study indicates that high (100 mg/kg) dietary Fe inhibited phytase efficacy and subsequently reduced the overall performance and nutrient utilisation of broilers.