8个水培叶用莴苣品种比较

【目的】为了筛选出适宜水培生产的叶用莴苣品种。【方法】设置产量、形态、营养、风味4个维度指标,通过隶属函数法综合评价8个水培叶用莴苣品种优劣。【结果】单株质量最大的是‘橡叶绿’,净菜率最高的是‘巴达维亚’。形态表现最优的是‘奶油红’,综合营养品质最好的是‘奶油红’,风味口感最好的是‘西班牙绿’。‘小奶油绿’的综合隶属函数值最高,为0.605 1;‘橡叶红’的综合隶属函数值最低,为0.324 6。【结论】‘小奶油绿’、‘橡叶绿’是较适宜水培生产条件的叶用莴苣品种,‘橡叶红’、‘脆叶绿’相对不适宜本试验中的水培生产条件。     

水培叶用莴苣叶片矿质元素和氨基酸分析

【目的】分析8种水培叶用莴苣叶片的矿质元素和氨基酸,为水培叶用莴苣资源的开发与利用提供理论依据。【方法】采用全谱直读等离子体发射光谱仪和全自动氨基酸分析仪,对大棚内水培的8种叶用莴苣叶片的9种矿质元素和17种氨基酸含量进行分析。【结果】水培叶用莴苣矿质元素和氨基酸含量丰富且在不同品种间差异较大。常量元素方面,钠元素含量波动较小,为40.46～67.85 mg/kg,钾、钙、磷等元素的含量波动较大,特别是钾元素,为742.33～1 433.00 mg/kg。微量元素方面,8种水培叶用莴苣的锰、锌元素含量较高,在1.41～3.48 mg/kg,铜元素的含量最低,在0.14～0.24 mg/kg。8种水培叶用莴苣的氨基酸含量丰富,人体必需氨基酸含量比例E/T值在41.90%～55.57%,人体必需氨基酸含量与非必需氨基酸含量之比E/N值在0.60～1.10,基本符合FAO/WHO关于理想蛋白质的要求。【结论】8个水培叶用莴苣品种的氨基酸种类及矿质元素含量丰富,是人体补充矿质元素和平衡氨基酸营养的优质食物源,其中‘奶油红’品种相较于其他品种而言,营养价值更高,可在食品和保健品方面进一步开发。     

不同浮板形式对静止浮板水培叶用莴苣生长的影响

研究了不同浮板形式对静止浮板水培叶用莴苣(Lactuca sativa L.)生长的影响,结果表明,使用上、下厚度均为2 cm的双层浮板栽培叶用莴苣效果最好。其株型较大,株高26.72 cm,开展度32.15 cm,茎粗10.90 mm,叶片数9.81片,叶长23.56 cm,叶宽14.63 cm,叶面积229.78 cm~2,根体积9.54 cm~3;生物积累量高,冠鲜质量为47.51 g,根鲜质量9.48 g,总鲜质量56.99 g,冠干质量3.037 0 g,根干质量0.935 3 g,总干质量3.972 3 g;营养品质与常规灯芯式深水培相近。因此,进行叶用莴苣静止浮板水培,可以使用上层厚2 cm,定植孔直径2 cm,下层厚2 cm,定植孔直径5 cm的双层浮板。     

大豆蛋白肽对水培叶用莴苣硝酸盐含量的影响

以叶用莴苣为试验材料,采用深液静止水培技术,在营养液中添加不同浓度的大豆蛋白肽,分析其对叶用莴苣的生长发育、硝酸盐含量、产量及品质的影响。结果表明,在营养液中添加大豆蛋白肽浓度为1/1 000的处理,能促进叶用莴苣的生长发育,产量为11.69 kg·m-2,比CK提高28%;其硝酸盐含量为699.37 mg·kg-1,显著低于其他处理;大豆蛋白肽提高了叶用莴苣VC的含量,改善了叶用莴苣的品质。     

不同氮素水平处理对水培叶用莴苣生长及生理特性的影响

以‘意大利耐抽薹’叶用莴苣为试材,研究了4种不同氮素水平处理(0.00 mmol∕L、3.25 mmol∕L、6.50 mmol∕L、9.75 mmol∕L)对水培叶用莴苣生长及生理特性的影响。结果表明:在6.50 mmol∕L的氮素水平处理(T2)下,水培叶用莴苣的地上部及地下部鲜干重和叶面积显著提高,光合气体交换参数的净光合速率P_n、蒸腾速率T_r、胞间CO₂浓度Ci及气孔导度G_s与其他处理相比均显著增加,叶绿素荧光动力学参数F_m、F_v∕F_m、Y(Ⅱ)及可溶性糖、可溶性蛋白含量提高,F₀值、丙二醛含量、过氧化物酶活性降低;在9.75 mmol∕L的氮素水平处理(T3)下,水培叶用莴苣的叶绿素a、叶绿素b、类胡萝卜素、光合色素含量显著高于其他处理,提高氮素水平有利于叶绿体色素积累。本研究初步探究了水培叶用莴苣氮素胁迫的适应性机制,可为水培叶用莴苣的氮素合理施用提供参考。     

绿色叶用莴苣优质高效栽培关键技术

叶用莴苣生长期短、病虫害少、易栽培,是安全、高效的优质蔬菜。近年来,由于经济效益好、发展前景广阔,山东省叶用莴苣种植面积、产量逐年递升,在农业增效和农民增收中发挥了重要作用。本文作者从产地选择、栽培条件、优选良种、精耕细作、施足基肥、醒种催芽、炼苗、温度管理、肥水管理、提升商品性等方面总结了叶用莴苣优质高效栽培关键技术要点,以期对绿色叶用莴苣产业发展提供技术参考。     

不同浓度营养液对水培莴苣的影响

为筛选出比较适合东北温室水培莴苣生长发育的营养液浓度,采用浮板式水培的方法,以美国大速生菜为材料,试验设3个处理、1个对照、3次重复,研究在莴苣生长发育过程中,不同浓度营养液对莴苣的株高、根重、叶重和干重的影响。结果表明:EC值为2.6mS.cm-1的营养液浓度比较适合莴苣生长。     

贵州夏秋反季节叶用莴苣无公害栽培技术

叶用莴苣又名生菜,质脆嫩,味微苦,蛋白质、维生素C含量较高,还含有甘露醇、莴苣素等物质,是一种低热量、营养丰富的蔬菜。近年来,在大中城市郊区发展迅速,贵州夏秋反季栽培面积也逐渐增加。为了适应市场对无公害蔬菜需求,我们通过近年来的试验,总结出一套贵州夏秋反季节叶用莴苣无公害栽培技术应用于生产。1选择适宜的环境条件以土层疏松透气、富含有机质、保水保肥力强、排灌方便的壤土或砂壤土最适宜。叶用莴苣喜冷凉,忌高温。种子发芽最低温度为4℃,适宜温度为15~20℃,30℃以上发芽受抑制;幼苗生长适宜温度为16~20℃;结球期适宜温度为白…     

不同品种半结球叶用莴苣抽薹特性分析

[目的]为了探明莴苣抽薹过程中的生理学基础,实现叶用莴苣的周年生产提供理论依据.[方法]采用高温33℃/25℃(日/夜)处理,研究5个品种的抽薹性,及抽薹过程中的农艺性状.[结果]根据茎尖花芽分化情况以及茎长快速伸长的时期,发现五种半结球叶用莴苣的耐抽薹性强弱依次是GB-25、GB-23、GB-26、GB-31、GB-30;半结球叶用莴苣的株高与抽薹性呈显著负相关关系.[结论]结果表明,GB-25、GB-23为耐抽薹品种,GB-31、GB-30为易抽薹品种,GB-26介于两者之间.耐抽薹性越强的品种株高增长得越迟缓.     

莴苣立柱盆式水培技术

介绍了莴苣立柱盆式水培设施的结构与建造,阐述了莴苣立柱盆式水培的技术要点,为莴苣优质、高效生产和发展观光农业开辟了一条可行途径。     

DA-6对水培生菜生长及生理特性的影响

在山崎生菜营养液中添加5个不同浓度(0、20、100、500、1000μg·L-1)的高能植物生长调节剂DA-6,研究其对生菜生长及生理特性的影响。结果表明:随着DA-6浓度的增加,生菜的生物量和根系指标呈先增加后降低的趋势。100μg·L-1DA-6处理较其他处理提升了根系活力,并显著增加了生菜地上部干鲜重和根系干鲜重,增幅分别达到33.58%~742.86%、11.56%~286.79%、18.60%~264.29%和11.12%~267.83%。高浓度1000μg·L-1DA-6处理较对照处理降低了生菜生物量和根系活力。不同浓度的DA-6对生菜各项品质指标影响不同,随着DA-6浓度的增加,生菜中硝酸盐含量先降低后升高,但抗坏血酸、可溶性糖和可溶性蛋白含量则先增加后减少。100μg·L-1DA-6处理生菜硝酸盐含量较对照处理显著降低了23.40%,而抗坏血酸、可溶性糖和可溶性蛋白含量分别较对照处理显著增加了24.24%、64.29%和22.92%。此外,100μg·L-1DA-6提高了生菜叶片SOD、POD和CAT活性,降低了MDA含量,增加了叶片SPAD值,提升了光合和叶绿素荧光特性。在该试验条件下,推荐水培生菜营养液中添加浓度100μg·L-1DA-6,既保证了水培生菜的高产又提升了品质。     

Effects of ozone-treated domestic sludge on hydroponic lettuce growth and nutrition

Here, the ozone-treated domestic sludge was diluted up to four different multiples and utilized as a nutritional source for hydroponic lettuce growth. Additionally, lettuce was cultured using the modified Hoagland nutrient solution as a control. The effects of ozone-treated domestic sludge on lettuce growth and nutrition were studied. Results showed that the lettuce treated with modified Hoagland inorganic nutrient solution had increased leaf number, plant height, fresh weight and dry weight compared to those treated with the ozone-treated domestic sludge dilution (P<0.05). However, the lettuce cultivated with the 2-fold ozone-treated sludge dilution showed significantly higher (P<0.05) contents of chlorophyll, soluble sugar and ascorbic acid (Vc) compared to that treated with modified Hoagland nutrient solution. And the nitrate concentration in the lettuce cultured with the 2-fold ozone-treated sludge dilution was 53.93% less than that cultured with the modified Hoagland nutrient solution, which was a significant improvement (P<0.05). This study suggested that the 2-fold ozone-treated sludge dilution is optimal for lettuce hydroponic nutrient requirements.     

钾浓度对水培生菜生长及矿质元素动态吸收的影响

【目的】研究不同浓度钾对水培生菜生长、品质、矿质元素利用效率以及矿质元素动态吸收的影响,以期筛选出适宜生菜生长的钾浓度。【方法】2014年3-5月,采用水培试验,设置5个不同的钾浓度(6,5,4,3,2mmol/L)处理生菜,在生菜生育期每隔10d测定1次生长指标,在收获后测定生菜品质,并计算生菜对不同矿质元素的利用效率,同时测定营养液中氮、磷、钾、钙、镁的浓度变化,以分析各阶段生菜对矿质元素的吸收情况。【结果】当钾浓度为2~6mmol/L时,生菜叶面积、根干(鲜)质量、地上部分干(鲜)质量、根冠比均随钾浓度的增加先增大后减小,当钾浓度为3mmol/L时,生菜以上生长指标均较大;随着钾浓度的增加,生菜硝酸盐、可溶性糖、可溶性蛋白含量均先增大后减小,Vc含量不断增大,其中当钾浓度为4mmol/L时,生菜的综合品质最好。各处理生菜总干物质积累量在整个生育期不断增大且差异越来越明显,其中3~4mmol/L钾素处理生菜收获时干质量明显高于其他处理,不同钾素处理生菜对氮、磷的吸收都是在第三阶段(05-03-05-13)达到最大,在其他生育阶段吸收较少;对钾的吸收量呈不断增加的趋势;对钙镁的吸收在整个生育阶段都较均匀,其中在第三阶段(05-03-05-13)吸收强度略有增加。较低的钾浓度处理(2~4mmol/L)生菜对矿质元素的利用效率均较高。【结论】当钾浓度为4mmol/L时,有利于生菜生长,获得较好的产量及品质,且矿质元素利用效率较高。     

不同氮磷钾水平对水培生菜产量和品质的影响

为了研究氮磷钾对水培生菜(Lactuck sativa L.var.ramosa Hort.)产量和品质的影响,分别对氮磷钾设置5个浓度梯度,在收获时测定生菜的产量和维生素C、硝酸盐、可溶性糖以及可溶性蛋白等品质指标.结果发现,随着氮素水平从3.0 mmol/L增加到9.0 mmol/L,生菜的产量、维生素C、硝酸盐、可溶性糖以及可溶性蛋白都呈现出先增大后减小的趋势;磷素水平从0.2 mmol/L增加到1.0 mmol/L,生菜的产量和硝酸盐先增大后减小,可溶性糖和可溶性蛋白逐渐增大,维生素C逐渐减少;钾     

The positive function of selenium supplementation on reducing nitrate accumulation in hydroponic lettuce (Lactuca sativa L.)

High nitrate(NO_3~- ) in vegetables, especially in leaf vegetables poses threaten to human health. Selenium(Se) is an important element for maintaining human health, and exogenous Se application during vegetable and crop production is an effective way to prevent Se deficiency in human bodies. Exogenous Se shows positive function on plant growth and nutrition uptake under abiotic and/or biotic stresses. However, the influence of exogenous Se on NO_3~- accumulation in hydroponic vegetables is still not clear. In the present study, hydroponic lettuce plants were subjected to six different concentrations(0, 0.1, 0.5, 5, 10 and 50 μmol L–1) of Se as Na2 Se O3. The effects of Se on NO_3~- content, plant growth, and photosynthetic capacity of lettuce(Lactuca sativa L.) were investigated. The results showed that exogenous Se positively decreased NO_3~- content and this effect was concentration-dependent. The lowest NO_3~- content was obtained under 0.5 μmol L–1 Se treatment. The application of Se enhanced photosynthetic capacity by increasing the photosynthesis rate(Pn), stomatal conductance(Cs) and the transpiration efficiency(Tr) of lettuce. The transportation and assimilation of NO_3~- and activities of nitrogen metabolism enzymes in lettuce were also analysed. The NO_3~- efflux in the lettuce roots was markedly increased, but the efflux of NO_3~- from the root to the shoot was decreased after treated with exogenous Se. Moreover, Se application stimulated NO_3~- assimilation by enhancing nitrate reductase(NR), nitrite reductase(Ni R), glutamine synthetase(GS) and glutamate synthase enzyme(GOGAT) activities. These results provide direct evidence that exogenous Se shows positive function on decreasing NO_3~- accumulation via regulating the transport and enhancing activities of nitrogen metabolism enzyme in lettuce. We suggested that 0.5 μmol L–1 Se can be used to reduce NO_3~- content and increase hydroponic lettuce yield.     

七彩千年木水培技术研究

以七彩千年木为试材,采用水培法经过不同浓度萘乙酸(NAA)处理,进行清水、遮黑扦插等条件诱导水生根系试验,筛选诱导水生根系的最佳NAA浓度,再进行不同营养液(清水、1/4MS、Hoagland溶液、KC营养液、必绿水溶性肥料)的培养试验.结果表明:采用低浓度NAA短时间(1 d)处理可促进根系生长,NAA最佳诱导浓度为1 mg/L.在供试营养液中,Hoagland溶液对促进七彩千年木的生长发育效果最好.     

Automated system developed to control pH and concentration of nutrient solution evaluated in hydroponic lettuce production

Lettuce is one of the most widely consumed leaf vegetables. In hydroponic the growth depends upon the composition of nutrient solution. Due to its nutrient absorption, the conductivity and pH suffer continuous variations. This paper describes the development of a system completely managed by a lab-made software. It monitors the conductivity and pH throughout 24 h during the whole cycle of production. Also, allows adjust automatically any variation, through solenoid valves which dispense solutions of acid/base or nutrient. The efficiency of the proposed instrumentation was evaluated by simultaneously cultivation of same kind of lettuce (Vanda) in two different ways, hydroponics in greenhouse controlled with the developed devices, and grown conventionally in soil, adopted as referential. Agronomic and chemical parameters of commercial interest were analyzed for both crop, attesting the precocity in harvest (64 against 71 days) with reduced labor, better control and higher productivity, especially in fresh and dry matter of aerial parts, presenting 267.56 and 13.33 g plant⁻¹ respectively, using the developed system. The data sequence regarding the concentration of nutrients for the automated hydroponic system was similar to those obtained by the mentioned researchers, as follows: K > N > Ca > P > Mg > S > Fe > Zn > Mn > Cu. This similarity highlights the efficiency of controlling the parameters of conductivity and pH in the instrumental system applied to hydroponics, offering the producer an effective and viable alternative in the production of lettuce.     

基于转录组信息的叶用莴苣MADS-box转录因子家族分析

[目的]基于转录组数据鉴定分析叶用莴苣MADS-box基因家族,筛选高温促进叶用莴苣抽薹过程中MADS-box家族特异性表达的基因,以期为叶用莴苣高温诱导抽薹的分子机制鉴定提供理论依据.[方法]从叶用莴苣转录组数据中鉴定获得MADS-box家族转录因子并进行生物信息学分析,利用qRT-PCR技术分析叶用莴苣易抽薹品种'S39'在高温处理下MADS-box基因的表达模式.[结果]在叶用莴苣转录组中共鉴定到14个MADS-box转录因子,其编码的蛋白质含有212～253个氨基酸,蛋白质大小为24026.50～29380.16 Da,理论等电点范围为5.27～9.44,其中2个为稳定蛋白,12个属于不稳定蛋白,均为亲水性蛋白.亚细胞定位预测结果显示所有蛋白质均定位于细胞核.qRT-PCR结果表明,在高温处理下,LsMADS32表达量无显著规律;Ls-MADS16和LsMADS37表达总体呈下降趋势;LsMADS5,LsMADS14,LsMADS15,LsMADS29,LsMADS35,LsMADS39,LsMADS43,LsMADS45,LsMADS48,LsMADS54和LsMADS56表达趋势基本相同,呈先上升后下降趋势,LsMADS15在高温处理7d后达到峰值,其他基因在高温处理5d后达到峰值,其中LsMADS54在高温处理5d后骤升1000倍,LsMADS56在高温处理5d后骤升70倍.[结论]MADS-box家族中的部分成员可能与高温诱导抽薹密切相关,LsMADS54和LsMADS56是叶用莴苣响应高温诱导后抽薹开花调控网络中的潜在的重要转录因子.     

Selenium distribution and nitrate metabolism in hydroponic lettuce(Lactuca sativa L.): Effects of selenium forms and light spectra

A deficiency in selenium(Se) in the human diet is a worldwide problem. The intake of Se-rich vegetables can be a safe way to combat Se deficiency for humans. However, most leafy vegetables can accumulate a high content of nitrates, which poses a potential threat to human health. Light is an important environmental factor that regulates the uptake and distribution of mineral elements and nitrogen metabolism in plants. However, the effects of Se forms and light conditions, especially light spectra, on the uptake and translocation of Se and on nitrate reduction are poorly understood. In this study, lettuce(Lactuca sativa L.) was treated with exogenous Se applied as selenate(10 mmol L~(-1)) and selenite(0.5 mmol L~(-1)) and grown under five different light spectra: fluorescent light(FL), monochromatic red LED light(R), monochromatic blue LED light(B), and mixed red and blue LED light with a red to blue light ratio at 4(R/B=4), 8(R/B=8), and 12(R/B=12), respectively. The effects of light spectra and Se forms on plant growth, photosynthetic performance, Se accumulation and nitrate reduction were investigated. The results showed that the light spectra and Se forms had significant interactions for plant growth, foliar Se accumulation and nitrate reduction. The Se concentration and nitrate content in the leaves were negatively correlated with the percentage of red light from the light sources. Compared to Se applied as selenite, exogenous Se applied as selenate was more effective in reducing nitrate via promoting nitrate reductase and glutamate synthase activities. The lowest nitrate content and highest plant biomass were observed under R/B=8 for both the selenate and selenite treatments. The significant effect of the light spectra on the root concentration factor and translocation factor of Se resulted in marked variations in the Se concentrations in the roots and leaves. Compared with FL, red and blue LED light led to significant decreases in the foliar Se concentration. The results from this study suggest that the light spectra can contribute to Se distribution and accumulation to produce vegetables with better food quality.     

营养液培莴苣硝酸盐含量的控制方式与效果

以不同的营养液配方、营养液的不同浓度以及结合供营养液和断营养液对莴苣生长发育、产量、硝酸盐含量的影响进行研究,结果表明:不同的营养液配方、营养液的不同浓度对莴苣生长发育、产量的影响不大,对硝酸盐含量影响差异显著.断营养液间隔1周采收可有效地降低硝酸盐的积累,对产量影响不大.