不同用量纳米材料对生菜种子发芽的影响   总被引：1，自引：0，他引：1  

赖钰  汪瑞  李鑫  沈荣晨  刘浩林  孙光闻 《蔬菜》2019,(4):10-14

以意大利生菜和红脆香生菜种子为试验材料,研究不同用量石墨相氮化碳纳米材料(0、50、100、150、200 mg/L)对2种生菜种子萌发的影响。结果表明:纳米材料用量在50～150 mg/L时对2种生菜发芽势、发芽率、发芽指数均有促进作用,用量在100 mg/L时,意大利生菜的发芽率、发芽指数最高;用量在150 mg/L时,红脆香生菜发芽势、发芽率、发芽指数最高。纳米材料用量达到200 mg/L时,对生菜种子萌发的促进效果减小,甚至出现抑制萌发的现象。较高用量(150、200 mg/L)的纳米材料可以促进生菜胚根的伸长,用量在150 mg/L时,意大利生菜胚根最长,比对照(CK)增加了24.80%;用量在200 mg/L时,红脆香生菜胚根最长,比对照增加了37.20%。施加纳米材料对生菜胚芽长度的影响不显著。总之,纳米材料用量在50～150 mg/L时,可以促进生菜种子的萌发;较高用量(150、200 mg/L)的纳米材料可以促进生菜种子胚根的伸长;施加纳米材料对胚芽长的影响不显著。  相似文献   

Physiological Races and Vegetative Compatibility Groups of Fusarium oxysporum f. sp. lactucae Isolated from Crisphead Lettuce in Japan     

Hideki OGISO  Masashi FUJINAGA  Hideki SAITO  Toshiaki TAKEHARA  Shigeru YAMANAKA 《Journal of General Plant Pathology》2002,68(4):292-299

One hundred and sixteen isolates of Fusarium oxysporum f. sp. lactucae obtained from 85 fields in three crisphead lettuce-producing areas in Nagano Prefecture, Japan were typed for races using differential cultivars Patriot, Banchu Red Fire and Costa Rica No. 4. They were also grouped into vegetative compatibility groups (VCGs) using complementation tests with nitrate non-utilizing (nit) mutants. Two California strains reported as F. oxysporum f. sp. lactucum, a type culture of F. oxysporum f. sp. lactucae, and 28 avirulent isolates of F. oxysporum obtained from crisphead lettuce were included for comparison. Among Nagano isolates, 66 isolates were identified as race 1, and 50 as race 2. Race 1 strains derived from Shiojiri and Komoro cities and race 2 from Kawakami village and Komoro city. All isolates of race 2 were biotin auxotrophs, and the race could be distinguished based on its requirement for biotin on minimal nitrate agar medium (MM). Pathogenic isolates were classified into two VCGs and three heterokaryon self-incompatible isolates. Strong correlations were found between race and VCG. All the race 1 strains were assigned to VCG 1 except self-incompatible isolates, and all the race 2 strains to VCG 2. The 28 avirulent isolates of F. oxysporum were incompatible with VCG 1 and VCG 2. California strains was vegetatively compatible with VCG 1, and they were assigned to race 1. Based on vegetative compatibility, these two races of F. oxysporum f. sp. lactucae may be genetically distinct, and F. oxysporum f. sp. lactucae race 1 is identical to F. oxysporum f. sp. lactucum. Received 7 May 2002/ Accepted in revised form 6 September 2002  相似文献   

Movement of Xanthomonas campestris pv. vitians in the stems of lettuce and seed contamination     

J. D. Barak  S. T. Koike  R. L. Gilbertson † 《Plant pathology》2002,51(4):506-512

Xanthomonas campestris pv. vitians , the causal agent of bacterial leaf spot of lettuce (BLS), can be seedborne, but the mechanism by which the bacteria contaminates and/or infects lettuce seed is not known. In this study, the capacity of X. campestris pv. vitians to enter and translocate within the vascular system of lettuce plants was examined. The stems of 8- to 11-week-old lettuce plants were stab-inoculated, and movement of X. campestris pv. vitians was monitored at various intervals. At 4, 8, 12 and 16 h post-inoculation (hpi), X. campestris pv. vitians was recovered from 2 to 10 cm above (depending on stem length) and 2 cm below the inoculation site. Xanthomonas campestris pv. vitians was also recovered from surface-disinfested stem sections of spray-inoculated plants. Together, these results are consistent with X. campestris pv. vitians invading and moving systemically within the vascular system of lettuce plants. To investigate the mechanism of seed contamination, lettuce plants at the vegetative stage of growth were spray-inoculated with X. campestris pv. vitians and allowed to develop BLS. Seed collected from these plants had a 2% incidence of X. campestris pv. vitians external colonization, but no bacteria were recovered from within the seed.  相似文献   

Variation and distribution of virulence phenotypes of Bremia lactucae in natural populations of Lactuca serriola     

A. Lebeda†  I. Petr&#;elová 《Plant pathology》2004,53(3):316-324

During 1997–2000 the virulence variation and distribution of virulence phenotypes of Bremia lactucae (lettuce downy mildew) in natural populations of Lactuca serriola (prickly lettuce) were studied. Altogether 139 isolates of B. lactucae originating from the Czech Republic, France and Germany were examined for the presence of 27 virulence factors (v-factors) and their combinations. In the Czech population, 37 different v-phenotypes (P1–P37) of B. lactucae were found to occur on L. serriola . Most v-phenotypes were characterized by v-factors that match resistance ( Dm genes/R-factors) carried by L. serriola . A wide diversity of v-phenotypes was recorded every year, but most were rare and did not reappear in other populations of B. lactucae . The three v-phenotypes P21, P28 and P29 were most frequent and widely distributed. There was variation both between spatially isolated populations and within populations of the pathogen. Geographic differences in virulence were found for the southern parts of Moravia, where the phenotypic composition of pathogen populations was completely different from the remaining part of the area investigated. However, some populations had v-phenotypes similar to those of spatially distant populations in Moravia.  相似文献   

Critical comparison of the vanadomolybdate and the molybdenum blue methods for the analysis of phosphate in plant sap     

《Communications in Soil Science and Plant Analysis》2012,43(8):839-852

Abstract

The performance of the vanodomolybdate and molybdenum blue methods for the routine determination of phosphate in plant sap were compared in order to assess their suitability for the detection of P deficiency at an early stage of plant growth. The molybdenum blue method was ca 10 times more sensitive than the vanadomolybdate one and required less sap to give a successful test. Recoveries of phosphate added to both sap and solution samples were close to 100% with both methods. The methods were in good agreement over a wide range of phosphate concentrations using sap samples from all leaves during the early stages of P deficiency, but increases in sap background colour caused the vanadomolybdate method to overestimate phosphate concentrations as the deficiency became more acute. Measurements on solutions of similar absorbance showed that the vanadomolybdate method was not significantly more variable than the molybdenum blue method but tended to overestimate phosphate concentration when very small volumes of sap were available. It was concluded that the molybdenum blue method was the most reliable for routine measurements of phosphate in plant sap.  相似文献   

赤霉素(GA_3)对叶用莴苣抽薹特性的影响     

张润花  刘旭东  王斌才  周国林  黄兴学  汪爱华  林处发 《长江蔬菜》2016,(22):67-69

以叶用莴苣耐抽薹品种意大利生菜和易抽薹品种佰根绿为试验材料,采用营养钵基质栽培法,研究了外源GA_3处理对叶用莴苣抽薹特性(薹中心柱长、抽薹率)的影响。试验结果表明,GA_3可显著促进叶用莴苣抽薹,显著增加薹高及抽薹率,佰根绿的薹高、抽薹率分别是对照(不喷GA_3)的5.7倍、2.25倍,意大利生菜的薹高、抽薹率分别是对照的5.5倍、2.01倍,易抽薹品种的抽薹特性对GA_3的响应较为敏感。  相似文献   

生菜品种筛选试验     

何秉青  祝宁  齐长红  陈加和  陈明远  于静湜  蔡连卫  武雷  韩立红  陈永利  李忠明 《蔬菜》2021,(6):79-81

为了筛选出适合北京地区秋茬种植的生菜品种,对日光温室内定植的18个品种进行评比。通过在采收期比较各个品种的口感、外形及产量等指标,筛选出适宜当地种植的品种。结果表明:结球生菜中,产量和口感较优的品种有北生3号和北生4号;散叶生菜中,产量和口感较优的品种有北散生4号、特波斯和北散生2号等;适宜观赏的生菜品种有富兰德里、大橡生2号、奶油红、脆叶绿和蒙黛。  相似文献   

巯基化坡缕石对碱性土壤镉污染的快速钝化修复效应   总被引：1，自引：1，他引：0  

何丽质  徐应明  宋常志  吴义茜  黄青青  梁学峰 《农业环境科学学报》2021,40(2):319-328

为了探究巯基化坡缕石作为钝化剂在镉污染碱性土壤上的适用性及应用潜力,选取典型镉污染碱性土壤,以青菜和生菜为模式作物开展盆栽试验和土壤培养试验,研究巯基化坡缕石对碱性土壤镉污染的快速钝化修复效应。结果表明：巯基化坡缕石在应用剂量为0.1%~0.3%（m/m）时可以使生育期内青菜地上部镉含量降低81.44%~93.44%,根系镉含量降低68.47%~85.63%,生菜地上部镉含量降低65.11%~92.18%,根系镉含量降低57.77%~91.92%。收获时可食部位镉含量满足国家食品卫生标准限量值要求,在极低的应用剂量下显著的钝化效应是其优势。巯基化坡缕石可使土壤DTPA浸提有效态镉含量降低68.57%~84.10%,钝化过程速度快,5 d左右达到平衡,可以用二级动力学拟合。连续浸提形态分析显示,巯基化坡缕石能够快速减少土壤中可交换态和碳酸盐结合态镉含量,并显著提高易还原金属氧化物结合态镉含量,使镉由活泼态向不活泼态转化,从而减少作物吸收累积。巯基化坡缕石同时抑制了青菜和生菜对镉的转运系数和生物累积系数,进一步降低了可食部位镉含量。研究表明巯基化坡缕石是一种在镉污染碱性土壤上具有快速钝化作用和良好应用潜力的高效钝化剂。  相似文献   

含氨基酸水溶肥料和EM微生物菌剂对设施莴笋生长和品质的影响   总被引：1，自引：0，他引：1  

王东升  王蓓  孙菲菲  李伟明  吴旭东  刘庆叶  陈莉莉  周晓平  陈奎礼  黄忠阳 《土壤》2020,52(4):796-801

以莴笋为供试材料,研究在莴笋叶面喷施、根部灌施EM微生物菌剂和含氨基酸水溶肥料对其植株生长、光合特性、产量和果实品质的影响。本试验设4个处理:不施用任何肥料(CK)、常规施肥处理(T1)、喷施+灌施EM微生物菌剂(T2)、喷施+灌施含氨基酸水溶肥料(T3)。试验结果表明:与对照CK相比,喷施+灌施EM微生物菌剂和喷施+灌施含氨基酸水溶肥料能显著提高莴笋的株高和茎粗,有效促进作物的生长;从光合特性看,T3处理的光合速率、气孔导度、胞间CO2浓度和蒸腾速率均显著优于对照CK,和常规施肥T1相比也有明显提高,说明喷施+灌施含氨基酸水溶肥料能提高莴笋的光合作用。产量上,T3T2T1CK,T1、T2和T3的产量相较于CK的增长幅度分别为20.17%、26.05%、31.65%,T2和T3相较于T1的增长幅度分别达到4.90%和9.99%,T3相较于T2的增长幅度为4.44%,表明EM微生物菌剂和含氨基酸水溶肥料均能提高莴笋的产量,而含氨基酸水溶肥料的效果更佳。  相似文献   

Effects of Coconut Husk and Sphagnum Moss-Based Media on Growth and Yield of Romaine and Buttercrunch Lettuce (Lactuca Sativa) in a Non-Circulating Hydroponics System     

Norman Q. Arancon  Nicholas Schaffer  Chad E. Converse 《Journal of plant nutrition》2015,38(8):1218-1230

A comparison was made to investigate the effects of two potting methods: coconut husk/ sphagnum moss and a plastic forestry tube with a peat-based medium (Sunshine® mix #1, Sungro Horticulture, Agawam, MA, USA), on the growth and yield of Romaine ‘Ridgeline’ and Buttercrunch ‘UH Manoa’ lettuce (Lactuca sativa) using a non-circulating hydroponics system. Two-week old lettuce seedlings were transplanted into 5 cm holes, 20 × 30 cm apart on polystyrene bead boards fitted on top of a 0.6 m wide, 1.2 m long and 25 cm deep hydroponics tanks. A standard hydroponics nutrient solution was prepared using Chem Gro® (Hydro-Gardens, Colorado Springs, CO) (8-15-36 + micronutrients), calcium nitrate [Ca(NO₃)₂] and magnesium sulfate (MgSO₄). Each tank contained either one lettuce variety, replicated 12 times in completely randomized design. Growth and yields significantly increased in both lettuce varieties grown in coconut husk/sphagnum moss plugs which were attributed by their relatively greater water holding capacities and a more favorable media that allowed better root growth.  相似文献