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   

厌氧发酵残留物对土壤酶动态特性的影响     

苏有勇  戈振扬  施卫省 《农机化研究》2007,(6):94-97

通过温室盆栽生菜试验,研究厌氧发酵残留物对土壤蔗糖酶、脲酶、多酚氧化酶和中性磷酸酶动态特性以及作物产量的影响.试验以菜园土作为栽培基质,并以是否施用厌氧发酵残留物和种植作物进行设计,生菜种植期为50天,试验中间隔10天测定一次土壤酶活性.结果表明,施用厌氧发酵残留物能明显提高土壤酶的活性,且施用量越多,酶活性越高,生菜的产量也越高.栽种生菜的土壤酶活性高于相应的对照组,酶活性的变化基本和生菜的生长过程一致,在30～40天之间达到最高酶活性.土壤酶活性的提高表明,施用厌氧发酵残留物能改善土壤结构和性能,提高土壤的肥力和生产能力.  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   

Phenotypic and histological expression of different genetic backgrounds in interactions between lettuce, wild Lactuca spp., L. sativa × L. serriola hybrids and Bremia lactucae     

Aleš Lebeda  Michaela Sedlářová  James Lynn  David A. C. Pink 《European journal of plant pathology / European Foundation for Plant Pathology》2006,115(4):431-441

Phenotypic and histological responses of cultivated lettuce (Lactuca sativa) and wild relatives L. saligna, L.␣virosa as well as interspecific crosses derived from L. sativa × L. serriola to two races of Bremia lactucae (CS2, CS9) were investigated. With the exception of L. sativa genotypes, all accessions and hybrids expressed incomplete or complete resistance to both pathogen races, with slight differences at seedling and adult plant stages, respectively. Histological features of the interactions (development of pathogen infection structures and host hypersensitive response to attempted infection) were studied on leaf discs 48 h after inoculation. Interactions with similar phenotypic expression of resistance were characterized by significant variation in rate of development of pathogen infection structures and hypersensitive reactions. Differences found within eight Lactuca spp. accessions and hybrids challenged by two distinct pathogen races are interpreted and discussed.  相似文献   

Occurrence in Italy and characteristics of lettuce downy mildew (Bremia lactucae) resistant to phenylamide fungicides     

Laura Cobelli  Marina Collina  Agostino Brunelli 《European journal of plant pathology / European Foundation for Plant Pathology》1998,104(5):449-455

Control of lettuce downy mildew (Bremia lactucae) with phenylamide fungicides has failed in some intensive lettuce-producing areas in Northern Italy since Spring 1993. Before then, these chemicals and particularly metalaxyl, provided the best disease control. The sensitivity of Bremia lactucae isolates collected in such areas to metalaxyl was evaluated in the laboratory. These strains grew and sporulated profusely on lettuce seedlings treated with 100 and 200 ppm of metalaxyl, whereas sensitive control strains were completely inhibited when treated with fungicide concentrations ranging from 0.5–1 ppm. Thus in Italy occurrence of resistance to phenylamide fungicides in Bremia lactucae has also been demonstrated, as in almost all the countries where these chemicals were previously authorised. Subsequently, a demonstration of occurrence of resistance was made and the virulence pattern of several strains (resistant and sensitive to metalaxyl) was characterised using differential NL series containing the 13 DM resistant genes or R factors. The results suggest the occurrence of a new pathotype in Italy different from all the 16 NL Bremia lactucae races studied.  相似文献