植物在水分胁迫下脯氨酸积累的研究─—Ⅳ关于植物体内脯氨酸积累的直接触发因子     

马宗仁 《草业科学》1994,(1)

依据干旱胁迫下数种植物幼苗体内游离脯氨酸、叶气孔、叶水量的变化，剖析了植物与环境因子、气孔因子、氧气因子、酶因子及能量因子之间的相互依存关系，提出了ＰＲＯ积累系统（ＰＡＳ）。认为水分胁迫下植物体内ＰＲＯ的大量积累是氧化受抑和合成受激共同调控的结果。氧气最有可能为直接触发因子。  相似文献   

Markers, old and new, for examining Phytophthora infestans diversity   总被引：4，自引：1，他引：3  

D. E. L. Cooke†  A. K. Lees 《Plant pathology》2004,53(6):692-704

Late blight, caused by Phytophthora infestans , is an ongoing threat to potato and tomato crop production worldwide and considerable fundamental and applied research is conducted with the long-term aim of improved disease control. Understanding the mechanisms, processes and rates of P. infestans evolution is an important factor in predicting the effectiveness and durability of new management practices. A range of phenotypic and genotypic tests has been applied to achieve this goal, but each has limitations and new methods are sought. Recent progress in P. infestans genomics is providing the raw data for such methods and new high-throughput codominant biomolecular markers are currently being developed that have tremendous potential in the study of P. infestans population biology, epidemiology, ecology, genetics and evolution. This paper reviews some key applications, recommends some changes in approach and reports on the status and potential of new and existing methods for probing P. infestans genetic diversity.  相似文献   

灌水量对不同类型晚稻生育及产量影响的初步研究     

周瑞庆  萧光玉 《湖南农业大学学报(自然科学版)》1993,(Z1)

采取盆栽遮雨人工定量灌水的方法,探讨了常规晚稻和杂交晚稻前后两大生育时期不同灌水量对生育和产量的影响.结果表明:两类型晚稻品种前后两个生育时期节水灌溉都能达到高产之目的,但不同类型和不同生育时期的最佳灌水量和节水效果不同.  相似文献   

植物叶面铺展剂的复配规律Ⅰ.SDS和TX100混合水溶液体相及表面层相互作用行为     

赵剑曦  赵叔唏  李清禄  唐南琦 《福建农林大学学报(自然科学版)》1991,(4)

2种典型固体表面铺展剂SDS和TX100混合水溶液,无论在其表面层或在混合胶团中两组分之间均存在一定程度的相互作用,使得以廉价的SDS为主的溶液中加入少许TX100组成的复配体系表面活性提高,在植物叶面上的润湿性能改善,并从理论上计算了其相互作用参数,初步解释了实验现象,上述结果不仅对指导优良植物叶面铺展剂配方具有指导意义,也预示了潜在的实用价值.  相似文献   

Detection, identification and significance of phytoplasmas in grasses in northern Australia     

K. R. Blanche‡  L. T. T. Tran-Nguyen  K. S. Gibb† 《Plant pathology》2003,52(4):505-512

Sugarcane yields have been severely reduced by white leaf and grassy shoot phytoplasma diseases in many parts of Asia. Australian sugarcane crops are not known to be affected by these diseases, but plant pathogenic phytoplasmas found in other introduced and native grasses in northern Australia could pose a serious threat to the Australian sugarcane industry. To further evaluate this threat, leaves from plants of 20 grass species, with and without symptoms, were collected during field surveys in northern Australia and tested to determine whether phytoplasmas were present and whether symptoms were reliable indicators of phytoplasma presence. Molecular tools were used to detect and characterize phytoplasmas. Four different phytoplasmas were found in seven grass species known to grow near healthy sugarcane crops. All the phytoplasmas were closely related to sugarcane white leaf phytoplasma (SCWL), one of the phytoplasmas that causes disease in sugarcane in Asia. Four of the host plant species and two of the phytoplasmas were new records. The relationship between symptoms and phytoplasma presence was poor. Because some plants with symptoms tested negative for phytoplasmas, a series of surveys was carried out in which flowers, leaves, roots and stems of two known host plant species, Whiteochloa cymbiformis and Sorghum stipoideum, were tested separately on nine occasions during two wet seasons. This was done to investigate the distribution of phytoplasmas within plants over time. Results showed that spatial and temporal variation of phytoplasmas occurred in these two host plant species. Hence, evaluation of disease distribution within a region requires repeated testing of all plant parts from plants without symptoms, as well as those with symptoms. To date, there is no report of a vector capable of transmitting to Australian sugarcane the phytoplasmas found in grasses in this study. If one is present, or occurs in the future, then native and introduced grasses could constitute a large reservoir of phytoplasma for vectors to draw on. This work provides an early warning for the sugarcane industry that the potential for infection exists.  相似文献   

Analysis of Growth and Productivity of Indian Mustard (Brassica juncea) in Relation to FYM, Nitrogen and Source of Fertilizer     

R. H. Patel  T. G. Meisheri  J. R. Patel 《Journal of Agronomy and Crop Science》1996,177(1):1-8

A field experiment was conducted during the winter seasons of 1992–93 and 1993–94 at Anand to study the effect of FYM, nitrogen and source of fertilizer on growth and yield of mustard [ Brassica juncea (L.) Czernj & Cosson]. The results showed significant variation in leaf area index (LAI), crop growth rate (CGR), dry matter production and seed yield. The direct effect of farmyard manure (FYM) was conspicuous in improving the growth of mustard. FYM application at 10 tonnes ha⁻¹ significantly increased the LAI, CGR and dry matter accumulation per plant at almost all the stages during first year study (1992–93) and in pooled analysis. Similarly, nitrogen application registered maximum LAI, CGR at 75 kg level and RGR and NAR at 50 kg level at almost all the during both years. Sulphur carrying source (Ammonium sulphate plus single super phosphate) increased all stages growth characters. Maximum dry matter accumulation per plant and seed yield were recorded with highest levels of FYM (20 tonnes ha⁻¹), N (75 kg ha⁻¹) and source having S. Seed yield was strongly associated with LAI and dry matter accumulation per plant at all the stages.  相似文献   

一次防治大豆灰斑病籽粒灰斑   总被引：1，自引：1，他引：0  

刘学敏  李利军 《东北农业大学学报》1996,27(3):231-234

通过室内及田间大豆不同生育期接种试验证明，籽粒感染灰斑病的关键时期是Ｒ３－Ｒ５期．Ｒ２期以前侵染不造成籽粒斑驳，据此提出一次防治大豆籽粒灰斑病的关键时期为Ｒ２－Ｒ４期．  相似文献   

Morphological characterization of the interaction between Diplocarpon rosae and various rose species     

O. Blechert  T. Debener † 《Plant pathology》2005,54(1):82-90

Blackspot, caused by Diplocarpon rosae , is the most severe and ubiquitous disease of garden roses, but information is lacking about genotype-specific forms of resistance and susceptibility of the host. Macro- and microscopic analyses of 34 rose genotypes with a defined monoconidial culture black spot inoculum identified susceptible and resistant rose genotypes and further genotype-specific subdivisions, indicating the presence of partial forms of resistance and different resistance mechanisms. In total, eight interaction types were characterized, five representing compatible (types 1–5) and three representing incompatible interactions (types 6–8). The incompatible interactions were characterized by the lack of any visible fungal structures beneath the cuticle (type 8), single-cell necroses (type 7) or necroses of larger cell clusters (type 6), the latter two types with penetration hyphae and haustoria in epidermal cells.  相似文献   

陆地棉功能叶不同生育时期酶活性及脂质过氧化作用的研究   总被引：5，自引：0，他引：5  

王新望  王惠萍 《作物学报》1995,21(2):215-222

对不同熟性棉花品种功能叶几种酶活性及脂质过氧化水平（以丙二醛含量表示）的研究结果表明，超氧物歧化酶（ＳＯＤ）活性在吐絮前呈波动上升，吐絮盛期争剧下降；丙二醛（ＭＤＡ）含量吐絮前缓慢上升，吐絮后明显增加；过氧化氢酶（ＣＡＴ）活性在结铃以前随叶片发育而上升，结铃后急剧下降；过氧化物酶（ＰＯＤ）活性始终呈上升趋势。进一步对ＰＯＤ同工酶进行电泳发现，其酶谱构成随生育进程而变化，早熟品种在开花期酶带条数最多  相似文献   

Effect of planting density of maize on the progress and spread of northern leaf blight fromExserohilum turcicum infested residue source     

E. Adipala  J. P. Takan  M. W. Ogenga-Latigo 《European journal of plant pathology / European Foundation for Plant Pathology》1995,101(1):25-33

Effect of plant density (37,037, 44,444 and 55,555 plants/ha) on the increase of northern leaf blight in time and space on two maize cultivars planted at spacings of 90, 75 and 60 between rows and 30 cm within rows was investigated.Exserohilum turcicum infested maize residue was used as an inoculum source. Maize density did not significantly affect the disease indices, but significantly influenced the grain yield of the two cultivars. In contrast, the two cultivars differed significantly (P0.01) in disease severity, but not grain yield. Higher disease severities and grain yields were associated with higher plant densities, whereas the apparent infection rate was lower in higher plant density. Distance from the maize residue (inoculum source) significantly influenced disease severity. The percentage leaf area blighted, area under disease progress curve and disease progress curve intercept decreased with distance from the maize residue area, but the apparent infection rate on EV8429-SR appeared to increase with distance. Disease gradients (b) were higher in closely planted maize and flattened with time in one location only.  相似文献