苹果果实日灼人工诱导技术及阈值温度研究   总被引：10，自引：3，他引：10  

张建光  刘玉芳  孙建设  施瑞德 《园艺学报》2003,30(4):446-448

 使用自制的日灼诱导设备，在无风或微风的晴天对活体果实进行田间日灼诱导，通过改变诱导室内的气温来控制和调节果面温度，从而确定了不同苹果品种果实发生日灼的阈值温度。试验证明： 自制的诱导设备运行平稳，诱导期间可保持果温基本稳定，大多数情况下，处理期间果面平均温度与实际设定温度的差异小于0．12℃ ，温度变化幅度一般小于±0．5℃ 。本试验所测定的9个苹果品种日灼阈值温度为(45．9±0．5)℃ (48．5±0．5)℃。光照对日灼发生有重要影响，即使在同样的阈值温度下，有光的处理果实发生日灼，而无光的处理则不发生日灼。  相似文献   

琯溪蜜柚光合特性的研究   总被引：30，自引：2，他引：30  

易干军  姜小文  霍合强  张秋明  周碧容 《园艺学报》2003,30(5):519-524

 利用Li-6400 光合作用仪对田间条件下7 年生琯溪蜜柚的光合特性进行了系统研究。结果表明: (1) 琯溪蜜柚外围叶片晴天的净光合速率(P_n) 日变化为双峰曲线, 首峰出现在8～10 时, 次峰值小于首峰值, 出现在14 时以后; 阴天呈单峰曲线; 内膛叶片P_n 日变化有双峰、单峰和锯齿形3 种类型。(2)观测期内P_n季节变化近似双峰曲线。(3) 不同月份和不同枝条叶片Pn 对光和CO₂ 响应有较大差别, 光补偿点和饱和点分别为16～46 和1 026～1 656μmol·m^-2·s^-1 , 表观量子效率0.01725～0.05431 ; CO₂ 补偿点和饱和点分别为51～80 和822～926μmol·mol ^-1 , 羧化效率0.01769～0.05191 ;P_n对CO₂ 的响应进程近似双曲线。(4) P_n与气孔导度、蒸腾速率、光照强度正相关, 与胞间CO₂ 浓度负相关, 与温度、湿度和叶面水气压亏缺的相关性比较复杂。(5) P_n 与叶片的叶绿素含量和比叶重之间没有明显相关性。(6) 光合适温为24～34 ℃。  相似文献   

黄瓜幼叶细胞中钙调素的免疫胶体金定位     

田景花  张红  李明  王梅 《园艺学报》2003,30(6):728-730

 采用免疫胶体金电镜技术对黄瓜幼叶叶肉细胞中的钙调素(CaM)进行定位。结果表明：适温下生长的黄瓜幼苗叶肉细胞中的CaM主要分布于细胞核和叶绿体内，细胞核中CaM主要存在于染色质和核仁上，叶绿体中CaM主要存在于类囊体膜上；线粒体中也有一定量的CaM分布；细胞质、液泡、液泡膜及质膜上只有少量CaM存在；而细胞壁和细胞间隙却很难发现显示CaM存在的金颗粒。  相似文献   

种块大小对生姜生长及产量的影响   总被引：3，自引：0，他引：3  

王光美  徐坤  张玉海 《中国蔬菜》2003,1(1):13-15

本试验条件下,生姜出苗期随种块的增大而提早。幼苗期,较大种块处理的植株长势较旺,但茎叶旺盛生长期后,过大或过小的种块处理都不利于生姜的生长和产量的提高。生姜产量以75 g左右的种块处理为最高,达3 572.4 kg·(667 m2)-1,而100、50、25 g种块处理的生姜产量分别为3 250.2、3 077.9、2 600.1 kg·(667 m2)-1。  相似文献   

β-氨基丁酸、茉莉酸及其甲酯诱导辣椒抗TMV作用的研究   总被引：5，自引：2，他引：5  

梁俊峰  谢丙炎  张宝玺  冯兰香 《中国蔬菜》2003,1(3):4-7

β -氨基丁酸 (BABA)、茉莉酸 (JA)及其甲酯 (MeJA)喷雾处理辣椒叶片和茎秆后可诱导辣椒获得对TMV的抗性。研究结果表明 :3种诱抗剂对不同辣椒品种所表现的诱抗效果没有显著差异 ;诱抗效果受诱抗剂的使用浓度、作物的生育期和TMV的接种浓度所影响 ;最高的诱抗效果可达到 5 0 %以上 ;BABA处理后 5～ 6d ,JA与MeJA处理后 6～ 10d接种TMV ,辣椒植株开始表达出较高的诱导抗性 ,这种抗性可持续 15d以上 ,并表现出与数量抗病性相似的特性。  相似文献   

Herbicide options for weed control in papaya     

R.K. NISHIMOTO 《Integrated Pest Management Reviews》1997,2(3):109-111

This paper reviews the literature on weeds and weed control in papaya. There is limited research on this topic, and nearly all of the research focuses on herbicides. Effective use of paraquat and glyphosate in papaya is dependent on avoidance of spray contact to green bark and foliage. Pre-emergence herbicide tolerance is dependent on papaya age, size and maturity, and soil type. Only one herbicide, oryzalin is shown to be tolerated by papaya immediately after transplanting. Herbicides such as diuron and oxyfluorfen with a broader spectrum of weed control generally injure young papaya, however they can be effectively used if the initial application of these herbicides is delayed until papaya attains certain size or maturity indices. There is a need for further research on weeds and weed control to improve the efficiency of papaya production  相似文献   

Phylogenetic relationships between rice dwarf phytoreovirus isolates from five countries     

B.C. Lee  Y.K. He  K. Murao  M. Isogai  G. Dahal  I. Uyeda 《European journal of plant pathology / European Foundation for Plant Pathology》1997,103(6):493-499

Rice dwarf virus isolates were collected from several locations in Japan, the Philippines, China, Nepal and Korea. Genomic dsRNA segment profiles in polyacrylamide gel electrophoresis differed among the isolates. There were less differences in the profiles between isolates from Japan and Korea than in those between these two Countries and others. Nucleic acid hybridization was used to examine the extent of genomic variation. Full-length cDNAs to all genomic segments encoding non-structural proteins (S4, S6, S9, S10, S11 and S12) were synthesized from two Japanese isolates, and were used for dot-blot hybridization. Hybridizations using probes generated from the full-length cDNA clones failed to differentiate isolates from different geographical areas. However, cDNA probes covering a variable region of S12 were able to distinguish Japanese and Korean isolates from those of other countries. Phylogenetic tree analysis based on the amino acid sequence of P12 encoded by S12 grouped Japanese and Korean isolates together. The Chinese isolates from two different locations (Yunnan and Fujian) were closely related to each other, and were the most distantly related to Japanese and Korean isolates.  相似文献   

Effect of soil moisture content on the suppression of Rhizoctonia stem canker on potato by the nematode Aphelenchus avenae and the springtail Folsomia fimetaria     

M. LOOTSMA  & K. SCHOLTE 《Plant pathology》1997,46(2):209-215

The effect of soil moisture content on the suppression of Rhizoctonia stem canker on potato by mycophagous soil animals was studied in growth chambers. Three soil moisture levels were established in two bioassays, in which potato sprouts grew through a 15-cm soil layer inoculated with sclerotia of Rhizoctonia solani (AG-3). In one experiment two levels of R. solani inoculum were applied. The effect on plant disease of mycophagous soil fauna was assessed by adding the springtail Folsomia fimetaria and/or the nematode Aphelenchus avenae to the soil. In the absence of mycophagous organisms, Rhizoctonia disease severity on potato stems was highest in dry soil. A. avenae and F. fimetaria reduced Rhizoctonia stem canker when applied at populations found in the field. They were effective over a broad range of soil moistures. The stimulatory effect of dry soil conditions on Rhizoctonia stem canker was counteracted by a greater efficacy of the mycophagous soil fauna under these conditions. Mild drought stress did not seem to be a limiting factor in the biological control of stem canker by these two organisms.  相似文献   

Development of a powder formulation of Pseudomonas fluorescens for control of rice blast     

P. VIDHYASEKARAN  R. RABINDRAN  M. MUTHAMILAN  K. NAYAR  K. RAJAPPAN  N. SUBRAMANIAN  & K. VASUMATHI 《Plant pathology》1997,46(3):291-297

Pseudomonas fluorescens strain Pf1, inhibitory to the growth of the rice blast pathogen Pyricularia oryzae in vitro , was developed as a talc-based powder formulation. When rice seeds were treated with this formulation, the bacteria spread to roots, stems and leaves of the plants and protected against leaf infection by P. oryzae . When applied as a foliar spray, the bacteria survived on the leaves. The powder formulation controlled leaf blast under greenhouse conditions. In tests as a seed treatment and foliar spray in four field trials it effectively controlled the disease and increased grain yield.  相似文献   

Geographical cline of DNA variation within the F intersterility group of Heterobasidion annosum in Italy     

N. LA PORTA  P. CAPRETTI  K. KAMMIOVIRTA  R. KARJALAINEN  & K. KORHONEN 《Plant pathology》1997,46(5):773-784

Eighty-six Heterobasidion annosum isolates, mainly belonging to the F intersterility group and obtained from 32 different geographical localities in Italy, were subjected to genetic analysis by the Random Amplified Polymorphic DNA (RAPD) markers. The similarity between F and S groups was higher than that between F and P. In UPGMA Cluster Analysis, the F isolates originating from the same locality usually grouped in the same cluster. The isolates also showed a tendency to group at the level of larger geographical areas. Within the F group, isolates from the south of the Italian peninsula showed the highest genetic variation and northern isolates from the Alpine regions showed the lowest. This indicates a gradual cline along the peninsula. The genetic variability in the Italian F group is discussed in relation to the past and present distribution of the host species in Italy and Europe.  相似文献