蔬菜嫁接机器人研制与试验

在中国,蔬菜嫁接仍以人工作业为主,为解决人工嫁接存在的作业效率低、成活率低、质量难以保证等问题,该文基于瓜、茄苗通用的"贴接法"嫁接技术,采用双工位上苗方式设计搬运装置、切削装置、上苗及送夹装置,利用虚拟样机技术构建瓜、茄类蔬菜嫁接机器人。经试验得出:切刀旋转半径为68mm,切刀转速为120r/min时,秧苗切削成功率98%,满足嫁接技术要求;嫁接速度为884株/h,嫁接成功率为95.7%,成活率为96.8%。因此,蔬菜嫁接机器人可有效解决人工嫁接存在的问题,取代人工嫁接作业。

蔬菜嫁接机器人切削装置设计与试验

根据"贴接法"的嫁接机理,采用旋转切削作业方式,设计了蔬菜嫁接机器人的切削装置,包括接穗切削装置和砧木切削装置,实现接穗苗茎部、砧木苗单子叶和生长点的快速切除。试验结果表明:当切削气缸转速ω=120r/min、输入空气压力P=490.3kPa时,接穗和砧木的削成功率均值达93.2%,接穗和砧木的切口长度为5.8～7.3mm,切削效果满足嫁接要求。

Effects of Liquid Seaweed Bio-organic Fertilizer on Seed Germination and Seedling Growth of Vegetables

[Objective] This study aimed to investigate the effects of liquid seaweed bio-organic fertilizer on seed germination and seedling growth of different vegetables. [Method] Serial dilution concentrations of liquid seaweed bio-organic fertilizer were prepared for seed soaking and pot incubation of cucumber, tomato and chili, to ob- serve the effects of liquid seaweed bio-organic fertilizer on seed germination and seedling growth of vegetables. [Result] Compared with the control, germination rate of cucumber and tomato seeds applied with 600-fold liquid seaweed bio-organic fer- tilizer varied significantly; germination rate of chili seeds applied with 400-fold liquid seaweed bio-organic fertilizer varied significantly; germination energy and germination index of chili seeds applied with different dilution concentrations of liquid seaweed bio-organic fertilizer presented no significant differences. In addition, 200-fold and 400-fold liquid seaweed bio-organic fertilizer significantly improved the root length, plant height, plant fresh weight, plant dry weight, chlorophyll content and leaf area of cucumber, tomato and chili seedlings; after treated with 600-fold liquid seaweed bio-organic fertilizer, root length, chlorophyll content and leaf area of cucumber seedlings varied significantly compared with the control, but no significant differences were observed in plant height, plant fresh weight and plant dry weight; after treated with 600-fold liquid seaweed bio-organic fertilizer, root length, chlorophyll content, plant height, plant fresh weight and plant dry weight of chili and tomato varied sig- nificantly compared with the control, but no significant differences were observed in leaf area. [Conclusion] Soaking vegetable seeds with liquid seaweed bio-organic fer- tilizer can significantly improve seed generation rate and seedling growth.

Molecular Characterization of Pythium Spp. Isolated from Tomato Seedlings in the Syrian Coast

Tomato seedlings damping-off is a limiting factor in commercial greenhouse production. To determine the causal agents of disease, sampling and fungal isolation were performed during 2012. Samples were collected from infected seedlings growing in greenhouses in the Syrian coastal region. Isolation of fungi was done in the laboratories of the Agronomical Reaserch Center, in Lattakia and the molecular analyses were done in the Biotechnology Center at Tishreen University, Lattakia, Syria, during the years 2012, 2013. Eight isolates ofPythium sp. obtained were purified using hyphal tip method （named P1, P2, P3, P4, P5, P6, P7 and P8）. Isolates were morphologically identified by optical microscope, then molecularly Characterized using genus specific ITS primers. The results of morphological characterization of pathogenic species suggested the detection of Pythium aphanidermatum, P. ultimum. The analysis of DNAs from the different isolates with ITS primers, recognizing the inter transcript spacer of nuclear ribosomal DNA proved that the eight, isolates were belonging to the species P. ultimum. The complete sequences of ribosomal DNA internal transcribed spacers regions of selected isolates were determined and submitted to GenBank. The GenBank-BLAST homology search revealed P. ultimum as the most similar sequence （〉 96% identity） with GenBank entry AB355596.

Use of Spent Mushroom Substrate as Growing Media for Tomato and Cucumber Seedlings

The aim of this research was to evaluate weathered spent mushroom substrate （SMS）, made from spent Flammulina velutipes mushroom substrate, as a growing medium for nursery seedlings. Two vegetable species, cucumber （Cucumis sativus L. cv. Jinchun No. 2） and tomato （Solanurn lycopersicum L. cv. Mandy）, were grown in 8 media of SMS in various ratios with perlite or vermiculite. A mixed substrate of peat with perlite （1：1; v：v） was used as the control （CK）. The experiment was arranged in a completely randomized design under greenhouse conditions. Prior to sowing, some physical and chemical properties of the growing media were determined. Results showed that all the mixtures had desirable physical and chemical properties for their use in nursery tomato and cucumber seedlings except for the T4 （SMS：vermiculite = 1：1; v：v） and the T8 （SMS：perlite = 2：1; v：v） mixtures. Compared with the CK, increased plant height, leaf area, fresh weight, dry weight and index of seedling quality were found in the T3 （SMS：vermiculite = 2：1; v：v） and T6 （SMS：perlite = 4：1; v：v） growing media. SMS should be considered as an alternative for the widely used but expensive and resource-limited peat in greenhouse cultivation.