植物病害标本的采集制作与保存Collection making and preservation of plant disease specimens.docx

1、植物病害标本的采集制作与保存Collection making and preservation of plant disease specimens植物病害标本的采集制作与保存（Collection, making and preservation of plant disease specimens）Collection, making and preservation of plant disease specimensPlant disease specimens are indispensable in the teaching of plant pathology in highe

2、r agricultural colleges. They are intuitive and free from seasonal and regional restrictions in teaching. Therefore, the collection, manufacture and preservation of plant disease specimens are essential knowledge and skills in the experimental teaching of plant pathology.1 collection of plant diseas

3、e specimensIn the north, because of the distinct seasons and rich varieties of crops, plant diseases occur frequently, and most plant disease specimens can be collected from the fields. However, the occurrence of disease has a certain regularity, and it is necessary to fully grasp the seasonal patte

4、rn of disease occurrence and the growth of host, in order to harvest symptoms typical samples.1.1 tools for collection of disease specimensPlant disease occurs mostly in root, stem, leaf and fruit, so the tools used for different parts, commonly used tool knife, scissors, hoe, saws, and specimen cla

5、mp, specimen box, paper, small specimens of glass bottles, paper bags, labels and records etc.1.2 collection of specimensField collection was divided into season collection and host collection. Seasonal collection is based on diseases that occur only once in a particular period of the year. Such as

6、powdery mildew with sexual stage, wheat powdery mildew can be collected every year in 5-6 months; the gray mold of plant is easy to come into being under the condition of low temperature and rain, and it is easiest to pick up every 3-5 months. According to the host acquisition mainly for a wide rang

7、e of host diseases such as downy mildew, can be found in the leaves of many plant diseases, common with lettuce, grapes, cabbage etc.; epidemic diseases such as tomato and potato, pepper etc.1.3 records of specimens collectedIn order to distinguish the different specimens collected, records should b

8、e recorded during collection. It mainly includes the name, time and place of the host, the name of the collector, the main occurrence and the necessary ecological environment factors.2 production of plant disease specimensAfter the specimen was collected and removed as the specimens for isolation, t

9、he specimens were usually preserved by dry or dipping methods, and the original characters of the specimens could be preserved as much as possible. Some small can be made more difficult to keep the glass specimen, and special specimens through multimedia system or scanning microscope system into the

10、 computer, made the corresponding style of graphics, animation, video etc.2.1 specimen drying method2.1.1 pressing method. Plant disease specimen collected, if after drying easy roll (such as rice leaf), the best with mining pressure. The others can be placed in the collecting box and carried back a

11、nd then pressed into the absorbent paper. The specimen is clamped and the sun is dried. In the meantime, always replace specimen paper. Summer temperature and humidity higher, easy to sample mildew, discoloration, specimen paper should be replaced frequently. Usually, the former 34 D is changed 12 t

12、imes /d, and the 23d is changed 1 times later, until the sample is completely dried.2.1.2 hot dry method or silica gel drying method. These 2 methods can be used without preparation as a separate specimen. In order to speed up the drying of specimens and the specimens better keep the original color,

13、 can be just the samples put irons back and forth rapidly hot dry or the loading of toilet paper and silica powder of dried specimens of clip tie in the water of paper or cloth, placed in the oven at 50 23 D, which is fast drying.2.1.3 microwave oven drying and color retention method. In order to ma

14、ke up for the deficiency of hot drying method, Liu Chunyuan et al. (2003) reported a set of microwave drying and color retention method according to the texture of plant disease specimens. This method is fast drying and has better color retention effect. It can be preserved for a long time without f

15、ading. Such as legume disease leaves treatment 1 min, the effect is best, the symptoms are well preserved.2.1.4 freeze drying method. Is a better method at present. The specimens are dried in the presence of freezing and almost completely retain their original color and shape.2.1.5 natural drying me

16、thod. Specimens with little moisture, such as branches and stems, etc., do not need to be dried by any means. They can be dried naturally in the air.2.2 impregnated specimen making methodFor the fruit diseases and diseases as well as juicy fleshy ascomycetes and basidiomycetes fruiting bodies can be preserved by impregnation method. However, this method accounts for large area and limited storage time, and can only be used to preserve small amount