SN/T 1820-2006Identification of Phytophthora cryptogea Pethybridge and Lafferty (English PDF)

2.1 Classification status

2.2 Quarantine principle

The host plant of Phytophthora sinensis is very wide, and it is harmful to hundreds of economic crops. It is gerbera, aster, carnation, Christmas flower, tomato and other plants.

Important pathogens (see Appendix A). Mainly with strong anti-reverse oospores in the medium soil and host residues in winter and long-term survival, when the field temperature and humidity are appropriate, the oospores break the dormant germination and produce sporangia. Sporangia soon after rain or after irrigation the release of a large number of zoospores, eventually invading the host through the roots or wounds, can cause roots and stems to rot, causing the plants to be infested after infection Wilted and died.

2.3 Identification basis

The symptoms of the Phytophthora infestans on the host plant, the morphological characteristics of the pathogen, and the biological characteristics are the basis for identifying the bacteria.

3.1 Equipment

Biological microscope, stereo microscope, autoclave, dry heat sterilizer, ordinary balance, analytical balance, ultra-clean workbench, biological incubator.

3.2 Laboratory equipment

Alcohol lamps, medical scissors, tweezers, beakers, petri dishes, slides, coverslips, flasks, measuring cylinders, straws, jars.

5.1 Basic medium

It is used for observation and measurement of preservation and culture traits of Phytophthora sinensis.

Use carrot medium (CA), V8 medium (V8A) or lima bean medium (LBA), the preparation method and steps are shown in section B. Chapter 1.

5.2 Selective medium

It is used for the germination of zoospores and the isolation and purification of pathogenic bacteria.

When 1000 mL of basal medium is routinely sterilized and cooled to about 55 ° C, the following antibiotics (all active ingredients) are added. Penicillium 50mg, rifampicin 20mg, carbendazim 25mg, pentachloronitrobenzene 25mg, shake well, made into a plate.

In the absence of pentachloronitrobenzene, the same amount of benzoate can be used instead.