Pythium myriotylum

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Pythium myriotylum
Systematics
Department : Egg mushrooms (Oomycota)
Class : Oomycetes
Order : Peronosporales
Family : Pythiaceae
Genre : Pythium
Type : Pythium myriotylum
Scientific name
Pythium myriotylum
Wood turner, (1930)

Pythium myriotylum is a soil-borne necrotrophic phyto-pathogen belonging to the Pythiaceae familywithin the group of egg fungi with a broad host range.

Hosts and Symptoms

Pythium myriotylum causes slight root rot in economically relevant crops such as peanuts , tomatoes , rye , wheat , oats , cucumbers , soybeans , millet , tobacco , cabbage and corn . Pythium myriotylum causes the seedlings to wilt before the seedlings emerge , infecting the seeds and causing them to rot before the plant grows. This causes the seedlings to shrivel and turn soft and brown. In a study carried out on soybeans, the symptoms observed also included decay of the roots and diseased seedlings, which also rotten and bleached. Pythium myriotylum can also cause peanuts to wilt after germination, resulting in discoloration of cotyledons and roots and a soggy appearance; in many areas this usually leads to seedling death.

Life cycle

Pythium myriotylum causes the disease by entering the host directly with the help of appressoria . This is also by the secretion (of cell wall destroying enzymes english cell wall degrading enzymes - CWDEs) supported. On the one hand, P. myriotylum has an asexual reproductive cycle , which consists in the fact that a mycelium produces sporangia . These sporangia germinate and release zoospores that can move with the help of two flagella . The zoospores are released in a moist environment and swim through the soil to infect new hosts. The pathogen, on the other hand, also has a sexual reproductive cycle in which fertilization occurs between an oogon and an antheridium . This results in a thick-walled structure called oospore , which represents a permanent stage for the pathogen, which also enables overwintering. The oospore also represents the initial inoculum , which germinates after a period of rest. It is difficult to break the dormancy of the oospores.

ecology

Pythium myriotylum is a soil-borne necrotrophic egg fungus. The disease caused by P. myriotylum is more pronounced in warm regions and in the summer months in the temperate zones. The pathogen thrives in very humid conditions. It prefers moist soils at lower altitudes, where the water lingers for long periods of time. At these lower elevations, it can also contaminate sprinkler and irrigation systems and thus spread to other crops, especially hydroponics.

Individual evidence

  1. ↑ a b c C. Geethu, AK Resna, R. Aswati Nair: Characterization of major hydrolytic enzymes secreted by Pythium myriotylum, causative agent for soft rot disease . In: Antonie van Leeuwenhoek . 104, No. 5, November 2013, ISSN  1572-9699 , pp. 749-757. doi : 10.1007 / s10482-013-9983-4 .
  2. ↑ a b P. H. Wang, CY Chung, YS Lin, Y. Yeh: Use of polymerase chain reaction to detect the soft rot pathogen, Pythium myriotylum, in infected ginger rhizomes . In: Letters in Applied Microbiology . 36, No. 2, February 1, 2003, ISSN  1472-765X , pp. 116-120. doi : 10.1046 / j.1472-765X.2003.01272.x .
  3. ↑ Keisuke Tomioka, Toshiaki Takehara, Hideki Osaki, Hiroyuki Sekiguchi, Koji Nomiyama, Koji Kageyama: Damping-off of soybean caused by Pythium myriotylum in Japan . In: Journal of General Plant Pathology . 79, No. 2, 2013, pp. 162-164. doi : 10.1007 / s10327-013-0434-x .
  4. ↑ a b Pythium myriotylum . Retrieved December 15, 2017.
  5. ↑ PH Wang, CW Chang: Detection of the low-germination-rate resting oospores of Pythium myriotylum from soil by PCR . In: Letters in Applied Microbiology . 36, No. 3, March 1, 2003, ISSN  1472-765X , pp. 157-161. doi : 10.1046 / j.1472-765x.2003.01287.x .
  6. ↑ S. Fukuta, R. Takahashi, S. Kuroyanagi, Y. Ishiguro, N. Miyake, H. Nagai, H. Suzuki, T. Tsuji, F. Hashizume: Development of loop-mediated isothermal amplification assay for the detection of Pythium myriotylum . In: Letters in Applied Microbiology . 59, No. 1, July 2014, ISSN  1472-765X , pp. 49-57. doi : 10.1111 / lam.12244 .

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