Puccinia melanocephala

Puccinia melanocephala on sugarcane

Puccinia melanocephala is a Ständerpilzart from the order of rust fungi ( Pucciniales ). The fungus is an endoparasite of sugarcane ( Saccharum officinarum ) and Erianthus species. Symptoms of infestation by the way are rust-colored spots and pustules on the leaf surfaces of host plants. Their range includes India and China.

Features

Macroscopic characteristics

Puccinia melanocephala with the naked eye can be seen only on the basis of the projected on the surface of the host spore deposits. They grow in clusters that appear as yellowish to brown spots and pustules on the leaf surfaces.

Microscopic characteristics

The mycelium of Puccinia melanocephala grows intercellular as with all Puccinia species and forms Saugfäden that grow in the storage tissues of the host. Aecien the kind are not yet known. The zimtbraunen uredia grow on both sides of the leaves of the host. Your also zimtbraunen uredospores are mostly ovate, 28-33 × 18-23 microns in size and finely stachelwarzig. The Telien the type are black brown, early open lying and compact, they grow leaf underside. The hazel teliospores are two-celled, clavate and usually 30-43 × 17-21 microns in size; its stem is brown and up to 12 microns long.

Artabgrenzung

Puccinia melanocephala differs from also occurring in sugarcane Puccinia kuehnii ( in English-speaking orange rust ) by the formation capitate paraphyses. The Urediniosporen are usually smaller than that of Puccinia kuehnii and its cell walls are of uniform thickness. The teliospores of Puccinia melanocephala are pigmented, with the upper cell dark brown, the lower is, however, pale colored.

Dissemination

The original area of ​​distribution of Puccinia melanocephala extends from India to China. The species is found everywhere, where sugar cane is grown.

Ecology

The host plants of Puccinia melanocephala are sugar cane and Erianthus species from the Süßgrasunterfamilie Panicoideae. The fungus feeds on the present in storage tissues of the plant nutrients, its spores bearing later break through the leaf surface and set free spores. The species appears to have a development cycle, from the date only Telien and uredia and their host are known spermogonia and Aecien have not yet been described.

Importance

Puccinia melanocephala together with Puccinia kuehnii the most harmful rust fungus in sugar cane cultivation. He was allegedly used by the U.S. in the 1970s as a biological weapon in Cuba. However, these allegations come only from Cuban sources and has not been confirmed. It is likely that two factors came together: on the one hand, spores were spread in a natural way with the wind from West Africa to the Dominican Republic, where the pathogen was first detected in the Caribbean. The transport over such long distances could be detected. On the other hand, the rust -prone variant B was grown on a large scale in 4362 in Cuba.