Pucciniastrum epilobii

Pucciniastrum epilobii on a fuchsia leaf

The pine needle rust or white fir pillars rust ( Pucciniastrum epilobii ) is a rust fungus that lives on different firs in the haploid phase. In the phase dikaryoten he lives on Fireweed, but also on fuchsias cultures, which is why he is known in horticulture under the name Fuchsia rust.

Characteristics and life cycle

The wintering of dead host plants such as fireweed teliospores germinate in the spring from in damp weather to a septate basidium, the basidiospores pinches. This in turn affected by wind dispersal young pine needles and it starts the haploid phase. Early to mid-June then arise on the underside of infected needles white, pin-shaped aecia, which release yellow-orange aecidiospores at maturity. These spores can infect only Fireweed, where he first yellow Uredolager with uredospores and later in the fall then forms brownish Teleutolager, thus closing the cycle.

Microscopic characteristics

The Uredolager are subepidermal on the underside of leaves and blow at maturity the epidermis. The little feinwarzigen uredospores are individually stalked and staffed with a few fine warts. They measure 13-18 × 17-24 microns. The dark-colored Telien form sheets subepidermal stock. The teliospores are thin-walled. The aecia are also subepidermal on the underside of leaves and are cylindrical - flat. They measure 120-30 microns in diameter and about 1 mm high. The yellow aecidiospores are Kettig, feinwarzig, 15 × 19 microns in size and with an elongated smooth spot.

Ecology and distribution

The pine needle rust is one of the heterözischen rust fungi, which means that it occurs in its development on two different, systematically unrelated host plants. In the haploid phase include firs, in Central Europe therefore primarily the silver fir, otherwise the Greek fir, Nordmann fir, the Grand Fir and Colorado Spruce. In North America, it attacks except the latter two species, the purple - fir Subalpine Fir and Balsam Fir. In the dikaryotic phase they change on species of Onagraceae, in Europe mainly on different willow herb, especially on the narrow-leaved willow herb. But he is also known from fuchsias cultures, in which case, however, are known only to the Uredolager. In North America the rust also occurs on the Sommerazalee.

Pucciniastrum epilobii has a very wide distribution. He is known except in Europe and North America, Guatemala, Ecuador, China, Australia and New Zealand.

System

The pine needle rust was in 1801 described as Uredo pustulata by Christian Hendrik Persoon. In 1861 he was awarded by Gustav Heinrich Otth the still valid name. The occurrence of Fuchsia was initially as a separate species as Pucciniastrum fuchsiae Hirats. described. However Gäumann realized that it is the same way as Pucciniastrum epilobii. Poelt and Zwetko beat the division into two forms: Pucciniastrum epilobii f.sp. Abieti - chamaenerii with change of host on fireweed and Pucciniastrum epilobii f.sp. palustris on fuchsia. It still is but at the same Article

Measures

The fir is rarely a serious threat even after several attacks, most likely in young cultures. With the obligatory change of host, the disease most effectively by removing the intermediate host ( fireweed ) is fought. A notable form of biological pest control is a migrant shepherd drives his flock of sheep by so quickly through a fir culture that the fireweed be eaten, but there is no browsing of the firs. In horticulture, however, the fuchsia rust is regarded as a serious disease and is treated with fungicides.