Paper, 'Mahonia aquifolia as a nurse of the wheat mildew' by Charles B [Bagge] Plowright

Description

Plowright writes: 'It has always been difficult to account for the widely-spread nature of outbreaks of wheat mildew in districts in which the common barberry is either entirely absent or very uncommon. In the year 1874 the Rev. James Stevenson found at Glamis, in Forfarshire [Scotland], an Æcidium upon Mahonia aquifolia, which the Rev. M. J. Berkelev pronounced to be Æcidium berberidis. In the following year Dr. Paul Magnus found the same fungus at Lichterfelde, near Berlin, but since that time it does not seem to have been noticed by any one. On the 31st of May, 1883, Mr. William C. Little, of Stagsholt, March, gave me a freshly gathered specimen of Mahonia aquifolia, upon the berries of which the Æcidium was abundant. Knowing that upon the barberry no less than three different AEcidia occur, I determined to prove by direct experimental culture whether this one was the Æeidium berberidis of Persoon (the æcidiospore of Puccinia graminis). At 10pm on the evening of the 31st May I placed some of the spores upon the cuticle of some wheat-plants which had been cultivated under a bell-glass. In eleven days the uredo of Puccinia graminis made its appearance upon these plants. The details of this, as well as of two other experiments, are appended. On the 13th June I placed some of the secidiospores upon a piece of wheat cuticle; in twelve hours they had germinated, and a little later the germ-tubes were seen entering the stomata, in the same manner as those of Æcidium berberidis do (see figure). It is then clear that the Æcidium upon Mahonia aquifolia is identical with the Æcidium berberidis (Pers.), and is a part of the life-cycle of Puccinia graminis, and is unconnected with the Æcidium magellanicum (Berk.), and the Æcidium of Puccinia berberidis (Mont.). The Mahonia in question is widely cultivated in gardens throughout England and is a favourite evergreen in shrubberies. It is also extensively planted in woods as a covert for game.'

Annotations in pencil and ink.

Subject: Botany / Agriculture

Received 23 July 1883. Read 15 November 1883. Communicated by [Joseph Dalton] Hooker.

A version of this paper was published in volume 36 of the Proceedings of the Royal Society as 'Mahonia aquifolia as a nurse of the wheat mildew (Puccinia graminis)'.

Reference number

PP/4/1

Earliest possible date

1883

Physical description

Ink and graphite pencil on paper

Page extent

7 pages

Format

Manuscript