Albugo ipomoeae-panduratae . [Descriptions of Fungi and Bacteria

Abstract

Abstract A description is provided for Albugo ipomoeae-panduratae . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On members of the Convolvulaceae , especially on species of Ipomoea (Quamoclit, Merremia ) and Convolvulus . Economic hosts include Ipomoea batatas (sweet potato, I. pes-tigridis and probably I. aquatic (= I. replans - water spinach); I. horsfalliae, I. purpurea and Calonyction aculeatum are amongst ormentals attacked. DISEASE: White rust of sweet potitto. common white (blister) rust of Ipomoca (Convolvulus etc.). Sporangial pustules are produced on lower leaf surfaces, (petioles, stem and flowers), separately from the oospores, the latter often developing in pronounced swellings, galls or elongated tumour-like growths of stem and branches (flowers, petioles, roots) (Singh & Bedi, 1966; Farlow, 1889). The disease may cause trailing species to assume an upright habit (11, 545) and individual branches may show a witches broom effect. Diseased plants can also exhibit chlorosis, general distortion, defoliation and flower abortion (Singh & Bedi, 1965, 1966; Harter & Weimer, 1929). GEOGRAPHICAL DISTRIBUTION: Widespread on Ipomoea and Convolvulus spp. in tropical and warmer temperate regions. Main areas incluide North America (USA), tropical and South America (most countries); Africa (Moroco, Sudan and countries south of Sahara); S.W. Europe (S. France, Italy, Malta); S.W. USSR (Azerbaijan, Turkmenistan, Uzbekistan) and Asia (India, Pakistan and Far East); Australia (Queensland) and Pacific. Apparently not recorded in S.E. Europe, nor in Middle Eastern countries from Egypt through to Afghanistan. See under notes for distribution on I. batatas . TRANSMISSION: By air-borne sporangia and by short distance water dispersal of sporangia and zoospores. Initial infection by oospores from overwintered host tissue can occur (Harter & Weimer, 1929; 39, 750).