Abstract
Urediospores ofPuccinia recondita f.sp.tritici were applied to wheat seedlings. Inoculated plants were placed in a growth chamber to expose the spores to dry periods from zero to nine days at near-optimal temperatures (ca 18 °C). The dry period was followed by a wet period varying from 2 to 24 hours for germination of spores and infection of plants. Infection results were subjected to analysis of variance. The main effects dry period, wet period, and temperature were highly significant. The dry period×wet period interaction was significant. The interaction implied that the effects of post-detachment, ripening of germinable spores appeared in their resulting infectivity. There were two forms of post-detachment ripening, a slow ripening during the dry period and a faster ripening during the wet period. The two forms of ripening showed a non-additive compensatory interaction. The effect of post-detachment ripening on infectivity of germinated spores was more pronounced at 15 than, at 18 or 20 °C; the effect was strongest during the first day of the dry period. At dry periods of over 6 days, infectivity of germinated spores decreased, especially at the higher temperatures. Prolonged exposure, of spores to a dry period apparently damages the spores even though they are still able to germinate.
Samenvatting
Uredosporen van de bruine roest van tarwe (Puccinia recondita f.sp.tritici) werden over het eerste blad van tarwekiemplanten verstoven. De aldus geïnoculeerde planten werden in een klimaatkamer geplaatst bij ca. 18 °C om de sporen bloot te stellen aan droge perioden van 0 tot 9 dagen. De droge perioden werden gevolgd door natte perioden van 2 tot 24 uur om de sporen te laten kiemen en de planten te infecteren. Na de natte periode werden de planten bij verschillende temperature geplaatst om de latente periode en de vorming van sporenhoopjes te bepalen. De hoofdeffecten op de vorming van sporenhoopjes waren zeer significant: duur van de droge periode, duur van de natte periode en temperatuur. Twee vormen van sporenrijping werden gevonden bij rijping vnn sporen, die los op het blad lagen (rijping, buiten de sporenhoopjes), een langzame rijping tijdens de droge periode en een snelle rijping tijdens de natte periode. Deze twee vormen van rijping vertoonden statistische interactie met enige wederzijdse compensatie. Het effect van deze sporenrijping (buiten de sporenhoopjes) op de infectiviteit van gekiemde sporen was bij 15 °C duidelijker dan bij 18 en 20 °C; het effect was het sterkst tijdens de eerste dag van de droge periode. Bij droge periodes langer dan 6 dagen daalde de infectiviteit, vooral bij de hogere temperaturen.
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References
Chester, K.S., 1946. The nature and prevention of the cereal rusts as exemplified in the leaf rust of wheat. Chronica Botanica Cy., Waltham (Mass.), 269 pp.
Mehta, Y.R. & Zadoks, J.C., 1970. Uredospore production and sporulation period ofPuccinia recondita f.sp.triticina on primary leaves of wheat. Neth. J. Pl. Path. 76: 267–276.
Rouse, D.I., MacKenzie, D.R. & Nelson, R.R., 1981. A relationship between initial inoculum and apparent infection rate in a set of disease progress data for powdery mildew on wheat. Phytopath. Z. 100: 143–149.
Zadoks, J.C. & Hees-Boukema, E.M. van, 1986. Postponed germination ofPuccinia recondita urediospores deposited on wheat seedlings. I. Ripening, and longevity of urediospores with postponed germination. Neth. J. Pl. Path. 92: 57–69.
Zadoks, J.C. & Schein, R.D., 1979. Epidemiology and plant disease management. Oxford University Press, New York, 427 pp.
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Van Hees-Boukema, E.M., Zadoks, J.C. Postponed germination of Puccinia recondita urediospores deposited on wheat seedlings. II. Infectivity of urediospores after postponed germination. Netherlands Journal of Plant Pathology 92, 71–80 (1986). https://doi.org/10.1007/BF01998063
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DOI: https://doi.org/10.1007/BF01998063