Distribution of Polymyxa graminis Ledingham in different host plants
1999
Doucet, D. | Legreve, A. | Maraite, H. (Universite catholique de Louvain, Louvain-la-Neuve (Belgium). Unite de phytopathologie) | Delfosse, P. | Devi, P.S.
The plasmodiophorid Polymyxa graminis is considered to be the vector of Indian peanut clump virus (IPCV), an economically important pecluvirus in tropical and subtropical semi-arid areas infecting several graminaceous crops and weeds. This vector also colonises several plant species which may favour the build up of peanut clump inoculum potential. Polymyxa graminis infection under natural conditions was studied during the rainy season in Andhra Pradesh, India (field RCW17A, ICRISAT centre) on barley, finger millet, groundnut, maize, pearl millet, rice, sorghum and wheat. Eight plants per species were sampled in four replications at regular intervals (once a week during the establishment of the disease and every two weeks during the rest of the season) over seven weeks and the roots were stained with boiling cotton-blue lactophenol for assessment of P. graminis colonisation. Polymyxa graminis sporosori were observed in the roots of finger millet, maize, pearl millet and sorghum. The percentage of infected plants reached a maximum of 31/ during the growing season. The same eight species were also grown individually on sterile sand inoculated with the Indian monosporosorus isolate I1-1 (15,000 sporosori per plant). The plants were maintained in a greenhouse and flooded every 6 hours with a half-strength Hoagland solution using an automatic immersion system. Four plants were harvested after four weeks and four others after six weeks of culture, and the roots were stained for P. graminis sporosori detection. Finger millet, groundnut, maize, pearl millet, sorghum and wheat were infected. The number and localisation of sporosori in the roots varied according to the plant species. The distribution of sporosori in cross sections of maize and sorghum roots was observed using light microscopy. Sporosori were observed in the epidermis, cortex cells and endodermis in sorghum. In maize, the epidermis and the first two layers of cortex cells were colonised. The influence of plant species on the inoculum potential of IPCV is discussed.
اظهر المزيد [+] اقل [-]الكلمات المفتاحية الخاصة بالمكنز الزراعي (أجروفوك)
المعلومات البيبليوغرافية
تم تزويد هذا السجل من قبل University of Liège