Variation in Phytophthora palmivora (Butl.) Butl. Isolates from Durian : Morphology and Mating Type

Abstract

Twenty five isolates of durian Phytophthora from different durian orchards in Nakorn Nayok , Rayong, Chanthaburi, Trat, Chumphon, Surat Thani and Si Sa Ket province were collected and characterized. They were identified as P. palmivora, however, the variabilities in some morphological features, including colony morphology, size and shape of sporangia, gametangia and oospores among is olates were found. These isolates were separated into two groups on the basic of the sporangial length namely breadth ratios (L:B> 1.7 and L:B< 1.7). All isolates were heterothallic, mating type A1 and amphigynous antheridia. Oogonia, oospores and chlamydospores were averaged at 27, 23 and 37 µm respectively, in diameter.