Abondance relative et diversité des Endogonacées dans un sol de verger du Québec

Studies of soil samples from an apple orchard in Frelighsburg revealed the presence of seven species of Endogonaceae, six of which generated vesicular and arbuscular mycorrhizae on Tagetes erecta L. While Glomus constrictum Trappe, Glomus mosseae (Nicol. & Gerd.) Gerd. & Trappe, and Sclerocystis rubiformis Gerd. & Trappe made up more than 90% of the organisms observed, Gigaspora calospora (Nicol. & Gerd.) Gerd. & Trappe, Glomus aggregatum Schenck & Smith, and Glomus etunicatum were seen in approximately half of the samples. An enumeration of the Endogonaceae observed is followed herein by a discussion dealing with the frequency and the relative abundance of these species in the soil and with the practical interest which arises from this type of survey.