Res. on Crops 11 (3) : 745-748 (2010) Printed in India Identification and incidence of seed-borne fungal disease agents on bottle gourd (Lageneria siceraria) seeds SIBEL DERVIS, SONER SOYLU* AND HALIT YETISIR 1 Department of Plant Protection Agriculture Faculty, Mustafa Kemal University, Antakya, Hatay-31034, Turkey *(e-mail : soylu@mku.edu.tr) ABSTRACT Seed-borne fungal diseases are major biotic constraints to seeds. This study was conducted to determine identification and incidence of seed-borne fungal disease agents on seeds of different bottle gourd [Lageneria siceraria (Mol.) Standl.] genotypes which were collected from different parts of Turkey bottle gourd seeds. Using agar plate and blotter method as recommended by ISTA, the seed-borne mycoflora of 21 different samples of bottle gourd seeds collected from infested plants growing in the different parts of Turkey was investigated. Agar plate method yielded greater number of fungi followed by blotter method. The occurrence and average per cent incidence of fungi in seed samples tested revealed that Macrophomina phaseolina, Fusarium oxysporum, Epicoccum purpurascens and Sordaria fimicola were the most frequently isolated seed-borne fungal agents from 70.0, 10.0, 9.5 and 4.6% seed lot samples of bottle gourd, respectively. The sources of primary inoculum in seeds are still not well documented but indications suggest that keeping bottle gourd fruits in fields for maturations play an important role in disease transmission from soils. Seed treatment may prove useful as a part of an integrated disease management approach based on improved resistance and good agronomy. Key words : Bottle gourd, Lageneria siceraria, seed-borne fungi 1 Department of Horticulture. INTRODUCTION Cultivated Lageneria siceraria (Mol.) Standl. is commonly known as the white- flowered bottle gourd. Bottle gourd fruits are generally consumed as a vegetable in Africa and Asia. An important horticultural utilization of L. siceraria is as rootstock for watermelon. Grafting on L. siceraria was used widely in watermelon to control soil-borne fungal disease such as Fusarium wilt (Lopez- Galarza et al., 2004) and to increase the plant growth and the absorption of water and plant nutrition (Pulgar et al., 2000; Yetisir et al., 2006). Grafting has increased dramatically over the years. The use of grafted seedlings in vegetables, particularly in watermelon, has increased dramatically in Turkey. In a previous study, we collected and evaluated 210 L. siceraria genotypes from ecologically different parts of Turkey (Yetisir and Sari, 2003). Based on the morphological characteristics of plants and fruits, we established a L. siceraria genotype collection for further studies. Seed-borne fungal diseases are major biotic constraints to seeds of agronomically important plants. Seed-borne diseases are able to spread across international borders very easily and are often difficult to control because they are difficult to identify, with typical symptoms being rare on seed surfaces except in some legumes. As the economic impacts of seed-borne diseases have increased in recent years, their importance has increased with regard to many kinds of crops in Turkey as well as worldwide. Seed pathological studies have mainly dealt with cereals and vegetables, whereas few investigations have been concerned with plants used as root-stock as in the case for bottle gourd. This study was conducted to determine identification and incidence of seed-borne fungal disease agents on seeds of different bottle gourd genotypes which were collected from different parts of Turkey.