New Record on the Occurrence of Cyst Nematode, Heterodera cajani Koshy, 1967 on Sesame, Sesamum indicum in Myanmar

Abstract

Sesame, Sesamum indicum L. occupies for nearly half of the area sown to oilseed crops in Myanmar. It is cultivated for domestic consumption and export. During 2003, sesame cultivars, Sinyadnar3, Sinyadanar5, Magway7/9 and Khwaylayni grown in Oilseed Crop Research Farm, Department of Agricultural .Research, Magway were found to be heavily infected with Heterodera cyst nematodes. In 2004, cysts were also found from the soil samples collected from the previously infested plots. Infested field showed patches in which the plants were stunted, chlorotic, and caused wilting. When the infected plants were uprooted, curving of tap root, and red-girdling and dark browning of lateral and tap roots were observed. Lemon-shaped cysts were found attaching to the root surface. Young females were white or creamy colour whereas old cysts with eggs were tan colour. A few bullae were found on the posterior portion of the female. Larvae were vermiform with elongate conoid tail. Males were cylindrical or elongated with short tail without bursa. According to the morphological characters of the nematode and disease symptoms of sesame, the nematode was supposed to be identified as Heterodera cajani. There was no report o cyst nematode, Heterodera spp. in Myanmar. The present finding, the occurrence of Heterodera cajani on sesamum, is the first record of Heterodera spp. in Myanmar