No abstract

Karnal bunt of wheat (Triticum aestivum) caused by Tilletia indica is a major concern in international trade because it can degrade quality significantly, and it is a quarantine pest for Indonesia. Tilletia infected seeds can be the source of fungal inoculum of other areas. The current research was aimed to determine the effectiveness of temperature and exposure time to control Tilletia using air heat treatment without reducing the quality of grain. The experiments were conducted in vitro, initiated by seed testing, including morphology-based detection and identification of Tilletia followed by a viability test of the seed. Air heat treatment was performed by adjusting the oven temperature at 75, 80, 85 °C and 28 °C (control) for 4 and 6 hr exposure time, each with three replications. The results showed that air heat treatment of the wheat at 75 °C for 4 hr was able to suppress teliospores germination of 56.7–61.7%, without denature protein content of the wheat.

SummaryUltrastructural analysis of the early development of nematodes is hampered by the impermeability of the eggshell to most commonly used fixatives. High-pressure freezing (HPF), a physical cryo-fixation method, facilitates a fast rate of fixation, and by using this method the issue of the uneven delivery of fixative is circumvented. Although HPF results in a superior preservation of the fine structure, the equipment costs impede a wider application of this method. Self-pressurised rapid freezing (SPRF) is an alternative low-cost cryo-fixation method, and its usefulness was evaluated in an ultrastructural study of the eggshell and the cuticle of unhatched second-stage juveniles (J2) of Globodera rostochiensis and Heterodera schachtii. A comparison with conventional (chemical) fixation demonstrates that SPRF fixation results in a remarkably well-preserved ultrastructure of the entire egg including both the eggshell and the cellular details of the unhatched J2. Therefore, SPRF fixation is proposed as an affordable, relatively easy-to-use and time-efficient technique to study the ultrastructure of unhatched J2 and eggs of nematodes.