Resistance of rice cultivars to white tip disease caused by Aphelenchoides

Aphelenchoides besseyi is a seed-borne plant parasitic nematode and is widely distributed in most rice growing areas. Application of resistant cultivars requires the identification of resistance source, which can then be included in breeding programs to improve the local rice cultivars. Fourteen Iranian rice genotypes including improved and local varieties were evaluated for resistance to A. besseyi in greenhouse condition. Screening for resistance carried out based on symptom expression and nematode populations. Among the cultivars tested, Binam, Domsiah, Khazar and Hassansarayi showed high resistance. Moderate resistance was identified with Sepidroud, Kadus, Hassani and Ramezani. Hashemi, Deilamani and Alikazemi were moderate susceptible and Tarom, Nemat and Neda ranked as high susceptible to nematode. Susceptible plants expresses also other typical symptoms such as shortening of flag leaf which twisted at apical portion and hinders the emergence of panicle, reduction of panicle length and the grain number, spikelets with distorted glumes and deformed kernels. Sometimes symptomless but infested plants were also found.