Determination Of The Role Of Berberis SPP. In Wheat Stem Rust In China

The barberry(Berberis spp.) had been considered don’t contribute to the transmission and variation of the stem rust fungus Puccinia graminis f. sp. tritici since it has been identified as alternate host of stem rust. However the effect of the Berberis can not be ignored since stem rust is a great plant disease latent in China.Wheat-growing areas of all over the world have never relax their vigilance to it because stem rust is a paroxysmal plant disease which can be burst popular without any precondition. So it is of significance to have an intimate knowledge of the disease characteristics and the experience of prophylaxis and treatment and the distribution of stem rust.Previous studies on the relationship of Berberis spp. and wheat stem rust suggested that,although some barberry species can serve as alternate hosts for the stem rust fungus P. graminis f. sp. tritici,barberry plants play no role in wheat stem rust development and virulence variation of P. graminis f. sp. tritici in China. In the present study,severe rust infections on Berberis shensiana,B. brachypoda,B. potaninii,B. soulieana,and B. aggregata were observed during field surveys in 2011 and 2012. Through artificial inoculation of wheat seedlings(‘Mingxian 169’) under greenhouse conditions with aeciospores from naturally infected barberry plants,185 isolates of P. graminis f. sp. tritici were obtained. From the 27 selected isolates that were tested on a set of wheat genotypes used to differentiate P. graminis f. sp. tritici races in China,19 races were identified,and other 8 races were new races,as Chinese 21 and 34 race groups. In addition to the information of virulence or avirulence patterns on the Chinese differentials,none of the races were virulent to resistance gene Sr31. This study shows that P. graminis f. sp. tritici can produce new races through sexual reproduction on Berberis spp. in China..So we consider that Berberis spp as alternate host of stem rust where it’s sexual process occurs played an important role to the virulence variation of stem rust in China.And it is further studied that how could it be possible that the new strains be popular in local nature conditions and wheat cultivars.