| Wheat stripe rust caused Puccinia striiformis f. sp. tritici (Pst), has been considered oneof the important disseas of wheat, and a serious threat to wheat production. Previous studiessuggested the virulence variation of Pst exsts in the over-summering zone of Pst in china.,especially in Gansu over-summering zone of Pst, in where Pst is prone to develop and is easyto survive. So it is known as "variable area" of the wheat stripe rust fungus and the “Center oforigin†of new Pst races. It is also play an important role in occurrence and prevalent of wheatstripe rust in oversummering regions of Gansu, Shaanxi, Sichuan, Yunnan and Guizhouprovinces in China. The southwestern over-summering are of Pst covers ninglang, Yunnan,and liangshan, Sichuan province. Together with the over-summering zones of longnan,Gansu, and the northwestern over-summering zone, constituting a large over-summering zoneof Pst from north to south in China. This prodvides a natural contiditon for effectiveness ofthe epidemic of wheat stripe rust in China. In this study, an investigation on Berberis spp. wasperformed in the over-summering zone and part of the epidemic area in Gansu, Shaanxi,Sichuan, Yunnan and Guizhou provinces to identify the alternate host of Pst, being ofimportant significant for exploring the mechanism of virulence variation and genetic diversityof Pst in China.Berberis spp. were documentally recorded with a wide distribution in the wild in Chinasometimes coexisting with wheat located in areas where Pst can over-summer and the diseasehas been frequently prevalent. The barberry had been confirmed as the alternate host of Pst inrecent years, but it’s unknown whether there’s how many of it should be regarded as thealternate host or not. This study was to complete a survey in the over-summering areas andpart of the epidemic area in Gansu, Shaanxi, Sichuan, Yunnan and Guizhou provinces, andto identify Berberis spp. serving as alternate host of Pst. The results are as follows:1. The results of the distribution area of barberry plants based on the survey showed thatbarberry plants was various and numerous in the over-summering area of Pst in Gansu,Sichuan, Shaanxi，Yunnan and Guizhou provinces. In total,20kinds of barberry werecollected, incorporating evergreen, fallen-leaves, and half evergreen three types. There are4barberry species in Gansu (Berberis aggregata， B. stenostachya， B. soulieana, B.brachypoda),4in Shaanxi (B. shensiana, B. circumserrata, B.dasystachya, B. potaninii),2in Sichuan (B. soulieana, Berberis atrocarpae),9in Yunnan (B.wangii, B. phanera, B. davidii,B. aggregata var. integrifolia, B. jamesiana, B. rdinandi-coburgi, B. platyphylla, B.jamesiana, B. coryi,),1in Guizhou(B. guizhouensis), and Beijing (B. poiretii), respectively.2. The results of identification of barberry in greenhoused indicated that, among the20kinds of barberries by inoculating the germinated teleutospore of Pst, there were18kinds ofbarberry plants (Berberis brachypoda, B. aggregata, B. potaninii, B. soulieana, B.dasystachya, B. shensina, B. atrocarpa, B. ferdinandi-coburgii, B. phanera, B. aggregata var.integrifolia, B.davidii, B. stenostachya, B. wangii, B. circumserrata, B. poiretii, B.guizhouensis, B. platyphylla, and B. jamesiana) generated pycnia and aecia afterbasidiospores infection. Aecia produced on barberry were inoculated on wheat Mingxian169generating typical uredia of Pst on wheat leaves, indicating these18barbery species can serveas alternate host of Pst. With some replications, only2kinds of barberries (Berberis vernalis,B. coryi) failed to generate pycnia and aeci，and we thought these2barberry species can’t beserve as alternate host of PstAbove all, based on this study, it suggested that there’s a wide distribution of barberriesin the over-summering area of Pst in Gansu, Shaanxi, Sichuan, Yuannan, and Guizhou China,and meanwhile the most collected barberries in these areas were identified as the alternatehost of Pst.. |
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