| Cereal cyst nematode (CCN) was one of the major plant-parasitic nematodes of wheat, barley, oats, rye and other cereal crops. Wheat cyst nematode(Heterodera avenae Wollenweber,1924) was a important pathogen on wheat, belongs to Heteroderidae, Heterodera. CCN occurs in Australia, Canada and more than40countries and now widely distributs in Beijing, Hebei, Henan, Hubei, Nei Mongolia, Anhui and other provinces and cities in China, threatening China’s wheat production. Wheat was one of the most important food crops in Anhui province, based investigstions we carried before, the disease occurred widely in the wheat producing areas of Anhui. Yingshang (E116.26°N32.63°) was an important wheat growing areas in Anhui province, located in the basin of Huaihe River and the Ying River, the southern tip of the North China Plain. For the aim to understand CCN occurrence law, yield casued by CCN, systematic investiagation and relative field experiments were carried out in wheat area of Yingshang County and Waibei.By’zig-zag method’,140soil samples were collected of wheat rhizosphere from13wheat areas in northern Anhui province, CCN cysts were separated from soil samples by Fenwick&Oostenbrink method, egg density of CCN was assessed, egg density frequencies were calculated in Wanbei wheat area. The results show CCN egg density ranged in0/g soil～42.8/g soil. CCN detected from94%of smaple sites. CCN egg density ranged in1/g soil～10/g soil was detected in62%of sample sites.Soil-borne disease risk was assessed by Center Detection of Plant Disease of South Australian Research and Development Institute (SARDI) based on19soil samples collected by’zig-zag method’from shuanglou village of Huangqiao, Yingshang County (SHY). The results show that there are4risk soil-borne pathogen in the wheat rhizosphere, then CCN, Pratylenchus neglectus, Bipolaris spp. and Fusariun.culmorum. Among them, CCN was the dominant pathogen; the average egg density was between1/g soil and20/g soil and was high-risk.Heterodera avenae was identified based on the morphological characterization of the cyst vulva cone and Juvinile2respectively separated by Fenwick&Oostenbrink method and Baermann funnel method from soil samples collected in SHY.The CCN distribution type was investiaged based on data of egg density from60plots in SHY according to diffusion coefficient. The results show the diffusion coefficient wheat plots was2.1in SHY, and the distribution type belonged to block type.CCN dynamic population was monitored during120d after sowing to flowering stage (February15to June30in the year) by systematic observation in soil depth of0mm～300mm in SHY. The results show J2congregate in soil depth of100mm-200mm. J2population peaked (0.95/g soil), around Jingzhe (March19in year) in soil depth of100mm～200mm. Earliest infection of J2in wheat root system was observed after sowing151d (March18that year) in SHY by acid fuchsin staining method.Field loss of3wheat varities experiments caused by CCN was carried out in SHY. The yield loss was between9.8%and14.9%. yield loss of Fanmai-5was significantly reduced compared to control area (14.9%, p<0.01).Plant source nematicides screening experiments was carried out in SHY. The results show that the increased rate of wheat plant height was between-5.20%and6.5%. Control efficiency was13.06%, and wheat panicles increaed19%compared to control ploat.In summary, this paper revealed that density of CCN widely distributed in most wheat growing areas of northern Anhui, Heterodera avenae was dominant pathogen in SHY. The distribution type belonged to block type, J2congregated in the soil depth of100mm-200mm soil. Earliest infection of J2in wheat root system was observed after sowing151d. The time of wheat cyst nematode infection was first observed to151d after sowing in SHY. Yield loss of Fanmai-5was14.9%in SHY. One plant source nematicidal agent was screened with control effenicy13.9%. |
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