The Spatial Distribution and Genetic Diversity of the Soybean Cyst Nematode, Heterodera glycines, in China: It Is Time to Take Measures to Control Soybean Cyst Nematode

Abstract

The continuous evolution and spread of virulent forms of the soybean cyst nematode (SCN) driven by the environment and anthropogenic intervention is a serious threat to the soybean production worldwide, including China. Especially in China, the implemented measures to control SCN are insufficient for sustainable agricultural development yet. We summarized our knowledge about the spread and spatial distribution of SCN in China and the virulence diversity in the main soybean growing areas. To reveal the genetic relatedness and diversity of SCN populations, we re-sequenced 53 SCN genomes from the Huang-Huai Valleys, one of the two main soybean growing areas in China. We identified spreading patterns linked to the local agroecosystems and topographies. Moreover, we disclosed the first evidence for the selection of complex virulence in the field even under low selection pressure in an example from North Shanxi. SCN is present in all soybean growing areas in China but SCN susceptible cultivars are still largely grown indicating that SCN-related damage and financial loss have not received the attention they deserve yet. To prevent increasing yield losses and to improve the acceptance of resistant cultivars by the growers, we emphasized that it is time to accelerate SCN resistance breeding, planting resistant cultivars to a larger extent, and to support farmers to implement a wider crop rotation for sustainable development of the soybean production in China.

Identification of resistant sources from Glycine max against soybean cyst nematode

“…Here, Handou 10 achieved an FI of 36.4 which corresponds to an MS reaction. In general, the number of harvested cysts is environmentally affected by temperature, humidity, watering, etc., and even when the bioassay is Zhonghuang 57 also showed resistance to race 2 and race 4, two races that increasingly spread in soybean-growing areas worldwide (Xu et al, 2021;Lian et al, 2022). With resistances against all five races, Zhonghuang 57 is the most resistant cultivar in our study material and this multiplex resistance is comparable with one of the most resistant genetic resources for SCN resistance, PI 437654 (Shi et al, 2015).…”

“…Heinong 531 is a known resistant cultivar with resistance to race 3 ( Wang et al., 2022 ). Heinong 84 is a cultivar showing rgh1 and Rgh4 resistance marker loci ( Lian et al., 2022 ). Fengdou 1, Nenfeng 15, Nenfeng 17 ( Chen et al., 2023 ), Nenfeng 18 ( Chen et al., 2023 ), Nenfeng 19, Nongqingdou 24, and Qinong 5 derived from soybean breeder Dr. M. Yuan and were selected with race 3 in the field.…”

“…All the 12 cultivars are yellow seeded and have a higher 100-seed weight between 16 and 23.9 g as required for food use (Table 1). None of these registered varieties with SCN resistance have been well released in the local production area (Duan and Peng, 2014;Peng et al, 2021) except "Heinong 84", which accounted for 4% of the soybean planting area in Heilongjiang in 2019 (Lian et al, 2022).…”

Evaluation Soybean Cultivars for Reaction to Heterodera glycines Populations HG Types 7 and 1.3.4.7 in Northeast China

“…SCN resistance was strongly associated with black seed coat. Soybean breeders need to make numerous backcrosses for improving undesirable traits related to the linkage of genetic background [ 17 ]. In this study, some cultivars which have yellow seed coat and good agronomic characteristics will be used in breeding programs as SCN resistance sources.…”

“…Eleven H. glycines (HG) Types 0, 1.2.3.5.7, 1.2.3.7, 1.3.4.7, 1.3.7, 2, 2.5.7, 2.7, 6, 6.7, and 7, were reported in Heilongjiang province [ 16 ]. However, a big challenge for the management of SCN in the field is the presence of multiple SCN HG types [ 17 ]. In northeastern China, the majority of the resistant cultivars are derived from Peking via cultivar Franklin and/or its derived cultivars, whereas long-term, ongoing use of the same resistant source (Peking) caused the adaption of SCN populations in Heilongjiang [ 18 ].…”