Soybean cyst nematodes: a destructive threat to soybean production in China

Abstract

Soybean cyst nematode (SCN), Heterodera glycines, is one of the most important pests in soybean production worldwide. In China, 11 different races of SCN, including a newly identified race ‘X12’ with super-virulence, have been surveyed and found to be distributed in 22 provinces. Among them, races 1, 3 and 4 are dominant in the two principal soybean-producing areas, Northeast China and Huanghuaihai Valley, causing over 120 million dollars of annual yield loss. Rapid and reliable PCR-based approaches have been developed for the molecular diagnosis of SCN. High-throughput methods for the identification of soybean resistance against SCN are also developed with specific single nucleotide polymorphism markers by using Kompetitive Allele Specific PCR technology. Over 10,000 soybean germplasm sources were evaluated for their SCN resistance, and 28 SCN-resistant soybean accessions were selected to construct an applied core collection, which has been used for soybean breeding in China. Recently, the genome sequences of SCN and soybean are publically available, and two major SCN-resistant genes (rhg1 and Rhg4) have been identified in soybean, which greatly facilitate the researches on SCN virulence and soybean resistance, and also soybean resistance breeding against SCN. However, the management of SCN still faces many bottlenecks, for instance, the single resistance genes in soybean cultivars can be easily overcome by new SCN races; the identified resistance genes are inadequate to meet the practical breeding needs; and our understanding of the mechanisms of SCN virulence and soybean resistance to SCN are limited. SCN is a destructive threat to soybean production throughout the world including China. In this review, the major progress on soybean SCN is summarized, mainly focusing on the recent research progress in SCN, soybean resistance to SCN and integrated management of SCN in China, and aiming at a better understanding of the current SCN research status and prospects for future work.

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

“…It is not only the source of both vegetable protein and edible oil for human food, it is also the source of feed for animal and industrial processes ( Hannah Ritchie and Roser, 2021 ). Facing the gap between limited domestic production of soybean and an expanding demand on one side and on the other side the continuous evolution of SCN virulence genes, it is of vital importance for China to promote domestic soybean production but also to reduce yield losses due to SCN damage ( Yan and Baidoo, 2018 ; Peng et al, 2021 ). Additionally, this situation is aggravated by the fact that minor but significant losses due to SCN damage are easy to ignore by farmers ( Niblack et al, 2008 ) but may be common in the main production areas in China according to the survey data ( Lian et al, 2016 ; Chen et al, 2021 ) as summarized in Figure 1 , and accumulated yield losses are relevant nation-wide.…”

“…Although the SCN has spread almost everywhere in the two major soybean planting areas in China, the planting area of cultivars with SCN resistance is very limited. So far, some varieties with SCN resistance have been registered already a long time ago in China but with almost no growing area, such as Zhonghuang 12 and Zhonghuang 57, a series of Kangxian cultivars ( Liu et al, 2008 ; Duan and Peng, 2014 ; Peng et al, 2021 ). According to the survey of cultivars/breeding lines for use in the Huang-Huai Valleys, only a few of these exhibit SCN resistance loci ( Lian et al, 2019a ).…”

“…Heterodera glycines ( H. glycines , HG; soybean cyst nematode, SCN) is considered to be one of the most damaging pests in soybean worldwide, and the loss of revenue from SCN damage is estimated to be billions of dollars per year worldwide ( Koenning and Wrather, 2010 ; Bradley et al, 2021 ). There are few sporadic reports that SCN is also widely distributed in China but not many actions taken to control it yet ( Lian et al, 2016 ; Chen et al, 2021 ; Peng et al, 2021 ). Furthermore, it has also been reported that virulent nematode populations have developed over time and overcome the resistance of most known plant resistant sources, such as PI 88788 ( Niblack et al, 2008 ; Mitchum, 2016 ).…”

Identification of Candidate Genes Controlling Soybean Cyst Nematode Resistance in “Handou 10” Based on Genome and Transcriptome Analyzes

“…Soybean cyst nematode (SCN, Heterodera glycines Ichinohe) is a devastating pest affecting soybean ( Glycine max [L.] Merr.) production worldwide ( Riggs, 1977 ; Koenning and Wrather, 2010 ; Tylka and Marett, 2014 ; Mitchum, 2016 ; Miraeiz et al, 2020 ; Peng et al, 2021 ). SCN has caused approximately 36% of yield losses in the total soybean production from 1996–2014 in the United States ( Kim et al, 2016 ).…”

Host-induced silencing of a nematode chitin synthase gene decreases abundance of rhizosphere fungal community while enhancing

“…A steady increase in soybean production is required to meet growing world food and energy demands. Soybean cyst nematode (SCN, Heterodera glycines Ichinohe) is one of the most economically damaging pathogens in soybean worldwide, significantly constraining soybean production and causing huge yield losses annually (Peng et al 2021). SCN secretes a series of effectors mainly through a spear-like feeding structure called a stylet, penetrating host root cell walls and inducing the formation of complex feeding sites (syncytia) near the vascular cylinder, from which SCN obtains nutrition.…”