Nematode Resistance in Soybean - Translational Genomics for Crop Breeding: Biotic Stress - page 95

Chapter 7

Nematode Resistance inSoybean

TriD.Vuong,YongqingJiao,J.GroverShannon,andHenryT.Nguyen

Abstract

Soybean [ Glycine max (L.) Merr.] is an important leguminous crop that produces the major sources of
edible vegetable oil and protein closest to the optimum dietary essential amino acid profiles for human
consumption and livestock feed. However, like many other crop plants, soybean can become infested
with and severely damaged by three common plant-parasitic nematode species: cyst nematode ( Het-
erodera glycines ), root-knot nematode ( Meloidogyne spp.), and reniform nematode ( Rotylenchulus
reniformis ). Nematode parasitism results in economically significant yield losses for soybean produc-
ers worldwide. For decades, breeding for resistance variety has been an effective and practical method
to control these pests. Soybean varieties with resistance to these nematodes have been successfully
developed using traditional breeding and/or marker-assisted breeding approaches. Advancements in
genetic marker technologies have greatly facilitated the identification and characterization of genomic
regions or genes conveying resistance to different nematode species. Map-based cloning and microar-
ray gene expression profiling studies in both soybean and nematodes reported a large number of
transcription factors and candidate genes significantly associated with nematode parasitism and plant
resistance. The findings enhanced an understanding of mechanisms of host resistance and also enabled
scientists to elucidate the functionality of the genes involved in soybean-parasitic nematode interac-
tion. In the past, traditional genetic mapping using bi-parental populations has been widely utilized to
detect and characterize genomic locations associated with nematode resistance. However, this method
also has disadvantages in discovering novel functional variations or estimating allelic effects because
of the limitations of population structure. Recently, in conjunction with next-generation sequencing
(NGS) technology and various genomics analysis approaches, traditional bi-parental genetic map-
ping has shifted to genome-wide association studies (GWAS), nested-association mapping (NAM),
multi-parent advanced generation intercrosses (MAGIC), and so forth. It is anticipated that progress in
new genetic mapping methods, coupled with the applications of omics-assisted analysis, significantly
facilitate genomic-based selection and transgenic strategies, which can lead to the improvement of
soybean resistance to these three important nematode species.

the world's vegetable fats, oils, and protein
meal (Wilson 2004). The origin of the soy-
bean plant is in eastern Asia, where people have
grown it for thousands of years. The value of

Introduction

Soybean [ Glycine max (L.) Merr.] is an annual
leguminous

crop that supplies over half of