Inheritance in Soybean of Resistant and Necrotic Reactions to Soybean Mosaic Virus Strains

Abstract

Five soybean [Glycine max (L.) Merr.] cultivars, PI96983, ‘Ogden’, ‘York’, ‘Marshall’, and ‘Kwanggyo’, were studied to determine the inheritance of their resistant (R) or necrotic (N) reactions to soybean mosaic virus (SMV) strains G4, G5, G6, G7, and G7A. Each parent was crossed reciprocally with a susceptible (S) cultivar (‘Essex’ or ‘Lee 68’) to determine the number of genes for resistance or necrosis. The R parents were also crossed with each other to test the allelism of the genes conditioning the R or N reaction. All the F2 populations from N × S crosses segregated in a 3:1 ratio with necrosis being dominant to susceptibility. The absence of S segregants in F2 populations of N × N and R × R crosses and the lack of segregation in S × S crosses indicate that the single dominant genes in the five non‐susceptible parents are alleles at a common locus. All R × S crosses produced a combination of R, N, and S plants and gave a good fit to a 3(R + N):1S ratio. Two different SMV‐strain × resistance‐gene interactions were observed to produce the N reaction: (i) alleles which are necrotic to specific strains in the homozygous state are dominant to alleles which are resistant or susceptible to the same strain, (ii) alleles which are resistant in the homozygous state to a strain often exhibit necrosis when they occur in a heterozygote with a susceptible allele.

Loss and Gain of Elicitor Function of Soybean Mosaic Virus G7 Provoking Rsv1 -Mediated Lethal Systemic Hypersensitive Response Maps to P3

“…Perturbation of Avr or R genes (15,20,41), graft inoculation instead of mechanical inoculation (6,28,69,72), change in genetic background of the R gene-carrying plant (45), heterozygosity rather than homozygosity of the R-genotype plant (10,52,56), prevention of salicylic acid accumulation in the R-genotype plant (19,42), or temperature shift (30,70) can result in virus escape to distant tissues, provoking systemic HR (SHR) in resistant genotypes. Occasionally, SHR will result in the death of the infected plant, a condition termed lethal SHR (LSHR) (28,29).…”

Genetic analysis of lethal tip necrosis induced by Clover yellow vein virus infection in pea

“…The spectrum of reactions includes resistance to systemic necrosis, lethal necrosis, and mosaic. Chen et al (1994) suggested that this range of complexities is controlled by the same gene. In Vigna unguiculata L., the Mvn-1 allele controls both the hypersensitive response to cowpea mosaic virus strain CPMV-LL and lethal necrosis to CPMV-TN (Patel 1982).…”

“…The genes involved in the systemic necrosis response are genetically closely linked to resistance genes that condition the hypersensitive response. For instance, soybean cultivar PI 96983, which carries the gene Rsv1 (Kiihl and Hartwig 1979), has resistance to soybean mosaic virus (SMV) strains G1 to G6 (Chen et al 1994), but develops systemic necrosis when infected with strain G7 (Cho and Goodman 1979). In F 2 populations derived from crosses of PI 96983 with several cultivars that develop mosaic symptoms, the necrosis phenotype segregated 3 : 1 after inoculation with G7, suggesting that a single dominant gene, possibly Rsv1, controls necrosis (Chen et al 1994).…”

“…For instance, soybean cultivar PI 96983, which carries the gene Rsv1 (Kiihl and Hartwig 1979), has resistance to soybean mosaic virus (SMV) strains G1 to G6 (Chen et al 1994), but develops systemic necrosis when infected with strain G7 (Cho and Goodman 1979). In F 2 populations derived from crosses of PI 96983 with several cultivars that develop mosaic symptoms, the necrosis phenotype segregated 3 : 1 after inoculation with G7, suggesting that a single dominant gene, possibly Rsv1, controls necrosis (Chen et al 1994). Recently, Ma et al (2003) reported that the lethal necrosis induced after infection of PI 507389 with either G1 or G6 is controlled by Rsv1-n. Rsv1-n is recessive to Rsv1, but the dominance relationship between Rsv1-n and susceptible allele rsv1 is not defi nitive, because the necrosis phenotype in plants heterozygous for rsv1 depends on the virulence of the SMV strain and the developmental stage of the plant.…”

Detection, Understanding and Controlof Soybean Mosaic Virus

“…It was initially named Rsv and found in PI96983 soybean (Kiihl and Hartwig, 1979) and later renamed Rsv1 (Chen et al, 1991). Subsequent studies on soybean cultivars resistant to SMV revealed additional eight different Rsv1 alleles, from cultivars Ogden, York, Marshall, Kwanggyo, 'Raiden', 'Suweon 97', LR1 and PI507389, respectively (Kiihl and Hartwig, 1979;Buss et al, 1997;Buzzell and Tu, 1989;Chen et al, 1991Chen et al, , 1993Chen et al, , 1994Chen et al, , 2001Chen et al, , 2002Ma et al, 1995;Zheng et al, 2005). The responses of soybeans carrying these Rsv1 alleles to different SMV strains are diverse, ranging from extreme resistance and necrosis to mosaic symptoms.…”