Effect of Sugarcane Mosaic Virus Infection in Parental Stock on Panicle and Seed Production of Virus-Free F₂ Progeny in Sorghum (Sorghum bicolor). R. G. Mock, Plant Pathologist, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, MD 20705. I. E. Stokes, Agronomist (Retired), and A. G. Gillaspie, Jr., Research Plant Pathologist, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, MD 20705. Plant Dis. 69:310-312. Accepted for publication 26 September 1984. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1985. DOI: 10.1094/PD-69-310.

Virus-free F₂ progeny of the original sorghum cross MN 4611 × Planter were analyzed to compare panicle and seed production among populations derived from parental stock infected with sugarcane mosaic virus strain A (SCMV-A) or not infected. Virus-infected crosses had only one parent infected with SCMV-A, either female or male. The virus was not present in F₁ or F₂ plants. Data were collected on 441 F₂ plants in greenhouse tests. Analysis of variance and LSD comparisons showed a significant reduction (P = 0.005) in seeds per panicle and an increase in panicles per plant (P = 0.070) of F₂ progeny derived from crosses with SCMV-A-infected MN 4611 compared with F₂ data from uninfected crosses. Our data suggest that there is varietal variation with respect to panicle and seed production in the F₂ in response to virus infection in the original crosses. Total number of seeds per plant did not vary significantly between F₂ progeny of uninfected vs. virus-infected groups because of the long period of plant growth (7 mo).

Keyword(s): genetic deviation, yield components.