Submitted to: Crop Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/28/2005
Publication Date: 5/18/2006
Citation: Sterrett, S.B., Haynes, K.G., Yencho, G.C., Henninger, M.R., Vinyard, B.T. 2006. 4x-2x potato clones with resistance or susceptibility to internal heat necrosis differ in mineral status. Crop Science. 46:1471-1478. Interpretive Summary: Internal heat necrosis (IHN) is a physiological disorder resulting in patches of dead potato tuber tissue that has been associated with low levels of tuber calcium. We bred potato parental material from related potato species with resistance to IHN and used these parents to study the nutritional differences in IHN resistant and susceptible parents. IHN resistant parents had higher tuber concentrations of manganese and sulfur, but lower concentrations of phosphorus, than IHN susceptible parents. Our parental materials had higher levels of calcium and greater incidence of IHN than previously published levels in commercial potatoes, indicating that modifying soil fertility with additional calcium alone will not be sufficient to control IHN. The results of this research will be used to develop IHN-resistant potato varieties in the future. This research will benefit potato producers in warm temperature growing environments.
Technical Abstract: Internal heat necrosis (IHN) is a physiological disorder resulting in necrotic tissue in the pith of potato tubers. Susceptibility is associated with localized Ca deficiency within the tuber, but Ca availability may be influenced by other nutrients. Studies in VA, NC, and NJ in 2001 and 2002 determined the influence of soil-applied calcium on tuber yield, specific gravity, IHN, and nutrient concentration. Furrow-applied calcium sulfate (+ 448 kg ha-1 Ca) was applied to IHN-resistant or susceptible interspecific 4x-2x S. tuberosum X S. phureja -S. stenotomum hybrids. Tuber yield, specific gravity (SG), incidence and severity of IHN, and nonperiderm concentrations of P, K, Mg, Ca, S, Na, Zn, Mn, Cu, and Fe were determined. Clones differed significantly for yield, SG, and IHN expression. Resistant clones were lower in IHN incidence than susceptible clones but the clone x Ca interaction was not consistently significant within location-years. Incidence was fit with a classification and regression tree (CART) model with the 10 nutrients as regressors, which revealed that IHN-resistant clones had higher tuber concentrations of Mn and S, but lower P. These results suggest that resistance or susceptibility to IHN is a complex function of tuber tissue mineral status. Mn, S, and P may make a more important contribution to clonal IHN resistance than calcium. Additional work is needed to verify the potential for minimizing IHN by either nutrient management or genetic enhancement.