Diploid Potato Hybrids as Sources of Resistance to Blackspot Bruising

Abstract

Resistance to bruising is an important quality trait of potato depending on multiple genetic and environmental factors. Thirty one interspecific diploid hybrids and two tetraploid standards were evaluated for resistance to bruising in 2 years. Diploids originated from crosses between wild and primitive Solanum species and dihaploids of S. tuberosum. Two-year mean values of bruising resistance of tested genotypes indicated significant variability of the trait. Analysis of variance showed significant effects of genotype, year and interaction between them on the trait. Broad-sense heritability of bruising resistance was estimated as moderately high, Hb=0.73. Content of L-tyrosine, the main substrate of discoloration reaction, was not significantly correlated with brusing in tested diploid hybrids. The clones, that were resistant to blackspot bruise, also combined quality traits and resistances to many pathogens. All these traits could be transferred together into tetraploid level in 4x×2x crosses via male 2n gametes produced by diploid hybrids.Resumen La Resistencia al daño mecánico es un carácter importante en la calidad de la papa que depende de múlti-ples factores genéticos y del ambiente. Se evaluaron 31 híbridos diploides interespecíficos y dos estándares tetraploides para resistencia a la magulladura en dos años. Los diploides se originaron de las cruzas entre especies silvestres y primitivas de Solanum y dihaploides de S. tuberosum. Los valores de las medias de dos años de resistencia al daño de los genotipos probados indicaron variabilidad significativa del carácter. El análisis de varianza mostró efectos significativos de genotipo, año e interacción entre ellos en el carácter. Heredabilidad, en un amplio sentido de resistencia al daño mecánico, se estimó como moderadamente alta, Hb=0.73. El contenido de L-tirosina, el principal sustrato de la reacción de oscurecimiento no estuvo correlacionado significativamente con el daño en los híbridos diploides probados. Los clones, que fueron resistentes a la mancha oscura, también combinaron los caracteres de calidad y resistencia a muchos patógenos. Todos estos caracteres pudieron transferirse juntos a nivel tetraploide en cruzas 4x × 2x vía gametos macho 2n producidos en híbridos diploides.

Natural losses in tuber weight during storage as a predictor of susceptibility to post‐wounding blackspot in advanced potato breeding materials

“…In the studies on the heritability of this feature, Komorowska‐Jędrys et al ., Domański et al . and Hara‐Skrzypiec and Jakuczun have shown that the degree of genetic determinants of the feature is very high and is about H n = 0.85. Therefore, the 178 genotypes were divided into three groups based on their sensitivity to after‐wounding blackspot, according to Aeppli: group 1 had an I bs of 0–19.9 (low susceptibility) and included 58 genotypes; group 2 had an I bs of 20–39.9 (medium susceptibility) and included 77 genotypes; group 3 had an I bs of ≥40 (high susceptibility) and included 43 genotypes (Table ).…”

“…Many studies have examined the formation of after‐wounding blackspot and their relation to natural losses, but no strict relationship between these characteristics has yet been demonstrated.…”

“…The problems related to after‐wounding blackspot of potato tubers have been the subject of research in various areas, including genetics, environmental, agricultural and storage technology factors . This research has revealed the chemical and physical mechanism of blackspot formation, and allowed us to classify mechanical damage, which results in dark color in the flesh, and to identify the factors that cause susceptibility to this damage.…”

Reconditioning and weather conditions affect black spot damage during storage of potato (Solanum tuberosumL.) tubers

“…The process of the formation of BSD is complex and depends on many factors. In studies on the heritability of this characteristic, Hara‐Skrzypiec and Jakuczun showed that the degree of genetic preconditioning for this trait is high and amounts to approximately H n = 0.85. Studies by Urbany et al found seven genes that were differentially expressed at the protein level between groups and for which DNA polymorphisms were associated with the investigated traits; these included a putative class III lipase that was identified as a novel factor contributing to the natural variation of bruising.…”

“…Research related to BSD in tubers has been undertaken to examine many factors, including genetics, environmental conditions, agronomic practices and storage conditions . Studies have determined the chemical and physical mechanisms that underly the development of black spots, have classified the mechanical damage that results in BSD, and have determined the factors that make potato susceptible to this physiological disorder.…”