Identification of molecular markers associated with leptine in reciprocal backcross families of diploid potato

Abstract

Solanum phureja clone 1-3 and S. chacoense clone 80-1 have a zero and high leptine content in their foliage, respectively. An F(1) hybrid (CP2) was intermediate for the trait, but self-incompatible. Two reciprocal backcross families, PBCp ( phu 1-3 x CP2) and PBCc (CP2 x phu 1-3), and a family of monoploids derived by anther culture of CP2, were characterized for leptine as the aglycon, acetylleptinidine (ALD), content in leaves by gas chromatography. ALD was present in 43 of 87 genotypes in the PBCp backcross, implying simple genetic control by a dominant gene. However, the ALD levels were low compared to CP2. In the PBCc backcross, only 7 of 42 genotypes expressed ALD at a level generally higher than in PBCp. This ratio was significantly different from the 1:1 segregation observed in the reciprocal backcross and suggests a cytoplasmic influence. ALD levels in the CP2 monoploids ranged from 0 to 8,968 &mgr;g.g(-1) of dry weight (dw) with 18 individuals expressing ALD and five with 0 ALD content. Ten high (mean ALD = 546 &mgr;g.g(-1) of dw) and ten low (mean ALD = 0) individual plants within PBCp and seven high (mean ALD = 3,037 &mgr;g.g(-1) of dw) and eight low (mean ALD = 0) individual plants within PBCc were used for bulk segregant analysis (BSA) using 214 RAPD (randomly amplified polymorphic DNA) primers. Three RAPD primers (OPQ-2, OPT-16 and OPT-20) amplified bands exclusively in bulks containing DNA mixes of high ALD producers in both PBCp and PBCc populations. These results suggest that these markers were associated in coupling to ALD content. ANOVAs for ALD content verified association between the markers and the trait. A CAPS (cleaved amplified polymorphic sequence) marker, GP82A, was also significantly associated with ALD production in both the monoploid and the PBCp populations. None of the RAPD markers was associated to ALD in the monoploids but one was associated in repulsion. The monoploid data indicate the likelihood of a recessive gene(s) that controls leptine production, but the backcross data indicate the action of modifying loci.

Self‐fertility and resistance to the Colorado potato beetle (Leptinotarsa decemlineata) in a diploid Solanum chacoense recombinant inbred line population

“…Leptine production was successfully introduced into diploid breeding germplasm using a RIL individual from the F 4 generation. Continuous variation in field defoliation resistance among the F 1 MSHH786B hybrids supports the hypothesis that multiple recessive genes contribute to the Colorado potato beetle resistance phenotype (Boluarte‐Medina et al., 2002; Hutvágner et al., 2001; Manrique‐Carpintero et al., 2014; Ronning et al., 1999). Because Colorado potato beetle resistance is more likely fixed in the strongly resistant, highly homozygous F 5 inbreds, they are a more efficient vehicle to introgress host plant resistance into cultivated diploid backgrounds.…”

“…The high leptine‐producing diploid S. chacoense accession USDA8380‐1 (80‐1) has demonstrated strong antibiosis properties against the Colorado potato beetle (Sinden et al., 1986). Unfortunately, the presence of multiple loci contributing to leptine production and the recessive inheritance of key functional and/or regulatory genes in the leptine biosynthesis pathway (Boluarte‐Medina et al., 2002; Hutvágner et al., 2001; Kaiser et al., 2020; Manrique‐Carpintero et al., 2014; Ronning et al., 1998; Ronning et al., 1999; Sagredo et al., 2009; Sagredo et al., 2006) has prevented the successful introgression of Colorado potato beetle resistance into cultivated potato.…”

Pathways to defense metabolites and evading fruit bitterness in genus Solanum evolved through 2-oxoglutarate-dependent dioxygenases

“…Cultivated potato varieties do not produce leptinines and leptines in any of their tissue parts. While several quantitative trait loci (QTL) regions associated with leptinine and leptine biosynthesis were identified in segregating potato populations ( S. tuberosum × S. chacoense ), none of the genes partaking in leptinine/leptine biosynthesis have been discovered to date 19–22 . The formation of leptinine I and leptinine II via hydroxylation of α -chaconine and α -solanine, respectively, is the crucial intermediate step in the leptine biosynthetic pathway.…”

Sequence Diversity in Coding Regions of Candidate Genes in the Glycoalkaloid Biosynthetic Pathway of Wild Potato Species

“…Breeding for resistance mediated by SGAs is complicated by polygenic inheritance, by the high correlation in SGA content between foliage and tubers, and because SGA accumulation is influenced by environmental factors and crop management activities (Tingey 1984). Previous studies seeking to identify molecular markers associated with SGA production demonstrated the complexity of the genetic control of SGA production (Yencho et al 1998; Ronning et al 1999; Hutvágner et al 2001; Boluarte-Medina et al 2002; Van Dam et al 2003; Sagredo et al 2006). Identification and cloning genes associated with synthesis and accumulation of SGAs present an alternative to either marker-assisted selection or genetic transformation.…”