Temporal dynamics of tuber formation and related processes in a crossing population of potato (Solanum tuberosum)

Abstract

The chronological relationships between stolon formation, stolon tip swelling, tuber initiation, flowering, senescence, growth and resorption of tubers were studied under field conditions in a diploid population of potato with 238 genotypes, the parental clones and seven tetraploid cultivars. Timing of tuber initiation was not closely related to the timing of stolon formation, flowering and duration of the plant cycle. Tuber initiation very often preceded stolon branching. The number and size distribution of tubers were largely influenced by the degree of stolon branching, the length of the stolon swelling period and tuber resorption. The peak production of stolons and swollen stolon tips largely took place within the flowering period, although in most genotypes, some stolon tip swelling took place until the end of the plant cycle. More information on the general temporal relationships between events related to tuber formation and plant development will contribute to a better understanding of the physiological and genetic basis of the processes leading to the production of harvestable tubers.

Understanding the genetic basis of potato development using a multi-trait QTL analysis

“…In the E parent this QTL has a huge effect with values -log10(p) going up to 50; for most traits, the explained variances for this QTL are very high going up to 60 % for onset of senescence (Table 2). This finding is in agreement with previous reports indicating a major effect of a QTL in the same chromosomal region associated with plant maturity with pleiotropic effects on many developmental traits (Celis-Gamboa 2002;Hurtado et al 2012;Kloosterman et al 2013;Malosetti et al 2006). According to our results there is no major contribution of this QTL to the agronomic traits as indicated by the low explained variances.…”

“…Together with the SNP markers, AFLP, SSR and CAPS with expected segregation ratios 1:1 and 1:1:1:1, respectively, were used to construct more saturated maps of parent C and E (additional file 1). JoinMap 4 (van Ooijen 2009) was used to map 521 and 560 markers on the C and E maps, respectively, with 12 linkage groups (LG) for each parent as reported previously (Celis-Gamboa 2002).…”

“…Belowground, number of tubers and total tuber weight were assessed after the final harvest. Euphytica (2015) 204:229-241 231 The evaluation of flowering and senescence was done using a scale from 0 to 7 and 1 to 7 respectively, as described in (Celis-Gamboa et al 2003). Flowering was recorded 17 times with intervals of 2-6 days at 38,40,42,45,47,49,52,54,56,59,61,63,66,68,70,74,80,83,87,89 and 95 days after planting (DAP).…”

Organ specificity and transcriptional control of metabolic routes revealed by expression QTL profiling of source-sink tissues in a segregating potato population

“…The question arises whether the high number of QTLs found in this small genomic region on linkage group 5 can be attributed to a single 'master switch' controlling the expression of many genes. The variation in timing of senescence and tuber formation has been phenotyped in the C × E population and has previously been mapped as the earliness locus ( El ) in the same genomic region as the eQTL hotspot found for the tuber data on chromosome 5 [32]. The C × E population shows a strong variation in the onset of tuber formation (early--late) and to allow a comparison of gene expression in tubers of equivalent physiological state, a choice was made to extract RNA of 'mature' tubers harvested several weeks after haulm killing.…”

“…This population is derived from an original cross between potato clones C (USW533.7) and E (77.2102.37) and is described in detail in [32]. Tuber samples originate from a field experiment, grown in repeats during the normal potato-growing season in the Netherlands (April-September).…”