QTL Mapping For Microtuber Dormancy, GA₃ And ABA Content In A Diploid Potato Population

Dormancy is a vital phenomenon for various plant species,short dormancy is a widespread problem especially during storage.Too long dormancy is also a problematic issue due to nonuniform germination in the field.Currently,advancement is being made with regards to the regulation of dormancy.Developments in our consideration of the molecular mechanisms that are intricate in dormancy,along with strategies by means of applied genetics,will provide new approaches through which the required level of dormancy can be introduced into plant species.However,genetic control of dormancy is still poorly understood in most plant species.Dormancy is a prominent feature of the potato for tuber storage.With the micro-tuber system in which tubers were produced in vitro and stored at 20°C,a quantitative trait locus?QTL?analysis was performed for dormancy,gibberellic acid?GA3?,and Abscisic Acid?ABA?content in an F1 population consisting of 178 genotypes derived from an interspecific cross between Solanum chacoense acc.PI 320285?long dormancy?and S.phureja acc.DM1-3 516 R44?short dormancy?.In this analysis,174 markers were used to construct a genetic map with a total length of 591.8 cM.The QTL analysis identified 22 markers;PGSC21436₁60 was most closely linked with the timing of dormancy release and GA3 content.The alleles from the male parent promoted long dormancy,with the largest effect at a QTL on chromosome I,which explained 9.4 % of the phenotypic variation.Surprisingly,the QTLs for dormancy and GA3 were localized at the same position,genetically confirming that potato tuber dormancy and sprouting are related to GA3 synthesis.The identified QTLs provide the physiological and genetic dissection of potato dormancy which has potentials for dormancy regulation in potato breeding.The QTL analysis identified 11 markers associated with the timing of dormancy release and ABA content after harvesting?AH?and after sprouting?AS?.To our knowledge,this is the first study in potato to identify QTLs for dormancy and ABA traits.Most of the QTLs identified,have the possibility of being used for potato dormancy regulation in breeding programs.The obtained results increase our knowledge of the trait inheritance associated for potato variety development.This study provides the physiological and inherited segmentation of potato dormancy.The identified QTLs will also serve as useful targets for potato breeding.Our determination has been to find the quantitative trait loci associated with tuber dormancy in a segregating diploid population,and then to correlate with GA3 and ABA content after harvesting?AH?and after sprouting?AS?concerned in the regulation of this important traits.We have found QTL for dormancy and GA3 coincided in the same location.As for ABA content,ABA?AH?2014 and?AS?2015 also mapped in the similar position on CHR I.Such commonality proposed that GA and ABA play vital role in dormancy regulation.We also mapped ABA?AH?2014,?AH?2015 and?AS?2014 on CHR IV.In this mapping,procedures are responsive to the identification of QTLs for GA3 and ABA content together with more traditional morphological advances could enhance our empathetic of how GA3,ABA?AH?and?AS?are involved in the regulation of dormancy.The studies have probable significance for the breeder as well as for the physiologist.It is feasible that marker assisted breeding will be more efficacious if the GA3 and ABA QTLs related with the markers are considered.The likelihood of accidental linkage or pleiotropic influence could be decreased.This research could also support avoiding the selection of genetic factor with adverse pleiotropic influence when genes are transferred by molecular approaches.