Genetic analysis of traits controlling water use efficiency and rooting in mulberry (Morus spp.) by molecular markers

Abstract

Mulberry is the most important crop of sericulture industry. The major constraint in realizing the newlinepotential mulberry leaf yield is due to prevalence of soil moisture stress in vast sericultural zones of the newlinecountry. Development of mulberry varieties with moisture stress tolerance is the one of the rewarding newlinestrategy to address the problem. Many investigations have revealed that water use efficiency (WUE) newlineand root characters play a pivotal role in drought tolerance mechanism in plants. However, it has been newlinealso understood that WUE and root traits are complex characteristics and governed by many genes. In newlinethis context, the present study is an effort towards understanding of moisture stress tolerance in newlinemulberry by development of trait specific (WUE and root) linkage maps and then to map QTLs newlinecontrolling the traits for utilization in directional improvement through marker assisted selection. newlineCharacterization of about 300-mulberry germplasm using growth traits, rooting and D13C newlineresulted in the identification of contrasting accessions for WUE (5 Nos.) and root trait (4 Nos.). Parent newlinespecific linkage maps were constructed by genotyping WUE mapping population (200 Nos.) from the newlinecross Himachal Local x MS-3 using 76 RAPD primers (196 polymorphic markers). Based on newlinephenotypic data of two different seasons, QTL analysis resulted in identification of loci governing newlineaverage shoot length and inter-nodal distance on female (LG7) and male (LG3) map respectively. The newlinemapping population from the cross Dudhia White x UP were utilized for linkage analysis and QTL newlinemapping of root traits. Composite Interval Mapping analysis of the female parent based on the trait newlinevalues of two seasons identified many putative QTLs on LG9. Shoot weight (in saplings) and length of newlinethe longest root were mapped on female LG5 by Interval Mapping (IM) with LOD score gt 3.0 which newlinewas concurrent with Composite Interval Mapping analysis.