ABSTRACT
Lentil is one of the most important food legume species, however its genetic and genomic resources remained largely uncharacterized and unexploited. In the past few years, a number of genetic maps have been constructed and marker resources have been developed in lentil. These resources could be exploited for understanding the extent and distribution of genetic variation in genus Lens and also for developing saturated and consensus genetic maps suitable for quantitative trait loci (QTL) mapping and marker-assisted selection. The present study aims to enrich polymerase chain reaction-based linkage map of F10 recombinant inbred lines (RILs) population of 94 individuals derived from cross WA8649090 9 Precoz and identification of QTLs linked to early plant vigour traits. Of the 268 polymorphic markers (93 simple sequence repeats (SSR), three inter-simple sequence repeats (ISSRs) and 172 random amplified polymorphic DNA (RAPDs)), 265 (90 SSRs, three ISSRs and 172 RAPDs) were mapped on seven linkage groups, varying in length between 25.6 and 210.3 cM, coverage of 809.4 cM with an average marker spacing of 3.05 cM. The study also reported assigning of 24 new cross-genera SSRs of Trifolium pratense on the present linkage map. The RILs along with the parents were screened for shoot length, root length, seedling length, dry weight, number of leaves and number of branches based on two replications under polyhouse conditions. A QTLhotspot consisting of six QTLs for shoot length (cm), root length (cm) and seedling length (cm) was observed between a map distances of56.61 and 86.81 cM on LG1.
Subject(s)
Genome, Plant , Lens Plant/growth & development , Lens Plant/genetics , Seedlings/growth & development , Seedlings/genetics , Chromosome Mapping , Chromosomes, Plant/genetics , Crosses, Genetic , DNA, Plant/genetics , Genetic Association Studies , Genetic Linkage , Genetic Markers , Microsatellite Repeats , Phenotype , Polymorphism, Genetic , Quantitative Trait LociABSTRACT
Seed weight and seed size both are quantitative traits and have been considered as important components of grain yield, thus identification of quantitative trait loci (QTL) for seed traits in lentil (Lens culinaris) would be beneficial for the improvement of grain yield. Hence the main objective of this study was to identify QTLs for seed traits using an intraspecific mapping population derived from a cross between L. culinaris cv. Precoz (seed weight-5.1g, seed size-5.7mm) and L. culinaris cv. L830 (seed weight-2.2g, seed size-4mm) comprising 126 F8-RILs. For this, two microsatellite genomic libraries enriched for (GA/CT) and (GAA/CTT) motif were constructed which resulted in the development of 501 new genomic SSR markers. Six hundred forty seven SSR markers (including 146 previously published) were screened for parental polymorphism and 219 (33.8%) were found to be polymorphic among the parents. Of these 216 were mapped on seven linkage groups at LOD4.0 spanning 1183.7cM with an average marker density of 5.48cM. Phenotypic data from the RILs was used to identify QTLs for the seed weight and seed size traits by single marker analysis (SMA) followed by composite interval mapping (CIM) which resulted in one QTL each for the 2 traits (qSW and qSS) that were co-localized on LG4 and explained 48.4% and 27.5% of phenotypic variance respectively. The current study would serve as a strong foundation for further validation and fine mapping for utilization in lentil breeding programs.
Subject(s)
Chromosome Mapping , Lens Plant/genetics , Quantitative Trait Loci , Chromosomes, Plant , DNA, Plant/genetics , Genes, Plant , Genetic Linkage , Genomic Library , Microsatellite Repeats , Organ Size , Phenotype , Polymorphism, Genetic , SeedsSubject(s)
Biometry , Epistasis, Genetic , Lens Plant/genetics , Altitude , Analysis of Variance , Climate , Crops, Agricultural/chemistry , Crops, Agricultural/genetics , Crops, Agricultural/physiology , Crosses, Genetic , Genetic Variation , Genotype , India , Inheritance Patterns , Lens Plant/chemistry , Lens Plant/physiology , Plant Proteins/analysis , Plant Proteins/chemistry , Random Amplified Polymorphic DNA Technique , Seeds/chemistry , Seeds/genetics , Seeds/physiology , Tryptophan/chemistryABSTRACT
The fluorescent in situ hybridization (FISH) technique has been applied to somatic chromosomes in the medicinally important species, Bunium persicum, to elucidate its karyotypes. The bicolour FISH technique involving 18S-5.8S-26S and 5S ribosomal RNA genes as probes was used to assign physical localization and measurement of rDNA sites on homologous pairs of chromosomes. The two 18S-5.8S-26S rRNA gene sites were at the terminal regions of the short arms of the chromosomes 1 and 2 involving NOR region of chromosome 1. The 5S rDNA sites were found on subtelomeric region of the long arm of the chromosome number 5 and at interstitial regions of the short arm of chromosome 7. Based on direct visual analysis of chromosome length, morphology and position of FISH signals, a pioneer attempt has been made to construct metaphase karyotype in Bunium persicum, an endangered medicinal plant of North Western Himalayas.