Molecular mapping of important agro-botanic traits in sesame
Keywords: Sesame, Agro-botanic traits, Genetics, Molecular Markers, QTLs
AbstractSesame (Sesamum indicum L.) ((2n=26) is one of the most ancient oilseed crop of the world. The present study was undertaken to develop a molecular map of the important agro-botanic traits in sesame. Two sesame genotypes Chandana and TAC-89-309 that differ in respect of the important agro-botanic traits were crossed to study the inheritance of these traits. The F2 population along with the F1 and parents was evaluated under field conditions and observations were made on nine agro-botanic traits using International Board for Plant Genetic Resources (IBPGR) descriptor grading. For mapping trait related QTL, a genetic framework linkage map was constructed employing a mapping population of 120 F2 individual plants and effective 60 RAPD polymorphic markers chosen based on the study of parental polymorphism (23.07 %). The linkage map places the 60 markers on nine linkage groups spanning a total length of 1547.16 cM at an average distance of 25.78 cM between markers. These nine linkage groups could be covering about 60% of the map length of the genome. Length of the linkage groups ranged between 58.8 (Linkage Group 8) to 423.8 cM (Linkage group 9). The segregation and normal distribution observed in respect of most of the traits in the F2 population have been indicative that the mapping population had sufficient amount of genetic variability for mapping trait specific QTL. Seventeen QTL have been identified for the nine agro-botanic traits by single marker analysis. In all, 19 QTL have been identified by using QTL cartographer v 2.5. Of which, 7 and 12 QTL have been identified by Simple interval mapping and Composite interval mapping respectively. Two genomic regions - one on LG 1 and the other on LG 6 had more than one QTL. The marker interval between OPAE 15350 and OPD 6480 on the linkage group 1 has three QTL viz., leaf angle, capsule hair length and stem hairiness, while on LG 6 between the markers OPP 8380 and OPR 8980, two QTL for basal leaf shape and capsule hair density are distributed. In all, nine tightly linked markers for nine different traits have been identified with marker-QTL distance of < 2.6 cM. Out of the 19 QTL detected, five explaining high phenotypic variation are promising. These include one QTL for corolla colour, two for capsule shape and one each for capsule hair density and number of nodes.
It is certified that:
- The corresponding author is fully responsible for any disputes arising due to the publication of his/her manuscript.
- The article has been seen by all the authors who are satisfied with its form and content.
- The sequence of names of authors in the by-line is as per their relative contribution to this experiment, giving due credit to all scientists who made notable contribution to it.
- All the authors fully understand that inclusion of any other co-authors or exclusion of any co-authors is not possible once the article has been submitted to the journal.
- The corresponding author takes full responsibility for this article.
- The address of the organization where the research was conducted is given.
- The article is exclusive for this journal, and the results reported here have not been sent (and will not be sent during its consideration by this journal) for publication in any other journal.
- Authors agree to abide by the objective comments of referees and do agree to modify the article into a short note as per the recommendation, for publication in the Electronic Journal of Plant Breeding.
- If published in Electronic Journal of Plant Breeding, the copyright of this article would vest with the Indian Society of Plant Breeders, who will have the right to enter into any agreement with any organization in India or abroad engaged in reprography, photocopying, storage and dissemination of information contained in it, and neither we nor our legal heirs will have any claims on royalty.