Fine Mapping of Candidate Gene for Root Length for Adaptation to Drought Inheritance and Validation of Gene Based Markers Linked to Aroma in Upland Rice Oryza sativa L

Abstract

An investigation was carried out to fine map the candidate gene for root length newlineqAZRL9 on chromosome 9 and its validation in local land races of rice; morphological and newlinemolecular characterization of local short grain aromatic genotypes, inheritance and validation newlineof gene based markers linked to aroma. The qAZRL9 (RM242-RM201) was fine mapped to newlinesmall genomic regions between RM24569-RM242 (0.13 Mbp) and RM5661-RM24579 (0.40 newlineMbp). The marker RM242 was found to be closely linked to increased root length in local land newlineraces of rice, thus can be effectively used in MAS and MABC programmes. newlineMorphological characterization of 42 landraces revealed that, landrace Gandhasali newlinewas superior for test weight and grain yield per plant, Pusa suganda-4 was superior for grain newlineyield per plant while, Kalanamak and Ambemohor were rich in Fe and Zn in grains. Genetic newlinediversity analysis indicated that inter cluster distance was not consistent with the geographic newlinedistribution of land races. The land races belonging to diverse ecological regions were newlineclustered together, whereas, land races of the same region were grouped into separate newlineclusters. Grain yield per plant had maximum contribution towards the genetic divergence newlinefollowed by grain length and plant height. Molecular characterization by SSR and InDel newlinemarkers revealed presence of variation between basmati and short grain aromatic genotypes. newlineMost of the basmati genotypes were grouped to one cluster while, all the local short grain newlinearomatic genotypes were grouped into another cluster. These markers can be used for newlinepreventing adulteration of Indian basmati rice with other basmati rice. newlineStudy on inheritance pattern of aroma in three populations viz., the F2 of IR-64 × newlineAmbemohor, F7 RILs of IR-38 × Jeerige sanna and BC2F2 of Kalinga III × Azucena NILs newlineindicated that, aroma was controlled by single recessive gene. The validation of gene based newlinemarkers linked to aroma has shown that BAD II had maximum phenotypic variation; hence newlinecan be used for MAS programmes for selecting aromatic genotypes