Vol. 8, Issue 12, Part D (2024)

The demand of aromatic rice is increasing in the world every day. This fragrant rice has high economic value in the markets. There are many traditional landraces and improved basmati, short/medium-grain aromatic rice varieties which have aromatic trait but in initial stage of plant identification aroma is difficult. Many conventional methods have been utilized by plant breeders for detection of grain aroma in the field level for varietal selection, which are time consuming, labour intensive and more over unreliable due to saturation of sensory organs. Since past few decades, with the availability of molecular markers to discriminate between aromatic and non-aromatic genotypes, marker assisted selection approach is being widely employed to separate aromatic lines/genotypes from the non-aromatic ones. Hence, the present study was carried out with 29 traditional landraces and improved basmati, short/medium-grain aromatic rice varieties with 19 microsatellite or SSR and functional markers. 
For the molecular analysis 29 rice genotypes seedling used for DNA extraction. The received product were amplified and run with 19 markers (13 SSR and 6 functional) were used to detect the aromatic gene in traditional landraces and improved basmati, short/medium-grain aromatic rice varieties. The markers showed 2-5 alleles per marker. The average PIC value calculated of all the markers was 0.396. Out of 19 markers fifteen the markers (14 SSR and 5 Functional) showed good amplification which allowed to differentiate between the aromatic and non-aromatic varieties. The functional markers BADEX7-3, BADEX7-4, BADEX7-2, BADEX7-5, BADEX7-1 showed clear and distinct banding pattern as they were closely linked to the fgr locus. They easily distinctive differentiation of the genotypes based on the product size which was either of aromatic or non-aromatic. 
The ten SSR marker SCU017RM, RM342A, RM223, CP04133, BO3_127.8, 10L03_FW, RM515, ARSSR-3, F05_103.0, E11_44.5 showed amplification in all the genotypes and markers which are very closely linked to the aroma gene fgr. The genotypes like Kothambiri sal, Tilsha, CSR-27, Chinor, Karjat shatabdhi, Kasturi, Jeeraga Samba, Karnal local, Kachari kothambir, Kanak jeera, Ghansal, Pusa Basmati-1. Pusa Basmati-376, Basmati-306, Pusa Sugandha-2, Assam Basmati, Pakisthan Basmati, Manohar sal, Ambemohor and Indrayani were observed to be highly aromatic based on molecular studies, similarly the genotypes Kasbai, Pusa Basmati-63, Pusa Basmati-6524, Pusa Sugandha-1, Pusa Sugandha-3, Pusa Sugandha-5,Mahi Sugandha were observed absence of aroma. Which supports the assumption of a probable existence of a second gene for fragrance in rice other than badh2. Hence, the confirmation of aroma controlled by different genes within the rice genome was done.
The presence of different genes and QTLs for aroma was confirmed. The dendrogram of the 29 genotypes showed the similarities and grouped them according to their type of aroma. The present investigation concluded that the genes present in rice on chromosome 8 are responsible for the aroma and can be detected using molecular technique and this data can be used for the further development of the aromatic rice varieties and to design more specific marker system for detection of aromatic germplasm.