Genetic Diversity of Aromatic Rice Germplasm Revealed By SSR Markers

Abstract

Aromatic rice cultivars constitute a small but special group of rice and are considered the best in terms of quality and aroma. Aroma is one of the most significant quality traits of rice, and variety with aroma has a higher price in the market. This research was carried out to study the genetic diversity among the 50 aromatic rice accessions from three regions (Peninsular Malaysia, Sabah, and Sarawak) with 3 released varieties as a control using the 32 simple sequence repeat (SSR) markers. The objectives of this research were to quantify the genetic divergence of aromatic rice accessions using SSR markers and to identify the potential accessions for introgression into the existing rice breeding program. Genetic diversity index among the three populations such as Shannon information index (I) ranged from 0.25 in control to 0.98 in Sabah population. The mean numbers of effective alleles and Shannon's information index were 0.36 and 64.90%, respectively. Similarly, the allelic diversity was very high with mean expected heterozygosity (He) of 0.60 and mean Nei's gene diversity index of 0.36. The dendrogram based on UPGMA and Nei's genetic distance classified the 53 rice accessions into 10 clusters. Analysis of molecular variance (AMOVA) revealed that 89% of the total variation observed in this germplasm came from within the populations, while 11% of the variation emanated among the populations. These results reflect the high genetic differentiation existing in this aromatic rice germplasm. Using all these criteria and indices, seven accessions (Acc9993, Acc6288, Acc6893, Acc7580, Acc6009, Acc9956, and Acc11816) from three populations have been identified and selected for further evaluation before introgression into the existing breeding program and for future aromatic rice varietal development.

Genetic Architecture and Anthocyanin Profiling of Aromatic Rice From Manipur Reveals Divergence of Chakhao Landraces

“…SSRs are highly useful in assessing diversity among closely related rice cultivars (Singh et al, 2013;Yadav et al, 2013) as they provide better resolvability, are multi-allelic, provide genomewide coverage, are highly reproducible, are easy to score, and are cost-effective (Akagi et al, 1997;Singh and Singh, 2015). There are several studies that used SSR markers for finding the genetic structure of the rice germplasm, as one of the most widely used molecular markers for genetic diversity studies (Nachimuthu et al, 2015;Singh et al, 2016;Aljumaili et al, 2018;Islam et al, 2018a,b;Pathaichindachote et al, 2019;Suvi et al, 2019;Verma et al, 2019). Further, SSR markers are also proven to be efficient in delineating major genetic groups of rice, namely, indica, temperate japonica, tropical japonica, aus, and aromatic (Roy et al, 2015(Roy et al, , 2016Wang et al, 2014).…”

Is the genetic variability of elite rice in southern Brazil really disappearing?

“…The intense use of these genotypes on farms as well as in breeding programs has raised the food production in these countries but has also caused losses with regard to the genetic variability (genetic erosion) (Govindaraj et al 2015). In fact, the genetic progress in rice breeding has declined steadily over the last decades in several countries, due to the narrow genetic base of the accessions used for crosses (Aljumaili et al 2018), even though some variability is still available within the rice gene pool. However, this diagnosis of the genetic variability has to be established for each specific germplasm, e.g., for South Brazilian paddy rice, mainly because the southern region produces C Busanello et al…”

“…Studies on genetic variability can improve the efficient use and conservation of genetic resources (Aljumaili et al 2018). Genetic variability has been frequently measured based mainly on morphological traits.…”

Diversity Maintenance of Some Barley (Hordeum Spp) Genetic Resources Using SSR-Based Marker

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