Phylogenetic Similarity of Popular Rice Varieties from Different Sources

Abstract

Superior rice varieties tend to be highly adopted by farmers across the country. Over time, samples of a variety coming from different places may exhibit some differences. Morphological descriptors are traditionally used to determine these differences however; these descriptors are limited in number and suffer from drawbacks such as influence of environment on trait expression and could not differentiate morphologically identical varieties. The highly reproducible molecular marker assay offers a powerful alternative to establish true identity and discriminate morphologically identical varieties. A study was conducted to determine the identity of several rice varieties based on DNA fingerprinting using genome-wide SSR markers. Samples of NSIC Rc240 from four sources, Aromatic Rice from three sources, and IR64 from two sources, were included in the study. Genetic similarity was calculated as proportion of shared alleles and cluster analysis was conducted using UPGMA. Results showed that the genetic similarity of three NSIC Rc240 samples was 1.0 confirming that these three samples were 100% genetically similar with each other while a fourth NSIC Rc240 sample from another source was only 89% similar to the other three. On the other hand, the three Aromatic Rice samples formed separate clusters at a range of 71-80% similarity. Lastly, a farmer's "improved" IR64 was only 59.5% similar to the original IR64. The observed divergence of samples with the same names in the study could be a result of further selection, gene flow, drift, admixture, or a combination of these mechanisms. This study underscores the importance of DNA fingerprinting analysis in variety identification, variation arising from selection and possible protection biopiracy.

DNA fingerprinting at farm level to map wheat variety adoption across Nepal

“…However, studies have shown that information gathered during these surveys has an accuracy of around 30% (Jaleta et al., 2020), particularly in countries where informal seed systems are prevalent. Phenotypic identification of cultivars also can vary due to genetic and environmental influences (Caguiat & Yabes, 2016). These challenges can be overcome by the application of molecular marker technologies to identify varieties grown in farmer fields.…”

Assessment of wheat variety adoption in Bangladesh through DNA fingerprinting

“…BARI Gom 21, BARI Gom 26, and BARI Gom 23 ranked 2nd, 3rd, and 4th, respectively, in the proportion of wheat cultivated area (Rashid & Hossain, 2016). Varietal adoption studies done through morphological descriptors (Caguiat & Tabanao, 2016), expert opinions, and conventional household surveys (Jaleta et al., 2020; Rabbi et al., 2015) may lead to inaccurate results in adoption and impact assessments. Clear distinctions between varieties grown are needed to assess the diffusion and market penetration of improved varieties.…”