Use of seed protein polymorphism for discrimination of improvement level and geographic origin of upland rice cultivars

Abstract

Grain proteins from 58 Brazilian and nine Japanese upland rice cultivars (Oryza sativa L.) were electrophoretically separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Densitometric scanning of the electrophoretic profiles permitted the estimation of the relative concentration of 16 protein fractions, which were used as variables for the calculation of Fisher's canonical discriminating functions. Significant differences between mean values of protein fractions were useful in distinguishing Brazilian and Japanese cultivars, as well as improved and non-improved Brazilian rice cultivars in scattered plots. Electrophoretically detectable protein polymorphism in rice grain can indicate geographic origin as well as breeding improvement level of a cultivar. Improved cultivars were those released by plant breeding institutes.<br>Proteínas de grão de 58 genótipos de arroz brasileiro e nove japoneses foram separadas por meio de eletroforese (SDS-PAGE). A observação densitométrica dos perfis eletroforéticos permitiu avaliar as concentrações relativas de 16 frações protéicas que foram usadas como variáveis para a estimativa de funções discriminantes de Fisher. Diferenças significantes foram encontradas entre as frações protéicas dos grupos brasileiros e japoneses, assim como entre os genótipos melhorados e não melhorados. O polimorfismo protéico detectável eletroforetica-mente nos grãos de arroz pode indicar a origem geográfica e o nível de melhoramento dos cultivares

Review of methods for the detection and quantification of adulteration of rice: Basmati as a case study

“…Important protein-based methods includes isozymes based gel electrphoresis, immunoassays (Vlachos and Arvanitoyannis 2008), Sodium dodecyl sulfate polyacrylamide gels (SDS-PAGE) (Montalvan et al 1998), Western blotting (Li et al 20011;Singh et al 2004) and Kjeldahl method and Soxhlet apparatus (Storck et al 2005) (Table 1).…”

“…Subsequently, six rice varietal groups which includes two major groups viz., Group I (indica) and Group VI (japonica), two minor groups Group II (aus) and V (Basmati) and two satellite ones Group III and IV (deepwater rices) have been reported using eight isozyme markers detected by starch gel electrophoresis (Glaszman 1987). Montalvan et al (1998) by means of SDS-PAGE separated the rice grain proteins from Brazilian and Japanese upland rice cultivars electrophoretically. Densitometric scanning of the electrophoretic profiles allowed the estimation of the relative concentration of protein fractions, which were used as variables between the rice cultivars.…”

“…Determination of the geographical origin of rice is important feature especially Basmati rice as unscrupulous producers/ traders attempts to increase their profits by mislabelling the inferior/low quality products grown outside their regular cultivated area of foot hills of Himalayas. Earlier, grain proteins (Lan et al 2002;Montalvan et al 1998) and isozymes (Li and Rutger 2000) were used for discrimination of rice cultivars grown in different geographical regions. The principle underlying this method is that trace element and isotope composition of the rice grains reflect the soil and latitude of the area in which it is grown.…”

Determination of rice type by 1H NMR spectroscopy in combination with different chemometric tools

“…Moreover, ICA showed better representative ability compared with the classical PCA, being able to completely separate the Basmati rice samples from the round-grain rice group. The conclusions that have been made during PCA about the clustering of specific rice samples (42)(43)(44)(45)(46) on the scatter plot are definitely valid also in the case of ICA ( Figure 5); scores of red rice (sample 45) and black rice (sample 46) were located distinctly differentiated from the others, and samples 31 and 32 (unpolished long-grain rice) had extreme score values along IC1.…”

“…Multivariate data analysis based on analytical results of eight volatiles in rice was used for the differentiation of several rice varieties (Basmati, Ambemohar, and Kolam) . The analytical data from ICP‐AES, ICP‐HRMS, and gel electrophoresis analytical platforms have also previously been subjected to PCA, canonical analysis, and cluster analysis to trace the geographical origin of rice . An artificial neural network has been employed for the classification of about 1800 Italian rice samples of 11 varieties according to their cultivar using physical measurements that are routinely determined for the commercial classification of the product .…”