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Mineral nutrition of potassium (K), calcium (Ca), sodium (Na), magnesium (Mg), iron (Fe), zinc (Zn), copper (Cu) and manganese (Mn) are important for human health. The method of inductively coupled plasma mass spectrometry (ICP-MS) was employed to determinate the contents of K, Ca, Na, Mg, Fe, Zn, Cu and Mn in milled rice ( Oryza sativa L.) of 274 rice genotypes. The results showed that the visible difference could be found for the contents of eight elements in milled rice among rice genotypes studied. It existed the possibility to select the genotype(s) with abundant of mineral nutrient from the genetic resource. Meanwhile, the contents of mineral elements in brown rice were significantly higher than those in milled rice. The averages of K, Mn and Cu contents of indica rice were significantly lower than those of japonica rice, while no significant difference was found for other five element contents between indica and japonica rice genotypes. The average contents of Na and Cu in non-glutinous rice genotypes were higher than those in glutinous ones, whereas the averages of K and Mn contents in non-glutinous rice genotypes were lower in present experiment. Additionally, the K, Ca and Mg contents of milled rice from white brown rice were significantly higher than those from red brown rice, and Ca content of milled rice from white brown rice was also visibly higher than that from black brown rice. For microelements, significant difference was observed for Zn content between milled rice from red and white brown rice, or between milled rice from red and black brown rice. Some genotypes with abundant mineral nutrient in milled rice had been selected and could be used in rice nutrient breeding. [ABSTRACT FROM AUTHOR]

Investigations to identify quantitative trait loci (QTLs) governing cooking quality traits including amylose content, gel consistency and gelatinization temperature (expressed by the alkali spread value) were conducted using a set of 241 RIL populations derived from an elite hybrid cross of “Zhenshan 97” × “Minghui 63” and their reciprocal backcrosses BC1F1 and BC2F1 populations in two environments. QTLs and QTL × environment interactions were analyzed by using the genetic model with endosperm and maternal effects and environmental interaction effects on quantitative traits of seed in cereal crops. The results suggested that a total of seven QTLs were associated with cooking quality of rice, which were subsequently mapped to chromosomes 1, 4 and 6. Six of these QTLs were also found to have environmental interaction effects. [ABSTRACT FROM AUTHOR]

The quantification of germanium in rice (Oryza sativa L.) was studied by atomic fluorescence spectrometry (AFS). The optimum experimental conditions or the generation of germanium hydride were 360-V photomultiplier tube voltage, 80-mA hollow cathode lamp, 2.5% (w/v) KBH4 in 0.5% KOH solution and 20% H3PO4 mixture with 5% H2SO4. With these experimental conditions, the correlation coefficient (R 2) of calibration curve was up to 0.9992. As a convenient and sensitive calibration curve, it was proposed for the determination of trace amounts of germanium in brown and milled rice samples. The results showed that the content of germanium in brown rice was higher than that in milled rice. The means of the content of germanium were 4.98 and 18.10 ng/g in milled rice and brown rice, respectively. PRACTICAL APPLICATIONS Rice is an important food for human nutrition because it supplies starch, protein and the majority of micronutrients to humans, particularly in Asia. So determination the content of Germanium in rice is important for human health. In this study, we developed the method of AFS which was suitable for determination rice grain. With this method, the content of Ge could be analyzed accurately in rice, so that the good materials would be selected form germplasm resources of rice, which could be used to study physiological and genetic mechanisms and enhance germanium in diets for human. [ABSTRACT FROM AUTHOR]

The selection of an appropriate sampling strategy and a clustering method is important in the construction of core collections based on predicted genotypic values in order to retain the greatest degree of genetic diversity of the initial collection. In this study, methods of developing rice core collections were evaluated based on the predicted genotypic values for 992 rice varieties with 13 quantitative traits. The genotypic values of the traits were predicted by the adjusted unbiased prediction (AUP) method. Based on the predicted genotypic values, Mahalanobis distances were calculated and employed to measure the genetic similarities among the rice varieties. Six hierarchical clustering methods, including the single linkage, median linkage, centroid, unweighted pair-group average, weighted pair-group average and flexible-beta methods, were combined with random, preferred and deviation sampling to develop 18 core collections of rice germplasm. The results show that the deviation sampling strategy in combination with the unweighted pair-group average method of hierarchical clustering retains the greatest degree of genetic diversities of the initial collection. The core collections sampled using predicted genotypic values had more genetic diversity than those based on phenotypic values. [ABSTRACT FROM AUTHOR]