NILs of Cold Tolerant Japonica Cultivar Exhibited New QTLs for Mineral Elements in Rice.

Chilling stress at booting stage can cause floret deterioration and sterility by limiting the supply of food chain and the accumulation of essential mineral elements resulting in reduction of yield and grain quality attributes in rice. Genomic selection of chilling tolerant rice with reference to the accumulation of mineral elements will have great potential to cope with malnutrition and food security in times of climate change. Therefore, a study was conducted to explore the genomic determinants of cold tolerance and mineral elements content in near-isogenic lines (NILs) of japonica rice subjected to chilling stress at flowering stage. Detailed morphological analysis followed by quantitative analysis of 17 mineral elements revealed that the content of phosphorus (P, 3,253 mg/kg) and potassium (K, 2,485 mg/kg) were highest while strontium (Sr, 0.26 mg/kg) and boron (B, 0.34 mg/kg) were lowest among the mineral elements. The correlation analysis revealed extremely positive correlation of phosphorus (P) and copper (Cu) with most of the cold tolerance traits. Among all the effective ear and the second leaf length correlation was significant with half of the mineral elements. As a result of comparative analysis, some QTLs (qBRCC-1, qBRCIC-2, qBRZC-6, qBRCHC-6, qBRMC-6, qBRCIC-6a, qBRCIC-6b, qBRCHC-6, and qBRMC-6) identified for calcium (Ca), zinc (Zn), chromium (Cr) and magnesium (Mg) on chromosome number 1, 2, and 6 while, a novel QTL (qBCPC-1) was identified on chromosome number 1 for P element only. These findings provided bases for the identification of candidate genes involved in mineral accumulation and cold tolerance in rice at booting stage.

[The zonal characteristics and cultivated types difference of functional components in brown rice for core collection of Yunnan rice].

The zonal characteristics and cultivated types difference of functional components in brown rice of 907 accessions for primary core collection for rice landrace from 16 prefectures of five rice regions in Yunnan Province were determined by ultraviolet spectrophotometry of DU640 type from BECKMAN. The analytical results showed that the contents mg x (100 g)(-1) of total flavone in brown rice is 306.98 +/- 192.75, the content of upland (341.74 +/- 185.11) is the most significantly higher than that of lowland (290.41 +/- 193.72), that of the glutinous (315.54 +/- 197.64) is significantly higher than non-glutinous (171.68 +/- 11.76), that of early-mid (318.25 +/- 197.93) is the most significantly higher than late (282.12 +/- 178.11), that of red rice (379.22 +/- 197.70) and purple rice (365.61 +/- 195.44) are the most significantly higher than white rice (216.96 +/- 142.11), and that of nuda (332.68 +/- 196.22) is significantly higher than non-nuda (300. 48 +/- 191.14). Among five rice regions, in turn III (327.13) > LL (324.23) > IV (273.11) > V (270.16) > I (258.26), namely it is the most significantly highest (p < 0.01) for contents of total flavone from South Yunnan (II, III) than that of middle Yunnan; It is the most significantly highest from Simao prefecture than that of 8 prefectures, but it is the most significantly low from Baoshan prefecture than that of 7 prefectures. The contents mg x (100 g)(-1) of g-amino butyric acid (GABA) in brown rice is 7.43 +/- 2.53, the content of lowland (7.59 +/- 2. 56) is the most significantly higher than that of upland (7.09 +/- 2.45), that of non-glutinous (8.55 +/- 2.88) is the most significantly higher than glutinous (7.10 +/- 2.32), that of late (7.88 +/- 2.64) is the most significantly higher than early-mid (7.23 +/- 2.45), that of white rice (8.38 +/- 2.66) is the most significantly higher than red rice (6.63 +/- 2.14) and purple rice (7.34 +/- 2.18); Among five rice regions in turn II (7.69) > I (7.40) > IV (7.39) > III (7.33) > V (6.64), viz. the content of GABA from South Yunnan single/double cropping rice region is clearly higher than that of Northwest Yunnan cold highland japonica rice region; It is significant difference of GABA content in brown rice for that Simao prefecture South Yunnan and Yuxi as well as Baoshan prefecture, at least than that of 5 prefectures. The contents (%) of resistant starch in brown rice is 0.75 +/- 0.29, the contents of indica (0.78 +/- 0.35) is significantly higher than japonica (0.74 +/- 0.24), that of glutinous (0.78 +/- 0.31) is the most significantly higher than non-glutinous (0. 67 +/- 0.22), that of late (0.77 +/- 0. 35) is the most significantly higher than early-mid (0.75 +/- 0.26), that of red rice (0.81 +/- 0.30) and purple rice (0.70 +/- 0.30) is the most significantly higher than white rice (0.69 +/- 0.27); Among five rice regions in turn I (0.83) > II (0.79) > III (0.76) > V (0. 55) > IV (0.50), namely it is the highest (p < 0.01) for contents of resistant starch from the middle and South Yunnan province (I, II, III) than that of northern rice regions (V, IV), and the lowest for contents of resistant starch of Lijiang prefecture of northwestern and Zaotong of northeastern in this province compared to that of 13 prefectures except Diqing prefectures. These results not only reveal the most significant difference between lowland versus upland, glutinous versus nonglutinous, early/mid rice and red/purple versus white rice based on the contents of total flavone and resistant starch as well as g-amino butyric acid (GABA) in brown rice (p < 0.01), and no significant difference between indica and japonica, awn and no-awn, and common rice and aromatic/soft rice, but also elucidate obvious zonal characteristics of three functional components in brown rice of Yunnan rice. The above results provided theory bases for the genetic breeding and production of functional rice and solve the problems of chronic for human being.

[Correlation of mineral elements between milled and brown rice and soils in Yunnan studied by ICP-AES].

In the present paper, the contents of 18 mineral elements in milled and brown rice of 55 accessions elite cultivars as well as corresponding soils were determined by ICP-AES technique. The method proves to be simple, rapid, highly sensitive and accurate, and can be used to determine many elements at the same time, its recovery ratio obtained by standard addition method ranged between 93.1% and 110.2%, and its RSD was from 0.8% to 5.1%. The analytical results showed that 18 mineral elements (S, Mo, Ba, Ni, Fe, Cr, Na, Al, Cu, P, Sn, Zn, B, Mn, Mg, Ca, Sr and K) are the important active compositions of functional rice, and their mean contents in milled rice are in the order of P>K>S>Mg>Ca>Zn>Na>Al>Mn>Fe>Cu>B >Mo>Ni>Sn>Cr>Ba>Sr, in brown rice in the order of P>K>Mg>S>Ca>Zn>Mn>Al>Na>Fe>Cu>B>Mo>Sn> Ni>Cr>Ba>Sr, but in soil in the order of Fe>Al>Ca>K>Mg>P>S>Mn>B>Na>Ba>Zn>Cr>Cu>Ni>Sn>Mo> Sr; 16 mineral elements in milled and brown rice (except for S and P) are clearly lower than that in soils. The correlation of 8 microelements (Mo, Ni, Cr, Sr, Mn, Zn, Cu and Na) in milled and brown rice is closer than that of 6 macroelements (P, K, Mg, Ca, S and Al). There are rich Fe, Al and Ca in Yunnan soils, but 4 elements (P, K, Mg and S) are in high priority in milled and brown rice; The milled rice used for the staple is easier to place a premium on chronics than brown rice. The above results provided reliable data and theory bases for genetic breeding and production of functional rice, and for further solving the chronics and the malnourished problems with insufficient Fe, Zn and Ca for 4 billion people in the world.

[Determination of mineral elements in brown rice of near-isogenic lines population for Japonica rice by ICP-AES].

In the present paper, the contents of 17 mineral elements (S, Mo, Ni, Fe, Cr, Na, Al, Cu, P, Sn, Zn, B, Mn, Mg, Ca, Sr and K) in brown rice of 264 plant lines in near-isogenic lines (NILs) population and parents for Japonica rice were determined by ICP-AES technique. The method proved to be simple, rapid, highly sensitive and accurate, and can be used to determine many elements at the same time. Its recovery ratio obtained by standard addition method ranged between 92.3% and 110.27%, and its RSD was lower than 6%. The analytical results showed that NILs for various mineral elements based on the BC5F5 population consisting of 261 lines were developed from a cross between NIL (BC4F5) and Towada. To our knowledge, this is the first report on that near-isogenic lines NIL(BC4F5) with the important value for high mineral elements associated with cold tolerance at booting stage have been bred. The results of the determination show that the brown rice is rich in eleven elements such as P, K, Mg, S, Ca, Zn, Mn, Na, Fe, Cu and Al necessary to human health. There is smaller variation of 5 macroelements (11.15%-16.45%) but larger variation of 12 microelements (16.57%-94.96%) in brown rice from populations. There is significant correlation among 95 from 136 pairs in 17 elements, moreover, especially the correlation (0.531**-0.921**) among 15 pairs of six micro-elements (Mo, Ni, Al, Sn, Cr and Sr) associated with the active components of functional rice is relatively higher than that of 10 pairs (0.175**-0.867**) of 5 macroelements (P, K, Ca, Mg and S), revealing the importance of microelements to catalysing and synthesizing the active components of functional rice. The above results provided reliable data and theory bases for gene location and cloning of controlling elements contents in brown rice, and further revealed the molecular and physiological mechanism of the relation between mineral elements in brown rice and cold tolerance at booting stage in japonica rice from Yunnan Province of China.