106 Rice Science, 2004, 11(3): 106–112 http://www.ricescience.info

Analysis on Mineral Element Contents in Associated with Varietal Type in Core Collection of Rice

1 2 2 1 3 3 ZENG Ya-wen , LIU Jia-fu , WANG Lu-xiang , SHEN Shi-quan , LI Zi-chao ，WANG Xiangkun , 1 1 WEN Guo-song , YANG Zhong-yi (1Crop Germplasm Resources Institute, Yunnan Academy of Agricultural Sciences, 650205, ; E-mail: [email protected]; 2Analysis and Testing Center, Yunnan Academy of Agricultural Sciences, Kunming 650223, China; 3College of Crop Science, China Agricultural University, Beijing 100094, China)

Abstract: Eight-element contents of 653 unpolished rice samples harvested from Xingping experiment farm, Yunnan Province under the same ecological conditions were analyzed by ICP-AES method. The mineral elements content were closely related to low diversity, high-yielding, and multi-resistance breeding; The K, Mg, Ca and Mn content in high-yielding and resistant varieties were high, and other nutrients such as P, Fe, Zn and Cu were low, which was connected with the heredity and physiological mechanism of mineral nutrients. There is zonal distribution of mineral elements content from Yunnan rice, especially for P, Fe, Zn and Cu co-related with the diversity center, paddy versus upland, glutinous and non-glutinous, glume-hair versus nuda, rice color, rice flavor, soft rice versus non-soft rice, but it did not find any association with indica-japonica types. The results supported the ecological variety group view of 5-grade taxonomic system “species-subspecies-ecological groups-ecological variety groups–varietal types”. Key words: Yunnan rice; core collection; mineral elements; varietal type

Rice improvement in grain mineral elements content rice genetic and ecological diversity in China, and 13 is always one of the major targets for rice breeders. An counties where constituted the genetic diversity center of investigation conducted by FAO showed that the Yunnan rice landraces [8, 9]. On the basis of Cheng element contents such as Fe, Zn, Mn, etc. in the foods of Kansheng and Wang Xiangkun’s taxonomic studies most developing countries decreased obviously in conducted on Asian cultivated rice, Yu Luqi’s divided 1979-1995. For example, in Asia, about 40% of sterile 6 121 accessions of Yunnan rice landraces into 2 women and 50% of pregnant women suffered from subspecies, 6 ecological groups and 58 ecological iron-deficiency anemia, and there were more than 1 500 variety groups. In Yunnan, the number of ecological millions children being short of Zn. For this reason, varieties is almost the total of those found in China, and seeking the crop germplasm resources and breeding new the cultivars account for 8.6% of the whole cultivars in crop varieties with high mineral elements content China. The characteristics of these varieties and their became the key aim to resolve this risk of nutrition. As English names had been reported systematically [10]. In mineral elements play a very important role in any this paper, contents of eight mineral elements for the biological organism, they are not only important in the core collection of Yunnan rice were measured, the composition of botanical genes-enzyme (e.g. P, Fe, Zn, relationship of mineral elements content with variety Cu and Mn), but also the key factors for the types was analyzed, which should provide a basic physiological and biochemical reactions of plant (e.g. K, reference for rice quality breeding, rice variety Ca, Mg) [1-3]. Some studies on genetic analysis for the classification and the industrial development of special contents of several mineral elements in rice were widely purpose rice. undertaken in China and abroad, as well as the relationship with rice color, original location and the MATERIALS AND METHODS K-efficient genotype [4-7], but there was no report to date about the variation in element content between different Location and site characteristics type rice such as indica and japonica, paddy and upland, glutinous and non-glutinous, grain color, awn or awnless, Experimental plots were located at Bamencun hard and soft-, fragrant-rice under the same ecological village of Yaojie town, Xinping County, Yunnan conditions. Yunnan is thought to be the main center of Province, regarded as double-cropping rice zone with an elevation of 500 m and a very hot climate. Because of Received: 24 October 2003; Accepted: 12 January 2004 strong desilicification and Al enrichment during soil forming, the red mudstone paddy soil is slightly acidic ZENG Ya-wen, et al. Analysis on Mineral Element Contents in Associated with Varietal Type in Core Collection of Yunnan Rice 107 with rich contents of Fe and Al, the organic matter 1.8%, solution was properly diluted and analyzed with N 0.06%, P 0.03%, K 1.8% in topsoil. The previous crop ICP-AES meter. of the experimental plots was watermelon. Six hundred and fifty-three accessions of core collection from RESULTS Yunnan rice were sowed on 28 April, transplanted on 20 May and harvested in October 1999, without any Analysis of phosphorus (P) and potassium (K) fertilizer application during the whole growth period. contents High temperature and rich rainfall constituted the characteristics of weather from tillering to heading stage, The average value of P content in core collection of the highest water temperature of 41℃ in the fields was Yunnan rice reached to 3 812.56 mg/kg, including rice recorded during early tillering stage. Even during grain landraces with a value of 460.34 mg/kg being higher filling and ripening stages, rainfall was relatively higher than that of improved cultivars. The highest value was yet. Besides the two times of irrigations applied during recorded in Laolaihong from and the tillering phase, the rich rainfall provided enough water to lowest one was Xiaohuangguanuo from Puer County for rice during all of the other growth periods. rice landraces; the maximum value was noticed in Dianrui 449 and the lowest one was Dianyu 1 for Determination of element content improved cultivars (Table 1). There were 72 accessions The contents of 8 mineral elements, i.e. P, K, Ca, landraces whose P contents were higher than that of the Mg, Fe, Zn, Cu and Mn in rice seeds were tested at highest one in improved cultivars, and these 72 Analysis and Testing Center, Yunnan Academy of accessions landraces were widely distributed in 28 Agricultural Sciences. Unpolished rice (0.5 g) of each counties such as Yongde (15), Menghai (13), etc., which sample was put into a beaker, followed by adding 5 mL mainly constitute the genetic diversity center of Yunnan of nitric acid and 1 mL of perchloric acid. The beaker rice landraces. Most of the rice landraces with a P was heated electrically in sand bath to nitrify and content higher than 5 000 mg/kg belonged to Yongde (6) decompose rice till the solution became clear. The and Menghai counties. Therefore, rice diversity center clear solution was continuously heated and evaporated to was probably also the rich area for rice effective P gene just dry, the residue was dissolved with 5 mL of 1:1 resources. The variation in P content for core collection hydrochloric acid and the solution was transferred into a of Yunnan rice was not associated with the difference in 50-mL volumetric flask to test. Finally, the resultant characters such as indica-japonica, paddy-upland,

Table 1. Phosphorus and potassium contents in core collection of Yunnan rice. mg/kg

No. of Phosphorus (P) Potassium (K) Rice type accessions Mean SD Minimum Maximum Mean SD Minimum Maximum Core collection 653 3812.56 500.36 2162 5370 2673.22 395.51 1719 4528 Improved cultivar 70 3401.57 350.53 2634 4422 3368.83 369.34 2769 4628 Landraces 583 3861.91 493.10 2162 5370 2589.7 306.4 1719 3634 indica 274 3856.08 476.78 2559 5282 2592.62 286.72 1981 3580 japonica 307 3865.56 508.35 2162 5370 2588.27 318.96 1719 3634 Paddy 405 3904.42 496.09 2162 5370 2598.14 294.82 1909 3580 Upland 177 3865.94 474.73 2634 5354 2571.07 332.18 1719 3634 Glutinous 465 3865.41 490.65 2634 5370 2559.54 300.38 1719 3580 Non-glutinous 118 3848.1 504.54 2162 4899 2708.56 288.39 1909 3634 White 332 3883.28 460.47 2162 5370 2630.51 291.96 1909 3634 Red 233 3826.14 523.79 2559 5290 2516.26 304.61 1719 3485 Purple 18 3930.72 619.77 2634 4899 2787.56 374.58 1981 3492 Glume hair 504 3888.98 499.59 2162 5370 2596.79 304.14 1719 3634 Nuda 79 3689.20 412.05 2902 5044 2544.44 318.76 2049 3189 Awn 40 4078.20 508.41 3081 5290 2590.94 307.64 1179 3634 Awnless 543 3847.81 488.14 2162 5370 2572.88 292.27 1996 3264 Common rice 565 3862.67 496.47 2162 5370 2588.49 308.71 1719 3634 Fragrant rice 18 3837.94 382.19 3127 4498 2627.44 225.84 2146 3150 Soft rice 12 4179.41 557.23 3505 5282 2516.67 337.01 2174 3033 108 Rice Science, Vol. 11, No. 3, 2004

Table 2. Calcium and magnesium content in core collection of Yunnan rice. mg/kg

No. of Calcium (Ca) Magnesium (Mg) Rice type accessions Mean SD Minimum Maximum Mean SD Minimum Maximum Core collection 653 263.72 510.23 57.9 3107.0 1549.08 225.60 14.6 2564.0 Improved cultivar 70 1274.52 1120.88 57.9 3107.0 1822.99 246.48 1307.0 2564.0 Landraces 583 142.35 70.71 61.6 917.0 1516.19 199.27 14.6 2021.0 indica 274 142.62 50.88 61.8 688.0 1500.35 171.45 14.6 1966.0 japonica 307 142.07 84.84 64.0 917.0 1530.10 221.05 15.8 2021.0 Paddy 405 142.07 66.27 61.8 917.0 1532.67 200.20 15.8 2021.0 Upland 177 141.17 80.25 64.0 711.0 1479.01 192.98 14.6 1910.0 Glutinous 465 145.22 76.98 61.8 917.0 1472.85 198.66 14.6 1910.0 Non-glutinous 118 131.06 34.70 72.3 240.0 1506.59 221.58 15.8 1928.0 White 332 138.71 64.74 61.8 711.0 1525.91 194.39 14.6 1976.0 Red 233 146.42 62.21 71.9 917.0 1510.76 207.46 18.1 2021.0 Purple 18 156.78 30.72 119.0 224.0 1490.06 178.39 1178.0 1869.0 Glume hair 504 146.28 74.32 61.8 917.0 1526.57 195.09 15.8 2021.0 Nuda 79 117.28 30.77 64.0 199.0 1449.98 213.81 14.6 1846.0 Awn 40 149.94 100.70 82.6 711.0 1569.28 166.18 1174.0 1902.0 Awnless 543 141.79 68.74 61.8 917.0 1512.27 201.07 14.6 2021.0 Common rice 565 142.27 70.91 61.8 917.0 1515.50 200.74 14.6 2021.0 Fragrant rice 18 144.66 65.76 91.6 349.0 1537.72 148.18 1230.0 1894.0 Soft rice 12 124.05 11.16 98.7 143.0 1523.41 127.93 1323.0 1748.0 glutinous and non-glutinous, rice color, but closely in fragrant rice and the lowest one was in red and soft related to glume-hair versus nuda, awn or awnless, soft rice. In addition, the standard deviation of K content in or hard, the maximum P content value was found in soft improved rice was higher than that in rice landraces. rice and the lowest was in nuda . This result evidenced Standard deviation of K content in fragrant rice was that soft rice was the valuable resource for relatively lower and that in purple and soft rice was environment-beneficial rice breeding and development. higher. In addition, the standard deviation of P content for fragrant rice was relatively lower and those of purple, Analysis of calcium (Ca) and magnesium (Mg) soft, red rice were higher. contents Table 1 also displayed that the average value of K Table 2 highlighted that the average value of Ca content in core collection of Yunnan rice was 2673.22 content was 263.72 mg/kg in core collection of Yunnan mg/kg, and rice landraces bore 779.13 mg/kg in K rice, being obviously lower in rice landraces than in content lower than that of improved cultivars. The improved cultivars; the highest one was found in highest K content was detected in Haoa from Funing Yanshuanggu from County and the County and the lowest one was in Shanluoping from minimum one was Haomile from Cangyuan County for Mojiang County for rice landraces; the maximum one rice landraces; the highest value for improved cultivars was found in Dianrui 449 and the lowest one was was recorded in Hexi 36 and the lowest one was in Wendao 1 for improved cultivars. There were 15 Dianlong 201. There were 39 improved cultivars such improved cultivars such as Hexi 4, Jining 78-102, as Hexi 12, Chujing 14, Yunjing 33, Yunjing 135, Diannong S-1, Yunguang 8, Dianrui 449, Diantun 502, Dianyu 1, Jingdiao 3, Dianxun 1, 78-251, Jining 78-102, Dianrui 453 and Dianrui 408, whose K contents were Keqing 3, Yun’ertian, Dianjing 8 and Wendao 1, whose higher than that of the leading entry of rice landraces. Ca contents were found to be higher than that of the rice The discrepancy in K content for core collection of landraces with tremendously increasing values. Fourteen Yunnan rice landraces was not co-related with the accessions of landraces rice with a value of Ca content character difference as indica-japonica, paddy-upland, more than 300 mg/kg and 39 accessions lesser than 90 glume-hair versus nuda, awn versus awnless, but closely mg/kg were fragmentarily distributed in Yunnan, associated to glutinous and non-glutinous, rice color, indicating that Ca content of rice had not any direct fragrant and soft, the highest K content value was found association with diversity center but closely related to ZENG Ya-wen, et al. Analysis on Mineral Element Contents in Associated with Varietal Type in Core Collection of Yunnan Rice 109 cold-tolerance rice breeding. The variation in Ca content did not display any direct connection with diversity for core collection of Yunnan rice was not connected center but closely related to good grain quality and yield with the character differences as indica-japonica, paddy- breeding of rice. The difference of Mg content for core upland, glutinous and verso, awn and verso, but closely collection of Yunnan rice was not connected with the related to glume-hair versus nuda, rice color, soft and character variation as indica-japonica, paddy-upland, verso, the highest Ca content value was found in purple glutinous and verso, rice color, awn and verso, rice and the lowest was in nuda and soft rice. In addition, soft-fragrant and verso, but closely related to glume-hair the diversity of Ca content for improved rice was versus nuda, the highest Mg content value was found in obviously higher than that of rice landraces. The awn rice and the lower in nuda rice. In addition, the standard deviations of Ca content for soft and nuda rice standard deviation of Mg content for improved rice was landraces were relatively higher, and that for japonica relatively higher than that for rice landraces; and the rice was relatively lower. standard deviations of Mg content for soft and fragrant Table 2 exhibited that the average value of Mg of landraces rice were relatively lower, those for contents was of 1549.08 mg/kg in the core collection of glutinous and japonica rice were comparatively higher. rice. The average value in rice landraces was evidently Analysis of ferrum (Fe) and zinc (Zn) contents lower than that of improved rice. The highest one for landraces was found in Lengshuidiao from Songming It has been shown in Table 3 that the average value County and the lowest one was in Dabaigu from of Fe content was 49.87 mg/kg in the core collection, in Wenshan County; the maximum value for improved which the landraces was obviously higher in average cultivars was Dianrui 449 and the minimum one was in value of Fe content than improved cultivars. The highest Hexi 34. There were 16 improved cultivars such as one was found in Aizinuo from Baoshan and the lowest Dianrui 449, Diantun 502, Dainrui 453, Dianrui 408, ones in Landigu, Laoyalin, Anlaogu, Jixuenuo and Jining 78-102, Dalixiang (big grain and fragrant rice) 1 Fanhaopi from Gengma County for landraces; the and 7, Yunxiangnuo 1, whose Mg contents were maximum value for improved cultivars was noticed in detected to be greater than that of the highest of rice Denong 211 and the minimum one was Hexi 39. There landraces. Fourteen accessions of rice landraces with a were 11 landraces whose Fe contents were exceeding the value of Mg content higher than 1 900 mg/kg and 49 highest one of improved rice. Ninety-three accessions of lines lower than 1 300 mg/kg were fragmentarily landraces were with a value of Fe content less than 10 distributed in Yunnan, indicating that Mg content of rice mg/kg and 64 of them came from diversity center, which

Table 3. Ferrum and zinc contents in core collection of Yunnan rice. mg/kg

No. of Ferrum (Fe) Zinc (Zn) Rice type accessions Mean SD Minimum Maximum Mean SD Minimum Maximum Core collection 653 49.87 145.22 0.40 2089.00 34.72 24.66 3.90 444.00 Improved cultivar 70 44.09 46.01 9.63 348.00 22.16 6.48 13.30 46.90 Landraces 583 50.57 152.87 0.40 2089.00 36.22 25.60 3.90 444.00 indica 274 44.88 129.91 0.40 1636.00 35.20 15.51 18.90 129.00 japonica 307 55.81 171.26 0.40 2089.00 31.20 32.08 3.90 444.00 Paddy 405 49.21 142.19 0.41 2089.00 34.47 15.09 3.90 117.00 Upland 177 53.88 175.62 0.40 1636.00 40.19 41.50 17.20 444.00 Glutinous 465 55.79 169.85 0.40 2089.00 36.78 27.56 3.90 444.00 Non-glutinous 118 29.97 36.01 0.40 262.00 34.02 15.54 18.80 175.00 White 332 38.86 88.63 0.40 1063.00 34.32 16.10 3.90 175.00 Red 233 68.75 216.37 0.40 2089.00 39.28 35.38 17.90 444.00 Purple 18 31.06 23.33 2.87 95.60 31.77 8.82 22.90 55.20 Glume hair 504 54.04 163.45 0.40 2089.00 36.67 27.12 3.90 444.00 Nuda 79 28.38 38.69 0.40 230.00 33.38 11.57 17.20 80.00 Awn 40 34.03 50.90 1.05 331.00 33.18 9.65 18.70 67.20 Awnless 543 51.78 157.75 0.40 2089.00 36.45 26.38 3.90 444.00 Common rice 565 49.61 149.22 0.40 2089.00 36.35 25.92 17.20 444.00 Fragrant rice 18 80.64 245.60 0.50 1062.00 32.35 10.66 3.90 49.90 Soft rice 12 23.68 10.18 12.80 49.00 26.51 5.76 20.70 30.8 110 Rice Science, Vol. 11, No. 3, 2004

Table 4. Copper and manganese content in core collection of Yunnan rice. mg/kg

No. of Copper (Cu) Manganese (Mg) Rice type accessions Mean SD Minimum Maximum Mean SD Minimum Maximum Core collection 653 15.53 13.24 0.31 130.0 15.19 2.81 5.35 26.6 Improved cultivar 70 11.49 2.10 5.59 16.3 18.63 2.75 13.10 26.6 Landraces 583 16.02 13.92 0.31 130.0 14.78 2.52 5.35 25.0 indica 274 15.67 14.28 1.76 130.0 14.58 2.25 9.10 21.2 japonica 307 16.39 13.62 0.50 102.0 14.96 2.74 5.35 25.0 Paddy 405 15.77 14.07 0.31 130.0 14.76 2.44 9.10 22.7 Upland 177 16.6 13.64 0.54 102.0 14.82 2.71 5.35 25.0 Glutinous 465 15.79 14.12 0.31 130.0 14.68 2.48 9.10 25.0 Non-glutinous 118 16.91 13.12 0.50 60.6 15.15 2.63 5.35 21.8 White 332 16.39 13.67 0.50 130.0 15.06 2.44 9.51 25.0 Red 233 15.25 14.13 0.31 102.0 14.31 2.56 5.35 22.3 Purple 18 19.1 15.75 3.05 60.6 15.56 2.61 9.68 19.5 Glume hair 504 15.69 13.71 0.31 130.0 14.79 2.54 9.10 25.0 Nuda 79 18.31 15.10 0.54 102.0 14.68 2.37 5.35 20.7 Awn 40 17.51 17.06 1.55 102.0 15.10 2.46 9.53 21.8 Awnless 543 15.91 13.67 0.31 130.0 14.75 2.52 5.35 25.0 Common rice 565 15.9 13.98 0.31 130.0 14.74 2.49 5.35 25.0 Fragrant rice 18 19.57 10.60 1.22 43.7 15.88 3.31 10.90 22.3 Soft rice 12 13.65 10.18 3.73 34.5 14.95 0.67 13.90 16.1 indicated that rice varieties with lower content of Fe than 20 mg/kg were mainly from 9 counties as Menglian might connected directly with diversity center, and the and Yongde. These results showed that Zn content of rice breeding for high yielding and good grain quality core collection rice might be related with diversity center, made an obvious decrease in Fe content in rice. It is and rice breeding for high yielding and good grain evident also from those results that the difference of Fe quality made an obvious decrease of Zn content in rice. content for core collection of Yunnan rice was not The difference of Zn content for core collection of connected with the character difference as Yunnan rice did not provide any direct connection with indica-japonica, paddy-upland, but closely related to the characteristic variation as indica-japonica, glume- glutinous and verso, rice color, glume-hair versus nuda, hair versus nuda and awn, but closely related to paddy- awn and verso, soft-fragrant and verso; the highest Fe upland, soft and hard, purple and red rice; the highest Zn content value was recorded in fragrant rice and the content value was found in upland rice and the lowest in lowest was in soft rice. In addition, the standard soft rice. In addition, the standard deviation of Zn deviation of Fe content for improved rice was obviously content for improved rice was obviously lower than that lower than that for landraces; and those of soft rice and for landraces; and the standard deviations of Zn content purple rice were relatively lower, and those of fragrant for soft and purple rice were comparatively lower, those and red rice were higher in landraces. for upland and red rice were relatively higher in Table 3 indicated also that the mean value of Zn landraces. contents was of 34.72 mg/kg in the core collection, and Analysis of copper (Cu) and manganese (Mn) that rice landraces exhibited obviously a higher content contents than that in improved cultivars. The peak value for landraces was found in Wulugu from Jiangcheng County The mean value of Cu contents was 15.53 mg/kg in and the lowest one was in Xianggu (fragrant rice) from the core collection as shown in Table 4, being obviously Gengma County; the highest one for improved cultivars higher in landraces than in improved cultivars. The were Jining 78-102 and Dalixiang 7, the lowest one was highest one was found in Laojingnuo from Yuanyang Chujing 19. There were 61 landraces whose Zn and the lowest one was Ashugu from Jiangcheng County contents were higher than that of the leading improved for landraces; the maximum one for improved cultivar cultivars, most of them belonged to Southwest Yunnan. was detected in Hexi 4 and the minimum one was Most of the 12 landraces with a value of Zn content less Yunjing 135. There were 237 accessions rice landraces ZENG Ya-wen, et al. Analysis on Mineral Element Contents in Associated with Varietal Type in Core Collection of Yunnan Rice 111 whose Cu contents exceeded the highest one of of improved rice; the standard deviation of Mn content improved cultivars and most of them were from for soft rice was relatively lower and that for fragrant Southwest Yunnan. The 11 accessions landraces whose rice was relatively higher. Cu content was less than 1 mg/kg, were mainly from 7 counties such as Mojiang, Jiangcheng and Tengchong DISCUSSION etc. These results evidenced that Cu content of rice might be connected with diversity center and rice Breeding for high yielding rice with multi-resistance breeding for high yielding and good grain quality and decreasing of diversity were closely related to the difference of mineral element contents stemmed in an obvious decrease of Cu in rice. It has been showed also in Table 4 that the discrepancy of Cu During the breeding of high yielding rice with content for core collection of Yunnan rice was not multi-resistance, the contents of K, Mg, Ca and Mn connected with the characteristic difference as indica- which were associated strongly to stress tolerance (as K japonica, paddy-upland, but closely associated to and Ca), disease-resistance (K), photosynthesis (K and glutinous and verso, glume-hair versus nuda, awn and Mn) and high-yielding (K, Mg, Ca, and Mn) increased verso, soft and fragrant. The highest Cu content value obviously, those of P, Fe, Zn and Cu which related was found in fragrant rice and the lowest one was in soft closely with important life activities as gene (P), rice, but the mean of Cu contents for all types of the metabolism (P, Fe, and Cu) and enzyme (P, Fe, Zn, and landraces was exceeded that for improved cultivars. In Cu) showed a downward trend [1-5]. These results addition, the standard deviation of Cu content for showed that the narrowing of rice gene diversity during improved rice was obviously lower than that for rice the high-yielding and multi-resistance breeding was landraces; and those of soft rice and fragrant rice were related closely with the content of mineral elements. relatively low, and that of awn rice was relatively higher Contents of K, Mg, Ca, Mn and P, Fe, Zn, Cu were for landraces. differently related with the diversity of Yunnan rice Table 4 also indicated that the prevailing average value of Mn contents was 15.19 mg/kg in the core The contents of K, Mg, Ca, Mn for core collection of Yunnan rice were co-related closely with high- collection, in which landraces had obviously lower yielding, fine grain quality and multi-resistance breeding content than improved cultivars. The highest one for of rice, and the contents of P, Fe, Zn, Cu may be linked landraces rice was found in Shuidaobai from Jinping to rice diversity center. The improved cultivars with high County and the lowest one was Baikedinuo from content of K and Mg belonged to good grain quality and ; the highest one for improved fragrant-soft rice types, respectively; the improved cultivars was Yunxiangnuo 1, the lowest one was Hexi cultivars with high content of Ca were mainly 34. The landraces whose Mn contents tended to be high-plateau japonica rice with cold-tolerance; high more than 22 mg/kg, were Shuidaobai (from Jinping yield potential and good grain quality breeding County), Xiaohuangnuo (Malong County), Baixiang- expressed an tendency to increase Mn content of rice. P nuogu (), and Yanzhidiao (Dayao content and its diversity in landraces may be connected County), and there were also 82-42, Dalixian 20, with the rich region of effective P gene; the landraces Dalixiang 5, Yunxiangnuo 1, Dianrui 449 xuan, Dianrui rice with low Fe content, or high Zn or Cu content were 453 and Diannong S-1 for improved rice, which mainly from Southwest Yunnan, the genetic diversity indicated that Mn content of core collection of rice center of Yunnan rice. These results highlighted that the landraces was not affected directly by the diversity mineral element contents of core collection of Yunnan center, and rice breeding for high yielding and good rice related not only with rice breeding, but also with its grain quality showed a tendency to increase the Mn diversity center. The differences of Fe, Zn, Ca and Se content of rice. It also showed that the difference of contents between husked rice from Yunnan, , Mn content for core collection of Yunnan rice was not Beijing and Jilin expressed remarkably, the notable directly connected with the character difference as positive relation of Ca and Zn in rice affirmed further [7] indica-japonica, paddy-upland, glutinous and verso, this thesis . glume-hair versus nuda, awn and verso, but closely Contents and diversity of mineral elements for core related to rice color and flavor; the highest Mn content collection of Yunnan rice differentiated greatly with value was found in fragrant rice and the lower in red rice, the cultivar’s characters but not with indica or but the average of Mn contents for all types of landraces japonica was less than that of improved cultivars. In addition, the The characteristics as nuda and verso, awn and verso, diversity of Mn content for landraces was similar to that soft and verso for core collection of Yunnan rice 112 Rice Science, Vol. 11, No. 3, 2004 differentiated greatly with its content of P, i.e., P content the third taxonomic character, but also settled a theoretic of soft rice was the highest, and that of nuda rice was the foundation for the industrial development of special rice lowest; the standard deviation of P content for fragrant in Yunnan. rice was small and those for purple, soft and red rice was big. K content between glutinous and non-glutinous, rice ACKNOWLEDGEMENTS color, fragrant-soft rice and verso differentiated greatly, i.e., the highest content of K was found in purple rice and the lowest were in soft and red rice; the standard This work partly supported by the cooperative deviation of K content for fragrant rice was lower and program of Yunnan Province and China Agricultural those for soft and purple rice were comparatively higher. University, titled “Establishing of the core collection Ca content between nuda and verso, rice color, soft rice bank of rice germplasm resources of Yunnan (98ZN07)”, and verso displayed variation greatly, i.e., the highest and by the National Natural Science Foundation of content of Ca was found in purple rice and the lowest China (30260060), and a grant from the Natural Science was in soft rice; the standard deviation of Ca content for Foundation in Yunnan Province of China. soft rice was small as compared to japonica rice Mg content between nuda and verso rice showed REFERENCES discrepancy greatly, i.e., the highest content of Mg was found in rice with hair and the lowest was in nuda rice; the standard deviation of Mg content for fragrant-soft 1 Yu S W, Tang Z C. Plant Physiology and Molecular Biology. Beijing: Science Press, 1998. (in Chinese) rice was lower than those for japonica and glutinous rice. 2 Marschner H. Mineral Nutrition of Higher Plants. 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