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 cl...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' .展开更多
The seedlings of three rice varieties (Damagu,Ligeng 2, and Xiuzinuo) were cultivated at 25 ±1℃. After chilling injury (at 2~C), blacksediments of lead phosphate appeared on plas-
Correlations between four grain quality, 24 plant morphological traits and eight element contents of 653 accessions from Yunnan rice were analyzed. P, K, Ca and Mg contents of core collection were closely correlated t...Correlations between four grain quality, 24 plant morphological traits and eight element contents of 653 accessions from Yunnan rice were analyzed. P, K, Ca and Mg contents of core collection were closely correlated to the most plant morphological and grain quality traits, and there were highly significant correlations （P 〈0.01） among some traits including P content to number of stems and tillers, K content and amylose content, Ca content and plant height, Mg content and protein content. Mn, Zn, Cu and Fe contents of core collection were closely related to a few traits, such as Fe content and gel consistency （-0.1121^＊＊）, Zn content and seed setting rate （-0.1411^＊＊）, Cu content and number of grains per panicle （-0.1398^＊＊）, Mn content and plant height （-0.2492^＊＊）.展开更多
There exists a single nucleotide polymorphism, G or T, at the first base of the donor splice site of waxy gene intron 1 in rice. In order to study the relationship between the first base of the donor splice site of wa...There exists a single nucleotide polymorphism, G or T, at the first base of the donor splice site of waxy gene intron 1 in rice. In order to study the relationship between the first base of the donor splice site of waxy gene intron 1 and amylose content in rice, the one-step PCR method was used to determine whether it is G or T in 220 Yunnan indigenous rice varieties from 14 districts, 55 towns/counties of Yunnan Province, and 101 varieties of which were validated by the PCR-Acc I method. According to the G/T polymorphism, 164 rice varieties showed GG-genotype, while the other 56 fell into TT- genotype, accounting for 74.5% and 25.5% of all the test varieties, respectively. When all the rice varieties were divided into indica and japonica subspecies, it was found that 80.5% of indica rice and 67.0% of japonica rice belonged to GG-genotype. The rice varieties with GG-genotype had significantly higher amylose content （18.95% on average） than those with TT- genotype （all below 16%）, but 33 rice varieties with GG-genotype still had low amylose content ranging from 3.91% to 15.93%, and most of them came from the Dai minority area in the Southwest of Yunnan Province. However, there was no significant difference in the mean amylose content of the same GG or TT genotypes between indica and japonica rice, suggesting that different genetic backgrounds, indica or japonica, had no effect on amylose content. The coefficient of correlation between the genotype and amylose content was 0.733 （P〈0.01）.展开更多
The pathogenicity of 36 isolates of Xanthomonas oryzae pv. oryzae （Xoo）, which were collected from japonica rice varieties in the Yunnan Plateau, China, was evaluated. It was evaluated on 29 rice varieties including...The pathogenicity of 36 isolates of Xanthomonas oryzae pv. oryzae （Xoo）, which were collected from japonica rice varieties in the Yunnan Plateau, China, was evaluated. It was evaluated on 29 rice varieties including a set of seven varieties to identify pathogenicity, i.e., Haonuoyang, TN1, Kogyoku, Zhenzhu＇ai, IR26, Nanjing 33, and Kinmaze, which may be considered as a set of differential varieties for Xoo races from Yunnan japonica rice. The efficiency of the seven varieties was further confirmed. The results showed reversible and specific interactions between isolates and varieties. The isolates were classified into nine pathotypes from pathotyp Ⅰ to Ⅸ according to their pathogenic reactions on the seven rice varieties. The pathotype V was the epidemic, whereas pathogen Ⅶ was the most pathogenic. Most japonica varieties grown in the Yunnan Plateau were susceptible to Xoo. The rice lines IRBB21 （Xa-21）, Zhachanglong （Xa-22,, Xa- 24,）, and IR1545-339 （xa-5）, which were resistant to all the isolates tested, can be used as donors of resistant genes for bacterial blight in japonica rice breeding in the Yunnan Plateau.展开更多
Factors affecting rice quality and their impacts on market price were investigated in this study. On-farm survey and market survey was undertaken in three selected sites namely Kunming, Dali, and Xishuangbanna in Yunn...Factors affecting rice quality and their impacts on market price were investigated in this study. On-farm survey and market survey was undertaken in three selected sites namely Kunming, Dali, and Xishuangbanna in Yunnan Province, China. Market sampling was conducted to determine important rice quality characteristics. Sixty milled rice samples were collected from domestic markets of the three sites during a period of Mar to Apr in 1994. The grain physicochemical properties of the milled rice samples were analyzed on the basis of Chinese Agricultural Ministry Standard for testing rice quality. A hedonic price model (implicit price model) was further employed to quantify relationships between quality characteristics and market prices of rice. The model can be expressed mathematically as the following function (1) This function shows that the average price paid by consumer for different grades of rice with attribute Xj. Using the ordinary least square (OLS) regression of observed market prices on measures展开更多
文摘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' .
文摘The seedlings of three rice varieties (Damagu,Ligeng 2, and Xiuzinuo) were cultivated at 25 ±1℃. After chilling injury (at 2~C), blacksediments of lead phosphate appeared on plas-
基金supported by the National Natural Science Foundation of China(30260060)a grant from the Natural Science Foundation of Yunnan,China(2002C0077M).
文摘Correlations between four grain quality, 24 plant morphological traits and eight element contents of 653 accessions from Yunnan rice were analyzed. P, K, Ca and Mg contents of core collection were closely correlated to the most plant morphological and grain quality traits, and there were highly significant correlations （P 〈0.01） among some traits including P content to number of stems and tillers, K content and amylose content, Ca content and plant height, Mg content and protein content. Mn, Zn, Cu and Fe contents of core collection were closely related to a few traits, such as Fe content and gel consistency （-0.1121^＊＊）, Zn content and seed setting rate （-0.1411^＊＊）, Cu content and number of grains per panicle （-0.1398^＊＊）, Mn content and plant height （-0.2492^＊＊）.
文摘There exists a single nucleotide polymorphism, G or T, at the first base of the donor splice site of waxy gene intron 1 in rice. In order to study the relationship between the first base of the donor splice site of waxy gene intron 1 and amylose content in rice, the one-step PCR method was used to determine whether it is G or T in 220 Yunnan indigenous rice varieties from 14 districts, 55 towns/counties of Yunnan Province, and 101 varieties of which were validated by the PCR-Acc I method. According to the G/T polymorphism, 164 rice varieties showed GG-genotype, while the other 56 fell into TT- genotype, accounting for 74.5% and 25.5% of all the test varieties, respectively. When all the rice varieties were divided into indica and japonica subspecies, it was found that 80.5% of indica rice and 67.0% of japonica rice belonged to GG-genotype. The rice varieties with GG-genotype had significantly higher amylose content （18.95% on average） than those with TT- genotype （all below 16%）, but 33 rice varieties with GG-genotype still had low amylose content ranging from 3.91% to 15.93%, and most of them came from the Dai minority area in the Southwest of Yunnan Province. However, there was no significant difference in the mean amylose content of the same GG or TT genotypes between indica and japonica rice, suggesting that different genetic backgrounds, indica or japonica, had no effect on amylose content. The coefficient of correlation between the genotype and amylose content was 0.733 （P〈0.01）.
文摘The pathogenicity of 36 isolates of Xanthomonas oryzae pv. oryzae （Xoo）, which were collected from japonica rice varieties in the Yunnan Plateau, China, was evaluated. It was evaluated on 29 rice varieties including a set of seven varieties to identify pathogenicity, i.e., Haonuoyang, TN1, Kogyoku, Zhenzhu＇ai, IR26, Nanjing 33, and Kinmaze, which may be considered as a set of differential varieties for Xoo races from Yunnan japonica rice. The efficiency of the seven varieties was further confirmed. The results showed reversible and specific interactions between isolates and varieties. The isolates were classified into nine pathotypes from pathotyp Ⅰ to Ⅸ according to their pathogenic reactions on the seven rice varieties. The pathotype V was the epidemic, whereas pathogen Ⅶ was the most pathogenic. Most japonica varieties grown in the Yunnan Plateau were susceptible to Xoo. The rice lines IRBB21 （Xa-21）, Zhachanglong （Xa-22,, Xa- 24,）, and IR1545-339 （xa-5）, which were resistant to all the isolates tested, can be used as donors of resistant genes for bacterial blight in japonica rice breeding in the Yunnan Plateau.
文摘Factors affecting rice quality and their impacts on market price were investigated in this study. On-farm survey and market survey was undertaken in three selected sites namely Kunming, Dali, and Xishuangbanna in Yunnan Province, China. Market sampling was conducted to determine important rice quality characteristics. Sixty milled rice samples were collected from domestic markets of the three sites during a period of Mar to Apr in 1994. The grain physicochemical properties of the milled rice samples were analyzed on the basis of Chinese Agricultural Ministry Standard for testing rice quality. A hedonic price model (implicit price model) was further employed to quantify relationships between quality characteristics and market prices of rice. The model can be expressed mathematically as the following function (1) This function shows that the average price paid by consumer for different grades of rice with attribute Xj. Using the ordinary least square (OLS) regression of observed market prices on measures
