| genetic diversity and disease control in rice. | crop heterogeneity is a possible solution to the vulnerability of monocultured crops to disease. both theory and observation indicate that genetic heterogeneity provides greater disease suppression when used over large areas, though experimental data are lacking. here we report a unique cooperation among farmers, researchers and extension personnel in yunnan province, china--genetically diversified rice crops were planted in all the rice fields in five townships in 1998 and ten townships in 1999 ... | 2000 | 10963595 |
| high levels of genetic differentiation of oryza officinalis wall. ex watt. from china. | in order to determine the population genetic structure of wild rice (oryza officinalis wall. ex watt.), an endangered tropical and subtropical species, allozyme diversity encoded by 24 loci was analyzed electrophoretically in 145 individuals of eight natural populations from hainan, guangxi, and yunnan provinces, china. a fairly high genetic differentiation (f(st) = 0.882 and mean i = 0.786) was found among the studied populations. our results suggest that restricted gene flow may play a signifi ... | 2001 | 11948221 |
| [sequence analysis of ran4 of a severe isolate of rice stripe virus in china]. | rna4 segment of a severe isolate of rice stripe virus, isolated from liaoning province and designated as pj isolate, was amplified, cloned and sequenced. rna4 of pj isolate had 2157 nucleotide in length. when compared with rna4 of t and m isolates of japan and cx isolate of yunnan province of china that had been previously reported, we found that these four isolates could be divided into two groups. pj, t and m isolates shared 97.0% and 97.0%-97.5% identities in vorf4 and vcofr4 at the nucleotid ... | 2001 | 12549184 |
| [cloning and sequencing analysis of rice stripe virus genome segment 4 of chinese isolate y]. | the cdna fragment covering full-length sequence of rstv rna4 of yunnan isolate in china was obtained by rt-pcr. the pcr-derived fragment was then cloned into vector pcrii. the cloned cdna was sequenced. comparison of the nucleotide and deduced amino acid sequences with those of the japanese isolate t was made. the results showed that at the nucleotides level, vorf, vcorf and the intergenic region had 94.9%, 94.1% and 86.1% identity respectively, the 5'-untranslational region was exactly the same ... | 1999 | 12555399 |
| [characteristics of yunnan province rice landrace core collections under phosphorus deficiency]. | soil phosphorus (p) deficiency is a major yield-limiting factor in rice production. employing 526 rice landrace accessions from 5 rice-planting regions and 16 prefectures in yunnan province, this paper studied their p-deficiency tolerance characteristics by comparing the relative plant dry weight under acid red soil condition. the results showed that northwest yunnan cold highland japonica rice-planting region was most abundant in p-deficiency tolerance core collection of indica, and there was n ... | 2005 | 16262081 |
| [sequence aanlysis of intergenic region of rice stripe virus rna4: evidence for mixed infection and genomic variation]. | the intergenic region (ir) of the rna4 of 22 isolates of rice stripe virus (rsv) in china was cloned and sequenced. the ir sequences were compared with one another and with that from japan. sequence comparisons showed that these isolates could be divided into three different types, with the ir length of 634 bp, 654 bp and 732 bp, respectively. it is interesting to note three different types all occurred in yunnan rsv natural population, whereas other province only existed 654 bp type length isol ... | 2003 | 16281554 |
| fine mapping of s32(t), a new gene causing hybrid embryo sac sterility in a chinese landrace rice (oryza sativa l.). | ketan nangka, the donor of wide compatibility genes, showed sterility when crossed to tuanguzao, a landrace rice from yunnan province, china. genetic and cytological analyses revealed that the semi-sterility was primarily caused by partial abortion of the embryo sac. genome-wide analysis of the linkage map constructed from the backcross population of tuanguzao/ketan nangka//ketan nangka identified two independent loci responsible for the hybrid sterility located on chromosomes 2 and 5, which exp ... | 2007 | 17146664 |
| genetic structure and phylogeography of rice landraces in yunnan, china, revealed by ssr. | yunnan province is one of the largest centers of genetic diversity of oryza sativa l. in china, and in the world. using a genetically representative core collection of 692 rice landraces from yunnan, the genetic structure, differentiation, and geographic diversity of this rice germplasm were analyzed. the accessions were classified into different populations, according to the model-based structure analysis. model-based populations were characterized through the reconstruction of a neighbor-joini ... | 2007 | 17546073 |
| abundant within-varietal genetic diversity in rice germplasm from yunnan province of china revealed by ssr fingerprints. | in order to estimate genetic diversity of rice (oryza sativa l.) germplasm in yunnan province of china, 60 varieties from different regions were analyzed by microsatellite (ssr) fingerprints. nine selected ssr primer pairs amplified a total of 55 alleles from these varieties, and high genetic diversity (0.706) was found, although it was not evenly distributed across the regions. marked genetic variation was detected within the traditional varieties. a upgma dendrogram based on ssr polymorphism i ... | 2007 | 17929162 |
| construction of a bacterial artificial chromosome (bac) library of common wild rice (oryza rufipogon griff.) for map-based cloning of genes selected during the domestication of rice. | as a prerequisite for the map-based cloning of genes from common wild rice (oryza rufipogon griff.), which plays an important role in the domestication of cultivated rice (o. sativa l.), we constructed a median-insert size bacterial artificial chromosome (bac) library of the common wild rice isolate, yjcwr, collected from yuanjiang, yunnan province, china. the library consists of 52,992 clones, with an average insert size of 50 kb, and all clones were pooled into 46 three-dimensional super-pools ... | 2008 | 17999149 |
| [cloning and analyzing of rice blast resistance gene pi-ta+ allele from jinghong erect type of common wild rice (oryza rufipogon griff) in yunnan]. | a 4,672 bp dna sequence including the whole coding region and partial non-coding region of rice blast resistance gene pi-ta+ has been cloned from jinghong erect type of common wild rice (oryza rufipogon griff) in yunnan by polymerase chain reaction method. the coding region shares 99.86% and 98.78% identity with the corresponding regions of the reported cultivated rice yashiro-mochi and yuanjiang type of common wild rice respectively. there are 4 nucleotides difference in the coding region and 6 ... | 2008 | 18244911 |
| [response of water quality to agricultural cultivation in liangwanghe river catchment of fuxianhu lake region]. | response of water quality to agricultural cultivation was investigated for the liangwanghe river catchment of fuxianhu lake region in yunnan province of china. two typical tillage lands-the rice-wheat rotation (r-w) and the tobacco-pea (t-p) rotation were selected and monitored. groundwater quality and water quality of liangwanghe river were monitored simultaneously, as well as the farmland cultivation situation at that time. it was found that cultivation activities, such as transplanting, base ... | 2007 | 18268995 |
| cadmium-hazard mapping using a general linear regression model (irr-cad) for rapid risk assessment. | research undertaken over the last 40 years has identified the irrefutable relationship between the long-term consumption of cadmium (cd)-contaminated rice and human cd disease. in order to protect public health and livelihood security, the ability to accurately and rapidly determine spatial cd contamination is of high priority. during 2001-2004, a general linear regression model irr-cad was developed to predict the spatial distribution of soil cd in a cd/zn co-contaminated cascading irrigated ri ... | 2009 | 18311588 |
| [construction and analysis of cdna library of yunnan yuanjiang o. rifupogon leaf]. | the cdna library of yuanjiang oryza rifupongon leaf was constructed by using smart technology. the titers of the non-amplified library and the amplified library were 1.1 x 106 pfu/ml and 3.98 x 107 pfu/ml, respectively. the recombination rate was more than 91%. the dna sequence length of the most cdnas in the library was between 500-2 000 bp. some cdnas chosen by random were sequenced. after blast analysis of some cdnas, their possible function were predicted. it is found that these cdnas show 9 ... | 2008 | 18550503 |
| genetic diversity and population structure of rice stripe virus in china. | rice stripe virus (rsv) is one of the most economically important pathogens of rice and is repeatedly epidemic in china, japan and korea. the most recent outbreak of rsv in eastern china in 2000 caused significant losses and raised serious concerns. in this paper, we provide a genotyping profile of rsv field isolates and describe the population structure of rsv in china, based on the nucleotide sequences of isolates collected from different geographical regions during 1997-2004. rsv isolates cou ... | 2009 | 19264655 |
| genotypic variation in element concentrations in brown rice from yunnan landraces in china. | the mineral elements present in brown rice play an important physiological role in global human health. we investigated genotypic variation of eight of these elements (p, k, ca, mg, fe, zn, cu, and mn) in 11 different grades of brown rice on the basis of the number and distance coefficients of 282 alleles for 20 simple sequence repeat (ssr) markers. six-hundred and twenty-eight landraces from the same field in yunnan province, one of the largest centers of genetic diversity of rice (oryza sativa ... | 2010 | 19554457 |
| [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, m ... | 2009 | 19650503 |
| [the zonal characterization of elemental concentrations in brown rice of core collection for rice landrace in yunnan province by icp-aes]. | in the present paper, the contents of 8 elements in brown rice of 789 accessions core collection for rice landrace from 16 prefectures of five rice regions in yunnan province 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 from 97.1% to 110.2%, and its rsd was from 0.7% to 4.4%. the analytical results showed that t ... | 2009 | 19810562 |
| identity, diversity, and molecular phylogeny of the endophytic mycobiota in the roots of rare wild rice (oryza granulate) from a nature reserve in yunnan, china. | rice (oryza sativa l.) is, on a global scale, one of the most important food crops. although endophytic fungi and bacteria associated with rice have been investigated, little is known about the endophytic fungi of wild rice (oryza granulate) in china. here we studied the root endophytic mycobiota residing in roots of o. granulate by the use of an integrated approach consisting of microscopy, cultivation, ecological indices, and direct pcr. microscopy confirmed the ubiquitousness of dark septate ... | 2010 | 20038691 |
| analysis of qtls for yield-related traits in yuanjiang common wild rice (oryza rufipogon griff.). | using an accession of common wild rice (oryza rufipogon griff.) collected from yuanjiang county, yunnan province, china, as the donor and an elite cultivar 93-11, widely used in two-line indica hybrid rice production in china, as the recurrent parent, an advanced backcross populations were developed. through genotyping of 187 ssr markers and investigation of six yield-related traits of two generations (bc(4)f(2) and bc(4)f(4)), a total of 26 qtls were detected by employing single point analysis ... | 2010 | 20227048 |
| diachronic analysis of genetic diversity in rice landraces under on-farm conservation in yunnan, china. | diachronic analysis showed no significant changes in the level of genetic diversity occurred over the past 27 years' domestication, which indicated genetic diversity was successfully maintained under on-farm conservation. rice (oryza sativa l.) is one of the earliest domesticated crop species. its genetic diversity has been declining as a result of natural and artificial selection. in this study, we performed the first analysis of the levels and patterns of nucleotide variation in rice genomes u ... | 2016 | 26498440 |
| [yield formation of different single-season rice (oryza sativa l. ) types and its relationships with meteorological factors in yunnan province of southwest china]. | by using the 1994-2010 observation data of paddy rice growth period and yield from 14 agro-meteorological stations at different altitudes in yunnan province, this paper studied the rice yield formation and the effects of meteorological factors on low-yield rice yield components. according to the systematic cluster analysis of rice yield components and the rice types at the 14 stations, the rice was divided into 4 types, i. e., low-yield japonica rice, low-yield indica rice, high-yield japonica r ... | 2013 | 24483077 |
| cytoplasm affects grain weight and filled-grain ratio in indica rice. | cytoplasmic effects on agronomic traits--involving cytoplasmic and nuclear genomes of either different species or different cultivars--are well documented in wheat but have seldom been demonstrated in rice (oryza sativa l.). to detect cytoplasmic effects, we introgressed the nuclear genomes of three indica cultivars--guichao 2, jiangchengkugu, and dianrui 449--into the cytoplasms of six indica cultivars - dijiaowujian, shenglixian, zhuzhan, nantehao, aizizhan, and peta. these 18 nuclear substitu ... | 2011 | 21631950 |