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Cooking and sensory properties of rice varieties are important quality indices that influence market value and consumer acceptability. The objective of this study was to evaluate the effect of processing conditions on cooking and sensory properties of five rice varieties grown in Nigeria. The rice varieties; FARO 44, FARO 52, FARO 60, FARO 61 and NERICA 8, were processed using four processing parameters at varying conditions [soaking temperature (65-75[degrees]C), soaking time (10-16 h), steaming time (20-30 min) and paddy moisture content (12-16%)] using response surface methodology. The effect of processing conditions on cooking properties (cooking time, water uptake ratio and elongation ratio) was analyzed using standard procedures. Quantitative descriptive analysis and principal component analysis were used to describe eleven sensory characteristics (uniform appearance, black specks, whitish appearance, yellow colour, brown colour, creamy flavour, typical rice odour, sweet taste, sticky texture, grainy texture and hard texture) of the rice varieties. The cooking time, elongation ratio and water uptake ratio ranged from 12.75 to 51.58 min, 0.91 to 1.94 and 2.21 to 4.95, respectively. The cooking properties differed with respect to rice varieties and processing conditions. The shortest cooking time, longest elongation ratio and highest water uptake ratio varied from one variety to another. It was observed that NERICA 8 had the shortest cooking time (12.75 min) at 65[degrees]C soaking temperature, 16 h soaking time, 20 min steaming time and 16% paddy moisture content while FARO 52 had the highest water uptake ratio (4.95) at 65[degrees]C soaking temperature, 16 h soaking time, 20 min steaming time and 16% paddy moisture content. The maximum elongation ratio (1.94) was observed at 65[degrees]C soaking temperature, 16 h soaking time, 30 min steaming time and 12% paddy moisture content in FARO 60. The sensory properties of the rice varieties were generally characterised as having uniform appearance, whitish appearance, sweet taste, creamy flavour and rice odour. The information on the cooking and sensory properties of the rice varieties would assist rice processors and consumers in selecting rice variety of choice. Key words: Cooking properties, Rice varieties, Processing conditions, Sensory properties, INTRODUCTION Rice belongs to genus Oryza, with the most cultivated ones being Oryza sativa and Oryza glaberrima. Oryza sativa originated from Asia while Oryza glaberrima was from Africa [1]. More [...]

In Brazil, rice (Oryza sativa L.) varieties adapted to different ecological regions are available on the market. However, these varieties exhibit highly similar morphologies, which makes their identification difficult. In this study we identified microsatellites in and around genes that are useful for the identification of the main rice varieties cultivated in Brazil. Thirteen microsatellites were selected from the region upstream of MADSbox genes and 37 were derived from expressed sequence tags (ESTs). Of the 50 microsatellites selected, 19 were polymorphic, and a small set of five primer pairs was sufficient to discriminate among the 37 rice varieties studied. The polymorphic information content (PIC) value of the 19 microsatellite markers varied between 0.05 and 0.94. Unweighted pair group method with arithmetic mean (UPGMA) analysis showed that these markers group the 37 varieties according to their subspecies, indica or japonica. These results indicate that it is possible to identify informative microsatellites in and around rice genes, and that these markers are capable of discriminating between closely related varieties of rice. Moreover, our findings suggest that microsatellite markers can play an important role as a source of additional information to supplement the morphological descriptors recommended by International Union for the Protection of New Varieties of Plants (UPOV).

The aim of this study was to characterize the Italian rice (Oryza sativa L.) gene pool, paying particular attention to its variation over time, to determine whether human activity can reduce genetic variability, and whether such a reduction actually occurred in Italian rice varieties. We analyzed 135 Italian rice accessions, representing genotypes either introduced from abroad or developed in Italy from 1880 to 2001, using two groups of molecular markers, amplified fragment length polymorphisms and simple sequence repeats. These accessions were divided into four groups for which different statistical analyses were performed. The levels of gene diversity, from 0.1023 to 0.1921, and genetic richness, from 0.1579 to 0.3064, increased over time. Genetic structure, as estimated by analysis of molecular variance, revealed that the within-component was overwhelmingly dominant (92%) compared with the among-component. These results show that the level of genetic diversity in Italian rice accessions has remained high since 1850 and continues to increase. This is most likely the result of Italian breeding programs that developed new cultivars and introduced others from abroad, without substituting previous accessions. Our results show that the management and improvement of rice germplasm in Italy have been successful in maintaining sufficient genetic diversity.

Transposable elements (TEs) represent ~45% of the human genome and 50-90% of some grass genomes. While most elements contain inactivating mutations, others are reversibly inactivated (silenced) by epigenetic mechanisms, including cytosine methylation. Previous studies have shown that retrotransposons can influence the expression of adjacent host genes. In this study, the methylation patterns of TEs and their flanking sequences in different tissues were undertaken using a novel technique called transposon methylation display (TMD). TMD was successfully applied on a highly copied (~1000 copies), newly amplified LTR retrotransposon family in rice called Dasheng. We determined that the methylation status of a subset of LTRs varies in leaves vs. roots. In addition, we determined that tissuespecific LTR methylation correlated with tissue-specific expression of the flanking rice gene. Genes showing tissue-specific expression were in opposite orientation relative to the LTR. Antisense transcripts were detected in the tissue where the sense transcripts from that gene were not detected. Comparative analysis of Dasheng LTR methylation in the two subspecies, japonica vs. indica revealed LTR-mediated differences in subspecies gene expression. Subspecies-specific expression was due either to polymorphic Dasheng insertion sites between the two subspecies or to subspecies-specific methylation of LTRs at the same locus accounted for observed differences in the expression of adjacent genes.

Abstract: Total genomic DNA was extracted from 29 samples of rice seed, including jasmine rice Oryza sativa L. subsp indica 'KDML105', 'KDML105'-derived varieties, nonaromatic Thailand rice, and japonica rice. Polymorphism [...]

Cultural ecology theoretical framework was found suitable to explain unemployment in agriculture in three villages in Bangladesh. Path analysis and multiple regression statistics were used to examine the direct, indirect, and total effects of eight independent human, social, environmental, and technology variables as well as their aggregate contribution on agricultural unemployment. The multiple regression model explains 86.2% of the total variation in unemployment in agriculture. Family labor size and farm size emerged as the most important causes of unemployment in agriculture; they were followed by environmental constraints and labor saving technology variables. Key Words: Bangladesh, unemployment in agriculture, cultural ecology, flood and drought, high yielding rice.

Production frontiers are estimated from survey data from a village in Bangladesh to examine the technical efficiency of farmers in the cultivation of traditional and high-yielding-variety (HYV) rice. In spite of much higher yields, HYV cultivation displays lower technical efficiency and much greater variability in efficiency. Also, efficiency is not independent of household endowments in that small farmers, and/or those with the least education and growing experience, are least efficient. Policies that promoted education and provided smaller farmers with greater access to public services would promote efficiency and equity, and help reduce HYV yield variability., The aim of this study is to examine a sample of rice farmers from the Bangladeshi village of Khilghati, in order to investigate the inter- and intra-crop patterns of technical [...]

Rice (Oryza sativa L.) yields are frequently low in the high hills of Nepal because of chilling temperatures throughout the growing season. Conventional screening for chilling sensitivity of different rice genotypes in breeding programs relies on visual observations in the field. The screening is subjective, time consuming, and subject to genotype X environment, interactions (e.g., stage of development when chilled). In this study, chlorophyll fluorescence analysis (CFA) was used to test its value in assessing chilling tolerance. Landraces and cultivars with known chilling sensitivities, including chilling-tolerant landraces and cultivars from Nepal, were compared. Detached leaves from plants of 16 rice genotypes at the tillering stage were chilled in growth cabinets before their photochemical efficiencies ([F.sub.v]/[F.sub.m]) were measured by CFA. Genotype differences were examined by three methods: absolute [F.sub.v]/[F.sub.m] ratios of excised leaves chilled for 24 to 72 h at 10 [degrees] C, decline in [F.sub.v]/[F.sub.m] ratios of excised leaves chilled for 24 to 72 h at 10 [degrees] C in comparison to unchilled checks, and absolute [F.sub.v]/[F.sub.m] ratios of chilled leaves after recovery of up to 72 h at 25 [degrees] C in the dark. Altitudes of the site of genotype adaptation correlated well with [F.sub.v]/[F.sub.m] ratios after chilling for 48 h, whether [F.sub.v]/[F.sub.m] values were the absolute values or percentages of corresponding unchilled checks. The absolute [F.sub.v]/[F.sub.m] ratios of the chilled plants after 48 h recovery at 25 [degrees] C gave the highest correlation with altitude but that correlation was not significantly better than the correlation obtained with the absolute [F.sub.v]/[F.sub.m] ratios determined in the absence of a recovery period.

Field studies conducted on semidwarf Lemont rice and standard-stature Lebonnet rice to analyze the absorption of N show that although the total N uptake is similar at panicle differentiation and heading, Lemont's accumulation of N continues between heading and heading + 21 d. Lemont shows a higher concentration of N at the panicle than Lebonnet. Differences in clay gathering are more prominent than differences in N uptake.

Scientists have found out that black rice contain much higher levels of water-soluble anthocyanin antioxidants than brown rice, while its extracts could yield naturally derived colorings. Methods of detecting Escherichia coli cells in beef and of rapidly cooling eggs have been developed at Perdue University. Metal-organic framework compounds from food-grade ingredients are described.

The physicochemical properties of commercially grown US and imported jasmine rice in the United States were investigated and their level of acceptance by Asian consumers in the US evaluated. The variables that affect quality in the different rice sample were identified.

Using Amplified Fragment Length Polymorphisms and Simple Sequence Length Polymorphisms to Identify Cultivars of Brown and White Milled Rice H. F. J. BLIGH,(*) N. W. BLACKHALL, K. J. EDWARDS, AND [...]

Pollen free type (PFT) genic male-sterile (GMS) line Nanguangzhan had turned into wild abortive(WA) type like cytoplasmic male sterile (CMS) line. The restoring and maintaining relationship of NT1 and NT2 (the two typical abortion type (TAT) variants derived from Nanguangzhan somaclones) was similar to that of WA type, viz. the restorer lines and maintainer lines of WA type were also fit for NT1 and NT2. NT1 had been backcrossed with its maintainer lines for ten generations and kept sterile all the way. This might be the first report of this kind of mutant derived from somaclones of rice which had turned into CMS from GMS.

Pollen free type (PFT) genic male-sterile (GMS) line Nanguangzhan had turned into WA type-like CMS line. The restoring and maintaining relationship of NTI and NT2 (two typical abortion type male sterile variants from Nanguangzhan somaclones) was similar to that of WA type. NTI had been backcrossed with its maintainer lines for 10 generations and kept sterile all the way. This might be the first report of this kind of mutant derived from somaclones of rice which had turned into CMS from GMS. There were four typical abortion type (TAT) variants in R1 regenerated plants which derived from Minghui 63 (coded S11-14), IR26 (coded 26-9-15-7), Zhenshan 97B (coded B2-9-15-4), and Baoyuan A (coded 28-18), whose restoring and maintaining relationship was the same as that of WA type. These variants had been backcrossed with their maintainer lines for five generations, and kept sterile all the way. The restoring and maintaining relationship of one of TAT variants which derived from Minghui 63 (coded S 10-2) was completely different from that of WA type, HL type and BT type, viz. S 10-2 was crossed with IR24, IR26, IR36, Ce 64, Taiyin 1 and Minhui 63 and kept sterile; while it was crossed with Zhenshan 97B, Erjiuai 4B, Hongyuan B and Baoyuan B and turned into fertility, both pollens and seeds were fertile. S10-2 had been back-crossed with its maintainer lines for five generations, and kept sterile all along. Five male-sterile variants, which derived from IR26 (coded 26-9-24-11, TAT), Hongyuan A (one was coded 24-1, stained abortion type (STAT); the other was coded S14-1, TAT) and Baoyuan A (one was coded 28-5, spherical abortion type (SPAT); the other was coded 28-19, TAT), kept sterile continuously for five generations when they were backcrossed with 10 fertile parents (Zhenshan 97B, Erjiuai 4B, Hongyuan B, Baoyuan B, IR24, IR26, IR36, Ce 64, Taiyin 1 and Minghui 63).

Young panicles from five rice varieties, Zhenshan 97A (WA type cytoplasmic male-sterile (CMS) line, indica), Hongyuan A (HL type CMS line, indica), Baoyuan A (BT type CMS line, indica), Nongken 58s (photoperiod-sensitive genic male-sterile rice (PGMR), japonica) and W6154s (thermo-sensitive genic male sterile rice (TGMR), indica), were cultured on different media. 10 cases of male-sterile variants in three rice varieties, Hongyuan A, Baoyuan A and W6154s were found. Abortive pollen of rice could be classified into four types: pollen free type (PFT), typical abortion type (TAT), spherical abortion type (SpAT) and stained abortion type (StAT). The phenomenon that type of pollen abortion could change from one to another through tissue culture was found in rice somaclones in RI generation. Male-sterile variants in R1 generation were crossed with ten typical maintainer lines and restorer lines (Zhenshan 97B, Erjiuai 4B, Hongyuan B, Baoyuan B, Taiyin 1, Minghui 63, Ce 64, IR24, IR26 and IR36) to investigate the restoring and maintaining relationship of these male-sterile variants. The main results were as follows: The restoring and maintaining relationship of one typical abortion type (TAT) variant in R1 regenerated plants which derived from Baoyuan A (coded 28-18) was the same as that of WA type. The variant had been backcrossed with their maintainer lines for five generations, and kept sterile all along. Four male-sterile variants, which derived from Hongyuan A (one was coded 24-1, StAT; the other was coded S14-1, TAT) and Baoyuan A (one was coded 28-5, SpAT; the other was coded 28-19, TAT), kept sterile continuously for five generations when they were backcrossed with the ten parents stated above. The other five male-sterile variants, which derived from Hongyuan A (coded 24-5), Baoyuan A (coded 28-35) and W6154s (coded WP-1, WP-2 and WS) turned into fertility with a lot of fertile pollens and more than 80% self seed set rate when they were crossed with the ten parents stated above.