Effect of Geographical Indication Information on Consumer Acceptability of Cooked Aromatic Rice.

Geographical indication (GI) labeling is used to represent information about specific geographical origins of target products. This study aimed at determining the impact of GI information on sensory perception and acceptance of cooked aromatic rice samples. Ninety-nine participants evaluated cooked rice samples prepared using each of three aromatic rice varieties both with and without being provided with GI information. Participants rated the acceptance and intensity of the cooked rice samples in terms of appearance, aroma, flavor, texture, and overall liking, and also reported how important the GI information was to them. The results showed that consumers rated the cooked rice samples higher in appearance and overall liking when provided with GI information. Interestingly, participants who valued "state-of-origin" information more highly exhibited increased hedonic ratings of cooked rice samples when provided with GI information, but not when no GI information was given. Participants provided with GI information rated flavor or sweetness intensities of cooked aromatic rice samples closer to just-about-right than those without such information. This study provides empirical evidence about how GI information modulates sensory perception and acceptance of cooked aromatic rice samples. The findings will help rice industry, farmers, and traders better employ GI labeling to increase consumer acceptability of their rice products.

Morphology of Rice Seed Development and Its Influence on Grain Quality.

Various quality attributes of rice seed are affected by the wide array of biochemical products accumulated during the course of reproductive development and the environmental conditions which impact the grain composition. The staging of rice plant reproductive development is needed in experiments to define phase transitions of seed biology. The application of the nomenclature and criteria of the rice growth staging system can facilitate recording the reproductive development by distinct stages. The meaningful progression from one stage to another in time can then be evaluated in a tabular or graphic manner. In order to determine the developmental stages of rice in experiments, it is desirable to select a representative group of plants and to record the development of those plants. We provide procedures for efficiently (1) observing and recording development of rice plants and (2) collecting, storing and seperating seed by developmental stages. It is necessary to divide seeds into differing groups to track development from fertilization until maturity. The earliest seeds to be fertilized on a panicle are superior grains and the latter seeds to develop are inferior grains. In some cases, it is necessary to divide individual seeds into the aforementioned groups and the different stages of development for various analyses. A procedure for dividing seeds into differing stages of development is presented to more appropriately select seeds for further analysis. The developmental record can then be statistically and graphically analyzed to better understand responses to treatments and interactions among treatments, years, and locations.

Utilizing the genetic diversity within rice cultivars.

Plant breeding of rice emphasizes improvement in yield, disease resistance, and milling quality. Numerous other traits (e.g., bran carotenoids) that historically have not been selected for could provide added value in expanding niche markets, as well as be useful tools for understanding the genetic control of these traits. Residual heterozygosity is present in many rice cultivars; therefore, it is possible to select for different alleles within an existing cultivar. By identifying and using cultivars with high levels of variability for a trait, we were able to develop separate lines from single cultivars that showed high and low levels of that trait. The rice cultivar RU9101001 and the warm- and cold-sprouting lines that were derived from it were used to demonstrate that residual heterozygosity was present within a cultivar and that the original heterozygosity was separated in the derived lines. Rice simple sequence repeat markers were heterozygous in the parent RU9101001 cultivar, but the cold-sprouting lines were homozygous for one set of alleles and the warm-sprouting lines were homozygous for the other set. Through detailed phenotypic screening, we developed lines that exhibited low and high levels of the following traits in the specified cultivars: cold-sprouting from RU9101001 and Bonnet 73, postharvest yellowing from Tominishiki, early tillering from Hei Jaio and Tominishiki, and bran carotenoid levels from Spring. If variability exists in a cultivar, then utilization of residual heterozygosity may provide a quicker and more efficient means to develop lines with special characteristics using cultivars that are already agronomically valuable or to develop near isogenic lines for genetic and biochemical investigations.

Rice amylopectin fine structure variability affects starch digestion properties.

UNLABELLED: The possibility to identify or develop new rice cultivars with low glycemic response was investigated. Twelve rice cultivars with a narrow range of amylose contents were selected based on their wide variation in rapid viscoanalyzer (RVA) pasting breakdown to study the relationship between starch digestibility and amylopectin fine structure and pasting properties. Rice flour samples were cooked for in vitro digestibility analysis using the standard Englyst assay. RVA was performed for pasting properties of starches. Results showed that rapidly digestible starch (RDS) was highly and negatively correlated (r = -0.86, p < 0.01; r = -0.81, p < 0.01) with FrI long and FrII intermediate/short debranched amylopectin linear chains, respectively, and positively correlated (r = 0.79; p < 0.01) with FrIII very short linear chains. Slowly digestible (SDS) starch was positively correlated (r = 0.80, p < 0.01; 0.76, p < 0.01) with FrI and FrII, respectively, and negatively correlated (r = -0.76, p < 0.01) with FrIII. RVA breakdown viscosity was positively correlated (r = 0.88, p < 0.01) with RDS and negatively correlated (r = -0.89, p < 0.01) with SDS. Thus, the RVA method potentially could be used as a screening tool for starch digestion properties. This study reveals a molecular basis in amylopectin fine structure variability for starch digestion properties in rice cultivars and could have value in identifying slowly digesting cultivars as well as developing a breeding strategy to produce low glycemic rice cultivars. KEYWORDS: Rice; starch; RVA; amylopectin; digestibility.

Rice Pi-ta gene Confers Resistance to the Major Pathotypes of the Rice Blast Fungus in the United States.

ABSTRACT The Pi-ta gene in rice prevents the infection by Magnaporthe grisea strains containing the AVR-Pita avirulence gene. The presence of Pi-ta in rice cultivars was correlated completely with resistance to two major pathotypes, IB-49 and IC-17, common in the U.S. blast pathogen population. The inheritance of resistance to IC-17 was investigated further using a marker for the resistant Pi-ta allele in an F(2) population of 1,345 progeny from a cross of cv. Katy with experimental line RU9101001 possessing and lacking, respectively, the Pi-ta resistance gene. Resistance to IC-17 was conferred by a single dominant gene and Pi-ta was not detected in susceptible individuals. A second F(2) population of 377 individuals from a reciprocal cross between Katy and RU9101001 was used to verify the conclusion that resistance to IC-17 was conferred by a single dominant gene. In this cross, individuals resistant to IC-17 also were resistant to IB-49. The presence of Pi-ta and resistance to IB-49 also was correlated with additional crosses between 'Kaybonnet' and 'M-204', which also possess and lack Pi-ta, respectively. A pair of primers that specifically amplified a susceptible pi-ta allele was developed to verify the absence of Pi-ta. We suggest that Pi-ta is responsible for resistance to IB-49 and IC-17 and that both races contain AVR-Pita genes.