Lodging has been a major roadblock to attaining increased crop productivity. In an attempt to understand the mechanism for culm strength in rice, we isolated an effective quantitative trait loci (QTL), STRONG CULM3 (SCM3), the causal gene of which is identical to rice TEOSINTE BRANCHED1 (OsTB1), a gene previously reported to positively control strigolactone (SL) signaling. A near-isogenic line (NIL) carrying SCM3 showed enhanced culm strength and increased spikelet number despite the expected decrease in tiller number, indicating that SL also has a positive role in enhancing culm strength and spikelet number. We produced a pyramiding line carrying SCM3 and SCM2, another QTL encoding APO1 involved in panicle development. The NIL-SCM2+SCM3 showed a much stronger culm than NIL-SCM2 and NIL-SCM3 and an increased spikelet number caused by the additive effect of these QTLs. We discuss the importance of utilizing suitable alleles of these STRONG CULM QTLs without inducing detrimental traits for breeding.

The Kjeldahl method using copper catalysts for digestion was established as an analytical method for the determination of crude protein in macaroni products in the Japanese Agricultural Standard (JAS). An interlaboratory study was performed to evaluate this Kjeldahl method. Eleven participating laboratories independently analyzed five test materials (five pairs of blind duplicates) of macaroni products. After removal of statistical outliers, the repeatability (RSD r ) and reproducibility (RSD R ) of the evaluated methods were 0.25-0.59 % and 1.2-1.5 %, respectively. The HorRat values (RSD R (%)/predicted RSD R (%)) of the total nitrogen content were calculated to be at 0.32 to 0.43. This method was shown to have acceptable precision in this study.

An interlaboratory study was conducted to evaluate the reproducibility of a combustion method for determining crude protein in macaroni products according to the Japanese Agricultural Standard (JAS). Fourteen participating laboratories analyzed five test materials (five pairs of blind duplicates) of macaroni products by the combustion method. Six different types of instruments commonly used for the combustion method in Japan were included in this study. After removal of statistical outliers, the repeatability and reproducibility of this method were found to be 0.16 − 0.53 % and 0.89 − 1.1 %, respectively. The HorRat values of this method were 0.25 to 0.31. The results for the combustion method were compared with those for the Kjeldahl method used on the same test materials and reported previously. Differences of means between the two methods were 0.10 − 0.13 % in five test materials. The differences did not considerably affect judgment near the standard values 11 % and 12 % of the JAS.Keywords: interlaboratory study, macaroni, JAS, Kjeldahl, combustion *To whom correspondence should be addressed. E-mail: akiko_hakoda@nm.famic.go.jp IntroductionMacaroni products have been standardized according to the Japanese Agricultural Standard (JAS) (Ministry of Agriculture and Forestry of Japan, 1973;1994). The JAS, established by the Ministry of Agriculture, Forestry and Fisheries, is a standard of quality, such as composition, grading and performance. The JAS system refers to the certification system that attaches JAS marks to the products inspected in accordance with the JAS. This macaroni standard indicates that the minimum crude protein contents of macaroni products with and without eggs are 11 % and 12 %, respectively. In general, the crude protein content in macaroni products has been calculated from determined total nitrogen content. A detailed description regarding the determination of total nitrogen content is not provided in the JAS, except for the use of the Kjeldahl method. Since 2000, a regular revision process of the JAS has been implemented every five years to meet the changing social needs for foods listed in the JAS. To review the standard for macaroni products, validated analytical methods were required. The Kjeldahl method has been validated in a previous study (Hakoda et al., 2009).The combustion method is another method for the determination of total nitrogen content. An organic substance is oxidized to inorganic gases such as NO 2 and CO 2 by furnace heating at an elevated temperature, in pure oxygen. A thermal conductivity detector quantitatively measures the resulting freed nitrogen. Each operation is performed continuously in a special instrument with a furnace, isolation system, and detection system. This combustion method employs less hazardous chemicals, supports easier operation, and allows more rapid determination (e.g., in about five minutes) than the Kjeldahl method. For example, an operation to determine nitrogen content involves only the measurement of the weight of a test portion, which i...

To determine the sex of asparagus (Asparagus officinalis) at the seedling stage, an easy, economical, and reliable method was developed. We used a modified single-step DNA extraction protocol, which resulted in a crude extract containing sufficient genomic DNA for use as a template. The male-specific marker (Asp1-T7sp) is a dominant marker and may lead to false negatives caused by an incomplete reaction; therefore, a multiplex polymerase chain reaction (PCR) was developed using a ribosomal RNA gene marker. The resulting banding pattern distinguished males from females without false negatives. To determine the best tissue for extraction of template DNA, phylloclades (a specialized stem that resembles and functions like a leaf) or root tips of individual asparagus plants were collected and weighed. A 4.0-mg phylloclade sample or a 0.8-mg root sample provided sufficient DNA for PCR analysis of asparagus. Root excision at day 19 did not affect subsequent growth of asparagus seedlings after 28 days. The method can determine the sex of asparagus at day 19 after seeding. A combination of single-step DNA extraction from root tips and multiplex PCR made for a simple and reliable screening method.

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