PK23-2, a line of six-rowed barley (Hordeum vulgare L.) originating from Pakistan, has resistance to Japanese strains I and III of the barley yellow mosaic virus (BaYMV). To identify the source of resistance in this line, reciprocal crosses were made between the susceptible cultivar Daisen-gold and PK23-2. Genetic analyses in the F(1) generation, F(2) generation, and a doubled haploid population (DH45) derived from the F(1) revealed that PK23-2 harbors one dominant and one recessive resistance genes. A linkage map was constructed using 61 lines of DH45 and 127 DNA markers; this map covered 1268.8 cM in 10 linkage groups. One QTL having a LOD score of 4.07 and explaining 26.8% of the phenotypic variance explained (PVE) for resistance to BaYMV was detected at DNA marker ABG070 on chromosome 3H. Another QTL having a LOD score of 3.53 and PVE of 27.2% was located at marker Bmag0490 on chromosome 4H. The resistance gene on chromosome 3H, here named Rym17, showed dominant inheritance, whereas the gene on chromosome 4H, here named rym18, showed recessive inheritance in F(1) populations derived from crosses between several resistant lines of DH45 and Daisen-gold. The BaYMV recessive resistance genes rym1, rym3, and rym5, found in Japanese barley germplasm, were not allelic to rym18. These results revealed that PK23-2 harbors two previously unidentified resistance genes, Rym17 on 3H and rym18 on 4H; Rym17 is the first dominant BaYMV resistance gene to be identified in primary gene pool. These new genes, particularly dominant Rym17, represent a potentially valuable genetic resource against BaYMV disease.

A quantity of 56,000 tons of six-rowed barley is produced annually in Japan. It is consumed mainly as pearled barley, and cooked with rice. Domestic pearled barley used for human food accounts for more than 90% of its consumption in Japan, particularly in terms of pearled-grain quality. Barley grain contains more fiber than other cereals, and the demand for pearled barley has recently increased, thus reflecting a growing interest in healthy food.Hokuriku district is a major producing area of sixrowed barley, accounting for 53.0% of the total cultivated acreage 13 , and the barley produced in Hokuriku district is priced higher by barley-processing companies because of its high quality, in particular, the whiteness of the pearled grain. However, the yield in Hokuriku district is relatively low and fluctuates each year. One of REVIEW AbstractHokuriku district in Japan is a major producing area of six-rowed barley, which is mainly consumed as pearled grain. However, the barley cultivated in this region has been damaged by scald, and commercial scald-resistant cultivars need to be developed. The influence of scald on yield reduction (previously addressed in many reports) and on pearled-grain quality was investigated. The whiteness of pearled grain, which is the most important quality in pearled barley, was not affected, but the pearling time tended to increase with the incidence of disease. Appropriate methods to evaluate resistance or susceptibility of cultivars in breeding programs were considered. Artificial inoculation in seedlings is not adequate to determine the resistance of cultivars because an outbreak of the disease has at times occurred after the heading stage. A field test with a source of infection, i.e., scattering leaves that were badly infected by prior inoculation of scald, accelerated the incidence and prevalence of the disease. When the source of infection was applied before the winter snows, it was especially effective in spreading the disease. The field test helped to determine resistant cultivars and breeding lines that inhibited the incidence of scald after the heading stage, although the occurrence of scald fluctuated according to weather conditions. Most Japanese commercial cultivars are highly susceptible in the field, whereas some foreign cultivars exhibit resistance to the dominant race of scald in Hokuriku district. We analyzed the resistance of "Brier" and showed that it was possibly controlled by one dominant gene at the heading stage, an observation that was in agreement with previous reports. On the other hand, three recessive genes are expected to confer resistance at the grain-filling stage. The heritability of resistance at the grainfilling stage was high, which means it is relatively easy to select resistant individuals in a breeding program even if it is controlled by several genes.

The muscular activity pattern, function and maximal contraction velocity during the starting dash and sprint running at maximal velocity were studied, The subjects were five adult male sprinters, whose sprint running moyements in the sagittal plain were analyzecl (100 fps) from videotape recordings made with a high-speed camera, The ground reaction forces and EMGs of eight leg muscles were also recorded, Changes in length from the origin to the insenion (muscle-tendon complex: MTC) of the eight leg muscles were calculated using several methods reported by Grieve et al,

A germplasm panel of 52 six-rowed barley landraces from northern Morocco was analysed by a Cleaved Amplified Polymorphic Sequences (CAPS) assay of a fragment of the elongation factor G (EF-G) gene. Forty-nine of these accessions carried allele A, and the other three carried allele D. The latter all originated from a narrow region close to the border with Algeria, whereas the former were represented across the whole collection area. Since six-rowed D allele carriers are present in North Africa, along with both two-rowed cultivated and wild barleys, it is likely that the European six-rowed barley varieties carrying the D allele have Moroccan parentage.