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This research paper addresses the challenge of providing effective feedback on spontaneous speech produced by second language (L2) English learners. As the position of pauses and lexical stress is often considered a determinative factor for easy comprehension by listeners, an automated pipeline is introduced to analyze the position of pauses in speech, the lexical stress patterns of polysyllabic content words, and the degree of prosodic contrast between stressed and unstressed syllables, on the basis of F0, intensity, and duration measures. The pipeline is applied to 11 h of spontaneous speech from 176 French students with B1 and B2 proficiency levels. It appeared that B1 students make more pauses within phrases and less pauses between clauses than B2 speakers, with a large diversity among speakers at both proficiency levels. Overall, lexical stress is correctly placed in only 35.4% of instances, with B2 students achieving a significantly higher score (36%) than B1 students (29.6%). However, great variation among speakers is also observed, ranging from 0% to 68% in stress position accuracy. Stress typically falls on the last syllable regardless of the prosodic expectations, with the strong influence of syllable duration. Only proficient speakers show substantial F0 and intensity contrasts.

Infection by the Japanese soil-borne wheat mosaic virus (JSBWMV) can lead to substantial losses in the grain yield of barley and wheat crops. While genetically based resistance to this virus has been documented, its mechanistic basis remains obscure. In this study, the deployment of a quantitative PCR assay showed that the resistance acts directly against the virus rather than by inhibiting the colonization of the roots by the virus’ fungal vector Polymyxa graminis. In the susceptible barley cultivar (cv.) Tochinoibuki, the JSBWMV titre was maintained at a high level in the roots during the period December–April, and the virus was translocated from the root to the leaf from January onwards. In contrast, in the roots of both cv. Sukai Golden and cv. Haruna Nijo, the titre was retained at a low level, and translocation of the virus to the shoot was strongly suppressed throughout the host’s entire life cycle. The roots of wild barley (Hordeum vulgare ssp. spontaneum) accession H602 responded in the early stages of infection similarly to those of the resistant cultivated forms, but the host was unable to suppress the translocation of the virus to the shoot from March onwards. The virus titre in the root was presumed to have been restricted by the action of the gene product of Jmv1 (on chromosome 2H), while the stochastic nature of the infection was suppressed by the action of that of Jmv2 (on chromosome 3H), a gene harbored by cv. Sukai Golden but not by either cv. Haruna Nijo or accession H602.

Rice (Oryza sativa L.) bran accumulates many compounds that are associated with the promotion and maintenance of human health, such as γ-oryzanol (gOZ) and γ-aminobutyric acid (GABA). These beneficial compounds in the bran fraction are mostly removed in polished rice. The present study sought rice cultivars with high concentrations of gOZ, and also of GABA, in polished rice, and examined the distribution of gOZ content in the outer layers of brown rice. The effects of germination treatment were also examined as a means to enrich gOZ and GABA in polished rice. GABA concentration showed no significant variation among 19 cultivars in polished rice, whereas a wide variation was detected in brown rice, for which cultivar Kinuhikari had the highest amount. Germination treatment for 5 h significantly enhanced GABA concentration. gOZ concentrations also showed a wide variation among cultivars in both brown rice and polished rice, with no clear correlation. Hattan, a sake-brewing cultivar, exhibited the highest gOZ concentration in polished rice. This cultivar involved higher gOZ in the outermost layer of polished rice, whereas it had a lower content in the bran fraction. This permeation of gOZ into polished rice might be related to the endosperm properties characteristic to sake-brewing cultivars. In contrast to GABA, gOZ concentration did not increase with germination treatment in brown rice or polished rice. Because the gOZ concentration in polished rice was insufficient even in the Hattan cultivar, breeding and/or other processing techniques are needed to obtain gOZ-enriched polished rice. Percentages of γ-oryzanol (gOZ) content in different layers and the core of brown rice. (a) Comparison among layers and the core in each of six rice cultivars, and (b) comparison among six cultivars in each of the layers and the core. Means with the same letter did not differ significantly at the 0.01 probability level, within each cultivar (a) and within each layer or the core (b). See text for layers and core.

γ-Oryzanol is a main oleophilic component in rice bran oil and has been well recognized as a good dietary supplement for human health, as well as having uses in industrial materials. japonica-type rice cultivars generally showed significantly higher contents of total γ-oryzanol in brown rice compared with indica-type cultivars, although within-group variation was significant. The objective of this study was to explore quantitative trait loci (QTLs) responsible for the difference in the γ-oryzanol content between japonica-type and indica-type rice cultivars, using recombinant inbred lines (RILs), backcross inbred lines (BILs), and corresponding chromosome segment substitution lines (CSSLs) derived from crosses between japonica-type and indica-type. Results from RILs and BILs showed that eight QTLs were detected with R2 from .09 to .16. Nine candidate regions for QTL were also suggested from corresponding CSSLs. These QTLs from RILs and BILs and the candidate regions from CSSLs were not overlapped, although one QTLs was mapped near the boundaries of the respective candidate region. At four QTLs and three candidate regions, alleles or segments from japonica-type caused higher contents than those from indica-type. On the other hand, at the other four QTLs and six candidate regions, alleles or segments from indica-type caused higher contents than those from japonica-type, which is a reverse result to the parental differences. This result strongly suggested that alleles with increasing effects on γ-oryzanol content could be accumulated not only from japonica-type but also from indica-type, leading to a potential for increase in γ-oryzanol content in future breeding programs.

Raising the degree of grain filling is an important issue for the genetic improvement of extra-heavy panicle type rice which does not always realize the high yield potential due to low degree of grain filling. The objective of this study was to analyze the variation and association of the traits related to grain filling in four cultivars, three extra-heavy panicle types and one non-extra-heavy panicle type as a control, under seven environments. The results showed wide variation among cultivars and among growing environments in most of the traits examined. In addition, significant interactions between cultivar and environment were detected. From the analyses of joint regression and genetic and environmental correlations, an extra-heavy panicle type cultivar, Milyang 23, showed a higher degree of grain filling and higher rate of grain filling (grain weight/ cumulative temperature), in response to several environments with a higher temperature and longer sunshine hours under which a large amount of photoassimilates would be available to grains. On the contrary, another extra-heavy panicle type cultivar, Akenohoshi, showed a lower rate of grain filling, even under the favorable environments mentioned above, resulting in a lower degree of grain filling. The difference in the rate of grain filling between Milyang 23 and Akenohoshi might be due to the difference in the growth of individual endosperm cells, not in the number of cells, because these two cultivars had similar grain sizes. This study obviously emphasized the importance of high grain sink activity in the genetic improvement of grain filling in extra-heavy panicle type rice.

Rice cultivars with numerous spikelets per panicle (extra-heavy panicle types) frequently fail to exhibit their high yield potential due to low grain filling. Existing genetic variation in grain filling, however, opens possibilities for genetic improvement for this trait. We studied the correlation between grain filling and the activities of enzymes for sucrose-starch conversion in developing endosperm. The activity of sucrose synthase (EC 2.4.1.13, SuSy) and ADPglucose pyrophosphorylase (EC 2.7.7.27, AGPase), were measured in three extra-heavy panicle types and a standard cultivar grown at two locations under different environmental conditions. The proportions of grains with definite specific gravities and the rate of grain filling were adopted as the parameters related to grain filling. AGPase activity, but not that of SuSy, was consistently correlated to high proportions of high-density grains (specific gravity > 1.20) and high rates of grain growth in spikelets, particularly in those on secondary branches in which low grain filling is the rule. Such correlation was also detected in spikelets on primary branches which generally show better grain filling, but only early stages. Therefore, a high activity of AGPase might contribute to the reduction of the sucrose concentration by accelerating sucrose metabolism at the developing seed, a sink terminus of the phloem. Thus the sink-directed phloem transport of sucrose would be promoted, resulting in improved grain filling of extra-heavy panicle types. SuSy would play some roles in such a cultivar difference in grain filling, but depending on environments.

We examined the involvement of genetic and environmental factors in the variations and associations of the rate and duration of grain filling and the final grain weight in rice cultivars, instead of the simple phenotypic correlation and variance. The estimations were conducted by analyses of variance and covariance in a two-way classification, using ten rice cultivars cultivated under three environments at different locations and years. Also examined were the differences in these parameters for various grain positions on a panicle ; the grains on primary rachis-branches and the grains on secondary rachis-branches. In both grain positions in a panicle, the rate and duration of grain filling differed widely with the environment and cultivar, and showed a very high negative environmental correlation between these two traits. The final grain weight (=filling rate×filling duration) showed a much smaller variation due to environmental fluctuations compared with the rate and duration of filling, which reflects the negatively associated environmental changes in the rate and duration of grain filling. The duration of filling, especially that in the grains on secondary rachis-branches, was more influenced by non-genetic factors than the rate of filling. The genetic correlation between the rate and duration of grain filling was not so high. The final grain weight, on the other hand, was strongly and genetically correlated only with the filling rate, not with the filling duration. This may have resulted from some constraints which do not allow longer filling durations to attain higher final grain weights.