Novel reovirus isolation from an Ostrich (Struthio camelus) in Japan

An orthoreovirus was isolated from an Ostrich (Struthio camelus) and rapidly identified as orthoreovirus by the rapid determination of viral RNA sequences (RDV) system and electron microscopy. Phylogenetic analysis of the sigma A protein indicated that the isolate belonged to avian species and was closely related to chicken orthoreovirus strain 138. The results of the present study indicated that an ostrich orthoreovirus is slight different from other chicken orthoreoviruses and provided evidence of diversity among avian orthoreoviruses. To our knowledge, this is the first genetic report of an orthoreovirus isolated from an ostrich.     

瘤胃保护氨基酸和脂肪酸对奶牛瘤胃发酵、产乳量、乳成分和血液成分的影响

选用8头经产荷斯坦泌乳牛分为对照和试验2 组(n=4),以1 期为2 周、共3 期的二乘反转法,研究了瘤胃保护氨基酸和脂肪酸添加物(RPLMF)对奶牛瘤胃发酵、产奶量、乳成分和血液成分的影响。对照组牛饲喂由苏丹草青干草(20%)、苜蓿草块(20%)、意大利黑麦草青贮(17%)和混合精料(43%)组成的典型日粮。试验组牛饲喂上述日粮外,每天另添加160 g/d RPLMF。RPLMF 中主要含有脂肪酸60%、赖氨酸8%、蛋氨酸4%、其他28%。结果表明,RPLMF的添加对瘤胃发酵无明显的影响。2组血浆尿素氮、总游离氨基酸和必需氨基酸浓度以及赖氨酸和蛋氨酸浓度间均无明显差异(P>0.1),而试验组血浆葡萄糖浓度有下降趋势(P<0.1)和组氨酸浓度显著下降(P<0.05)。试验组与对照组比较,干物质采食量无明显差异,分别为20.2和20.4 kg/d;产乳量和4%的标准乳量分别为24.2、22.3和25.6、24.1 kg/d,试验组分别增加了1.4 kg/d和1.8 kg/d(P<0.1);乳脂率有增加趋势(P<0.1),而其他乳成分无显著变化;乳脂肪、乳蛋白质和无脂固形物分别增加9.5%(80 g/d,P<0.05)、6.9%(50 g/d,P<0.1)和6.4%(130 g/d,P<0.1);乳脂脂肪酸组成中C18∶0 比例显著提高(P<0.05)。另外,RPLMF添加后饲料蛋白质向乳蛋白质的转化效率从23.9%提高到25 3%。以上结果显示:在暑热季节泌乳中期的     

Development of a high-throughput field phenotyping rover optimized for size-limited breeding fields as open-source hardware

Phenotyping is a critical process in plant breeding, especially when there is an increasing demand for streamlining a selection process in a breeding program. Since manual phenotyping has limited efficiency, high-throughput phenotyping methods are recently popularized owing to progress in sensor and image processing technologies. However, in a size-limited breeding field, which is common in Japan and other Asian countries, it is challenging to introduce large machinery in the field or fly unmanned aerial vehicles over the field. In this study, we developed a ground-based high-throughput field phenotyping rover that could be easily introduced to a field regardless of the scale and location of the field even without special facilities. We also made the field rover open-source hardware, making its system available to public for easy modification, so that anyone can build one for their own use at a low cost. The trial run of the field rover revealed that it allowed the collection of detailed remote-sensing images of plants and quantitative analyses based on the images. The results suggest that the field rover developed in this study could allow efficient phenotyping of plants especially in a small breeding field.     

Level of VERNALIZATION 1 expression is correlated with earliness in extra early-flowering mutant wheat lines

Four extra early-flowering mutants, named extra early-flowering1 (exe1), exe2, exe3, and exe4, were identified in Triticum monococcum strain KU104-1 following heavy-ion beam mutagenesis. The four exe mutants fell into two groups, namely Type I (moderately extra early-flowering type; exe1 and exe3) and Type II (extremely extra early-flowering type; exe2 and exe4). Analysis of plant development in a growth chamber showed that the speed of leaf emergence was accelerated in exe mutants at the reproductive stage compared to wild-type (WT) plants. The speed of leaf emergence was faster in Type II than Type I plants. Analysis of VERNALIZATION 1 (VRN1), a flowering promoter gene, showed that it was more highly expressed in seedlings at early developmental stages in Type II mutants than Type I mutants. These findings indicate that the difference in earliness between Type I and Type II mutants is associated with the level of VRN1 expression. The original KU104-1 is an einkorn wheat strain that carries a null allele of the VRN2 gene, a repressor of flowering. Thus, our results indicate that the level of VRN1 expression controls earliness in exe mutants independently of VRN2.     

Comparative study of the structure of chromosome 1R derived from Secale montanum and Secale cereale

We produced 15 dissection lines of common wheat carrying segments of chromosome 1R of wild rye (Secale montanum) (1R^m) by the gametocidal system. Using the 1R^m dissection lines and previously established 24 dissection lines of chromosome 1R from cultivated rye (Secale cereale cv. ‘Imperial’) (1Rⁱ), we conducted cytological mapping of 97 markers that were amplified in the 1Rⁱ addition line. Sixty‐eight of the 97 markers were amplified in the 1R^m addition line. To reveal what structural differentiation occurred in chromosome 1R during domestication, we compared the cytological map of chromosome 1Rⁱ with that of chromosome 1R^m, and also with the previously published cytological map of chromosome 1R from wheat cultivar ‘Burgas 2’ (1R^B). There was one discrepancy in marker order in the satellite region between chromosomes 1Rⁱ and 1R^B, while there were four discrepancies in marker order between chromosomes 1Rⁱ and 1R^m. These results suggested that during the domestication of rye, some intrachromosomal rearrangements had occurred in chromosome 1R, although this chromosome is regarded as the most stable chromosome in the rye genome.     

Trisomic analysis of new gene for late heading in rice, Oryza sativa L

A near isogenic line, T65-LH7 bred from a rice variety, Ketan Nangka by five times of successive backcrossing with Taichung 65 (T65) as recurrent parent was found to carry a recessive lateness gene tentatively designated as ef6(t). The present study was performed to investigate the allelic relationships between ef6(t) and other heading time genes, Ef1, Efx, ef2(t), ef3(t), ef4(t) and ef5 by allelism test and to locate the chromosomal location of ef6(t) by trisomic analysis. In allelism test, six testers carrying each of heading time genes, Ef1, Efx, ef2(t), ef3(t), ef4(t) and ef5 were used. Those testers were the near isogenic lines of T65. T65-LH7 was crossed with respective testers. Heading times in F₂ and/or B₁F₁ plants were examined. All F₂ and/or B₁F₁ populations derived from those crosses exhibited digenic segregations, respectively. These results suggested that ef6(t) was independent of Ef1, Efx, ef2(t), ef3(t), ef4(t) and ef5. Sub sequently, trisomic analysis of ef6(t) was performed using seven Triplo lines having extra chromosomes, 2, 4, 5, 7, 9, 10 and 12. These Triplo lines were the near isogenic lines of T65. They were used as maternal parent to cross with T65-LH7. Heading times in F₂ plants obtained from self-pollination of F₁ plants were observed. Among F₂ plants examined only those derived from a cross between Triplo-7 and T65-LH7 showed a typical trisomic segregation manner, suggesting that ef6(t) was located on chromosome 7. Consequently, the nomenclature of the present gene should be designated as ef6.