SSR-tagged breeding scheme for allogamous crops: a trial in bunching onion (<Emphasis Type="Italic">Allium fistulosum</Emphasis>)     

Hikaru Tsukazaki  Ken-Ichiro Yamashita  Akio Kojima  Tadayuki Wako 《Euphytica》2009,169(3):327-334

In several autogamous and vegetatively propagated crops, DNA markers have been used for cultivar identification. However, allogamous crops such as bunching onion (Allium fistulosum L.) are recalcitrant to marker-aided cultivar identification, as well as hybrid seed purity tests, due to the high degree of genetic heterogeneity within each cultivar. To aid cultivar identification and ensure its accuracy in bunching onion, we proposed the “SSR-tagged breeding” scheme in our previous study. The feasibility of this scheme was investigated here using a landrace of bunching onion with two populations tagged with two or four selected SSR markers. Compared with a control population, no significant differences were detected in the agronomic traits of the SSR-tagged populations. The targeted SSR loci were genetically uniform within each population whereas other loci maintained high heterogeneity. These results demonstrate that the SSR-tagged breeding scheme, even with a very small number of markers, is efficient for the identification of newly bred cultivars, and consequently for F₁ purity tests, in allogamous crops in which inbreeding depression is as severe as in bunching onion.  相似文献   

Genetic identification and morphology of naturally spawned eggs of the Japanese eel Anguilla japonica collected in the western North Pacific     

Tatsuki Yoshinaga  Michael J. Miller  Kazuki Yokouchi  Tsuguo Otake  Shingo Kimura  Jun Aoyama  Shun Watanabe  Akira Shinoda  Machiko Oya  Sachie Miyazaki  Kei Zenimoto  Ryusuke Sudo  Tetsuya Takahashi  Hyojin Ahn  Ryotaro Manabe  Seishi Hagihara  Hiroshi Morioka  Hikaru Itakura  Masamichi Machida  Kazuyuki Ban  Mayu Shiozaki  Bunpei Ai  Katsumi Tsukamoto 《Fisheries Science》2011,77(6):983-992

Eggs of the Japanese eel Anguilla japonica collected in the western North Pacific were identified by onboard species-specific polymerase chain reaction (PCR) and DNA nucleotide sequencing after the cruise. Fish eggs of various species were collected by large plankton net tows at 12 stations along the southern part of the West Mariana Ridge on 19–25 May 2009. A total of 43 fish eggs were distinguished morphologically as possibly being of A. japonica. Thirty-one of those were analyzed by PCR, which included 15 eggs collected at 12°50–55′N, 141°15–20′E (in 5 tows) that showed positive results. The 16S ribosomal RNA (rRNA) gene sequences of eggs determined after the cruise indicated that 31 A. japonica eggs had been collected. The remaining eggs were of mesopelagic eel species (Serrivomeridae and Derichthyidae), or unidentified species. The morphological characteristics of the A. japonica eggs were consistent with those of artificially spawned eggs, except they had a slightly larger diameter. The egg diameter range did not overlap with those of mesopelagic eels of the Serrivomeridae, which often spawn in the same area as A. japonica. These results suggest that egg diameter and embryo shape can be used to morphologically identify naturally spawned A. japonica eggs.  相似文献   

Structural Characteristics,Properties, and In Vitro Digestibility of Rice     

Masaki Okuda  Isao Aramaki  Takuya Koseki  Hikaru Satoh  Katsumi Hashizume 《Cereal Chemistry》2005,82(4):361-368

Using rice samples derived from normal rice cultivars and endosperm starch mutant, we investigated key factors contributing to the enzyme digestibility of steamed rice grains. The chemical composition of polished rice grains, structural features of endosperm starch, and enzyme digestibility of steamed rice grains were examined. The protein content of polished rice grains was 4.6–9.1%, amylose content was 4–27%, the DP_n of purified amylose was 900–1,600, the amylopectin short/long chain ratio was 1.2–5.9, and the enzyme digestibilities of steamed polished rice grains were 0.9–12.6 °Brix. Amylose content and RVA parameters (viscosity, breakdown, and setback) correlated significantly with enzyme digestibility of steamed rice grains. Multiple regression formulas were constructed to predict digestibility of steamed rice grain as a function of the molecular characteristics of the starch. When both amylose content and the short/long chain amylopectin ratio were used as predictor variables, they accounted for >80% of the observed variance in digestibility of steamed rice grains. Multiple regression revealed that the more digestible rice samples had starch with a lower amylose content and more short‐chain amylopectin. Reassociation of amylose‐lipid complex and recrystallization of amylopectin in the stored steamed rice grains was monitored by differential scanning calorimetry (DSC), and the observed retrogradation properties were related to the structural characteristics of starch and to the enzyme digestibility of steamed rice grains.  相似文献   

Effect of blue and red LED light irradiation on β-cryptoxanthin accumulation in the flavedo of citrus fruits     

Ma G  Zhang L  Kato M  Yamawaki K  Kiriiwa Y  Yahata M  Ikoma Y  Matsumoto H 《Journal of agricultural and food chemistry》2012,60(1):197-201

β-Cryptoxanthin (β-cry), an antioxidant abundant in citrus fruits, plays an important role in the prevention and treatment of certain diseases, especially cancers. In the present study, to increase the content of β-cry in citrus flavedo, the effects of blue (470 nm) and red (660 nm) light-emitting diode (LED) lights on the accumulation of carotenoids and expression of genes related to carotenoid biosynthesis were investigated in the flavedo of Satsuma mandarin. The results showed that accumulation of β-cry was induced by red light, while it was not affected by blue light. The accumulation of β-cry under red light was attributed to simultaneous increases in the expression of CitPSY, CitPDS, CitZDS, CitLCYb1, CitLCYb2, CitHYb, and CitZEP. The results presented herein might provide new strategies to enhance the commercial and nutritional value of citrus fruits.  相似文献   

Detection of novel kobu-like viruses in Japanese black cattle in Japan     

Konosuke OTOMARU  Yuki NAOI  Kei HAGA  Tsutomu OMATSU  Takehiko UTO  Motoya KOIZUMI  Tsuneyuki MASUDA  Hiroshi YAMASATO  Hikaru TAKAI  Hiroshi AOKI  Shinobu TSUCHIAKA  Kaori SANO  Sachiko OKAZAKI  Yukie KATAYAMA  Mami OBA  Tetsuya FURUYA  Junsuke SHIRAI  Kazuhiko KATAYAMA  Tetsuya MIZUTANI  Makoto NAGAI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2016,78(2):321-324

During surveillance for bovine diarrhea of unknown causes in Japanese black cattle in Kagoshima Prefecture, Japan, we found two types of novel kobu-like viruses in fecal samples of calves. Sequence analyses revealed that they had L protein and 2A protein with H-box/NC sequence motif, which are present in kobuviruses. Phylogenetic analysis revealed that they were related to kobuviruses; however, they clustered apart from other kobuviruses. In the prevalence study of two types of novel kobu-like viruses, 16.9% and 10.4% prevalence of these viruses were observed in the feces of diarrheal calves in this area.  相似文献   

Environmental influences on late-summer individual Japanese eel diel activity and space utilization patterns in a shallow western Japan brackish lake     

Itakura  Hikaru  Miyake  Yoichi  Wakiya  Ryoshiro  Kimura  Shingo 《Fisheries Science》2022,88(1):29-43

The late-summer diel activity patterns and space utilization of five Japanese eels, Anguilla japonica, were investigated using an acoustic telemetry positioning system in a shallow brackish lake in western Japan. Eels were highly nocturnal and crepuscular, with 98.1% of positions detected between sunset and sunrise, and were more active during dusk and dawn compared with nighttime, and during full moons compared with other lunar periods. Most diurnal activity occurred during darker conditions, and two individuals extended their activity into the morning, suggesting that overcast skies reduced light intensity and prolonged nocturnal activity into daytime. Individual eels had different home-range patterns, but appeared to rest nearshore during the day, with space utilization expanding offshore at dusk and night, followed by returning to nearshore at dawn. Their home ranges and core activity areas were bordered by the shoreline, with eels tending to exhibit small activity spaces and strong site fidelity. This study provides valuable ecological knowledge about the individual behavior of eels inhabiting a small brackish lake at the northern limit of the natural distributional range of the species along the Sea of Japan, which can contribute to management and conservation of the species.

  相似文献   

Isolation of 1,796 SSR clones from SSR-enriched DNA libraries of bunching onion (Allium fistulosum)     

Hikaru Tsukazaki  Tsukasa Nunome  Hiroyuki Fukuoka  Hiroyuki Kanamori  Izumi Kono  Ken-ichiro Yamashita  Tadayuki Wako  Akio Kojima 《Euphytica》2007,157(1-2):83-94

Bunching onion (Allium fistulosum L.) is one of the most important vegetables in Japan. To establish a genetic basis for molecular breeding of bunching onion, we isolated 1,796 simple sequence repeat (SSR) clones by large-scale sequencing of SSR-enriched genomic DNA libraries. Of these, 1,331 (74.1%) contained (GT) _n repeats (n > 5), while 314 (17.5%) were (GA) _n -containing clones. The average number of SSR repeats was 10.5 and 10.4 in the (GT) _n - and (GA) _n -containing clones, respectively. In a sample of five bunching onion inbred lines, an average of 3.2 alleles were detected in the 100 SSR loci investigated, with the polymorphic information content averaging 0.55. These results indicate that bunching onion SSRs are very rich sources of highly informative genetic markers.  相似文献   

Variations in the abundance of Pacific saury (Cololabis saira) from the northwestern Pacific in relation to oceanic-climate changes     

Yongjun Tian  Tatsuro Akamine  Maki Suda 《Fisheries Research》2003,60(2-3):439-454

Effects of oceanic-climate changes on the abundance of Pacific saury (Cololabis saira) in the northwestern Pacific during the last half century were investigated. Abundance indices of both large and medium size groups exhibit interannual–decadal variations, but their patterns were different. The large and medium size groups of saury are corresponding to the recruitments of winter- and spring-cohort, respectively. The abundance of large size group saury was significantly correlated with the winter sea surface temperature (SST) in the Kuroshio region, whereas the medium size group saury showed high correlations with SST in the Kuroshio–Oyashio transition zone and the Oyashio region, indicating that the two size groups are affected by subtropical and subarctic environment, respectively. Significant negative correlation between the abundance index and the southern oscillation index (SOI) suggested that El Niño-southern oscillation (ENSO) events have marked impacts on the large size group saury. Subtropical high pressure index and far east zonal index also show high correlations with the abundance of both large and medium size group saury, indicating a linkage between large-scale atmospheric circulation and the abundance of saury. These correlations demonstrate that the abundance of Pacific saury is directly affected by the SST fields through large-scale atmosphere–ocean interactions from the equatorial Pacific to mid- and high-latitude areas such as El Niño events.  相似文献   

Acaricidal activity of components of Cryptomeria japonica against spider mites     

Yohei Yamashita  Naoya Hashimoto  Norihisa Kusumoto  Hiromi Saijo  Ikumi Goto  Hikaru Kobayashi  Yuka Kurihara  Koetsu Takahashi  Tatsuya Ashitani 《Journal of Wood Science》2015,61(1):60-64

  相似文献   

Forest soil and litter as filtering media for suspended sediment     

Yoichi Okura  Hikaru Kitahara  Toshiaki Sammori 《Journal of Forest Research》1997,2(1):9-14

A series of two filtration experiments were conducted to evaluate the filtration function of forest soil experimentally. The first experiment evaluated the differences between the filtration capabilities of the A₀ horizon and A horizon, and the effect of overstory species on the filtration function of the A₀ horizon. Undisturbed A₀, A and A₀+A horizons were collected for the filter mediums with cylindrical samplers. Leaves ofQuercus serrata, Quercus myrsinaeforia, Sasa senanensis Pinus densiflora, Chamaecyparis obtusa, andCryptomeria japonica were also packed in the samplers. Various suspended sediment concentration of water were sprayed at constant intensity on the surface of samples. Filtering coefficients were not affected by SS concentration in all samples, and the order of filtering coefficient was: A₀ horizons>A₀+A horizons>A horizons in undisturbed forest soil samples, andQuercus serrata>Sasa senanensis>Quercus myrsinaeforia>Pinus densiflora”Chamaecyparis obtusa>Cryptomeria, japonica in leaf samples. These results led to the conclusion that SS from managed forests can best be prevented by buffer zones where a thick A₀ horizon is maintained. The second experiment evaluated the effect of turbid water supply rate on the filtration capacity. Undisturbed A horizons and four leaf types,Quercus serrata, Pinus densiflora, Chamaecyparis obtusa, andCryptomeria japonica were used as filter mediums. Filtering coefficients were inversely proportional to supply rate of turbid water in all samples.  相似文献