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1.
In 1999, a disease of chrysanthemum [Dendranthema grandiflorum (Ramat.) Kitamura], characterized by virescence of flowers, occurred in Okinawa Prefecture. The causal agent was identified as “Candidatus Phytoplasma aurantifolia” based on 16S rDNA sequencing. The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under accession number AB247462.  相似文献   
2.
On-farm conservation is recognized as a key component of a comprehensive strategy to conserve crop genetic resources. A fundamental problem faced by any on-farm conservation project is the identification of crop populations on which efforts should be focused. This paper describes a method to identify a subset of landraces for further conservation efforts from a larger collection representing the diversity found in the Central Valleys of Oaxaca, Mexico. Mexico is a center of origin and diversity for maize (Zea mays L.). The 17 landraces selected from an initial collection of 152 satisfy two criteria. First, they represent the diversity present in the larger collection. Second, they appear to serve the interests of farmers in the region. Data for applying the method were elicited through participatory as well as conventional techniques. They incorporate the complementary perspectives of both men and women members of farm households, and of plant breeders and social scientists.  相似文献   
3.
A panicle blight with sclerotia was found on mango (Mangifera indica L.) in Okinawa Prefecture, Japan, in March 2016. Water-soaked lesions with white mycelia developed on panicles in the flowering stage; softening and decay of panicles was followed by formation of sclerotia. The fungus isolated from these sclerotia was identified as Sclerotinia sclerotiorum based on morphology and analysis of rDNA-ITS sequences. The isolate reproduced the symptoms on mango panicles in an inoculation test and was reisolated from flower stalks. This is the first report of sclerotinia rot (kinkaku-byo in Japanese) on mango caused by S. sclerotiorum in Japan.  相似文献   
4.
Maize (Zea mays L. ssp. mays) was domesticated from one wild species ancestor, the Balsas teosinte (Zea mays ssp. parviglumis) about 9000 years ago. Higher levels of gene diversity are found in teosinte taxa compared to maize, following domestication and selection bottlenecks. Diversity in maize can be increased via gene flow from teosinte, which has certainly occurred from various taxa, but the rate of flow from different teosinte taxa and the final impact on maize evolution has been difficult to measure. One hundred populations from six Zea taxa, both domesticated (maize) and wild (teosinte), including domesticated landraces from Asia, Africa, and the Americas, were genotyped with 17 SSR markers using 15 individuals per population. Overall levels of diversity were high, and populations could be distinguished based on markers. Relationships between populations followed most published reports, or can now help resolve previously conflicting reports. Gene flow into maize from different teosinte groups, and gene flow between different teosintes, was estimated. Evidence for contributions from the Balsas teosintes and from Chalco teosintes (Z. mays ssp. mexicana) to the maize gene pool was found, as well as from Chalco into ssp. mexicana race ??Durango?? and Z. mays ssp. huehuetenengensis. These contributions are almost certainly the result of post-domestication (and ongoing) exchanges. This information must give more impetus to in situ conservation of teosinte species, and use of these teosintes to continue to direct the evolution of maize, especially in response to new diseases, insect pests, and other biotic and abiotic stresses.  相似文献   
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The WS-Y isolate of Watermelon silver mottle virus (WSMoV) causes severe necrosis in Tetragonia expansa. To determine the RNA segment that induces symptoms, genome reassorants between WS-Y and an isolate causing mild mottle, WS-O, were generated. The origin of each segment in the reassortants was identified by RT-PCR and subsequent restriction enzyme analysis of the amplified fragments. Thirty genome reassortants were isolated from co-infected T. expansa plants. The reassortants with the S RNA segment of WS-Y caused severe necrosis, while those with the S RNA segment of WS-O caused a mild mottle; hence, the S RNA determined symptom expression. The incidence of reassortants was disproportional among genotypes. The most frequent genome reassortant possesses the L RNA of WS-Y, the M RNA of WS-O and the S RNA of WS-Y. A similar ratio of genotypes was found in isolates of local lesions on Chenopodium quinoa. These results strongly suggested that competition occurred independently between the individual RNA segments in a co-infected T. expansa plant, not between isolates.  相似文献   
7.
Strawberry pear (pitahaya, pitaya) [Hylocereus undatus (Haw.) Britt. and Rose] postharvest fruit rot was found at an agricultural products store in Itoman city, Okinawa Prefecture in 2006. The symptoms included depressed, water-soaked lesions with olive to black powdery spots coalescing into a soft rot. The causal fungus was identified as Bipolaris cactivora (Petrak) Alcorn. This is the first report of strawberry pear fruit rot caused by B. cactivora.  相似文献   
8.
Chemical composition (moisture, total lipids, protein, and apparent amylose) and some physical features (1,000 kernel weight, hardness, and anatomical composition) were determined in 71 accessions representing races of maize from Latin America. Their microstructural characteristics (size and compaction of endosperm cell bodies, pericarp thickness, horny‐floury endosperm ratio, and morphology and size of starch granules) were also evaluated using environmental scanning electron microscopy (ESEM). Compaction was the most important microstructural feature of the maize kernels, representing kernel hardness. Highly compact kernels tended to be hard, with high protein, pericarp, and hard‐endosperm content and high pericarp thickness, but with low moisture, amylose content, and kernel weight and size. The opposite was observed in the least compact kernels. Highly compact kernels tended to have small, polygonal starch granules (<10 μm), while the least compact kernels contained large, spherical granules (>10 μm). These results suggest that microstructure is responsible for the physical features of maize kernels and that microstructure is related to chemical composition.  相似文献   
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10.
The objective of the present work was to evaluate the teratogenic effects of the interaction between acetylsalicylic acid (ASA) and ethanol on the epithelium of the lingual mucosa in rat fetuses. On the 10th pregnancy day, a single intraperitoneal ethanol dose (2.96 g/kg body weight) (Group I), ASA (200 mg/kg body weight) (Group II) and ASA plus ethanol, in the same doses (Group III), or saline (Group IV - control), were administrated. The epithelial alterations were assessed by means of histological and morphometric methods, on posterior dorsal, anterior dorsal and ventral regions of the tongue. ASA reduced, in rat fetuses, the ethanol deleterious effects on nuclear size in the epithelial prickle cell of the lingual mucosa. On the other hand, ASA did not influence the effects of ethanol in both epithelial layers of the lingual mucosa, when the nuclear shape, cell volume or epithelial layers thickness were evaluated.  相似文献   
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