云南热区五种特色蜜源植物的调查

经初步调查 ,云南热区有极其丰富的蜜源植物资源。对其中5种蜜源植物的资源状况、蜂蜜的感官指标及化学成分进行了分析研究 ,表明这5种蜜源植物的蜂蜜品质优良 ,各具特色 ,资源量大 ,且生长集中连片 ,具有很好的开发前景。除这5种蜜源植物外 ,还有数十种具有开发价值的蜜源植物待进一步分析研究。这充分证明云南热区还是一个尚待开发的“特色蜂蜜”宝库。     

基于数据包络分析法的广东农业信息化效率研究

针对广东农业信息化的效率问题建立了一套投入产出指标体系,利用数据包络分析法中的CCR模型、BCC模型和超效率模型,对2000-20012年广东省农业信息化的效率水平进行了测算.结果表明,2000-2012年期间广东农业信息化的发展可大致分为高效率发展阶段、调整阶段和继续提高调整阶段;在分析各个阶段的特征的基础上,提出了进一步促进广东农业信息化发展的意见与建议.     

Histological analysis of implanted embryos in large Japanese field mouse (Apodemus speciosus) and estimation of developmental stage

The large Japanese field mouse (Apodemus speciosus) is a small rodent species endemic to Japan. The genetic characteristics of A. speciosus include different chromosome numbers within the same species. Furthermore, A. speciosus has been used in radiation and genetic research. In the present study, a pregnant A. speciosus was obtained, and histochemical analysis of the implanted embryos was performed and compared with the developmental stages of the mouse (Mus musculus). Although there were some differences, the structures of the implanted embryos, including the primitive streak and placenta of A. speciosus were similar to those of mouse. Our study will be important for the construction of a developmental atlas of A. speciosus.     

Effect of quantitative trait loci for seed shattering on abscission layer formation in Asian wild rice Oryza rufipogon

Asian cultivated rice Oryza sativa L. was domesticated from its wild ancestor, O. rufipogon. During domestication, the cultivated rice lost its seed-shattering behaviour. Previous studies have shown that two major quantitative trait loci (QTLs; qSH1 and sh4) are responsible for the seed-shattering degree. Here, we produced introgression lines carrying non-functional alleles from O. sativa ‘Nipponbare’ at the two major QTLs in the genetic background of wild rice O. rufipogon W630, and examined the effects of the two QTLs on seed shattering and abscission layer formation. The introgression lines, with Nipponbare alleles at either or both loci, showed complete or partial abscission layer formation, respectively, indicating that other unknown loci might be involved in enhancing seed shattering in wild rice. We detected a single QTL named qSH3 regulating seed-shattering degree using an F₂ population between Nipponbare and the introgression line carrying Nipponbare alleles at the two QTLs. Although we generated an introgression line for qSH3 alone, no effects on seed shattering were observed. However, a significant effect on seed-shattering degree was observed for the introgression line carrying Nipponbare alleles at qSH3 and the two QTLs, suggesting an important role of qSH3 on seed shattering in coordination with the two QTLs.     

Stock assessment and management for walleye pollock in Japan

We review the stock assessment strategies and management procedures for walleye pollock Theragra chalcogramma in Japan. In Japan, walleye pollock is classified into 4 stocks. Because biological data, fishing conditions, etc. are different for each stock, the stocks are assessed by different methods. Harvest strategies aiming at stock recovery are proposed for the Northern Japan Sea stock and the Nemuro Strait stock, which are currently in poor condition. For the Japanese Pacific stock and the Southern Okhotsk Sea stock, which are in good condition, harvest strategies for current fishery operations are proposed. In Japan, fisheries co-management has traditionally been carried out, and in recent years a total catch limitation system called the total allowable catch, a resource recovery plan, and a resource management plan have also been implemented. Although a plan is devised that accounts for the stock conditions of walleye pollock, it is also necessary to consider socioeconomic factors, ecosystem factors, and so on. However, we consider that the main focus of stock management for walleye pollock will still be maintaining fishing pressure at an appropriate level, which includes regulating fish size and price during the fishing season.     

A new interspecific pear cultivar Yutaka: highly resistant to the two major diseases scab and black spot on Asian pears

Phytoplasma suspected symptoms of little leaf, flat stem, witches’ broom and leaf yellowing were recorded on the four legume species, cowpea (Vigna unguiculata (L.) Walp.), pigeon pea (Cajanus cajan (L.) Millsp.), lentil (Lens culinaris Medikus) and mung bean (Vigna radiata (L.) Wilczek) in the states of Delhi, Uttar Pradesh (UP) and Kerala from 2014 to 2016. DNA specific fragments of approximately 1.3 kb were amplified from symptomatic samples of cowpea, pigeon pea, lentil and mung bean in nested PCR assays by using two sets of universal phytoplasma nested specific primers P1/P7 followed by 3Far/3Rev. No DNA amplifications were observed in any of the non-symptomatic legume samples with same primer pairs. Pair wise sequence comparison, phylogeny and virtual RFLP analysis of 16S rDNA sequences of the four legume species confirmed the association of four different groups and subgroups of phytoplasmas in the present study. The mung bean witches’ broom at Delhi was identified to be associated with strain related to ‘Ca. P. aurantifolia’ (16SrII-D), pigeon pea little leaf at Faizabad, UP with strain related to ‘Ca. P. phoenicium’ (16SrIX-C), lentil witches’ broom at Faizabad, UP with ‘Ca. P. trifolii’ (16SrVI-D) and cow pea flat stem disease at Kerala with ‘Ca. P. cynodontis’ (16SrXIV-A). Association of ‘Ca. P. cynodontis' (16SrXIV-A) infecting cowpea, ‘Ca. P. trifolii’ (16SrVI-D) in lentil and phytoplasmas strain related to ‘Ca. P. phoenicium’ (16SrIX-C) infecting pigeon pea are the new reports to the world.     

Weeds as the potential inoculum source of <Emphasis Type="Italic">Colletotrichum fructicola</Emphasis> responsible for strawberry anthracnose in Nara,Japan

Colletotrichum fructicola is a major causal agent among anthracnose pathogens of strawberry in Nara, Japan. We hypothesized that a wide range of weeds growing in and around strawberry fields are inoculum sources of the disease and investigated their potential as hosts of C. fructicola. We also examined the influence of herbicide treatment on C. fructicola sporulation on weeds. The fungus was detected on 31 of 541 (5.7%) leaves sampled from 13 weed species from 2005 to 2008. The fungus was most frequently isolated from leaves of Amaranthus blitum with an isolation frequency of 17.9%; inoculation of A. blitum with the pathogen caused brown leaf spots. Other weeds such as Digitaria ciliaris, Galinsoga ciliata, Solidago altissima, Erigeron annuus, and Sonchus oleraceus were found to harbor the fungus at lower rates (4.3–8.1%) without symptoms. C. fructicola formed acervuli on leaves of A. blitum, D. ciliaris, and S. oleraceus after plants were killed by a herbicide (glyphosate). These results demonstrated that infected weeds associated with strawberry cultivation are potential inoculum sources of C. fructicola, especially after herbicide treatment.     

Cytological karyotyping of <Emphasis Type="Italic">Fusarium oxysporum</Emphasis> by the germ tube burst method (GTBM)

Fusarium oxysporum is an ascomycete fungus including plant pathogenic and nonpathogenic strains. Genome analyses have indicated that the karyotype of F. oxysporum is diverse among isolates. Here we used the germ tube burst method (GTBM), a more reliable method than conventional cytology or pulsed field gel electrophoretis, to karyotype isolates of F. oxysporum ff. spp. lycopersici and conglutinans and nonpathogenic F. oxysporum. In this first application of GTBM for F. oxysporum, pathogenic isolates were found to have more chromosomes than in nonpathogenic isolates. We also used a ribosomal DNA probe and fluorescence in situ hybridization (FISH) to analyze chromosome structure.