十字花科蔬菜虫害经济阈值研究概况及其分析

通过对国内、外十字花科蔬菜虫害损失率及经济阈值研究情况分析及蔬菜害虫幼虫食叶试验、功能叶剪叶试验和不同条件下虫害动态观察,结果表明:十字花科蔬菜缓苗期及结球始期对虫害敏感,莲座期及菜球充实期耐虫性强;菜球减质量与剪外叶减质量对产量影响趋于相同;莲座期外叶受损,有超补偿能力,可放宽防治指标;莲座期防治指标为菜青虫每株5头,斜纹夜蛾每株1.5头,甜菜夜娥每株7.5头等。     

Traditional seed production in landraces of daikon (Raphanus sativus) in Kyushu, Japan

Landraces of daikon, Japanese radish, Raphanus sativus var. hortensis, are grown and used traditionally in Kyushu, Japan. These landraces are maintained by seeds harvested from selected plants which are transplanted as dormant tap roots or are retained in a portion of field. Seeds kept in intact siliquas on the stems are harvested and stored until use, by hanging the dried stems. Although the relatively small number of plants used in a patch for seed production might be expected to result in a narrow base of genetic diversity of a farmers' lot in a landrace, addition of a few plants with contrasting features, pollen exchange between household patches, and contamination from other cultivars and feral forms may save the landraces from the rapid loss of diversity and deterioration caused by inbreeding depression. The seed production by transplanting described in medieval Japanese literature is relatively similar to the current practice. The factors responsible for maintenance of the landrace together with the cultural and climatic diversity of Japan may have contributed to a high diversity of landraces of the daikon. This revised version was published online in July 2006 with corrections to the Cover Date.     

Comparative genomics of Brassicaceae crops

The family Brassicaceae is one of the major groups of the plant kingdom and comprises diverse species of great economic, agronomic and scientific importance, including the model plant Arabidopsis. The sequencing of the Arabidopsis genome has revolutionized our knowledge in the field of plant biology and provides a foundation in genomics and comparative biology. Genomic resources have been utilized in Brassica for diversity analyses, construction of genetic maps and identification of agronomic traits. In Brassicaceae, comparative sequence analysis across the species has been utilized to understand genome structure, evolution and the detection of conserved genomic segments. In this review, we focus on the progress made in genetic resource development, genome sequencing and comparative mapping in Brassica and related species. The utilization of genomic resources and next-generation sequencing approaches in improvement of Brassica crops is also discussed.     

Pathotypes and phylogenetic variation determine downy mildew epidemics in Brassica spp. in Australia

Isolates of Hyaloperonospora brassicae inoculated onto cotyledons of 28 diverse Brassicaceae genotypes, 13 from Brassica napus, two from B. juncea, five from B. oleracea, two from Eruca vesicaria, and one each from B. nigra, B. carinata, B. rapa, Crambe abyssinica, Raphanus sativus and R. raphanistrum, showed significant effects (P ≤ 0.001) of isolate, host and their interaction. Host responses ranged from no visible symptom or a hypersensitive response, to systemic spread and abundant pathogen sporulation. Isolates were generally most virulent on their host of origin. Using an octal classification, six host genotypes were identified as suitable host differentials to characterize pathotypes of H. brassicae and distinguished eight distinct pathotypes. There were fewer, but more virulent, pathotypes in 2015–2016 isolates than 2006–2008 pathogen populations, probably explaining the increase in severity of canola downy mildew over the past decade. Phylogenetic relationships determined across 20 H. brassicae isolates collected in 2006–2008 and 88 isolates collected in 2015–2016 showed seven distinct clades, with 70% of 2006–2008 isolates distributed within clade I (bootstrap value (BVs) of 100%) and the remaining 30% in clade V (BVs 83.3%). This is the first study to define phylogenetic relationships of H. brassicae isolates in Australia, setting a benchmark for understanding current and future genetic shifts within pathogen populations; it is also the first to use octal classification to characterize pathotypes of H. brassicae, providing a novel basis for standardizing phenotypic characterization and monitoring of pathotypes on B. napus and some crucifer species in Australia.     

Trends in literature on new oilseed crops and related species: Seeking evidence of increasing or waning interest

Bibliographic records on eight new crop species Camelina, Crambe, Cuphea, Physaria, Limnanthes, Stokesia, Thlaspi, and Vernonia from Agricola, CAB Abstracts, Scopus, and Web of Science were analyzed for historical and recent trends on the areas of research, author distribution, and quantity and impact of publications. A total of 6786 non-redundant bibliographic records were curated and used in the analyses with about 59% of the records pertaining to the primary oilseed species. The highest number of records was found to be on Thlaspi while the least on Stokesia. Authors representing a total of 110 countries were determined to have worked in these new crops and their relative species during the past six decades with those from United States contributing about 27% in the total number of publications. There was an increase of more than ten-fold in the number of publications on new crops and relatives from 1950 to 2010 and this was paralleled by a similar increase on articles in popular and news media. The h-index values, indicating the collective impact of publications by researchers in the crop groups, show an increasing trend until the year 2000 then followed by a decline. It was determined that in recent times, there are fewer papers in the areas of chemistry, agronomy and horticulture, and more publications dealing with genetics and plant biology.     

Molecular characterisation of <Emphasis Type="Italic">Turnip mosaic virus</Emphasis> isolates from Brassicaceae weeds

Eight provinces of Iran were surveyed during 2003–2008 to find Brassicaceae reservoir weed hosts of Turnip mosaic virus (TuMV). A total of 532 weed samples were collected from plants with virus-like symptoms. The samples were tested for the presence of TuMV by enzyme-linked immunosorbent assay using specific antibodies. Among those tested, 340 samples (64%) were found to be infected with TuMV. Rapistrum rugosum, Sisymberium loeselii, S. irio and Hirschfeldia incana were identified as the Brassicaceae weed hosts of TuMV, and the former two plant species were found to be the most important weed hosts for the virus in Iran. The full-length sequences of the genomic RNAs of IRN TRa6 and IRN SS5 isolates from R. rugosum and S. loeselii were determined. No evidence of recombination was found in both isolates using different recombination-detecting programmes. Phylogenetic analyses of the weed isolates with representative isolates from the world showed that the IRN TRa6 and IRN SS5 isolates fell into an ancestral basal-Brassica group. This study shows for the first time the wide distribution and phylogenetic relationships of TuMV from weeds in the mid-Eurasia of Iran.     

Vegetable oil formulation as biopesticide to control California red scale (<Emphasis Type="Italic">Aonidiella aurantii</Emphasis> Maskell)

During laboratory tests, mineral oil in water emulsion (2%), containing Brassicaceae seed meals (2 g l⁻¹), induced total mortality (100%) among adult female California red scales on detached orange fruits, whereas only 47.5% of insect mortality was observed with the same mineral oil when used alone. These results were partially confirmed by two preliminary field trials. With the aim of improving biodegradability and the environmental impact of the insecticidal formulation, mineral oil was replaced by a vegetable oil without observing any significant variation of the product’s efficacy. In addition, a clear “dose-effect” of meal in mineral and vegetable oil was also demonstrated. The formulation, essentially based on oil, meals and some minor additives, shows the following advantages: (1) high insecticidal activity against an insect pest difficult to control such as Aonidiella aurantii (Maskell); (2) simultaneous control of several pathogens seems to be possible; (3) non-appearance of resistance phenomena in plant pathogens; and finally, (5) absence of phytotoxicity.     

硫代葡萄糖苷在十字花科植物应对非生物胁迫中的作用

硫代葡萄糖苷(glucosinolates,GSL)是广泛存在于十字花科植物中的一类富含氮、硫元素的次生代谢产物。从硫代葡萄糖苷参与植物对各种非生物胁迫的应答模式、应答机制和信号传导过程方面进行综述,并对该研究中存在的问题及今后研究前景进行展望,以期为硫代葡萄糖苷对植物非生物胁迫应答中的调控机制研究提供一定的参考。     

硫代葡萄糖苷在十字花科植物应对非生物胁迫中的作用

硫代葡萄糖苷(glucosinolates,GSL)是广泛存在于十字花科植物中的一类富含氮、硫元素的次生代谢产物。从硫代葡萄糖苷参与植物对各种非生物胁迫的应答模式、应答机制和信号传导过程方面进行综述,并对该研究中存在的问题及今后研究前景进行展望,以期为硫代葡萄糖苷对植物非生物胁迫应答中的调控机制研究提供一定的参考。