观赏向日葵引种栽培试验

从荷兰引进 6个观赏向日葵新品种进行栽培试验 ,观察记载了它们的植物学特征、生物学特性 ,明确了各品种的应用价值     

Is the Yelkouan shearwater Puffinus yelkouan threatened by low adult survival probabilities?

Many seabird species are experiencing population declines, with key factors being high adult mortality caused by fishery by-catch and predation by introduced predators on nesting islands. In the Mediterranean, both of these pressures are intensive and widespread. We studied the adult survival of an endemic Mediterranean seabird, the Yelkouan shearwater (Puffinus yelkouan), between 1969–1994 and 2007–2010 in Malta and between 2004–2010 in France using mark–recapture methods. Mean annual survival probabilities for breeding adults were below 0.9 for all colonies and periods. Between 1969–1994, annual survival for adults of unknown breeding status was on average 0.74 (95% confidence interval: 0.69–0.80) in Malta, possibly as a result of various human disturbances (including illegal shooting), light pollution and fisheries by-catch. Over the period 2004–2010, we found strong support for variation in adult survival probabilities between breeders and non-breeders, and islands with and without introduced predators in France. Survival probabilities for non-breeders (0.95, 0.81–1.0) appeared to be higher than for breeders (0.82, 0.70–0.94), but were imprecise partly due to low recapture probabilities. In Malta, we found evidence for heterogeneity in survival probabilities between two unknown groups (probably breeders and non-breeders), and seasonal variation in survival probability. Birds were more likely to survive the period including the peak breeding season than an equally long period during which they roam widely at sea. Although annual adult survival probability was still low (0.85, 0.58–1.0), colony protection measures appear to have reduced mortality at nesting cliffs. A population model indicated that colonies in France and Malta would currently require continuous immigration of 5–12 pairs per year to maintain stable populations. Our estimates of adult survival probabilities over the past four decades are consistent with overall population declines. Threats to Yelkouan shearwaters require immediate management actions to avoid ongoing population declines in the western Mediterranean.     

Survival of inoculant Bradyrhizobium japonicum in an Andosol

The survival of an antibiotic-resistant mutant of a commercial inoculant Bradyrhizobium japonicum strain, A1017ks, was studied in a volcanic ash soil (Andosol) in comparison with a non-volcanic ash soil (Fluvisol) over a period of 84 days. In a non-sterile soil system, the population decline in the Andosol (15% or 1.2 log units) was larger than in the Fluvisol (6% or 0.54 log units). In both soils, however, the inoculant bradyrhizobium survived at fairly high population levels after the period of incubation [10⁶ and 10⁷ colony-forming units (CFU) g^-1 dry soil in the Andosol and Fluvisol, respectively]. In sterile control soil, viable bradyrhizobium cells could not be detected after 1 week of incubation in the Andosol, whereas in the Fluvisol population of introduced bradyrhizobium was maintained throughout the period of incubation. Overall changes in the population of indigenous bacteria and fungi were also monitored. However, no clear pattern of interaction between the inoculant Bradyrhizobium japonicum and the indigenous microbes could be identified. The antibiotic-resistant mutant maintained its resistance in the Fluvisol throughout the 3-month period of incubation, making it a useful model for conducting ecological studies in the soil.     

337份外引种质对玉米丝黑穗病的抗性及评价

采用田间人工接种法对337份外引玉米种质进行抗丝黑穗病的鉴定和评价。结果表明:在337份玉米种质中,有14份材料表现高抗(HR),33份材料表现抗病(R),39份材料表现中抗(MR),各占供鉴材料的4.2%,9.8%和11.6%。其余251份表现感病(S)和高感(HS),共占鉴定材料数的74.5%。由此可见,供试玉米种质对丝黑穗病抗性表现存在差异,总体对丝黑穗病的抗病能力较低。分析发现,在261份美国自交系中,表现中抗及以上自交系共72份,占供试自交系的27.6%;在76个俄罗斯杂交种中,表现中抗及以上杂交种有14个,占供试杂交种的18.4%,说明美国自交系较俄罗斯杂交种的抗性资源丰富。     

西辽河平原引种芦笋研究初报

芦笋主产区频繁的涝灾和严重的病害是造成我国芦笋生长能力波动大、笋农收益不稳定的主要原因,而芦笋的北移种植则是解决这一问题的有效途径.2005年由美国加州芦笋种子公司引进3个芦笋品种在西辽河平原试种.结果表明:单株采笋支数和采笋重量均以阿特拉斯最高,格兰德最低,阿波罗居中;定植当年的茎数、第1分枝高度均与翌年单株采笋重量呈极显著的正相关,定植当年的株重与采笋支数、采笋重量均呈显著的正相关;三级笋、等外笋的比例高是影响芦笋高效栽培的瓶颈.     

桑树新品种盛东１号引种试验总结

１９９１年引进桑树品种盛东１号进行扦插和桑品种比试验,结果盛东１号扦插成活率为８８．０３％,面对照茶叶白为３．０２％,春桑叶产是比荷叶白市３０％左右,夏秋叶产量比荷叶白市５－１０％。     

红桤木引种栽培试验

2005-2007年,从美国引进红桤木在江苏六合和安徽南陵进行引种造林试验,结果表明红桤木具有较好的生长适应性,是一个优良的速生树种。造林3 a时,平均树高生长量分别达到3.98 m和5.01 m,地径生长量达到5.9cm和7.14 cm。实生红桤木个体间早期生长差异较大,地径与苗高生长显著相关。引种红桤木4年生时已大量开花结实,进入性成熟期。     

Long-term effects of post-harvest stump removal and N-fertilization on understory vegetation in Western USA forests

Intensive forest management practices often disturb understory vegetation, and the recovery of these plant communities may depend on the type and severity of the disturbance. We examined the effects of stump removal and N-fertilization on understory plant communities and functional group (shrubs, graminoids, forbs, and introduced species) cover and diversity at five study areas in the Pacific Northwest of North America 24–28 years after treatment. Treatments at each study area included stumped and non-stumped controls as well as four levels of broadcast ammonium nitrate (0, 336, 672, and 1345 kg N ha⁻¹) in all combinations. Stumping had significant effects on community composition at all sites, and several plant species were associated (p < 0.05) with either controls or stumped plots. Diversity of graminoids, forbs and introduced species increased in stumped areas region wide. Stumping reduced cover and diversity of shrubs at some sites. Cover of graminoids and forbs also increased in stumped plots at some study areas. Forbs like Viola sempervirens were often indicators of stump removal while shrubs such as Acer circinatum tended to be associated with non-stumped plots. N-fertilization affected community composition at only one study area, and had no effects on cover or richness of functional groups. Stump removal has lasting impacts on plant communities and may make them more vulnerable to colonization by introduced species.     

First record of the Q biotype of the sweetpotato whitefly, <Emphasis Type="Italic">Bemisia tabaci</Emphasis>, in Guatemala

Bemisia tabaci (Gennadius) adults and immatures were collected from poinsettia plants at two commercial production greenhouses in Guatemala during an invited tour to observe IPM practices within the facilities. Despite extensive scouting, only low numbers of insects were collected from vegetable, weed and wild ornamentals species located close to these facilities. Prior to molecular and biochemical analyses, whitefly immatures were initially identified as B. tabaci using morphological characters of the pupae to distinguish them from the greenhouse whitefly. The biotype status of adults and immatures was then established using esterase isozyme patterns and MTCO1 sequencing. The Q biotype was the only biotype found on commercially grown poinsettia plants. The previously recorded B biotype was observed outside the greenhouse facilities on Lactuca spp., Hibiscus spp. and Euphorbia spp. (wild poinsettia). The New World biotype was observed on wild poinsettia and field-grown beans (Phaseolus spp.). This is the first report of the Q biotype in Guatemala, and serves notice of the need for greater vigilance in the management of whiteflies on poinsettia mother stock used as a source of cuttings for export to the USA.     

<Emphasis Type="Italic">Teratosphaeria (Mycosphaerella) nubilosa,</Emphasis> the causal agent of Mycosphaerella leaf disease (MLD), recently introduced into Uruguay

Mycosphaerella leaf disease on Eucalyptus is well known in Uruguay but none of the more serious Mycosphaerella spp. and Teratosphaeria spp. causing this disease have yet been found. In the autumn of 2007, more severe defoliation than has been known in the past and associated with symptoms resembling Mycosphaerella infections was observed on Eucalyptus globulus. Isolations and identifications based on morphology and DNA sequence comparisons showed that the causal agent of the defoliation is the well known and serious pathogen Teratosphaeria nubilosa (=Mycosphaerella nubilosa). This is the first record of the pathogen in South America. Using ten microsatellite loci previously developed for T. nubilosa, only one multilocus haplotype was found from 46 T. nubilosa collected isolates. Interestingly, this haplotype was the same as one previously found in Portugal and Spain. The results suggest that T. nubilosa has recently been introduced into Uruguay and that it most likely originated from the Iberian Peninsula where E. globulus is widely planted.