13个引进砂梨品种生物学性状评价

2007～2009年对引进的13个新品种在遵义地区试种后的植株长势、枝叶花的特征、果实经济性状、各个品种的物候期反应和开花结果习性等生物学性状进行了调查.13个引进品种中,生物学性状综合评价表现最好是梨精47,其次是黄金梨、早香蜜和西子绿,再次是新2号、新8号、绿宝石和杂交37.加上配套的栽培技术措施,梨精47、黄金梨、西子绿和新8号可在遵义地区适量发展.     

空心莲子草无性繁殖体片段引入频率对其萌芽及幼苗生长的影响

[目的]探讨空心莲子草无性繁殖体片段引入频率对其种群建立的影响，为深入理解空心莲子草入侵机制和控制其蔓延提供基础。[方法]在2006年夏季，将空心莲子草地下茎片段和肉质根片段以不同引入频率埋植在带土塑料盆中，覆土2cm，每盆中的地下茎或者肉质根片段总数为15根，重复7次。最后一个地下茎片段或者肉质根片段埋植完成后，经过一个月的萌芽及生长，萌芽趋于稳定，不再产生新的萌芽，此时全部收获空心莲子草，测定每盆的萌芽数、分枝茎节数、总生物量。[结果]1次引入条件下，空心莲子草无性繁殖体（地下茎和肉质根）片段的每盆总萌芽数显著低于多次引入（P〈0．05，n=7），多次引入（3次、5次、15次）之间萌芽数差异不显著（P〉0．05，n=7）；1次引入和多次引入对空心莲子草的分枝茎节数、生物量均没有显著影响（P〉0．05，n=7）。[结论]空心莲子草无性繁殖体的多次引入对于保证空心莲子草的萌芽数有利，但增加了入侵的风险；即使是1次引入，只要有一定数量的萌芽出土，经过一段时间生长后，空心莲子草也能建立良好的无性系种群：     

川西北地区引进甘薯品种筛选研究

[目的]筛选适宜川西北地区种植的优质高产甘薯(Ipomoea batatas Lam.)品种。[方法]对引进的8个甘薯品种(南薯007、泉薯9号、渝5-12-57、川12-17、浙薯23、E01-09、宁23-1、浙薯70)进行栽培试验,以南薯88为对照。采用随机区组排列,3次重复。[结果]宁23-1、浙薯70鲜薯产量比南薯88分别增产4.91%和1.72%,浙薯70、川12-17淀粉产量比南薯88分别增产24.46%、24.10%,达到极显著水平。[结论]宁23-1、浙薯70、川12-17综合性状均较优良,可以在今后的生产中进行大面积推广与种植。     

Declines in common, widespread native birds in a mature temperate forest

Common, widespread species are important for ecosystem structure and function. Although such species have declined in some parts of the world, for most ecosystems there is a lack of information about changes in the population status of common species. We studied the abundance of common, widespread forest birds in Nelson Lakes National Park, New Zealand using standardised 5-min bird counts, carried out over a 30-year time span. There was a significant change in the bird community structure during this period. Five native species (bellbird, rifleman, grey warbler, New Zealand tomtit and tui) declined in abundance during the 30 years. All of these declined in abundance at low but not high altitudes, and the decline was substantial for all but New Zealand tomtit and tui. Three other native species increased in abundance (silvereye, yellow-crowned parakeet and New Zealand robin). There was no change in the abundance of introduced blackbirds. We suggest that invasive alien species are the most likely cause of the ongoing declines in common native species. A peak in brushtail possum abundance and the arrival of a new species of Vespula wasp were two large changes in Nelson Lakes forests that occurred during this study. Both are likely to have added to the ongoing impacts of predation by introduced rats and stoats. We suggest that it is necessary to actively manage introduced species in order to maintain populations of widespread, common native bird species in New Zealand.     

Protecting islands from pest invasion: optimal allocation of biosecurity resources between quarantine and surveillance

Removing pests from islands, and then keeping them pest free, is a common management goal. Given that goal we face a decision: how much effort should we invest in quarantine to reduce the risk of a pest arriving vs. surveillance, looking for the pest on the island with the view of eradicating it before it gets out of control. We use models of an island under threat of invasion by a pest (animal, plant or disease) and a cost minimisation approach to optimally allocate management resources between quarantine and surveillance. In the optimal allocations joint investment in both quarantine and surveillance is uncommon. Investment in quarantine is optimal if quarantine is more effective than surveillance or if large costs associated with pest impact and eradication are incurred at low pest density. Investment in quarantine is also favoured as our ability to eradicate a pest declines. Surveillance is optimal if it is considerably more cost-effective than quarantine and we can generate significant savings through early detection of the pest population. We illustrate how theses models are useful ways to examine these trade-offs by applying the model to the prevention of black rat (Rattus rattus) invasion on Barrow Island, Western Australia. Our model predicts an optimal strategy different to the management strategy currently being used on the island. We suggest that this is due to a risk-averse tendency in managers and the difficulty of estimating costs that combine management, environmental and social factors.     

甘蔗新品种引进试验结果初报

从国内外引进15个甘蔗新品种在广西3个不同的试验点进行了1年的新植试验。试验结果表明,表现高产的品种有：台98—2817、台98—1626、C1—2003、台98—0432、台引2号和粤糖96—86；表现高糖的品种是：台引2号、CP84—1198、福农15号、赣蔗18号、C1—2003和园林6号；综合性状较好的品种是C1—2003、园林6号和台引2号。     

基于DUS测试的上海地区小麦新品种评价

本研究通过分析小麦DUS测试指南中标准品种、测试性状在上海地区的表达差异,评价小麦DUS测试指南在上海的适应性,同时对15个引进品种及9个申请审定的品种在上海的表现进行评价。通过2016-2017年的田间种植试验,用符合系数对标准品种和测试性状在上海地区的性状表现与小麦测试指南中的代码进行了差异性分析,并对性状间的相关性进行了分析。结果表明,小麦测试指南中的33个测试性状中有8个性状的符合系数为1,占24.2%,数量性状的表现受环境条件的影响较大,符合系数小于0.9的2个性状都是数量性状;小麦测试指南中的42个标准品种中有21个品种的符合系数为1,其性状表达状态非常稳定。‘矮变1号’的符合系数最低,其次是‘川育6号’、‘济南16号’、‘科麦2号’,其他品种的符合系数均大于0.95。大部分品种可以作为标准品种应用于上海地区的小麦DUS测试。‘植株:高度’与多个性状存在显著相关性,3个蜡质性状间相关程度较高。‘籽粒:大小’与指南中的7个性状显著相关。引进品种在上海地区的表现较好,均具备一致性,亲缘关系较近。待审定品种‘润麦1号’表现优于所有参试品种。     

Patterns of nonindigenous herpetofaunal richness and biotic homogenization among Florida counties

Recent studies of geographic patterns of nonindigenous species richness suggest that a few key biogeographic and anthropogenic factors explain much of the variation in the richness of established species. It remains unknown, however, if the factors identified in these studies are taxon- and scale-specific or if general rules apply broadly across taxa and spatial scales. To address this issue, I used multiple regression analysis to identify factors that contribute significantly to variation in nonindigenous herpetofaunal richness at a relatively small spatial scale, the county level, in Florida, USA. Additionally, I used the Jaccard similarity index to determine if nonindigenous species affect the biotic similarity of the herpetofaunas of Floridian counties. In the regression analysis, county latitude strongly and negatively affected nonindigenous herpetofaunal richness, explaining approximately two-thirds of the variation in this variable. To a smaller degree, human population and university presence both related positively with nonindigenous herpetofaunal richness. Several other variables, including county land area, were not significantly related to nonindigenous herpetofaunal richness. The consistent importance of human population to nonindigenous species richness in this and past studies suggests that the influence of anthropogenic factors may be universal and are as or more important than the natural biogeographic factors that generally relate with native species richness. No evidence of overall homogenization was found based on Jaccard index values. However, a significant relationship between homogenization scores and distance between counties suggests that the effect of nonindigenous herpetofaunal richness on the similarity of county biotas is scale-dependent, such that adjacent counties tend to experience homogenization, while distant counties tend to experience differentiation as a result of the presence of nonindigenous herpetofauna. The results of this and similar studies may be useful in predicting the introduction and spread of nonindigenous species and in evaluating the effects of such introductions on native biodiversity.     

四川低山丘陵区冷季型牧草引种试验(简报)

我国西南温带和热带过渡区,牧草品种短缺,通过引种评价,很多品种得以推广利用^[1,2]。美国南方的自然条件在一定程度上和我国南方类似^[3],该地的牧草种植模式值得借鉴。本试验对引自美国的几种牧草进行评价,以补充我国草种资源,解决生产问题。1材料与方法1.1试验区自然概况试验区位于四川省洪雅阳平种牛场(北纬29°53,′东经103°22′),海拔514 m,年均气温16.8℃,7月月均气温25.7℃,无霜期303d,年均降水量1494mm。粘性黄泥土,pH 5.46,有机质含量2.70%,水解N 171.3 mg/kg,有效P 12.5 mg/kg,速效K 43.8 mg/kg。     

日本梨新品种引种试验

日本梨五个新品种(长寿梨、新水梨、幸水梨、丰水梨和新高梨),在安徽中部地区引种栽培六年,表现优质、丰产、抗病、结果早等特点,适于进一步推广栽培。