极小种群植物“川柿”生物学特性及种子萌发方法研究

摘 要：【目的】为了保护和发展极小种群植物川柿，开展此研究。【方法】采用观测法，连续3年对其生物学特性研究；种子萌发方法：（1）后熟0、30、45、60天，剥离清洗播种；（2）后熟60天，以GA300、600、1000 mg/L溶液浸种1h；播种基质为河沙（保持一定湿度），放置室内，统计萌发时间和出苗率。【结果】（1）川柿花期4-5月，10月为果熟期，单果直径32.7±5.80mm，单果重23.0±5.30g；种子肾形、千粒重1070g；成年植株呈隔年开花、结果现象；（2）种子经“后熟+河沙播种”，可萌发，其中以后熟60天的出苗率较高，为65%；直接播种种子，出苗率5%；“后熟+GA溶液浸种+河沙播种”，出苗率均高于65%，其中以GA600mg/L浸泡1h处理，出苗率最高为83.3%。【结论】极小种群植物川柿为常绿叶乔木，有隔年开花、结果现象； “果后熟60天+GA600mg/L浸泡种子1h +室内河沙播种”可提高种子萌发率，为川柿种子繁殖提供参考。     

2003-2017年陕西省NDVI时空变化及其影响因素

[目的] 研究影响陕西省植被覆盖主导气候类和非气候类因子，为区域生态文明建设提供科学依据。[方法] 基于2003—2017年MODIS NDVI数据，利用趋势分析和地理探测器模型等方法，研究了气候类和非气候因素对陕西省植被覆盖的影响。[结果] ①2003—2017年陕西省NDVI空间分布总体上为改善趋势，但在不同植被类型区和生态区有所差异。②降水是影响陕西省植被覆盖空间分布的主导气候类因素，其他因素对当地植被覆盖影响程度有所差异。③降水与气温、日照、风速、相对湿度的交互作用对陕西省植被覆盖空间分布起主导作用。且气温的作用只有在和降水的交互作用下才能体现出来。④植被类型和地貌是陕西省植被覆盖空间分布的主导非气候类因素，其他因素的影响有所差异。⑤植被类型、地貌和土壤类型之间的交互作用对陕西省植被覆盖空间分布起主导作用。人口、GDP的影响也只有在与其他因素的交互作用下才能显现出来。[结论] 气候类因素的影响大于非气候类因素，气候类和非气候类因素的共同作用能够充分的解释植被覆盖空间分布。     

基于稳定同位素的上海地产蔬菜种植模式及产地判别

为保护蔬菜的优质优价及质量安全,以上海9个农业产区(宝山区、崇明区、奉贤区、嘉定区、金山区、闵行区、浦东新区、青浦区和松江区)蔬菜为研究对象,分析不同产区蔬菜的δ¹⁵N值差异及其对种植模式(常规、绿色或有机种植)的指示;对δ¹³C、δ¹⁵N、δ²H和δ¹⁸O值进行单因素方差分析,并应用主成分分析(PCA)、偏最小二乘判别分析(PLS-DA)及支持向量机(SVM)方法,建立上海地产蔬菜产地判别模型。结果表明,宝山区、松江区和嘉定区蔬菜的δ¹⁵N值占前三,且分别与δ¹⁵N值最低的浦东新区蔬菜(4.44‰)存在显著差异,且仅有浦东新区蔬菜可能为绿色或有机种植的比例低于50%;δ¹³C、δ²H和δ¹⁸O值只在部分产区间差异显著,PCA可初步实现浦东新区蔬菜与其他8个产区的鉴别;PLS-DA最优模型可以很好地实现浦东新区蔬菜产地判别(预测准确率为98.80%),SVM最优模型可以很好地实现宝山区(预测正确率96.38%)、嘉定区(预测正确率92.77%)和青浦区(预测正确率91.57%)蔬菜的产地判别,SVM最优模型可以较好地实现金山区、松江区、崇明区和奉贤区蔬菜的产地判别。本研究结果为上海地产蔬菜种植模式及产地判别提供了参考方法,并为其溯源和质量安全保护提供了基础数据。     

稳定同位素技术鉴别库尔勒香梨产地可行性研究

为开展碳、氮、氢、氧(C、H、O、N)稳定同位素鉴别库尔勒香梨产地的可行性研究,明确新疆库尔勒香梨δ¹³C、δ¹⁵N、δ²H、δ¹⁸O值,本研究以甘肃香梨和陕西红香酥梨作为对照,采用稳定同位素比值质谱仪(IRMS)分析新疆库尔勒香梨与对照样品的δ¹³C、δ¹⁵N、δ²H、δ¹⁸O值,并采用正交校正的偏最小二乘判别分析(OPLS-DA) 鉴别新疆库尔勒香梨产地真实性。结果表明,新疆、甘肃两个产区香梨与陕西产区红香酥梨的δ¹³C、δ¹⁵N、δ²H、δ¹⁸O值存在显著差异(P<0.05)。新疆产区的66份库尔勒香梨判别准确率为95.45%;甘肃产区的20份香梨样品判别准确率为60%;陕西产区的23份红香酥梨样品判别准确率为95.65%。C、N、H、O 4种稳定同位素可有效鉴别新疆库尔勒香梨和陕西红香酥梨,但在新疆库尔勒香梨与甘肃香梨鉴别方面,误判率较高,如果能结合其他鉴别技术,则有可能出现较好的鉴别效果。本研究为库尔勒香梨产地真实性鉴别提供了科学依据。     

Whistle signal variations among three Indo-Pacific humpback dolphin populations in the South China Sea: a combined effect of the Qiongzhou Strait's geographical barrier function and local ambient noise?

Geographic variations in the dolphin whistles could be useful in assessing association and isolation among populations. Whistle of free-ranging Indo-Pacific humpback dolphins (Sousa chinensis) among the Pearl River Estuary (PRE), Leizhou Bei (LZB) and Sanniang Bay (SNB) populations were investigated. A total of 2850 whistles with legible fundamental contour were extracted and 15 acoustic parameters were measured. Contrary to SNB, PRE and LZB had the same relative proportion of tonal type compositions with flat and sine representing the most frequent types. The generalized linear model analysis showed significant acoustic difference among populations and tonal types. All frequency parameters in SNB were significantly higher than those in PRE and LZB, where no significant variation was observed in most of the parameters either at the population level or within each tonal type. Canonical discriminant functions analysis showed a smaller difference between PRE and LZB than between PRE and SNB and between LZB and SNB. Compared with previous recordings, recent recordings demonstrated a consistent pattern of becoming higher in whistle frequency parameters in both LZB and SNB populations, suggesting that noise pollution in LZB and SNB increasing with time according to the acoustic niche hypothesis. Dolphin whistle's geographic variations could be shaped by the combined function of the geographical barrier function of the Qiongzhou strait and local ambient noise. Considering the isolated condition and the relatively smaller population size of the humpback dolphin in the SNB, more effective and proactive conservation actions should be taken to prevent the extinction of small populations.     

极小种群野生植物八蕊单室茱萸的种群状况研究

八蕊单室茱萸为云南省特有的极小种群野生植物和濒危物种。通过查阅相关文献并结合访问调查,确定八蕊单室茱萸可能分布的区域,开展种群资源调查。结果显示:八蕊单室茱萸目前仅在普洱市和西双版纳州有10个天然种群,其种群规模已低于最小可存活种群,属极小种群野生植物和濒危物种,亟需开展保护工作。生境破坏和生境片段化是导致八蕊单室茱单室茱萸濒危的人为因素。提出收集种质资源、营建和管护近地保护种群、建立迁地和回归种群等保育建议。     

北京市蔬菜专业村产业集聚测度实证研究

以北京蔬菜专业村为研究对象,选取2012—2018年北京蔬菜专业村及蔬菜产业相关数据,运用区位商指数测算方法,从时间和空间两个层面对北京市蔬菜专业村产业集聚度进行测算;运用集中度指数测算方法,从专业村主导产业总产值和从业农户数两方面对集聚度进行测算。结果显示,北京市蔬菜专业村出现了集聚现象,但存在不稳定上下波动的问题,顺义区、通州区和平谷区总体集聚程度较高,并保持稳定集聚状态,集聚区域主要集中在顺义区和房山区。研究建议完善蔬菜专业村基础设施建设,打造蔬菜专业村区域品牌效应,发挥蔬菜示范村辐射带动作用,推进专业镇、基地及园区建设。     

地理标志农产品物流发展的路径选择——以地理标志农产品新会陈皮为例

深入调查研究地理标志农产品新会陈皮的物流发展情况及存在的问题,针对市场对地理标志农产品的认识和接受程度,加大地理标志农产品加工业的发展,在拓宽产品线的同时,实现地理标志农产品新会陈皮的品牌效应和经济效益,并以此带动区域经济发展。     

Temperature Before Cold Acclimation Affects Cold Tolerance and Photoacclimation in Timothy (Phleum pratense L.), Perennial Ryegrass (Lolium perenne L.) and Red Clover (Trifolium pratense L.)

The expected temperature rise in late summer/early autumn can change the conditions for acclimation and affect the winter survival of perennial crops. This study examined the effect of the temperature just before the onset of cold acclimation (pre‐acclimation) on freezing tolerance of timothy (Phleum pratense L.), perennial ryegrass (Lolium perenne L.) and red clover (Trifolium pratense L.) populations (both cultivars and breeding populations) adapted to either northern or southern parts of Norway. Using phytotron experiments, we studied whether increasing pre‐acclimation temperature delays growth cessation, affects photoacclimation and reduces freezing tolerance. Furthermore, we assessed whether these effects were related to the latitudinal adaptation of the plant material. The results showed that a rise in pre‐acclimation temperature decreased both cold acclimation capacity and photoacclimation in these species. This affected the freezing tolerance, which was reduced significantly more in northern‐adapted population of timothy and perennial ryegrass compared with southern‐adapted populations. Red clover was less affected by temperature changes than the grasses.