海南省琼中县橡胶园土壤磷素空间变异特征及磷肥分区管理分析     

覃怀德  吴炳孙  吴敏  韦家少  何鹏  王大鹏  高乐 《热带作物学报》2014,35(2):369-374

运用地统计学和GIS相结合对琼中县橡胶园土壤磷素营养进行了空间变异特征及分区管理研究。结果表明,琼中县胶园各土层土壤全磷和有效磷含量的最大相关距离是17.23~52.09 km,全磷含量以大块状变异为主,有效磷含量各等级的分布为大、小块状交叉分布;琼中县橡胶园0~20 cm土层、20~40 cm土层全磷含量处于第五等级的极低水平的比例分别为91.22%和82.8%,0~20 cm土层有效磷含量多数处于中等偏上水平,而20~40 cm土层有效磷含量处于第5等级及以下的极低水平的比例为60.6%;应用空间叠加方法,进行了橡胶园土壤磷素管理分区,琼中县胶园可分为11个管理分区,在胶园施肥管理中应根据不同管理分区的特点采取不同的磷素营养管理措施。  相似文献   

成都平原超级稻超高产群体产量形成与物质生产特点研究     

兰汉军等 《中国稻米》2014,(1):41-43

对Ⅱ优602、德香4103、Q优8号等3个超级稻品种不同产量级别群体的产量形成及干物质生产特点进行了研究。结果表明,超级稻品种从中产(产量≤9.0 t/hm2)实现高产(产量9.0~10.5 t/hm2)关键在于每穗粒数提高后库容的增大,并同时提高结实率;而要实现超高产(产量≥10.5 t/hm2)则有赖于大库条件下结实率的进一步提高。此外,超级稻品种产量分别与分蘖临界期后各阶段的干物质积累量存在显著或极显著的正相关关系,超级稻品种高产群体获得高产的关键是提高抽穗后物质生产能力,而要进一步实现超高产则需要抽穗前后干物质生产能力的协同提高。  相似文献   

Pseudaboydins A and B: Novel Isobenzofuranone Derivatives from Marine Fungus Pseudallescheria boydii Associated with Starfish Acanthaster planci     

Wen-Jian Lan  Wei Liu  Wan-Ling Liang  Zeng Xu  Xiu Le  Jun Xu  Chi-Keung Lam  De-Po Yang  Hou-Jin Li  Lai-You Wang 《Marine drugs》2014,12(7):4188-4199

Two novel isobenzofuranone derivatives, pseudaboydins A (1) and B (2), along with five known compounds, including (R)-2-(2-hydroxypropan-2-yl)-2,3-dihydro-5-hydroxybenzofuran (3), (R)-2-(2-hydroxypropan-2-yl)-2,3-dihydro-5-methoxybenzofuran (4), 3,3′-dihydroxy-5,5′-dimethyldiphenyl ether (5), 3-(3-methoxy-5-methylphenoxy)-5-methylphenol (6) and (−)-regiolone (7), were isolated from the culture broth of the marine fungus, Pseudallescheria boydii, associated with the starfish, Acanthaster planci. Their structures were elucidated primarily based on NMR and MS data. The absolute configurations of 1–4 were determined by CD spectroscopy and single-crystal X-ray diffraction studies. The cytotoxic and antibacterial activities of 1–4 were evaluated. Pseudaboydin A (1) showed moderate cytotoxic activity against human nasopharyngeal carcinoma cell line HONE1, human nasopharyngeal carcinoma cell line SUNE1 and human glandular lung cancer cell line GLC82 with IC₅₀ values of 37.1, 46.5 and 87.2 μM, respectively.  相似文献   

基于简化基因组测序技术的甘薯HRM分子标记开发及其应用     

冯俊彦  郎涛  张聪  李明  青莉芳  屈会娟  蒲志刚  康乐 《核农学报》2022,36(7):1350-1361

目前甘薯中针对SNP位点的分子标记开发及应用的报道较少。为开发甘薯特异SNP分子标记,本研究利用简化基因组测序技术对甘薯种质材料进行测序,筛选稳定的SNP位点,将其开发为基于HRM技术的分子标记,并在甘薯种质材料中进行验证。通过对23个甘薯种质材料简化基因组测序数据的分析,共发现835 756个SNP多态性位点,筛选其中的3 650个含有SNP多态性位点的高质量测序片段,成功设计了134对引物;初步验证发现,22对(16.42%)引物没有扩增产物,15对(11.19%)引物扩增产物2个以上,36对(26.87%)引物的扩增产物没有差异。61对(45.52%)引物在8个样本中的扩增特异性好,而且样本之间有差异。最后筛选34对扩增多态性丰富的引物对52份甘薯种质材料进行扫描,发现材料间多态性介于27.27%~90.91%之间,平均多态性达到59.35%。聚类分析表明,参试52份甘薯种质材料之间的差异较小,多数材料与骨干亲本南瑞苕、徐薯18之间关系较近,国外引进甘薯材料和地方品种差异较大。建议在今后甘薯育种中尽量选用地方品种和国外甘薯品种,从而更好地拓宽甘薯遗传背景。本研究初步建立了基于简化基因组技术和HRM技术开发甘薯SNP分子标记的新思路,为今后甘薯SNP分子标记开发提供了参考。同时本研究开发的甘薯分子标记,丰富了甘薯分子标记类型,为甘薯研究者开展快速的分子标记研究提供了支持。  相似文献   

苹果外部缺陷全表面在线检测分选装置研发     

彭彦昆  孙晨  刘乐  李阳 《农业工程学报》2022,38(23):266-275

中国是水果消费大国,但在水果产后检测装备方面相对滞后。针对目前在线装置无法采集苹果全表面图像信息且无法精确计算缺陷面积的问题,该研究以表面缺陷面积的快速检测为主要目标,提出苹果全表面图像合成算法,设计了一套苹果外部品质在线检测及分级装置。该研究以苹果为例,基于球模型提出苹果全表面图像合成算法、缺陷面积校正算法精确计算苹果的表面缺陷面积。通过试验验证,对苹果表面图像进行分割合成后,整体的图像的漏检率为0。提出缺陷面积校正算法,可以计算图像中位于任意位置的苹果缺陷真实面积,选取了120个样本进行验证,其中擦伤样本、碰伤样本、痘斑病样本、表面腐败样本各30个。擦伤样本缺陷面积预测值与真实值的决定系数R2为0.9787,标准误差RMSE（Root Mean Squared Error）为3.577 4 mm2,偏角试验中R2为0.975 8,RMSE为3.466 3 mm2。碰伤样本缺陷面积预测值与真实值的R2为0.973 0,RMSE为3.981 9 mm2,偏角试验中R2为0.974 2,RMSE为4.062 4 mm2。痘斑病样本缺陷面积预测值与真实值的R2为0.970 8,RMSE为3.836 6 mm2,偏角试验中R2为0.977 9,RMSE为3.895 3 mm2;表面腐败样本缺陷面积预测值与真实值的R2为0.9812,RMSE为3.178 1 mm2,偏角试验中R2为0.974 8,RMSE为6.304 4 mm2。在整个试验过程中,R2总体上高于0.97,RMSE小于6.304 4 mm2。装置检测苹果的速度为2个/s,评级准确率为95%,检测与苹果评级精度较高,工作较为稳定,实现了苹果外部缺陷的检测与分级评价,为苹果的外部品质检测提供了技术支撑。  相似文献   

Starch Digestion in Infants: An Update of Available In Vitro Methods—A Mini Review     

Rodríguez  Marianela Desireé  León  Alberto Edel  Bustos  Mariela Cecilia 《Plant foods for human nutrition (Dordrecht, Netherlands)》2022,77(3):345-352

Plant Foods for Human Nutrition - Complementary feeding starts at around six months of age because neither breast milk nor formula assure the proper nutrition of infants. Therefore, along...  相似文献   

天山花楸正丁醇部位降糖效果研究     

李乐  苏向辉  唐辉 《安徽农业科学》2014,(8):2303-2304

[目的]对天山花楸的有效成分进行提取分离,探索正丁醇部位的降糖效果。[方法]采用回流提取法对天山花楸进行提取,梯度洗脱,获得正丁醇部位,以链脲佐菌素(STZ)诱发小白鼠糖尿病模型,利用该部位进行降血糖试验。[结果]正丁醇部位给药组与模型组相比,有明显降糖效果。[结论]天山花楸具有一定的抗糖尿病作用。  相似文献   

毛竹竹黄片拉伸性能     

宋光喃  崔乐  孙正军  张秀标  刘焕荣 《林业机械与木工设备》2014,(10)

通过对竹筒直径的测量,得到试验材料平行段并进行取样,再通过端面扫描进行验证。通过对竹黄片拉伸性能测试,得知其拉伸强度平均值为61.37 MPa,竹筒内以及竹筒间强度变异性很大;拉伸弹性模量平均值为8.26 GPa,筒内及筒间变异性很小,具有可靠性。通过对拉伸端面的分析可知,纤维被拔出的拉伸破坏试件强度较大,而且纤维拔出数量越多,强度越大。  相似文献   

核桃绿枝嫁接技术     

吴冉  冯海宝  张德可  蔡斌  辛乐  何晓波 《现代农业科技》2014,(19)

从适期嫁接、选择适宜砧木及穗、科学操作等3个方面总结了核桃绿枝嫁接技术,以期促进当地核桃产业的发展。  相似文献   

Using ecological trajectories to track long-term taxonomic and functional changes in benthic shallow soft-bottom communities (Bay of Saint-Brieuc,English Channel)     

Anthony Sturbois  Gaëtan Cormy  Alexandre Le Moal  Gauthier Schaal  Caroline Broudin  Eric Thiébaut  Alain Ponsero  Patrick Le Mao  Auriane Jones  Pascal Riera  Olivier Gauthier  Nicolas Desroy 《水产资源保护:海洋与淡水生态系统》2021,31(11):3013-3033

1. Taxonomic and functional trajectories of benthic assemblages were studied in shallow soft-bottom sediments in the bay of Saint-Brieuc (Western English Channel). Changes were assessed at different spatial and temporal scales using a macrobenthic dataset based on 38 stations sampled in 1987 and 2019, coupled with data from one station sampled annually between 2005 and 2019 as part of the European Water Framework Directive monitoring programme.
2. Taxonomic trajectories indicated 1) changes in the structure and distribution of benthic assemblages, 2) an homogenization of the assemblages, and 3) significant functional shifts.
3. Fishing activities and nutrient enrichment are probably strong drivers of the observed changes, as suggested by the higher mortality rate of fragile, flexible, tubiculous and burrowing species, and the increase in the abundance of opportunistic species in the assemblages. Certain populations of macroinvertebrates seem jointly controlled by climate change and by the aforementioned local factors of disturbance.
4. The Community Trajectory Analysis framework appears as a new and interesting method to track ecological changes in marine ecosystems by measuring change with respect to a baseline state, to help define ecological recovery (station returning to the initial ecological state) and departure (station presenting increased changes over time), and to analyse trajectory similarity.
5. According to the degradation of habitat over time, we identify the need for the implementation of knowledge-based conservation strategies, especially within Natura 2000 sites.

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