首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   51篇
  免费   5篇
  国内免费   1篇
林业   9篇
农学   4篇
  4篇
综合类   23篇
水产渔业   1篇
畜牧兽医   5篇
园艺   7篇
植物保护   4篇
  2023年   3篇
  2022年   2篇
  2021年   2篇
  2020年   1篇
  2018年   4篇
  2017年   5篇
  2016年   3篇
  2015年   4篇
  2014年   1篇
  2013年   2篇
  2012年   3篇
  2011年   1篇
  2010年   1篇
  2009年   5篇
  2008年   4篇
  2006年   1篇
  2005年   3篇
  2004年   3篇
  2001年   1篇
  2000年   2篇
  1999年   1篇
  1996年   3篇
  1994年   1篇
  1990年   1篇
排序方式: 共有57条查询结果,搜索用时 31 毫秒
1.
We investigated oviposition behavior in three non-pollinating fig wasps: the sympatric speciesApocrypta bakeri Joseph onFicus hispida L.,A. westwoodi Grandi onF. racemosa L., andApocrypta sp. onF. semicordata Buch.-Ham. The oviposition behavior differs significantly between one pair of species (A. bakeri andA. westwoodi) and the other species (Apocrypta sp. onF. semicordata).A. bakeri andA. westwoodi were similar in the following aspects: the posture of the abdomen and the action of the hind legs before penetration, and the bending ovipositor sheath during penetration. In contrast, the oviposition behavior ofApocrypta sp. is quite different. This difference can be explained by the significant correlation between ovipositor length and syconial thickness.Apocrypta sp. has a shorter ovipositor than the two other species, which correlates with the thinner syconial wall of its host figF. semicordata. It is deduced that the ovipositor length adapts to the syconial thickness and induces the oviposition behavior in the different species to diverge. For all threeApocrypta species, the midleg length and hindleg length are significantly correlated with their ovipositor lengths. This may be explained as due to the fact that body movement adjusting the hindlegs and midlegs up and down, or forward and backward, is also influenced by the ovipositor length.  相似文献   
2.
无花果新品种‘紫宝’   总被引:1,自引:0,他引:1  
徐翔宇  曾令宜  张文  马会勤 《园艺学报》2016,43(8):1623-1624
‘紫宝’是从中国无花果主栽品种‘青皮’中获得的芽变品种。秋果平均横径33.6 mm,纵径35.7 mm,平均单果质量33.4 g;果皮紫色,果肉深红色,可溶性固形物18.5°Brix,果肉松软,果汁量适中,味道香甜,品质优。  相似文献   
3.
This research was conducted to assess polymorphism among local genotypes of common fig available in Jordan (one of countries of origin). Leaf samples were collected in spring for DNA isolation from 20 different local genotypes (5 cultivars and 15 landraces). Two more wild types and one foreign cultivar were included. The genotypes were assessed using the randomly amplified polymorphic DNA (RAPD) technique. Six of the 19 screened primers showed reproducible polymeric profiles. Out of 62 amplified bands, 48 were polymorphic (77%). They generated 1104 data entries (591 for present and 513 for absent bands). After determining Jaccard similarity index, some genotypes showed high genetic similarity (90% between F20 and F22), while other were less similar (3–18% between F11 and all other genotypes). Moreover, the primers were evaluated for their discriminating power, where primer RAPD06 showed the weakest power (0.431), while highest values of 0.989 and 0.996 were achieved for primers RAPD02 and RAPD13, respectively.  相似文献   
4.
榕属的4个亚属在西双版纳均有分布,目前已报道榕树69种、亚种和变种,占全国已报道榕树种类的69.4%,其中榕亚属23个种和变种:白肉榕亚属4个种:聚果榕亚属2种和变种;无花果亚属41个种、变种和亚种。在榕树隐头果内生活着种类专一的传粉榕小蜂和一些非传粉小蜂。西双版纳地区目前已分类鉴定29种榕树的30种传粉小蜂和170多种非传粉小蜂,其它榕树种类及其隐头果内的小蜂种类还未获得活体标本而没有确切的分类定名。传粉小蜂与非传粉小蜂以及各种非传粉小蜂之间相互影响,并影响着榕树与传粉小蜂形成的共生体系,它们共同构成了榕树隐头果内复杂的小蜂群落。对榕树隐头果内小蜂群落的研究目前还处于初级阶段,主要都集中在传粉小蜂的研究上,非传粉小蜂的研究国内外都较少,且对于各种小蜂之间的关系以及它们与榕树之间的关系,还需更深入、具体的生态学、生物学、遗传学、分子生物学等各方面的综合研究。  相似文献   
5.
【目的】筛选出适合新疆和田引种的无花果优势品种。【方法】在和田地区日光温室内,以引进的5个2年生无花果品种和1个当地品种为研究对象,调查枝叶生长指标,采用PP-Systerm公司的TPS-2光合仪测定叶片光合作用,运用直角双曲线修正模型对叶片光合作用和光合有效辐射强度进行拟合分析。【结果】金傲芬品种在上午时的净光合速率最大,达到23.4 μmol/(m2·s);新疆早黄、布兰瑞克、金傲芬3个品种的光补偿点较低,分别为30.0、27.5和30.0 μmol/(m2·s);布兰瑞克、日本紫果、金傲芬、新疆早黄4个品种的饱和光强较大,分别为2 277.2、1 939.4、1 929.4和1 899.4 μmol/(m2·s);在上午时金傲芬和美娜亚具有较高的内禀量子效率,为0.062和0.054 μmol/(m2·s);表观量子产额也相对较高,为0.126和0.049 μmol/(m2·s);在下午时金傲芬和日本紫果有较高的内禀量子效率,为0.051和0.048 μmol/(m2·s);日本紫果的表观量子效率也较高,为0.040 μmol/(m2·s);上午时新疆早黄的暗呼吸速率最低,为0.86 μmol/(m2·s),下午时布兰瑞克的暗呼吸速率最低,为0.57 μmol/(m2·s)。【结论】布兰瑞克、青皮枝条节间较短、叶片较小、生长势中庸,较适宜温室栽培;金傲芬光合性能最优;美娜亚、青皮、布兰瑞克、新疆早黄4个品种光合性能次之;日本紫果的综合光合性能较差;布兰瑞克、金傲芬较耐弱光。综合比较,金傲芬、布兰瑞克较适宜和田日光温室栽培。  相似文献   
6.
无花果温室栽培是南果北移的一个创新树种,在辽宁刚刚起步。就无花果如何进行绿色栽培,实现高产、优质作深入一步探讨。欲将定植方法、整形模式、合理施肥、温湿调控、病虫害防治、适时采摘等技术措施逐步完善。使北方无花果温室栽培、推广工作再上一个新台阶。  相似文献   
7.
以"新疆早黄"无花果为试材,在温度0~2℃,相对湿度(RH)80%~85%的环境下分别采用不同浓度1-MCP(0.5、1.0μL/L)或Cl O2(5、10μL/L)熏蒸处理12 h,并在相应环境下贮藏,研究不同浓度1-MCP或Cl O2处理对无花果采后生理的影响。结果表明:与对照组相比,1-MCP或Cl O2处理均能够推迟无花果呼吸高峰和乙烯释放高峰的出现时间,降低呼吸高峰和乙烯释放高峰,保持较好的超氧化物歧化酶(SOD)、过氧化物酶(POD)及过氧化氢酶(CAT)活性,抑制丙二醛(MDA)的累积,其中1.0μL/L1-MCP处理组效果最好。  相似文献   
8.
The trnL (UAA) intron and the intergenic spacer between the 3′ exon of trnL (UAA) and trnF (GAA) sequences were used as genetic markers for differentiating Ficus carica cultivars and establishing refined genetic relationships. The study was based on 20 fig cultivars, collected from south and centre of Tunisia. Since, the intron was thought to be more variable among close relatives than is the chloroplast spacer. The size of these non-coding regions varied from 554 to 589 and from 989 to 1022 bases pairs for the intron and the combined sequences correspondingly. The average of GC content was 33.9% and 34.6% in the intron and the combined intron and spacer respectively. High values of A + T contents were detected in both data sets and may explain the high proportions of transversions founded. The observed variation pattern of plastid DNA provides evidence of an important genetic diversity. The overall transition/transversion bias (R) was 0.202 in the intron and 0.27 in the combined regions. The RI index of 0.592 indicates that these combined sequences have clearly more homoplasy then the intron (RI = 0.705) and spacer (RI = 0.777) sequences separately. Phylogenetic trees were generated based on maximum parsimony (MP) and neighbor-joining (NJ) analysis of the chloroplast sequences data. Results proved that a typically continuous genetic diversity characterizes the local fig germplasm. In fact, relationships inferred from the cpDNA analysis suggest several clades, which do not show geographical or tree sex correspondence. Although the level of apparent diversity is considerable, we may conclude that non-coding regions of chloroplast genome provide a new and practical opportunity to evaluate genetic diversity and to discriminate fig cultivars. Revealed cytoplasmic DNA markers are reliable to elaborate a molecular data base to conduct management and breeding programs on local fig germplasm.  相似文献   
9.
为探明温度及成熟度对无花果贮藏期生理指标的影响,以新疆早黄无花果为试材,研究在常温和低温条件下,2种成熟度无花果的呼吸速率、乙烯释放、过氧化物酶(POD)活性、过氧化氢酶(CAT)活性、超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量的变化。结果表明,贮藏温度对无花果果实采后生理指标的影响有显著差异,低温可显著延长果实贮藏寿命和货架期,缓解有害代谢物MDA的累积,降低防御酶系的活性。不同成熟度的果实采后,过氧化酶活性及MDA含量无显著差异,但低成熟度果实呼吸及乙烯高峰出现时间与高成熟度果实相比推迟4~10h。因此,适当低温及低成熟度有利于新疆早黄无花果的采后保鲜贮藏。本研究为无花果的保藏运销提供了理论依据。  相似文献   
10.
为在山区五莲引进推广无花果栽培,本研究依托山东五莲本地历年汇编气象资料及近年气象数据,结合无花果的生物学特性,开展山东五莲无花果栽培气候适宜性分析,并对常见气象灾害及其防御进行探讨,分析五莲主要气候条件对无花果生长的影响。结果表明,对气象灾害采取适当的防范和补救,五莲气候条件基本满足无花果的生长发育。研究为进一步推广五莲县无花果的栽培,防御气象灾害,振兴农村经济提供借鉴和参考。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号