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81.
对矮砧苹果新植苗木和2~5年生幼树死亡的原因进行研究,表明苗木失水与轮纹病菌协同危害是主要原因;冻害、根部与主干病害、肥害及苗木质量差是重要原因。生产上及时发现问题,根据不同症状,进行准确的病因诊断,有针对性地采用不同的防控措施:培育不潜带轮纹病菌的苗木;苗木贮运、栽植和管理过程防止失水;栽植前用杀菌剂铲除部分病菌;防止冻害;2~5年生幼树合理肥水管理;防止贪绿徒长;有效地预防根部和枝干病虫害发生。 相似文献
82.
Orsolya Kutasi Nandor Balogh Zoltan Lajos Krisztina Nagy Otto Szenci 《Journal of Equine Veterinary Science》2011,31(7):400-410
Even though the respiratory system is one of the most accessible organs for diagnostic testing, it is not always easy to define chronic lower airway disease in the horse. Diagnostic procedures performed by first opinion veterinarians in the field are often restricted to taking the history and performing clinical examination. Respiratory tract endoscopy, tracheal or bronchoalveolar lavage, and blood sampling are sometimes used but other specific ancillary examinations are seldom performed in stable settings. Therefore, our objectives were to evaluate the diagnostic value of different techniques and examination types routinely used in the diagnostic workup of chronic equine lower airway cases in both stable and clinical circumstances. Another aim of this study was to estimate the prevalence of different chronic pulmonary disorders among horses admitted to a Hungarian referral clinic. According to the conditional inference tree method, age of the horse, history, clinical examination, respiratory tract endoscopy, and bronchoalveolar lavage cytology proved to be the most valuable tools to define pathology. It was also concluded that in 22% of cases, more specific ancillary diagnostic modalities, unavailable for the field veterinarian, were needed to establish the final diagnosis. According to our study, the most frequently diagnosed chronic pulmonary disorders in Hungary are of noninfectious origin, principally recurrent airway obstruction. Regardless of the cause, and interestingly including recurrent airway obstruction as well, these diseases occur primarily during the warm months. 相似文献
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Effect of different drip irrigation methods and fertilization on growth,physiology and water use of young apple tree 总被引:3,自引:0,他引:3
A pot experiment was conducted to investigate the effect of three drip irrigation methods (i.e. conventional drip irrigation (CDI), both sides of the root-zone irrigated with full watering, alternate drip irrigation (ADI), both sides of the root-zone irrigated alternatively with half of the full watering, and fixed drip irrigation (FDI), only one side of the root-zone irrigated with half of the full watering) on growth, physiology, root hydraulic conductance and water use of young apple tree under different nitrogen (N) or phosphorus (P) fertilization (i.e. CK (no fertilization), N1 (0.2 g N/kg), N2 (0.4 g N/kg), P1 (0.2 g P2O5/kg) and P2 (0.4 g P2O5/kg)). Results show that compared to CDI, ADI and FDI reduced mean root dry mass, daily transpiration, root hydraulic conductance (Kr), leaf photosynthesis rate, transpiration rate and stomatal conductance of young apple tree by 6.9 and 27.7, 29.3 and 45.0, 6.8 and 37.9, 2.5 and 4.8, 32.6 and 33.0, 22.1 and 22.3%, but increased leaf water use efficiency (WUE) by 31.3 and 29.8%, respectively when they saved irrigation water by 50%. Compared to the CK, N or P fertilization significantly increased Kr, and Kr was increased with the increased N or P fertilization level. There were parabolic correlations between Kr and root dry mass, daily transpiration and stomatal conductance. Our results indicate that ADI reduced transpiration rate significantly, but it did not reduce photosynthesis rate and Kr significantly, thus alternate drip irrigation improved WUE and the regulation ability of water balance in plants. 相似文献
86.
根据GenBank上已发表的其他真菌α–微管蛋白基因序列中的保守区域设计简并引物,扩增出银耳α–微管蛋白基因的cDNA部分序列。分别利用SEFA-PCR方法和RACE技术,克隆了银耳α–微管蛋白基因的DNA和cDNA全长序列。银耳α–微管蛋白基因DNA全长1 962 bp,含有9个内含子,cDNA全长1 347 bp,编码448个氨基酸。生物信息学分析结果表明:银耳α–微管蛋白基因的cDNA序列与新型隐球酵母有80%相似性,编码的蛋白质属于Tubulin_FtsZ超家族中的α–微管蛋白亚家族,氨基酸序列中存在保守的GTP结合区域GGGTGSG,系统发育树显示银耳与新型隐球酵母距离最近。 相似文献
87.
大多数木本常绿热带果树在闽东南适应性良好,有较高的经济开发价值和园林应用前景。针对目前闽东南水果品种不丰富和应用于园林绿化材料单调、配置单一的现状。在介绍几种新、优热带果树资源的基础上,探讨热带果树的开发前景和提出把热带果树应用于城市园林绿化建设的新思路,以丰富植物多样性和园林景观。 相似文献
88.
Diversity of the calabash tree (<Emphasis Type="Italic">Crescentia cujete</Emphasis> L.) in Colombia
Johanna Arango-Ulloa Adriana Bohorquez Myriam C. Duque Brigitte L. Maass 《Agroforestry Systems》2009,76(3):543-553
Germplasm of the calabash tree (Crescentia cujete L.) was collected in five major regions of Colombia, i.e. the Andes, Caribbean, Amazon, Orinoco, and Pacific regions. Collecting
this multipurpose tree was guided by the indigenous knowledge of farmers and artisans in each region. Large variation in fruit
shapes and sizes was found, of which some forms were typical for certain regions. Overall 56 accessions were collected and
roughly classified into 22 types by eight fruit shapes and eight sizes. Molecular markers (Amplified fragment length polymorphisms)
were applied to leaf tip tissue originating from vegetatively propagated plants in order to assess the diversity available
in the germplasm collected as well as to detect patterns of geographical or morphological similarity. One accession each of
C. alata H.B.&K. and C. amazonica Ducke were used as outgroups. Overall, genetic diversity was high (mean Nei and Li’s coefficient of 0.43). No relations could
be established between either geographical provenance or fruit morphology and patterns of genetic diversity. Concerning the
outgroups, the C. amazonica accession appeared to be a distinct species. The C. alata accession, however, did not seem to be sufficiently distinct from C. cujete to merit species status. The latter material may in fact be a hybrid or serve to challenge the validity of interspecific
organization of the genus Crescentia.
相似文献
Brigitte L. Maass (Corresponding author)Email: |
89.
银杏愈伤组织超低温保存的研究 总被引:13,自引:0,他引:13
本文对银杏子叶愈伤组织进行了超低温保存研究。结果表明 ,冰冻保护剂、冷冻速度对解冻后材料相对存活率影响较大 ,冻前预培养和预冻至某一温度停留一段时间也较为重要。在含高浓度山梨醇或甘露醇的培养基上预培养 2d的愈伤组织 ,用 10 %二甲基亚砜 +0 .5mol·L- 1 山梨醇作为冰冻保护剂 ,以 1℃·min- 1 速度降温 ,在 - 15℃、- 35℃分别停留 10min和 30min后 ,投入液氮中保存 1d ,细胞相对存活率可达 6 0 %以上。再培养时 ,细胞能恢复生长。 相似文献
90.