分子生物学技术在甘薯中的应用

甘薯是重要的粮食作物,它的遗传背景复杂,分子生物学研究进展落后于水稻、玉米等作物。分子标记技术主要应用于甘薯的遗传图谱构建、遗传多样性分析以及亲缘关系分析等方面。目前,已经构建了数张遗传图谱,亲缘关系分析表明三浅裂野牵牛I.trifida与甘薯有很紧密的亲缘性。基因克隆技术已经应用于甘薯在抗逆、品质以及块根发育等相关基因的分离,为甘薯的分子育种带来了有益的目的基因。在栗子香、新大紫等甘薯品种有转基因的报道,采用农杆菌介导的方法,已经取得了少量的转基因植株。     

甜柿品种引种栽培的研究

对４个甜柿品种在长沙地区的引种栽培及其生长发育和产量情况进行研究,证明甜柿可在长沙地区进行栽培,对４个甜柿品种的品比试验表明,湖南丘陵红壤地区宜选用富友和禅寺丸为主栽品种。     

Fire cycle of the Canada's boreal region and its potential response to global change

Interactions of fire cycle and plant species' reproductive characteristics could determine vegetation distribution pattern of a landscape. In Canada's boreal region, fire cycles before the Little Ice Age (c. 1850s) ranged from 30-130 years and 25-234 years afterwards until the settlement period (c. 1930s) when longer fire cycles occurred in response to climatic change and human interference. Analysis indi-cated that fire cycles were correlated with growing season (April-October) temperature and precipitation departure from the 1961-1990 nor-mal, varying by regions. Assuming that wildfires will respond to future warming similar to the manner during the past century, an assess-ment using climatic change scenarios CGCM1, CGCM2 and HadCM2 indicates fire cycles would divert to a range of 80-140 years in the west taiga shield, more than 700 years for the east boreal shield and east taiga shield, and 300-400 years for the boreal plains in 2050.     

中国杂交高粱的研究与利用(综述)

本文对我国高粱杂种优势研究和雄性不育遗传研究的主要结果进行了阐述,对杂交高粱的应用情况作了简要的介绍,并对杂交种选育问题提出了一些看法。     

哀牢山北部常绿阔叶林林窗小气候空间分布特征

该文利用哀牢山北部常绿阔叶林林窗的小气候实际观测资料 ,初步分析了林窗小气候要素空间分布特征 .由于受太阳辐射和林窗边缘树木的影响 ,林窗的小气候要素存在最大值区域随时间动态位移和要素的空间不对称分布 ,林窗不同区域热量传递方向截然相反的现象 .这将导致林窗的环境异质性差异 ,进而影响到林窗区域种子萌发、幼苗生长、发育 ,植物种群分布等 ,最终影响到森林的更新 .     

蔗糖对黄金合果芋试管苗生长及生理的影响

试验研究了培养基中不同蔗糖浓度对黄金合果芋试管苗生长及可溶性糖含量、叶绿素含量的影响.研究结果表明：黄金合果芋试管苗叶片数、叶长、叶宽、株高和可溶性糖含量、叶绿素a、叶绿素b、叶绿素总量均随蔗糖浓度的升高而出现先上升再下降的动态变化.向培养基中添加蔗糖浓度以3%～4%为宜,有利于合果芋试管苗碳水化合物的积累,实现异养向自养的转化,促进生长,提高移栽成活率.     

Surgical management of subvalvular aortic stenosis and mitral dysplasia in a golden retriever

A 12monthoid neutered male golden retriever was presented with a history of lethargy and exercise intolerance. Clinical examination, electrocardiography, radiography and echocardiography supported a diagnosis of fixed subvalvular aortic stenosis with a Doppler pressure gradient of 77.5 mmHg. Surgical inspection also revealed gross structural abnormalities of the mitral valve consistent with mitral dyspiasia. intervention consisted of resection of the dysplastic mitral valve and the subvalvular aortic stenosis. The mitral valve was replaced with a bioprosthetic valve. Total cardiopulmonary bypass time was 65 minutes and aortic crossclamp time was 55 minutes. A full recovery was made and 11 months postoperatively the aortic transvalvular gradient was 30 mmHg. At the time of writing, 12 months after surgery, the dog was clinically normal and requires no medication.     

Conformity and controversies in the diagnosis,staging and follow‐up evaluation of canine nodal lymphoma: a systematic review of the last 15 years of published literature

Diagnostic methods used in the initial and post‐treatment evaluation of canine lymphoma are heterogeneous and can vary within countries and institutions. Accurate reporting of clinical stage and response assessment is crucial in determining the treatment efficacy and predicting prognosis. This study comprises a systematic review of all available canine multicentric lymphoma studies published over 15 years. Data concerning diagnosis, clinical stage evaluation and response assessment procedures were extracted and compared. Sixty‐three studies met the eligibility criteria. Fifty‐five (87.3%) studies were non‐randomized prospective or retrospective studies. The survey results also expose variations in diagnostic criteria and treatment response assessment in canine multicentric lymphoma. Variations in staging procedures performed and recorded led to an unquantifiable heterogeneity among patients in and between studies, making it difficult to compare treatment efficacies. Awareness of this inconsistency of procedure and reporting may help in the design of future clinical trials.     

热带雨林林缘不同热力作用面热力特征初探

片断化森林林缘不仅具有水平空间特征 ,同时也具有立体空间特征 .为探讨立体林缘壁面的热力效应是否存在 ,该热力效应与林内外地面、林冠的差异 ,该文利用西双版纳热带雨林南向边缘的表温观测资料 ,采用同期资料对比方法 ,分析了片断化热带雨林林缘不同热力作用面表面温度的水平、垂直分布特征及其差异 .指出在片断化热带雨林林缘 ,林缘壁面的热力效应是不可忽视的 .在林缘区域 ,除了公认的林外地表面、林冠面和林内地表面 3个热力作用面之外 ,林缘壁面构成了一个新的第 4热力作用面 .对其进行深入细致的研究 ,将有助于解释森林边缘的小气候效应和生物效应