乳山寨滩涂缢蛏半人工采苗的研究

为解决北方沿海缢蛏养殖的苗种问题，在乳山寨滩涂建立缢蛏半人工采苗场，对苗坪适时进行翻耕平整，加强培育管理，１９９３年４ｈ采苗场共采蛏苗８７７０万粒，平均２２１５粒／，平均壳长２．５ｃｍ；１９９４年４０ｈ采苗场共采蛏苗５亿粒，平均１４２８粒／，平均壳长２ｃｍ。结果发现，附苗前翻松平整的苗坪附苗数量远高于未翻松平整的苗坪。山东沿海移养缢蛏性腺于９月中旬至１０月上旬进入成熟期，１０月上、中旬开始放散     

Probability Algorism for Attributes Reduction in Incomplete Information System

Attributes reduction based on rough set theory is an important but difficult task under incomplete information system. For the attributes reduction which is gained by the old attributes reduction algorisms , the attribute belongs to it or not . Nevertheless in the practice when there is the probability that the attribute can discern two objects , this shows the attribute may belong to the attribute reduction. Probability discernibility matrix is defined and corresponding discernibility function is given. Then a probability algorism for attributes reduction is proposed and an example shows the algorism is effective. The probability that the attribute belong to the reduction can be know from the reduction which is gained by the algorism.     

Discussion on Technological Innovation and Core Competence

In this paper, the meanings and features of technological innovation and core competence are analyzed firstly and then the relationship between technological innovation and core competence is discussed in brief. Finally, the suggestions that government should give play to promote the technological innovation and to accelerate the core competence of enterprises in China are brought forward.     

低酚棉品种资源聚类分析及核心品种抽取方法的探讨

对我国低酚棉品种资源进行了聚类分析并探讨了核心品种的抽取方法。以116份低酚棉品种为材料,通过16个性状的分析,采用离差平方和法进行聚类,根据树状图,将该低酚棉群体分为5个类群,对各类群品种性状进行了分析。根据取样比例,将该群体分为20个类群,在各类群内,采用随机抽样、按样品间最小遗传距离和最大遗传距离抽样三种方法,构建了3个低酚棉核心种质库,并加以比较。结果显示最大遗传距离法构建的核心种质库,能最大限度地保存原群体的遗传多样性。     

Resistance of Triticum dicoccoides to infection with Erysiphe graminis tritici

Summary The reactions of 233 Triticum dicoccoides acessions, collected at 10 sites in Israel and elsewhere, to infection with cultures of Erysiphe graminis tritici, were determined. The reactions indicated that the number of sources of resistance to E. graminis tritici which can be obtained from T. dicoccoides plants growing wild in Israel and elsewhere is almost unlimited. One hundred and fourteen or 49% of the accessions were resistant, and 137 or 59% of the accessions were resistant or moderately resistant to infection with four cultures of E. graminis tritici which possess the virulence genes corresponding to most of the identified resistance genes in wheat. Accessions collected at sites with marginal habitats where T. dicoccoides grows poorly and has lower grain weight, were more susceptible than were accessions collected at sites with an optimal habitat for growth of T. dicoccoides. The results agreed with those in a previous study with Hordeum spontaneum, and indicate that to obtain H. spontaneum or T. dicoccoides accessions with the highest level of resistance to the powdery mildew pathogens, plants should be collected at sites in ecological and geographic regions where those two species occupy optimum habitats and are exposed to the powdery mildew pathogens.     

Variation in Rauvolfia serpentina genetic resources in India

Summary Rauvolfia serpentina (L.) Benth. ex Kurtz genetic resources from several regions of India were evaluated at New Delhi in the period 1970–76 to understand the variation pattern for root yield and associated polygenic traits. The Uttar Pradesh populations represented the wides range of diversity for most of the traits; the populations from Assam possessed high root yield potential. In other states, too, variation was evident. On the basis of variation pattern, areas in the Indian subcontinent were identified for collection and conservation of Rauvolfia germplasm.     

The CPRO Cannabis germplasm collection

Summary A collection of more than a 150 Cannabis accessions is being established as a source for evaluation and breeding experiments. Origin of the accessions and maintenance of the collection are described.     

Land-races of wheat from the northern Negev in Israel

Summary Wheat has traditionally been grown by the Beduin population in the semi-arid (150 to 200 mm, mean total annual rainfall) northern Negev region of Israel.A collection was made in this area (the size of which is 150 km²) from small (0.1 to 0.5ha) fields of mixed wheat, resulting in 1553 collected spikes. Each spike was planted in a 1 m row at Bet Dagan, and grown under favorable conditions. Qualitative and quantitative data were collected from each row. Qualitative data were submitted to hierarchial clustering and the results were compared with published information on the identification, classification and distribution of the land-races of wheat in the Middle East. Triticum durum was represented in 84% of the collection. It was clustered into 22 populations, identified as 11 known varietas of T. durum. They were aggregated into five groups, similar to groups of old varieties recognized by Jacubziner (1932). While 38.5% of the collection consisted of T. durum groups villosa and sinaica, aboriginal to the northern Negev, it included also forms similar to several land-races found in the past in other parts of the Middle East. Each of the populations, and the durum collection as a whole, was very diverse for the quantitatively measured plant attributes. Triticum aestivum was represented in 15.6% of the collection, clustered into six populations. Most of the common wheat accessions were analogous to the old locally grown variety Hirbawi. Triticum compactum was represented in only eight accessions.The collection is now being evaluated as a potential genetic resource for durum wheat breeding.Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel No. 374-E, 1982 series.     

Assessing genetic diversity in the cassava (Manihot esculenta Crantz) germplasm collection in Brazil using PCR-based markers

Knowledge of the origin, organization and nature of the cassava (Manihot esculenta Crantz) germplasm collection in Brazil is incomplete due to lack of critical information on several aspects of the collection. This study verifies the utility of SSR-primed PCR markers for germplasm assessment and then utilizes these markers as well as RAPD's to characterize the Brazilian collection. We specifically address the following questions: 1)what is the relationship of morphologically closely related species to cultivated cassava? 2) What is the genetic diversity of cultivars within and between different habitats in Brazil? 3) Do agronomic traits and molecular markers reveal the same relationship among cassava accessions? 4) How complete is the Brazilian cassava collection and how well is it represented in the Word Core Collection of cassava, maintained by CIAT? Results of the interspecific studies of cassava and its wild relatives confirms the close relationship of cassava, Manihot esculenta ssp. esculenta to Manihot esculenta ssp. flabellifolia as well identifying several other closely related wild species. Next, PCR-based markers indicate a strong grouping of varieties related to the region of cultivation in Brazil. Moreover, important regions such as Cerrados and Amazon are relatively poorly represented in germplasm collections. Interestingly, the relationships of accessions based on agronomic traits are not fully congruent with relationships revealed with RAPD markers. Finally, the genetic diversity of the Brazilian cassava collection is not fully represented in the Core of the Word Core Collection of CIAT.     

真空预冷实验机的数据采集系统与实验研究

近年来,随着高品质新鲜食品需求的增长,真空预冷技术被越来越多地应用到食品保鲜领域中。介绍了上海水产大学绿色冷藏链教学实验中心的真空预冷实验机数据采集系统,并以纯水、卷心菜和青菜作为实验对象,进行初步研究。实验结果表明,实验机的真空箱内极限压力为201.41Pa;蔬菜不同部位的温度下降速度不同;水分含量多、比表面积大和结构松散的蔬菜适合采用真空预冷。该数据采集系统运行正常,满足实验要求。