As a high-efficiency modern molecular breeding technology, molecular marker assisted breeding has been used for crop improvement and breeding widely. In this paper, the articles on molecular marker assisted breeding of crop from the database of Science Citation Index-Expanded published before 2010 (including 2010) were analyzed by the software of Thomson Data Analyzer(TDA). The distribution of articles by time, country and institution, as well as the focus themes were indicated, influence of targeted countries and institutions were discussed, and the international status and trends of molecular marker assisted breeding of crop were revealed.?

The papers on the Antarctica and the Arctic were indexed from ISI Web of Science database. The quantitative analysis was done and the result showed that international polar research increases remarkably from the 1990s. The amount of papers has a close relationship with the regional superiority. The countries located in the southern hemisphere have more papers about the Antarctic, whereas the countries in the northern hemisphere have more papers about the Arctic. The subjects mainly involve multidisciplinary geosciences, oceanography, ecology, meteorology & atmospheric sciences, environmental sciences, biology, physical geography, geochemistry & geophysics. The hot topics include climate change, Arctic ecosystems and environmental pollution, Antarctic geological structure and krill, etc. For China, it is needed to pay more attention to the development trend of international polar research and encourage oceanographers, meteorologists, geologists, environmental ecologists, biologists, socio-economic and political scientists step by step to carry out research for a wider space, which can ensure our country to get wider development space for participating polar affairs.?