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马尾松无性系种子园结实初期异交水平分析 被引量:5
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作者 金国庆 秦国峰 +2 位作者 周志春 徐高健 储德裕 《林业科学研究》 CSCD 北大核心 2000年第5期464-468,共5页
利用 1993年和 1994年测定数据 ,采用球果饱满种子百分率方法估算马尾松无性系种子园异交率。研究发现 8~ 9年生马尾松无性系种子园在结实初期自交率较高 ,异交水平较低。利用不同杂交组合估算的各亲本无性系在自由授粉情况下的异交率... 利用 1993年和 1994年测定数据 ,采用球果饱满种子百分率方法估算马尾松无性系种子园异交率。研究发现 8~ 9年生马尾松无性系种子园在结实初期自交率较高 ,异交水平较低。利用不同杂交组合估算的各亲本无性系在自由授粉情况下的异交率差异较大 ,两年中分别为 4 4 .7%~98.1%和 30 .8%~ 96 .8% ,平均为 73.5% (标准误差 SE=17.3% )和 6 9.2 % (标准误差 SE=2 1.3% )。异交率在无性系间变异较小 ,在无性系内不同组合间变异较大 ,前者变异系数仅为后者的35.3%~ 53.0 %。相同双亲组合的异交率在相邻两年度间差异不显著 ,并存在着显著的正相关。同时 ,还发现异交率与座果率有显著的线性正相关关系。 展开更多
关键词 马尾松 无性系种子园 异交水平 饱满种子百分率
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DESIGN AND STUDY OF SHADOWNET-BASED BICULTURAL COMMUNICATION MODE
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作者 张艳莲 陆为欣 范学荣 《Chinese Journal of Applied Linguistics》 2007年第5期69-74,128-129,共8页
A ShadowNet-based communication mode was designed,and some related activities planned and carried out,for an experimental cooperative project between two universities in China and the US.The students' post-survey ... A ShadowNet-based communication mode was designed,and some related activities planned and carried out,for an experimental cooperative project between two universities in China and the US.The students' post-survey results from both parties were analyzed and compared and it appeared that the ShadowNet system helped the students improve the following:an awareness of cultural difference,an openness toward cultural diversity,and a deeper appreciation for the significance of cultural identity in language learning and teaching.It also facilitated some direct improvements in the language acquisition of the Chinese ESL learners and the teaching ability of their American counter-parts. 展开更多
关键词 cooperative project communication mode cultural difference language level and language teaching ability
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