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ZHAO Yong-guo Ofori Atta LU Chang-ming 《中国农业科学(英文版)》2009,8(8):931-938
The Brassica oilseed crops went through two major breeding bottlenecks during the introgression of genes for zero erucic acid and low glucosinolate content, respectively, which may lead to reduced genetic biodiversity of the crop. This study investigates the impact of these bottlenecks on the genetic diversity within and across European and Chinese winter B. rapa cultivars. We compared eight cultivars from Europe and China, representing three different seed qualities from three different breeding periods: (1) high erucic acid, high glucosinolates (++); (2) zero erucic acid, high glucosinolates(0+); (3) zero erucic acid, low glucosonolates (00, canola quality). Diversity was estimated on 32 plants per cultivar, with 16 simple sequence repeat (SSR) markers covering each of the B. rapa linkage groups. The analysis of molecular variance (AMOVA) showed that genetic variations within cultivars, across cultivars and across regions (Europe and China) were significant, with about 60% of the total variation within cultivars. There was a slight, but non-significant loss in genetic diversity within cultivars when comparing the three breeding periods as indicated by effective number of alleles (2.39, 2.23, and 1.99 for breeding periods 1, 2, and 3, respectively), Shannon information index (0.93, 0.90, 0.75), and expected heterozygosity (0.51, 0.49, 0.42). By cluster analysis (UPGMA dendrogram) and principal coordinate analysis, Chinese and European cultivars were clearly divided into two distinct groups. In conclusion, quality improvement did not significantly reduce the genetic diversity of European and Chinese B. rapa cultivars. 相似文献
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无论社会发展到什么阶段,粮食安全问题始终是我国最为关注的问题之一,因为它对于我国的经济发展以及国家是否安定都有着非常重要的现实意义。水稻是我国第二大粮食作物,有着广泛的种植历史,其种植面积和产量均约占粮食总生产面积和总产量的1/3,是我国第一大口粮品种。对保障我国粮食生产安全,坚定不移跟随党的引导与发展,全面建成小康社会,为现代化国家新征程做出努力。有道是“民以食为天,食以安为先”,在水稻的生产管理各技术环节过程中渗入绿色健康的意识,提高产量且保证产品健康安全的基础上帮助农民获取更大的收益,提高生态效益和社会效益。 相似文献
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<正>人们常用"黄花闺女"一词来形容十七八岁大姑娘花枝招展明艳动人的样子,只是不明白这"黄花"怎么跟"闺女"连到一块了?多年前登云台山,经过一片山林,山下桃花都凋落了,而林子里还缀满金灿灿的花朵,风一吹,花瓣轻飘,淡香入鼻,春意盎然,不由得痴了。怪不得白居易感叹归去的春天转入了山中呢!到了山西的外荒村,问山民黄花的名字,人家挠挠头,不好意思地说:"我们这儿都叫黄花!"黄花当然不是它真正的名字。后来得知这"黄花"学名就是连翘,果实是常见的中药材,花期清明前后,能开小半个月呢。再后来,初春时节,走过大大小小的山林沟寨,一路上,连翘花开得漫山遍野,走住金灿灿的花海里,满心满眼都是无可阻挡的逼人气 相似文献
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根据多年的实践.安排蔬菜上市时间对菜农的收益影响很大。目前番茄栽培多为春季栽培,产品集中在6-7月份上市,8月份以后番茄供应转入淡季。而麦茬番茄上市时间在8-10月份,正值番茄上市淡季,所以比较畅销,且价稳、收益高。
1.选择优良品种。夏季栽培番茄对品种要求严格,必须选择耐高温、高湿,抗病毒病、晚疫病等.对环境适应性强,坐果率高,丰产性、商品性好的品种。 相似文献
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苦瓜是一种含有丰富蛋白质、维生素等营养成分的瓜类蔬菜,深受消费青睐。冬春季节利用温室生产苦瓜,既能满足消费需要,也能给生产带来较高利润。 相似文献
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