【目的】利用SRAP分子标记对51份西瓜抗、感病毒病种质资源遗传多样性分析,为加速西瓜抗病毒病新品种的选育进程提供理论参考。【方法】利用筛选出的多态性引物对51份抗、感病毒病西瓜种质进行多态性扩增,利用NTsys-pc 2.1e中的非加权...【目的】利用SRAP分子标记对51份西瓜抗、感病毒病种质资源遗传多样性分析,为加速西瓜抗病毒病新品种的选育进程提供理论参考。【方法】利用筛选出的多态性引物对51份抗、感病毒病西瓜种质进行多态性扩增,利用NTsys-pc 2.1e中的非加权组平均法(UPGMA)计算获得遗传相似系数,利用PopGene Version 3.2计算不同类型西瓜的遗传多样性参数。【结果】从500对SRAP引物组合中筛选出18对扩增条带清晰稳定且多态性较高的引物,共扩增出402条清晰可辨的条带,其中多态性条带271条;平均每对引物可扩增出稳定清晰的条带22.33条,其中多态性条带15.06条,平均多态性比率达67.41%。观测等位基因数(Na)为1.6766、有效等位基因数(Ne)为1.3033、Nei’s基因多样性指数(H)为0.1878、Shannon’s信息指数(I)为0.2931,除感病毒型西瓜种质的Na高于抗病毒型西瓜种质外,感病毒型西瓜种质的其他遗传多样性指数均低于抗病毒型西瓜种质,表明抗病毒型西瓜种质的遗传多样性较感病毒型西瓜种质丰富。抗病毒型与感病毒型西瓜种质的遗传一致度为0.8924,遗传距离为0.1138。供试西瓜种质的遗传相似系数为0.62~0.95。在遗传相似系数0.78处,可将51份供试西瓜种质划分为四大类群,抗病毒型西瓜种质分布在Ⅰ和Ⅱ类群中,感病型种质均集中在第Ⅲ、Ⅳ类群中,野生西瓜种质与其他西瓜种质的亲缘关系最远。遗传相似系数矩阵和UPGMA聚类矩阵之间的相关性明显(r=0.914),可准确地体现供试西瓜种质之间的遗传关系。【结论】筛选出的SRAP引物组合具有较好的品种鉴别能力,可用于西瓜种质的遗传多样性分析。抗病毒型与感病毒型西瓜种质的亲缘关系较近,遗传多样性丰富度不高,应加大发掘优良抗病种质资源力度,以拓宽西瓜的遗传基础。展开更多
Deep phosphorus application can be a usefull measure to improve crops＇ performance in semi-arid regions, but more knowledge of both its general effects and effects on specific crops is required to optimize treatments...Deep phosphorus application can be a usefull measure to improve crops＇ performance in semi-arid regions, but more knowledge of both its general effects and effects on specific crops is required to optimize treatments. Thus, the aims of this study were to evaluate the effects of phosphorus（P） application at different soil layers on root growth, grain yield, and water-use efficiency（WUE） of winter wheat grown on the semi-arid Loess Plateau of China and to explore the relationship between root distribution and grain yield. The experiment consisted of four P treatments in a randomized complete block design with three replicates and two cultivars： one drought-sensitive（Xiaoyan 22, XY22） and one drought-tolerant（Changhan 58, CH58）. The four P treatments were no P（control, CK）, surface P（SP）, deep P（DP）, and deep-band P application（DBP）. CH58 produced larger and deeper root systems, and had higher grain yields and WUE, under the deep P treatments（DP and DBP） than under SP, clearly showing that deep P placement had beneficial effects on the drought-tolerant cultivar. In contrast, the grain yield and root growth of XY22 did not differ between DP or DBP and SP treatments. Further, root dry weight（RW） and root length（RL） in deep soil layer（30-100 cm） were closely positively correlated with grain yield and WUE of CH58（but not XY22）, highlighting the connections between a well-developed subsoil root system and both high grain yield and WUE for the drought-tolerant cultivar. WUE correlated strongly with grain yield for both cultivars（r=0.94, P〈0.001）. In conclusion, deep application of P fertilizer is a practical and feasible means of increasing grain yield and WUE of rainfed winter wheat in semi-arid regions, by promoting deep root development of drought-tolerant cultivars.展开更多
文摘【目的】利用SRAP分子标记对51份西瓜抗、感病毒病种质资源遗传多样性分析,为加速西瓜抗病毒病新品种的选育进程提供理论参考。【方法】利用筛选出的多态性引物对51份抗、感病毒病西瓜种质进行多态性扩增,利用NTsys-pc 2.1e中的非加权组平均法(UPGMA)计算获得遗传相似系数,利用PopGene Version 3.2计算不同类型西瓜的遗传多样性参数。【结果】从500对SRAP引物组合中筛选出18对扩增条带清晰稳定且多态性较高的引物,共扩增出402条清晰可辨的条带,其中多态性条带271条;平均每对引物可扩增出稳定清晰的条带22.33条,其中多态性条带15.06条,平均多态性比率达67.41%。观测等位基因数(Na)为1.6766、有效等位基因数(Ne)为1.3033、Nei’s基因多样性指数(H)为0.1878、Shannon’s信息指数(I)为0.2931,除感病毒型西瓜种质的Na高于抗病毒型西瓜种质外,感病毒型西瓜种质的其他遗传多样性指数均低于抗病毒型西瓜种质,表明抗病毒型西瓜种质的遗传多样性较感病毒型西瓜种质丰富。抗病毒型与感病毒型西瓜种质的遗传一致度为0.8924,遗传距离为0.1138。供试西瓜种质的遗传相似系数为0.62~0.95。在遗传相似系数0.78处,可将51份供试西瓜种质划分为四大类群,抗病毒型西瓜种质分布在Ⅰ和Ⅱ类群中,感病型种质均集中在第Ⅲ、Ⅳ类群中,野生西瓜种质与其他西瓜种质的亲缘关系最远。遗传相似系数矩阵和UPGMA聚类矩阵之间的相关性明显(r=0.914),可准确地体现供试西瓜种质之间的遗传关系。【结论】筛选出的SRAP引物组合具有较好的品种鉴别能力,可用于西瓜种质的遗传多样性分析。抗病毒型与感病毒型西瓜种质的亲缘关系较近,遗传多样性丰富度不高,应加大发掘优良抗病种质资源力度,以拓宽西瓜的遗传基础。
基金supported by the National Natural Science Foundation of China(31270553)the National 973 Program of China(2009CB118604)the Special Fund for Agro-Scientific Research in the Public Interest of China(201103003)
文摘Deep phosphorus application can be a usefull measure to improve crops＇ performance in semi-arid regions, but more knowledge of both its general effects and effects on specific crops is required to optimize treatments. Thus, the aims of this study were to evaluate the effects of phosphorus（P） application at different soil layers on root growth, grain yield, and water-use efficiency（WUE） of winter wheat grown on the semi-arid Loess Plateau of China and to explore the relationship between root distribution and grain yield. The experiment consisted of four P treatments in a randomized complete block design with three replicates and two cultivars： one drought-sensitive（Xiaoyan 22, XY22） and one drought-tolerant（Changhan 58, CH58）. The four P treatments were no P（control, CK）, surface P（SP）, deep P（DP）, and deep-band P application（DBP）. CH58 produced larger and deeper root systems, and had higher grain yields and WUE, under the deep P treatments（DP and DBP） than under SP, clearly showing that deep P placement had beneficial effects on the drought-tolerant cultivar. In contrast, the grain yield and root growth of XY22 did not differ between DP or DBP and SP treatments. Further, root dry weight（RW） and root length（RL） in deep soil layer（30-100 cm） were closely positively correlated with grain yield and WUE of CH58（but not XY22）, highlighting the connections between a well-developed subsoil root system and both high grain yield and WUE for the drought-tolerant cultivar. WUE correlated strongly with grain yield for both cultivars（r=0.94, P〈0.001）. In conclusion, deep application of P fertilizer is a practical and feasible means of increasing grain yield and WUE of rainfed winter wheat in semi-arid regions, by promoting deep root development of drought-tolerant cultivars.
