为探讨不同施钾量条件下甘薯块根形成的内源激素变化及其与块根数量的关系,本试验以结薯数差异显著的鲜食型甘薯品种‘烟薯25’和‘北京553’为试验材料,以氧化钾(K2O)为供试肥料,设置0(K0)、120(K1)、240(K2)和360 kg hm-2(K3)4个钾肥...为探讨不同施钾量条件下甘薯块根形成的内源激素变化及其与块根数量的关系,本试验以结薯数差异显著的鲜食型甘薯品种‘烟薯25’和‘北京553’为试验材料,以氧化钾(K2O)为供试肥料,设置0(K0)、120(K1)、240(K2)和360 kg hm-2(K3)4个钾肥梯度,研究不同施钾量对甘薯块根形成期粗根中的内源激素含量及相关代谢酶活性、收获期块根数量、块根整齐度等的影响。结果表明,与不施钾肥处理(K0)相比,施用钾肥降低了块根形成期粗根中吲哚乙酸氧化酶(indoleacetic acid oxidase,IAAO)、过氧化物酶(peroxidase,POD)的活性,提高了生长素(indole-3-acetic acid,IAA)含量;同时,增加了玉米素核苷(zeatin riboside,ZR)含量,降低了赤霉素(gibberellins,GA3)含量。施钾通过调控甘薯粗根中的内源激素水平,提升了初生形成层的活动能力,促进了不定根向块根的分化。与CK相比,增施钾肥显著提高了收获期烟薯25和北京553的单株结薯数与单薯重,提高了块根产量;烟薯25和北京553的单株结薯数增幅分别为3.16%~25.40%和3.85%~33.11%,产量增幅分别为4.22%~17.31%和3.94%~18.45%。2个品种各施钾处理相比,均为K2处理的单株结薯数最多,单薯重和块根产量最高,块根整齐度最好。展开更多
This paper presents the number of combinatorially distinct rooted Eulerian planar maps with the number of non-root-vertices and the number of non-root-faces as two parameters. The parametric expressions for determinin...This paper presents the number of combinatorially distinct rooted Eulerian planar maps with the number of non-root-vertices and the number of non-root-faces as two parameters. The parametric expressions for determining the number in tha loopless Eulerian case are also obtained.展开更多
基金Supported by the Italian National Research Councilthe National Natural Science Foundation of China.
文摘This paper presents the number of combinatorially distinct rooted Eulerian planar maps with the number of non-root-vertices and the number of non-root-faces as two parameters. The parametric expressions for determining the number in tha loopless Eulerian case are also obtained.
