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不同线虫接种量与盆栽番茄根结形成的关系探讨
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作者 孙玺文 《农业灾害研究》 2024年第6期19-21,共3页
为研究土壤中根结线虫对番茄生长的影响,开展了盆栽试验,测试不同密度的根结线虫对番茄根结形成时间、数量及增长率的影响。结果显示,在番茄幼苗根部接种南方根结线虫的前5 d内(包括5 d),无论接种密度如何,都未观察到明显的根结形成现象... 为研究土壤中根结线虫对番茄生长的影响,开展了盆栽试验,测试不同密度的根结线虫对番茄根结形成时间、数量及增长率的影响。结果显示,在番茄幼苗根部接种南方根结线虫的前5 d内(包括5 d),无论接种密度如何,都未观察到明显的根结形成现象,第6天开始,根结开始显现。随着接种时间的延长和接种密度的增加,根结的数量增加,形成速度也加快。这表明根结线虫对番茄根部的影响是逐渐显现并随着密度增加而加剧的。 展开更多
关键词 番茄 线虫 接种量 根结数 盆栽试验
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土壤修复剂协同昆虫病原线虫对南方根结线虫Meloidogyne incognita以及黄瓜幼苗生长的影响 被引量:2
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作者 李星月 刘奇志 +2 位作者 李贺勤 张林林 张鸿 《西南农业学报》 CSCD 北大核心 2016年第9期2144-2149,共6页
为了探究土壤修复剂SA协同昆虫病原线虫(Heterorhabditis beicherriana)对南方根结线虫(Meloidogyne incognita)的室内抑制效果,以及二者结合施用对黄瓜生长的促进效果,本文以千秋1号为供试黄瓜品种,采用室内试验方法,人工接种南方根结... 为了探究土壤修复剂SA协同昆虫病原线虫(Heterorhabditis beicherriana)对南方根结线虫(Meloidogyne incognita)的室内抑制效果,以及二者结合施用对黄瓜生长的促进效果,本文以千秋1号为供试黄瓜品种,采用室内试验方法,人工接种南方根结线虫,并施入土壤修复剂SA和昆虫病原线虫,从实验第7、14、21天时根结线虫二龄幼虫J2与H.beicherriana三龄幼虫J3的存活率,实验30 d时黄瓜幼苗的叶面积、株高、鲜重以及根结数几个方面做了研究。结果表明:实验第7、14、21天后,土壤修复剂SA和昆虫病原线虫处理组的根结线虫(J2)存活数却明显低于根结线虫清水对照组(M组),且第21天时SA处理组的死亡根结线虫数量约是M组的2倍,加入昆虫病原线虫的处理组中死亡根结线虫数量约是M组的3倍,然而昆虫病原线虫在SA处理组中的存活率却明显高于其他组。此外,土壤修复剂SA协同昆虫病原线虫加入到添加根结线虫的黄瓜土壤中,可以增加黄瓜幼苗叶面积、鲜重、株高,并能减少单位长度内根结数量,说明土壤修复剂SA协同昆虫病原线虫的施用,提高了植株抵抗根结线虫能力,减少了根结线虫对根系危害,该结果为有效修复被根结线虫污染土壤的研究提供理论基础。 展开更多
关键词 土壤修复剂 昆虫病原线虫 南方线虫 黄瓜 根结数
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The effect of 2, 4-Dichlorophenoxy acetic acid and Bradyrhizobium on induction of Para-nodule in wheat roots
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作者 Nagaraja R. Gurumurthy B. R. Devappa V 《Journal of Agricultural Science and Technology》 2009年第8期14-16,共3页
The investigation was conducted to know the effect of 2, 4-Dichlorophenoxy acetic acid and inoculation on Para-nodule formation and growth parameters in wheat. Formation of nodular outgrowth on the roots of wheat seed... The investigation was conducted to know the effect of 2, 4-Dichlorophenoxy acetic acid and inoculation on Para-nodule formation and growth parameters in wheat. Formation of nodular outgrowth on the roots of wheat seedlings treated with 2, 4-D commenced in 8-10 days. The maximum Para-nodule formation was found in 1 ppm of 2, 4-D when incubated with bradyrhizobium P-132. Inoculation of the same has helped to increase the number of Para-nodule, but not essential for Para-nodulation. Histological study shows that, these induced Para-nodules originated from the pericycle and these are appeared to be modified lateral roots and Para-nodule structure formations however, it enhanced by bradyrhizobial inoculation. 展开更多
关键词 Para-nodule 2 4-D PERICYCLE N-FIXATION
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Structure Polynomials and Subgraphs of Rooted Regular Trees
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作者 Daniele D'Angeli Alfredo Donno 《Algebra Colloquium》 SCIE CSCD 2018年第1期45-70,共26页
We introduce an algebraic structure allowing us to describe subgraphs of a regular rooted tree. Its elements are called structure polynomials, and they are in a one- to-one correspondence with the set of all subgraphs... We introduce an algebraic structure allowing us to describe subgraphs of a regular rooted tree. Its elements are called structure polynomials, and they are in a one- to-one correspondence with the set of all subgraphs of the tree. We define two operations, the sum and the product of structure polynomials, giving a graph interpretation of them. Then we introduce an equivalence relation between polynomials, using the action of the full automorphism group of the tree, and we count equivalence classes of subgraphs modulo this equivalence. We also prove that this action gives rise to symmetric Gelfand pairs. Finally, when the regularity degree of the tree is a prime p, we regard each level of the tree as a finite dimensional vector space over the finite field Fp, and we are able to completely characterize structure polynomials corresponding to subgraphs whose leaf set is a vector subspace. 展开更多
关键词 rooted tree structure polynomial rooted subtree automorphism group of a tree Gelfand pair
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Projection pressure and Bowen's equation for a class of self-similar fractals with overlap structure
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作者 WANGChen Wei CHENErCai 《Science China Mathematics》 SCIE 2012年第7期1387-1394,共8页
Let {Si}li=1 be an iterated function system (IFS) on Rd with attractor K. Let π be the canonical projection. In this paper, we define a new concept called "projection pressure" Pπ(φ) for φ ∈(Rd) under cer... Let {Si}li=1 be an iterated function system (IFS) on Rd with attractor K. Let π be the canonical projection. In this paper, we define a new concept called "projection pressure" Pπ(φ) for φ ∈(Rd) under certain arlene IFS, and show the variational principle about the projection pressure. Furthermore, we check that the unique zero root of "projection pressure" still satisfies Bowen's equation when each Si is the similar map with the same compression ratio. Using the root of Bowen's equation, we can get the Hausdorff dimension of the attractor K. 展开更多
关键词 projection entropy projection pressure Hausdorff dimension variational principle Bowen's equa-tion
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