Isolation and Characterization of Two Novel Nematicidal Depsipeptides from an Imperfect Fungus,Strain D1084

Two novel nematicidal cyclodepsipeptides, designated bursaphelocides A and B, were isolated from the culture filtrate of an imperfect fungus, strain D1084, belonging to Mycelia sterilia. Bursaphelocide A (1), containing 2-hydroxy-3-methylpentanoic acid, proline, isoleucine, N-methylalanine, N-methylvaline, and β-alanine in sequence, and bursaphelocide B (2), comprising 4-methylproline instead of proline in 1, are novel 2-hydroxy-3-methylpentanoic acid analogues of insecticidal destruxins.     

核桃属部分种的小孢子发生及核型研究

本试验采用常规压片法,观察了核桃属(Juglans L.)四个种花粉母细胞(PMC)的减数分裂过程和花粉形态,检测了两个种的花粉生活力,分析研究了七个种的核型。结果表明,普通核桃(J.regia)核桃楸(J.mandskurica Maxim.)和黑核桃(J.nigra L.)的PMC减数分裂基本正常,但河北核桃PMC的减数分裂过程都极不正常,供试的七个种,除普通核桃为2C核型外,其余均为2B核型,仅黑核桃一种带有随体染色体。根据核型特点把七个种分成三组,并探讨了组间与组内种间的亲缘演化关系。作者认为,河北核桃应为一种独立的种,核桃科在系统发育上可能来源于染色体基数为8的两群)不同植物。     

凤凰木种子蛋白的分离提纯和生化性质

研究了植物凤凰木种子中的蛋白质成分,试图分离出新的核糖体失活蛋白凤凰木种子经磷酸盐缓冲液抽提,硫酸铵分级盐析,分子筛和阴离子交换剂等多次柱层析,分离出三种组分ＤｒⅠ、ＤｒⅡ和ＤｒⅢ．ＳＤＳ－ＰＡＧＥ和ＩＥＦ实验表明这三种蛋白质均达到单一纯,而ＨＰＬＣ实验则表明它们的纯度不低于９０％。它们的分子量据ＳＤＳ－ＰＡＧＥ和ＨＰＬＣ实验分别约２３５００、２６０００、２８５００．ＩＥＦ实验测得三者的等电点均为５．２左右。测定了组分ＤｒⅠ的蛙卵泡裂解活性,其毒性约为天花粉蛋白的１／４０．分析了它们的氨基酸组成。估算了三种蛋白质的二级结构含量,结果表明三者均富含β折叠结构。已有的实验事实表明这三种蛋白质的生化行为明显异于核糖体失活蛋白,因而很可能不属于这一蛋白质家族。     

First report of Garella musculana (Erschov, 1874) (Lepidoptera: Nolidae) in Italy with insights into its identity

The Asian walnut moth, Garella musculana (Erschov, 1874) (Lepidoptera: Nolidae), is a major pest of walnut. Native to Central Asia, it was found to be invasive in 2008 in Sevastopol (Crimea) and nowadays widespread in Turkey, Bulgaria, Romania and Russia. Here, we account for the finding of G. musculana in NE Italy (Veneto region) in 2021, where adults were found in a light lamp, representing the first record of the Asian walnut moth for this country and Western Europe. Adult specimens were identified morphologically on both external characters and genitalia features. G. musculana larvae and damage were also observed on a plantation of Juglans regia L. (Fagales: Juglandaceae) located in Veneto in October 2021. A COI-barcoding analysis was performed to attain a molecular characterization of our specimens and probate our morphological identification. However, because no sequence of G. musculana was present in major gene databases and the similarity of our sequences with those attributed to Garella ruficirra (Hampson, 1905) (Lepidoptera: Nolidae) made clear that these taxa deserved further scrutiny regarding their specific distinction. Some subtle differences in the male terminalia could be found between them and their vast geographic distributions, but the strong similarity in most features calls for further morphological and genetical insights on a broad set of samples to assess whether they represent two closely related, substantially parapatric species, or a unique, geographically varying entity. Solving this issue may turn out crucial in the identification and proper management of walnut moths of the genus Garella.     

贵州核桃种质资源表型性状多样性研究

该研究以贵州省内的3个山脉(乌蒙山、苗岭山和武陵山)、19个核桃和泡核桃实生居群、245棵实生单株为研究材料,对坚果表型性状29个指标的多样性、相关性、聚类及变异进行分析,以揭示贵州核桃资源的表型遗传多样性水平,为贵州核桃资源的保存与利用及核心种质构建提供依据。结果显示：(1)核桃和泡核桃实生居群245份种质资源的18个表型质量性状Simpson指数为0.26～0.82,Shannon-Wiener指数为0.12～1.79;核桃小叶形状多样,易发生顶叶退化,坚果核壳表面特征、坚果形状及核仁皮色多样性丰富。(2)坚果表型变异系数为3.32%～47.67%,平均为21.28%且差异显著(P<0.05),居群间变异系数为9.42%～31.61%且差异显著(P<0.05);居群内和居群间变异均是核桃表型多样性的来源,但坚果性状在居群间差异显著性均高于居群内,说明居群间变异是该区域坚果表型变异的主要来源。(3)3个山脉区域核桃表型均有不同程度变异,其中,苗岭山核桃表型变异程度低,乌蒙山核桃表型变异程度高;UPGMA聚类结果显示,19个核桃实生居群依据贵州山脉区域划分为三类,表明贵州核...     

新疆野核桃自然保护区不同坡向丛生野核桃年龄结构及数量动态

通过对新疆野核桃自然保护区丛生野核桃(Juglans regia)进行普查,以径级结构代替年龄结构,采用匀滑技术编制种群静态生命表,并运用时间序列模型预测种群数量动态,从而获得丛生野核桃树的龄级结构与动态。结果表明,不同坡向丛生野核桃以中龄级为主,年龄结构呈两头小中间大的纺锤型;4个坡向种群年龄结构的动态指数Vpi虽大于0,但最大仅为19.10%,且Vpi’极低,最大为1.12%,阳坡种群增长趋势最高,抗干扰能力最强,种群稳定性最好,半阳坡种群增长趋势最弱,抗干扰能力最弱,种群稳定性最差;各坡向种群均存在多个死亡高峰,阳坡最高峰在15龄级,半阳坡在15和18龄级,阴坡和半阴坡均在9龄级,存活曲线更接近Deevey-Ⅱ型;在未来2、5、10龄级后,中龄级个体数量减少,老龄个体呈增加趋势,丛生野核桃种群稳定性难以长期维持。因此对丛生野核桃幼苗的保护非常关键。     

Pathogenicity of Macroposthonia xenoplax to Walnut

Preplanting treatment of soil naturally infested with Macroposthonia xenoplax with 1,2-dibromoethane (ethylene dibromide) significantly increased the growth rate of Juglans hindsii seedlings. When seedlings of J. hindsii, J. regia CV "Serf" and J. regia CV Eureka were inoculated with M. xenoplax, their growth was signilicantly less than that of nematode-free controls. This retarded growth rate was accompanied hy feeder root necrosis, longitudinal cracks in the older roots, and distinct lesions in the secondary phloem.     

Phytophthora cinnamomi Associated with Root and Crown Rot of Walnut in Turkey

Walnut decline caused by Phytophthora sp. occurred in an orchard in Sakarya province in Turkey. Affected young trees showed poor growth, leaf discolouration, root and crown rot and eventual death. A Phytophthora sp. isolated from necrotic taproots and crown tissues. The causal agent of the disease was identified as Phytophthora cinnamomi by morphological characteristics and comparing sequences of internal transcribed spacer (ITS) region. Upon conducting pathogenicity test, averaging 7.8‐cm‐long canker developed on basal stem within 2 weeks, while no cankers developed in the control plants.     

胡桃楸提取物对体外白念珠菌生物膜形成的影响

目的研究胡桃楸提取物对白念珠菌生物膜形成的影响。方法采用甲基四氮盐（XTT）还原法评价胡桃楸提取物对白念珠菌的生物膜形成及黏附性的影响。镜下观察胡桃楸提取物对白念珠菌生物膜的形态学影响。结果胡桃楸提取物抑制白念珠菌生物膜50％及90％的最小抑制药物浓度（SMIC50、SMIC90）分别为15．2μg、23．4μg。胡桃楸提取物作用浓度大于20μg时对该菌细胞黏附有抑制作用。30μg胡桃楸提取物可完全抑制白念珠菌生物膜的形成。结论胡桃楸提取物对体外白念珠菌生物的膜形成有较强的抑制作用。