Insecticidal activities and active components of the alcohol extract from green peel of Juglans mandshurica

The extract of green peel of Juglans mandshurica Maxim was extracted by common method for studying its insecticidal activities and analyzing the active components. Results showed that the alcohol extract and the chloroform part of extract （separated with chloroform from alcohol extract） form green peel of J. mandshurica have insecticidal activities in contact toxicity and stomach toxicity against larvae of Lymantria dispar L.. After application of the extracts for five days, the corrected mortality of larvae of Lymantria dispar for both extracts was more than 50% in contact toxicity and stomach toxicity at the concentration of ≥ 5 g·L^-1. The insecticidal activity for both alcohol extract and chloroform part of extract is more effect in contact toxicity than in stomach toxicity, but no significant difference in the insecticidal activities was found between alcohol extract and chloroform part of extract. The active components in the chloroform part of extract from green peel of.J. mandshurica were analyzed by GC-MS. The analyzed results showed that the active components in the chloroform part of extract are： （1） joglone （5-hydroxy-1,4- naphthaoquinone）, the relative content 27.11%, （2） 1,5-Naphthalenediol, the relative content 9.52%, （3） 7-Methoxy-1-tetralone, the relative content 6.81%, （4） Benzofuran, 2,3-dihydro-, the relative content 6.76%, （5） 4-Hydroxy-2-methoxycinnamaldehyde, the relative content 3.99%, （6） 2-Methoxy-4-vinylphenol, the relative content 3.05%.

A cytotoxic compound from the leaves of Juglans mandshurica

From Juglans mandshurica leaves, a new quinone compound was isolated through bioassay-guided fractionation. The structure elucidation of the compound was established based on spectroscopic studies, notably of the 2D NMR spectra. The compound exhibited moderate cytotoxic activities against Hela, MCF-7, BGC823 and 3T3-Llcell lines with IC50 ranges from 7.5 to 26.8 μmol/L.

Provenance Trials of Juglans mandshurica

The data of provenance trial on Juglans mandshurica young tree were investigated and studied from different provenance. Analysis methods of variance and correlation analysis were used to analyze these data. The following conclusions were obtainedf (1) The difference of growth characters of Juglans mandshurica is relatively significant among provenances, (2) The result of first trial has indicated that Julans mandshurica growth trend expresses two-way gradual change trend with different longitude and latitude, but the second trial has no obvious gradual change trend. Height of Juglans mandshurica is negatively correlated with elevation; (3) The provenance of Shulan. Mao'ershan and Baishishan were selected as superior provenance of afforestational seeds for Mao'ershan and its brink region.

Genetic Improvement in Juglans mandshurica and Its Uses in China:Current Status and Future Prospects

Juglans mandshurica is an economically and ecologically valuable species that is used for various construction purposes,making luxurious furniture,as food and sources of medicinal substances and landscaping because of its excellent wood,edible fruits and rich in various types of chemical compounds.In the past few decades,several genetic improvements of J.mandshurica were made,with a focus on the selection of improved varieties and on breeding technology.Many elite provenances and families were selected based on growth traits or wood properties.In recent years,with the increasing demand for high-quality seedlings in Chinese forestry production,the breeding goals of genetic improvement for J.mandshurica were redefined to include other traits,such as fruit yield and contents of medicinal component.However,the improvement processes were still slow due to the long breeding cycle and the limited use of advanced breeding technologies,resulting in the selection of fewer improved varieties.In this review,we summarized the research progresses on genetic improvements of J.mandshurica and other related works,and discussed research gaps and suggested future directions for genetic improvement of the species.The review provides valuable insight for the selection of improved varieties and production of excellent germplasms.

Spatial patterns of the main trees in a plant micro-reserve constructed in the 2022 Beijing Winter Olympics mountainous competition zone

Several plant micro-reserves were established to preserve the vegetation in local mountain areas during the construction of the Yanqing competition zone of the 2022 Beijing Winter Olympics.The spatial patterns of the main species in one of the micro-reserves and the factors affecting these patterns were characterized in this study.The distribution of arbor species was found to be mostly aggregated,especially at fine scales(<5 m).Minor species were found to be more aggregated than the major species in each forest layer.The spatial patterns were found to be affected by habitat heterogeneity,intraspecific relationships,interspecific competition,and seed dispersal limitation.Habitat heterogeneity was found to affect large-scale spatial patterns,and its effects were observed throughout population development.Interspecific competition is another factor affecting the distribution of the species,and its effects were stronger during the later stages of population development.Habitat heterogeneity was found to affect competition among species and is key for species coexistence.Both these processes are affected by the seed dispersal limitation,and intraspecific relationships are a legacy of seed dispersal.The point patterns can be used as a tool for the initial assessment of the status of communities within micro-reserves.The consideration of these relationships in the development,management,and formulation of policies for micro-reserves in mountainous areas will facilitate the achievement of conservation goals.The careful consideration of habitat conditions when selecting sites for micro-reserves establishment can promote species conservation.

Effect of Slope on Growth of Three Hard Broadleaved TreeSpecies in Northeast China

Analysis on tree hegiht and diameter(DBH) growth of the belt-mixed plantations of Fraxinus mandshurica,Phellodendron amurense and Juglans mandshurica(panted in 1986) were conducted by using the methods of variance analysis and multiple comparison. The results show that the position of slope is a significant physical factor to affect height growth and DBH growth. Fraxinus mandshurica grew best at meddle hill. Juglans mandshurica grew best at mid-down slope, and Phellodendron amurense grew best at down slope. The analysis of the positive edge effect was also made for belt-mixed plantation of Juglans mandshurica and Larix dahurica. The result indicated that Larix dahurica presented positive edge effect to growth of Juglans mandshurica present.

胡桃楸不同发育器官内源激素的动态变化

为探讨胡桃楸花芽、叶片及果实中内源激素含量的变化特点,提高胡桃楸坐果率,本试验选取生理分化期的花芽以及形态分化期的叶片和果实,采用酶联免疫吸附法(ELISA)分别测定生长素(IAA)、赤霉素(GA)、脱落酸(ABA)、细胞分裂素(CTK)、乙烯(ETH)、油菜素内酯(BR)、水杨酸(SA)、茉莉酸(JA)的含量,探讨胡桃楸性别分化过程中内源激素的调控作用。结果表明,两种类型胡桃楸的雌雄花芽中内源激素在生理分化初期各激素含量高低相反,叶片中各内源激素含量在7月初达到峰值,当胡桃楸开始结实,叶片中各激素含量下降;GA和ETH在胡桃楸结实之前含量较低,但在结实之后含量大幅上升。胡桃楸花芽分化过程中高浓度IAA促进开花,但浓度过高则会抑制开花,GA起到抑制成花的作用,SA和JA可能存在协同作用,为结实做准备,调节成花叶片中各激素含量在胡桃楸结实之前不断累积,GA和ETH在果实发育过程中起到关键作用。胡桃楸性别分化过程中主要内源激素的变化特点,可以揭示其调控生理分化期的花芽和叶片及果实的作用,为人工调控花期和坐果率提供理论依据。