RAPID DIAGNOSIS OF NUTRIENT ELEMENTS IN FINGERED CITRON LEAF USING NEAR INFRARED REFLECTANCE SPECTROSCOPY

In order to provide references for leaf nutrition diagnosis of fingered citron, the technique of near infrared reflectance spectroscopy (NIRS) was introduced to analyze nitrogen (N), phosphorus (P), potassium (K), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) in the dry-leaf samples of fingered citron. The best calibration model for N was developed with high RSQ_CAL (0.90), SD/SECV (2.73) and low SEC (1.06 mg g^?1), good calibration models were obtained for P, K, Fe and Mn, and no significant correlations were found between the spectra and the individual amounts of Zn and Cu. When tested using a validation set (n = 38), N was well predicted with low values of SEP (1.21 mg g^?1) and high RPD (2.5). The values of SEP and RPD were also acceptable for the external validation of P, Fe and Mn. Near-infrared spectroscopy analysis technique shows potential of diagnosing minerals in fingered citron, particularly for N, P, Fe and Mn.     

新疆野生果树资源数据库系统的设计与实现

摘要：新疆的野生果树种类丰富而独特,起源古老,为我国果树栽培提供了丰富的种质资源和物质基础。因此,建立新疆野生果树资源数据库对于新疆野生果树资源的保护与研究具有十分重要的意义。本文介绍了以Visual Basic 6.0为主导设计语言,结合后台关系数据库Access2003,建立新疆野生果树资源数据库信息系统的原理和方法,运用计算机的数据库技术开发出一套完整的可广泛应用于果树生产、科研、教学、社会服务等的野生果树种质资源数据库程序。本系统包括新疆的野苹果、野杏、野生樱桃李、野生欧洲李、野核桃等野生果树资源分布、植物学特征和农业生物学特征等数据内容。     

Relationship between effective solar radiation and sap flow process during an entire growing season in Western Mountains of Beijing

In order to explore the relationship between the time processes of solar radiation and sap flow, sap flow velocity (SFV) of Platycladus orientalis and Pinus tabulaeformis, effective solar radiation (ESR) and other environmental factors were synchronously monitored for one year in the Beijing Western Mountains by using a thermal dissipation probe (TDP) system and an automatic weather station. Results showed significant differences between changes in diurnal characteristics of ESR and sap flow in sunny days during three seasons. Starting times of sap flow occurred generally 1.5–3 hours later than those of solar radiation and there were small differences between Platycladus orientalis and Pinus tabulaeformis. But peak times and stopping times of sap flow varied con-siderably with large contrasts in ESR. The duration of sap flow showed clear differences among the seasons owing to the variable rhythms of climate factors in Beijing. Fluctuation amplitude in the duration of sap flow remained relatively stable during the autumn but changed greatly during spring and summer. Changes in diurnal sap flow velocity of both Platycladus orientalis and Pinus tabu-laeformis were about 0–3 hours later than those of ESR but with the same configuration. The start of sap flow was mainly induced by the sudden intensification of ESR (sunrise effect). Seasonal models of SFV indicated that a cubic equation had the best fit. It was more practical to simulate seasonal water consumption models of trees with ESR. In further investigations, these models should be optimized.     

2012年四川省稻飞虱大发生特点及原因分析

2012年四川省稻飞虱大发生,具有迁入时间特别早、迁入峰次多、灯下田间虫量大、发生面积大等特点。造成大发生的原因主要是境外虫源基数大,根据工作经验判断作为四川省虫源地的广西虫量大以及四川省今年的气候条件有利于稻飞虱的迁飞、繁殖。     

Do multipurpose companion trees affect high value timber trees in a silvopastoral plantation system?

Establishment of native timber trees on deforested land may contribute to the livelihood of farmers, to improved ecosystem services and to increased greenhouse gas uptake. Here, we present a new silvopastoral planting design to assess species performance and interspecific competition or facilitation effects among native timber and multipurpose trees in Central America. Two timber species, Tabebuia rosea and Cedrela odorata, were established in three low-density planting regimes allowing combined tree and future livestock production: (1) solitary planting, (2) companion planting with Guazuma ulmifolia, and (3) companion planting with the nitrogen-fixing Gliricidia sepium. We quantified survival, growth and reforestation potential of the two timber species subjected to the different planting regimes for the first 2 years after establishment. Nitrogen concentration as well as stable nitrogen and carbon isotope composition (δ¹⁵N, δ¹³C) of leaves of the timber saplings were determined. T. rosea showed higher survival and better growth than C. odorata under varying environmental conditions (soil, concomitant vegetation). Performance of the timber saplings was unaffected by either companion species. Planting regimes had no effect on foliar nitrogen concentration and δ¹⁵N of the two timber species, although δ¹⁵N values indicated nitrogen fixation activity in G. sepium trees. Planting regimes affected foliar δ¹³C values in T. rosea. δ¹³C values were significantly higher in solitarily growing individuals, suggesting lower exposition to water stress conditions in saplings surrounded by companion species. As we found positively correlated growth traits among timber and multipurpose trees, a combined planting may benefit farmers by providing additional goods and services.     

新疆杏属植物过氧化物酶儿茶酚氧化酶同工酶分析

根据酶谱及其分布率、扫描图的异同分析表明,杏不同种间的两种酶谱均有明显的差异,而种内品种间的差异较小,如西伯利亚杏(A.sibirica(L) lam)的酶谱较特别,与普通杏(A.vulgarislam)、辽杏(A.mandshurica(Maxim) Skvortz)、紫杏(A.dasycarpa Ehrh)有较大差异;紫杏有6条共同酶带,而普通杏中的白新那尔、阿克牙格勒克等与之相近;辽杏与紫杏有明显差异,但与栽培杏中的墨玉001、卡拉胡安娜等品种的酶谱较接近;普通杏中的野生杏明显地较栽培杏多一条强带.杏属植物有4条共同酶带,这4条酶带在各品种的分布率为98.7%～100%,2种酶活性均以CⅡ区最强,酶活性占60%～90%;其次为CⅠ区,酶活性占10%～30%,PⅢ、CⅢ区活性最弱,小于10%,两种酶有共同的趋势,但儿茶酚氧化酶的弱带有广泛的变异.     

HPLC法同时测定茶叶中4种儿茶素类成分

采用高效液相色谱（HPLC）分析4种儿茶素类化合物EC、EGC、EGCG、ECG。色谱柱为Hypersil ODS C18（5μm,150mm×4．6mm）,流动相为甲醇、水、冰醋酸（25：74：1）混合液,流速为1mL／min,检测波长270nm,进样量：10μL。线性方程分别为EGCG：Y=24．254X＋464．34,R=0．9993;EC：Y=669．55X＋19．14,R=0．9947;EGC：Y=5196．80X-65．17,R=0．9984;ECG：Y=518．76X＋71．53,R=0．9991。结果显示,本法操作简便,能同时用于4种儿茶素的含量测定;线性关系好;精密度RSD在1．0％左右;可在8h内测定;EC、EGC、EGCG、ECG的回收率分别为99．6％、98．7％、98．7％、99．4％。     

Rice <Emphasis Type="Italic">terpene synthase 18</Emphasis> (<Emphasis Type="Italic">OsTPS18</Emphasis>) encodes a sesquiterpene synthase that produces an antibacterial (<Emphasis Type="Italic">E</Emphasis>)-nerolidol against a bacterial pathogen of rice

Plant volatile compounds, including terpenes, are known to be involved in the rice defense system. In the present analysis of a terpene synthase, OsTPS18, in rice, we found that OsTPS18 was localized in the cytoplasm and synthesized the sesquiterpenes (E)-nerolidol and (E)-β-farnesene. The amounts of (E)-nerolidol and (E)-β-farnesene increased after jasmonic acid (JA) treatment. (E)-Nerolidol had significant antibacterial activity against Xanthomonas oryzae pv. oryzae (Xoo). These results suggest that (E)-nerolidol plays an important role in JA-induced resistance against Xoo and that it functions as an antibacterial compound in rice.     

Partitioning the multi-scale effects of human activity on the occurrence of riparian forest birds

Conservationists, managers, and land planners are faced with the difficult task of balancing many issues regarding humans impacts on natural systems. Many of these potential impacts arise from local-scale and landscape-scale changes, but such changes often covary, which makes it difficult to isolate and compare independent effects arising from humans. We partition multi-scale impacts on riparian forest bird distribution in 105 patches along approximately 500 km of the Madison and Missouri Rivers, Montana, USA. To do so, we coupled environmental information from local (within-patch), patch, and landscape scales reflecting potential human impacts from grazing, invasive plant species, habitat loss and fragmentation, and human development with the distribution of 28 terrestrial breeding bird species in 2004 and 2005. Variation partitioning of the influence of different spatial scales suggested that local-scale vegetation gradients explained more unique variation in bird distribution than did information from patch and landscape scales. Partitioning potential human impacts revealed, however, that riparian habitat loss and fragmentation at the patch and landscape scales explained more unique variation than did local disturbances or landscape-scale development (i.e., building density in the surrounding landscape). When distribution was correlated with human disturbance, local-scale disturbance had more consistent impacts than other scales, with species showing consistent negative correlations with grazing but positive correlations with invasives. We conclude that while local vegetation structure best explains bird distribution, managers concerned with ongoing human influences in this system need to focus more on mitigating the effects of large-scale disturbances than on more local land use issues. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.