茶树花青素形成分子机理的研究进展

花青素是由类黄酮合成途径产生的次生代谢产物,含量高时会使茶树新梢呈现红色或紫色。同时,花青素相比儿茶素等具有更明显的抗氧化、预防肿瘤等药理保健作用。文章就茶树花青素合成途径、转录及转录后调控等方面进行综述,以期更好地为高花青素茶树的育种研究提供理论依据。     

Compatibility of root growth and tuber production of potato cultivars with dynamic and static water‐saving irrigation managements

The important root characteristics of root length density (RLD) and root mass density (RMD) generally differ among irrigation managements and potato cultivars. The objective of this study was to investigate the RLD and RMD variations and their functional relationships with gross potato tuber yield for two commercial potato cultivars, Agria and Sante, under different irrigation strategies. Full irrigation and water‐saving irrigation strategies, deficit and partial root drying irrigations, were applied statically (S) and dynamically (D) based on daily crop evapotranspiration. Results showed that SPRD had significantly greater RLD (3.64 cm/cm³) and RMD (132.7 μg/cm³) than other irrigation treatments. Between the potato cultivars, Agria had significantly larger values of RLD (3.50 cm/cm³) and RMD (138.7 μg/cm³) than Sante. The functional relationship between the root growth characteristics and tuber yield showed that under water‐saving irrigations, Agria increased root mass at the expense of gross tuber yield but Sante increased root mass to maintain larger gross tuber yields. However, Agria produced more roots and gross tuber yield than Sante, and it is concluded that Agria is a more drought‐tolerant potato cultivar, which is recommended for tuber production in regions where water might be scarce. It was shown that larger root production in potatoes was associated with improved tolerance to water stress.     

浅谈人造薄木生产中单板的漂白

详细阐述了木材颜色的成因及漂白机理，重点介绍了人造薄木生产过程中单板漂白工艺。研究表明，经漂白处理的单板，颜色明显变浅，色调也比较均匀，而且还消除了板面污染，对单板的染色十分有利。     

The Phytotoxicity of Various Graminicides in Durum Wheat in Greece

The effect of three herbicides, diclofop-methyl (DM), imazamethabenz-methyl (IM) and fenoxaprop-ethyl (FE), was investigated at the recommended rate (×) and double the recommended rate (2×) in a durum wheat crop. FE had the smallest effect on root system characteristics, while IM had the greatest effect. For all herbicides, the double rate treatment gave a greater statistical reduction than the single rate for root system characteristics. FE had the smallest effect on the activity of aerobic microorganisms, while DM gave the greatest reduction, 10 days after application, and all three herbicides reduced earthworm abundance. DM gave the smallest reduction in the number of tillers and in plant height, while the double rate of IM gave the greatest reduction. For all three herbicides, double the recommended rate resulted in a significant reduction in the weight of 1000 seeds, while no statistically significant deviations were noted at the recommended rate. Finally, the use of all three herbicides resulted in significantly lower statistical yields compared to the sample (control plot), although there were no significant statistical differences among them, for either recommended or double recommended rates.     

苹果试管苗不定根起源及其发育状况的研究

利用光学和扫描电子显微镜观察结果表明,经琼脂生根培养基诱导产生的长富—2苹果 (Malus pumila Mill.) 试管苗的不定根起源于维管形成层。这种不定根发育不良,根表面缺乏根毛,内部解剖构造为典型的初生结构。为避免因不定根吸收、运输能力差而影响试管苗移栽成活,宜采用通透性良好的基质进行瓶内或瓶外生根,可诱导出优质不定根。     

Horizontal transmission and host-virulence attenuation of totivirus in violet root rot fungus Helicobasidium mompa

Monokaryotic strains of Helicobasidium mompa were used as vectors of a mycovirus between various H. mompa isolates to examine the transmissibility of one of the mycoviruses, totivirus (HmTV1–17 virus) in the hypovirulent isolate V17 of H. mompa. The isolates that acquired HmTV1–17 virus were also examined for any alteration in the virulence. Twelve dikaryotic isolates of H. mompa, belonging to 11 mycelial compatibility groups (MCGs) and being mycelially incompatible with isolate V17, were used as recipients of HmTV1–17 virus. Two monokaryotic isolates that were mycelially incompatible with isolate V17 and all of the recipients were also used as vectors of HmTV1-17 virus between isolate V17 and the recipients. When isolate V17 and recipients were directly paired on plate media, HmTV1-17 virus was transmitted from isolate V17 into 2 of the 12 recipients (i.e., 2 of the 11 MCGs). Two monokaryotic strains were paired with isolate V17, and the monokaryotic strains that acquired HmTV1-17 virus were then used as new virus donors. When the monokaryotic strains containing HmTV1-17 virus were paired with the 12 recipients, HmTV1-17 virus was transmitted into 7 of the 12 recipients from the monokaryotic strains (i.e., 7 of 11 MCGs). Based on these results, we concluded that monokaryotic strains could act as vectors to transmit HmTV1-17 virus into H. mompa isolates. When four of the H. mompa isolates that acquired HmTV1-17 virus were used to inoculate apple rootstock Malus prunifolia, the virulence of all of the isolates was attenuated from that of their parental isolates. Moreover, because the DNA fingerprints of the fungal isolates that acquired HmTV1-17 virus were the same as those of their parental isolates, the infection with HmTV1-17 virus is considered the cause of virulence attenuation of H. mompa.     

Fusarium oxysporum对苗期大豆根部的致病性和侵染规律

Fusarium oxysporum对苗期大豆具有较强的致病作用。病原菌自伤口或直接侵入大豆幼苗根部的皮层组织,随着病原菌的侵入和扩展,细胞出现坏死,组织发生崩解,根部组织表现红褐色病斑。环境因素对病原菌的侵染时期和在大豆体内潜育时间的长短有着明显的影响。侵染时期主要受病原菌侵入前自身所处状态和寄主的影响,侵入后潜育时间的长短则受植株状态的影响。土壤环境条件直接影响着病原菌的侵入和寄主的抗病性,间接影响着病原菌在大豆植株体内的扩展和病症的表现。     

The Effect of Detopping the Field Bean Plants (Vicia faba L. minor) and Lack of the Pod Setting on the Symbiosis with Root Nodule Bacteria

The plants of field bean var. Nadwiślaνski were detopped after about 1 month since the beginning of flowering and after that all flower buds were removed from some plants. The effect of a change in the trophic balance on the setting and subsequent growth of root nodules was studied.
The removal of pods had the greater effect on the increase in the weight of the remaining organs than the detopping of plants. Detopping retarded the ageing of the plants and delayed the phase of the greatest reduction of the number of pods. The detopping of plants revealed their considerable compensative possibilities in terms of production of the pod weight and the potential of leaves for biomass production. The data obtained indicate that plant detopping may disturb the root–bacteria exchange of signals, necessary to initiate the nodule development, while the further growth of nodules depends, above all, on the amount of available photosynthates.
A very high correlation between the dry weight of the whole plant to the dry weight of leaves ratio and the weight of nodules was observed. It proves the importance of the trophic balance of the plant for the root nodule weight production.     

菲莱氏温扬球虫(Wenyonella philiplevinei)受精和卵囊壁形成的超微结构研究

本文利用透射电镜研究了寄生于家鸭小肠上皮细胞的菲莱氏温扬球虫的受精和卵囊壁的形成过程。作者在感染后96 h 的样品中发现一例大、小配子已受精;小配子已进入大配子中,大配子胞质中有一根纵切的鞭毛,小配子的核呈流体状,位于大配子核附近。卵囊壁是由成囊颗粒内含物进入合子表面的膜之间沉积成层而形成。成囊颗粒Ⅰ形成外层卵囊壁,成囊颗粒Ⅱ形成内层卵囊壁。沉积于膜之间的成囊颗粒Ⅰ内含物逐渐浓缩,堆积成颗粒状,使卵囊壁外层外表面形成颗粒状突起。成熟的卵囊壁由三层组成:即薄的外周膜、外层和内层。其内的合子原生质还被两层单位膜包裹。     

Colonization and histopathology of susceptible and resistant carnation cultivars infected with Fusarium oxysporum f. sp. dianthi

Stems of the susceptible Early Sam and resistant Novada carnations were inoculated with a conidial suspension ofFusarium oxysporum f. sp.dianthi. Stem segments of either cultivar were sampled regularly and used for determination of fungal growth and for microscopical investigation.Early Sam showed typicalFusarium wilt symptoms and its stems were colonized intensively. The observed vascular browning appeared to be caused by discolouration of primary walls of infected vessels and surrounding cells. Vessels were rarely occluded with gel. Cell wall degradation led to the formation of stem cavities. Hyperplasia of xylem parenchyma was not seen.In Novada, fungal colonization remained low throughout the experiment. Macroscopic symptoms were absent except for longitudinal bursts in the stem, which appeared to be caused by hyperplasia of xylem parenchyma bordering infection. Vascular gelation occurred in the infected tissues, causing some vascular browning also. Xylem vessel regeneration was observed in the hyperplastic layer. Cavities were not formed, and wall discolouration was rare. Vascular gelation is considered part of theFusarium wilt resistance mechanism. It is followed by xylem vessel regeneration, which expresses a general plant response to vascular dysfunction rather than being part of the resistance mechanism.Although of different origin, vascular browning as such occurs in both susceptible and resistant interactions. In breeding for resistance, care should hence be taken with the current use of browning as an indication of disease.Samenvatting Anjers van de vatbare cultivar Early Sam en de resistente cultivar Novada werden geïnoculeerd met een conidiënsuspensie vanFusarium oxysporum f. sp.dianthi. Van beide cultivars werden regelmatig stengeldelen geoogst om deze microscopisch te onderzoeken en om de schimmelgroei te bepalen.Early Sam vertoonde de voor deze verwelkingsziekte kenmerkende symptomen en werd intensief gekoloniseerd. Aan het vaatweefsel waargenomen bruinkleuring bleek veroorzaakt te worden door verkleuring van de primaire wanden van geïnfecteerde vaten en de hen omringende cellen. Zelden trad er in de vaten gomvorming op. Celwandafbraak veroorzaakte de vorming van holten in de stengel. Hyperplasie van het houtparenchym werd niet waargenomen.In Novada bleef de schimmelgroei gedurende het hele experiment beperkt. Macroscopisch waren er enkel lengtescheuren in de stengel te zien, die veroorzaakt bleken te worden door hyperplasie van aan de infectie grenzend houtparenchym. In het geïnfecteerde vaatweefsel optredende gomvorming veroorzaakte ook enige bruinkleuring. In het hyperplastische weefsel werd regeneratie van houtvaten waargenomen. In de stengel werden geen holten gevormd, en verkleuring van de celwanden kwam weinig voor. De vorming van gommen in de houtvaten maakt waarschijnlijk deel uit van het resistentiemechanisme. De daarop volgende houtvatregeneratie is eerder een algemene reactie van de plant op vaatverstopping dan een deel van het resistentiemechanisme.Vaatverbruining, zij het van verschillende oorsprong, komt voor in zowel vatbare als resistente interacties. Om die reden moet men in de resistentieveredeling bij de anjer voorzichtig zijn met het gebruik van bruinkleuring als ziekteïndicatie.