Production of Regenerants in Sugar Beet

The experimental results are presented on production of plants-regenerants of the sugar beet (Beta vulgaris L.) via callus formation or direct organogenesis from the leaf tissues. The method of aseptic treatment was developed for the seeds with strong bacterial and fungal invasion. The regenerant plants were obtained in the presence of various concentrations of synthetic hormones, such as cytokinin (6-benzaminopurine) and auxin (naphthylacetic acid), and inhibitor of auxin transport in plants (2,3,5-triiodobenzoic acid). This combination of growth regulators made it possible to avoid callus formation. The genotype of initial plants affected the capacity for callus formation and regeneration. The temperature influenced rhizogenesis in regenerants.     

宁夏甜菜丛根病的研究

发生在宁夏甜菜上的一种病毒病的病株叶丛主要表现为黄化、焦桔和叶脉黄化坏死。从其分离的病毒粒子呈杆状,宽约20nm,长度为65—110nm、270—300nm和390—420nm,能侵染甜菜、菠菜、昆诺阿藜、苋色藜、番杏,与甜菜坏死黄脉病毒(BNYVV)抗血清呈阳性反应。综上所述,认为该病害是由BNYVV引起的。     

Modelling the Dynamical Components of the Sugar Beet Crop

Many models have been constructed to describe the growth ofthe sugar beet crop up to harvesting. In general, these modelshave a complex physiological basis, requiring a large numberof parameters yet relying on empirical functions with no mechanisticbasis to partition assimilates within the crop. An importantfactor in considering the growth of the crop, both from an economicand environmental point of view, is the response of the cropto varying amounts of available nitrogen in the soil. In thispaper, a model is described for crop growth using soil nitrogencontent and solar radiation as driving functions. The parsimoniousapproach to construction resulted in a 14 parameter model, sevenof which are associated with the driving variables. This issubstantially fewer than for other crop models. The model containsa new dynamical way of describing partitioning of assimilatesbetween shoot, storage root and fibrous roots. The partitioningmodel is derived from observations on the effect of soil nitrogenon crop growth. Interception of light is determined by foliagecover, which makes the model suitable for use with data collectedfrom satellite imaging. The model fits well to three independentdata sets with estimated parameters lying within biologicallyreasonable bounds. The model is used to test the sensitivityof yield to changes in soil nitrogen. Modelling; partitioning; parameter estimation; sugar beet; Beta vulgarisL.; nitrogen; crop growth dynamics     

Development of Nuclear Vacuoles in Sugar Beet Male Meiocytes

The formation, development and disappearance of nuclear vacuolesin three genetically different lines of Beta vulgaris L. arepresented. Nuclear vacuoles may be generated in zygotene bythe nuclear envelope, providing the membrane necessary for theformation of vacuoles within the nucleus. During subsequentstages of meiotic prophase nuclear vacuole volume increasesrapidly, peaking in pachytene. In diplotene/diakinesis totalnuclear vacuole volume falls gradually, and vacuoles eventuallydisappear in metaphase I. Maximum nuclear vacuole size in pachytenecoincides with a notable increase in nuclear surface. We thereforesuggest that nuclear vacuoles do not perform a mechanical functionin the contraction of the karyoplasm, but instead act as compartmentsin which products of nuclear metabolism may be stored, and subsequentlyparticipate in the elimination of nuclear products to the cytoplasm.These processes may be related to changes occurring preparatoryto the transition from sporophyte to gametophyte generation. Beta vulgaris L, sugar beet, meiocytes, nuclear vacuoles, ultrastructure     

Immunohistological Analysis of Chemically Induced Proteins in Sugar Beet

Tissue-specific distribution of basic β-1,3-glucanase (Glu2), basic class II chitinase (Ch2), basic class IV chitinase (Ch4), and acidic class III chitinase (SE2) were examined both in leaves and roots of sugar beet treated with salicylic acid (SA), benzothiadiazole (BTH) and glycine betaine. Protein localization was monitored by immunohistological analysis using specific antibodies. BTH, SA as well as glycine betaine induced both Glu2 and chitinase isozymes in leaves and roots of treated plants. The enzymes were accumulated in extracellular space and cell walls. They were mostly deposited in parenchyma cells of leaves and cortex parenchyma and endodermis of roots. In leaf tissues, BTH and SA induced proteins more effectively than glycine betaine but the effect of glycine betaine in roots was as efficient as BTH and SA. Glycine betaine induced the formation of extracellular globuli containing Ch4. Induced proteins were spatially distributed over the whole plant regardless the site of the inducer application. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effect of Photoperiod on Growth of Sugar Beet

Sugar beet grown in controlled environments were given similardaily amounts of visible radiation during three different photoperiodtreatments. Plants were given (a) 115 W m^–2 visible irradiancefrom fluorescent and tungsten lamps for 12 h; (b) 88 W m^–2of the same light for 16 h or (c) 115 W m^–2 from fluorescentand tungsten lamps for 12 h extended to 16 h with low intensity(3 W m^–2) incandescent light from the tungsten lamps only.Plant growth was increased similarly in both long day treatments[(b) and (c)] and dry weights were 25 per cent greater thanin the 12 h photoperiod (a) after 6 weeks. Leaf area was increasedby 18 per cent and net assimilation rate by 10 per cent in the16 h photoperiod at 88 W ^m–2 (b). By contrast, extendingthe photoperiod with 4 h of incandescent light (c) triggereda photomorphogenic increase in leaf expansion which increasedleaf area per plant by 47 per cent and leaf-area ratio by 12per cent.     

番茄突变体Epinastics的乙烯反应表现型分析

对番茄(Lycopersicoin esculentum Mil1.)突变体Epinastics(Epi)及其野生亲本VFN幼苗、成长植株和果实生长发育与成熟特性进行了系统研究和比较分析.Epi突变体从幼苗到果实都有乙烯过量合成,在黄化幼苗部分三重反应、成长植株叶柄严重上位生长、器官脱落和果实加速成熟等多方面表现出明显增强的乙烯反应,与已知的乙烯反应模式相符.强烈的顶端优势、紧凑的植株形态提示乙烯在植物的顶端优势调节中可能起着重要的作用.Epi突变体黄化幼苗项勾缩小、叶片和花瓣衰老延迟,与传统的乙烯反应不符,提示植物不同的生长发育特性由不同的乙烯信号转导途径调控.     

ABA Uptake in Source and Sink Tissues of Sugar Beet

The mode of abscisic acid (ABA) uptake was studied in excised leaf and root tissue discs of sugar beet (Beta vulgaris L.). Discs were incubated in buffered medium that contained 1 mm CaCl₂ and [¹⁴C]ABA. The sensitivity of ABA uptake to metabolic inhibitors and temperature indicated that the ABA transport system had an energy-dependent component. Energy-dependent uptake was greater in leaf than in root tissue (70% and 50%, respectively). Energy-dependent uptake by both tissues and passive uptake by root tissues were highly pH dependent. Maximal uptake was observed at pH 5.5. Leaf tissue incubated in the dark showed a 50% reduction of uptake as compared with tissue under light. The decrease was due to reduced passive uptake.     

Detection of Phenolic Compounds by Chromatography in Beet Sugar Molasses

Detection of phenolic compounds in beet sugar molasses was carried out by paper chromatography. Some of the phenolic compounds were identified with catechol, p-hydroxybenzoic acid, melilotic acid, salicylic acid, syringic acid, vanillin and vanillic acid and three other phenolic compounds were detected though they have not been identified.     

The Role of Leaves in the Perception of Vernalizing Temperatures in Sugar Beet

Annual and biennial sugar beet varieties require long days toinduce flowering but the biennial genotypes additionally requirevernalization. Previous research has suggested that the inabilityof non-vernalized biennial plants to flower can be explainedby a lack of competence of the leaves to respond to long days.In this study defoliation experiments were used to investigatewhich leaves could perceive long daylengths and, in particular,whether leaves initiated from a non-vernalized shoot apicalmeristem could perceive vernalizing temperatures and producea floral stimulus in long days. Annual and vernalized biennialplants flowered if young leaves (i.e. those formed during orafter vernalization) were kept on the plants, but they did notflower if only older expanded leaves (including those expandedprior to vernalization) were present. No evidence was obtainedto indicate that the older leaves contained inhibitors of floweringand it seems most likely that there is a decline in responsivenessto daylength with increasing leaf age. Exposure to vernalizingtemperatures accelerated flowering of the annual and was essentialfor flowering of the biennial. The presence of a single leafinitiated, but not expanded, prior to the transfer of biennialplants to vernalizing temperatures was sufficient to induceflowering. This indicates that expanding leaves do not needto be initiated from a vernalized apical meristem to becomecompetent to produce a floral stimulus in long days. Key words: Beta vulgaris L., sugar beet, vernalization, flowering     

Alkali Cation/Sucrose Co-transport in the Root Sink of Sugar Beet

The mechanism of sucrose transport into the vacuole of root parenchyma cells of sugar beet was investigated using discs of intact tissue. Active sucrose uptake was evident only at the tonoplast. Sucrose caused a transient 8.3 millivolts depolarization of the membrane potential, suggesting an ion co-transport mechanism. Sucrose also stimulated net proton efflux. Active (net) uptake of sucrose was strongly affected by factors that influence the alkali cation and proton gradients across biological membranes. Alkali cations (Na⁺ and K⁺) at 95 millimolar activity stimulated active uptake of sucrose 2.1- to 4-fold, whereas membrane-permeating anions inhibited active sucrose uptake. The pH optima for uptake was between 6.5 and 7.0, pH values slightly higher than those of the vacuole. The ionophores valinomycin, gramicidin D, and carbonyl cyanide m-chlorophenylhydrazone at 10 micromolar concentrations strongly inhibited active sucrose uptake. These data are consistent with the hypothesis that an alkali cation influx/proton efflux reaction is coupled to the active uptake of sucrose into the vacuole of parenchyma cells in the root sink of sugar beets.     

Sucrose Leakage from Isolated Parenchyma of Sugar Beet Roots

The kinetics of sugar efflux from slices of sugar beet rootswas investigated using washing solutions of different osmoticpressure and calcium concentration. The leakage of sucrose isstrongly reduced in solutions of high osmotic pressure (>0·8MPa) or high calcium concentration (10 mM). Turgor-dependentnecrosis of parenchyma cells (plasmoptysis) is the main causeof sucrose efflux from the tissue in hypotonic media with lowcalcium activity. This was shown by good correlation betweenthe percentage of leaked sucrose and the percentage of tissuewater, which was in the free space after the washing procedure.The kinetics of sugar leakage from beet root parenchyma is nobasis for the estimation of the sugar contents of the free spaceor the cytoplasm in situ.