Helicotylenchus vulgaris and its association with damage to sugar beet

Severe and irregular stunting of sugar beet has been associated with Helicotylenchus vulgaris but little is known of the pathogenicity of this nematode. A survey was made at 10 sites in East Anglia on calcareous soils (Wantage series) on which the original damage was reported. Numbers were usually maintained under a variety of crops, despite fluctuations during the period. In field trials, aldicarb treatment did not improve the yield of either sugar beet or winter wheat on land infested with H. vulgaris. In pot tests growth of sugar beet was stimulated by low nematode inocula; this effect diminished as numbers inoculated increased. Sugar beet grown at 10 °C and 15 °C with H. vulgaris grew markedly better in sterilised soil than in untreated field soil, especially at the higher temperature early in the experiment. It is concluded that though H. vulgaris may damage sugar beet it requires an atypical combination of external conditions to cause significant yield loss.     

Adaptability to drought in sugar beet cultivars

The effects of NaCl and polyethylene glycol (PEG) on superoxide dismutase (SOD) and peroxidase (P) activities, lipid peroxidation (LP) and proline content in seeds and leaves of drought tolerant (FC-506 and MS-100) and drought sensitive (MS-612 and MS-13) sugar beet cultivars were examined. After PEG and NaCl treatment in tolerant cultivars both in seeds and leaves SOD activity mainly increased, though P activity increased only in leaves of tolerant cultivars. In drought sensitive cultivars the decrease of SOD and P activity was mostly observed. LP increased in seeds and leaves of all examined cultivars. The proline content increased in the leaves of examined cultivars and was significantly higher in drought tolerant plants. On the other hand, in the seeds only slight increase in proline content was found. The results obtained indicated that drought tolerance could be correlated with high proline content and enzymatic defense against lipid peroxidation.     

Variation in annual and regional damage to sugar beet by pygmy beetle (Atomaria linearis)

SUMMARY
The reported amount of damage done by pygmy beetle to the sugar-beet crop varies greatly with year and with region. Annual variation in damage is most strongly correlated with soil temperatures of the previous August, implying improved breeding success in warm summers. The value of predicting damage using this relationship is discussed. Damage is most severe in areas of intensive beet growing, particularly on low-lying areas around The Wash.
There was no relationship between damage and the numbers caught in a 12.2 m suction trap in the spring. It is suggested that much of the damage is done by beetles which are present in the beet fields at or shortly after sowing, having arrived there before the great majority fly in May-July.     

Phenotypic polymorphism and allele differentiation of isozymes in fodder beet,multigerm sugar beet and monogerm sugar beet

Summary Thirteen enzymes (MDH, SDH, LAP, PGM, PX, IDH, GPI, 6PGD, APH, GOT, GDH, ME and SOD) of 3 cultivated beet (B. vulgaris L.) gene pools, comprising 12 accessions of fodder beet, 11 of old multigerm sugar beet and 10 of modern monogerm sugar beet, were investigated using horizontal starch gel electrophoresis. Eleven accessions of primitive or wild B. vulgaris were also included for the comparison of isozymes. Variation in isozyme phenotypes was investigated to detect diversity in the three cultivated forms of beet. Phenotypic variation was observed in all except ME and SOD, which were monomorphic. A high degree of phenotypic polymorphism (Pj) was found in GDH, PGM, IDH, APH and MDH. Differences in phenotypic polymorphism in MDH, GPI and PX were recognized between fodder beet and both sugar beet groups. Average polymorphism for 13 enzymes in both sugar beets was significantly higher than that in fodder beet. For 13 enzymes, the existence of high isozyme diversity in both sugar beet gene pools was revealed. Allele frequencies in 13 alleles of five enzyme-coding loci, Lap, Px-1, Aph-1, Got-2 and Gdh-2, were investigated. New alleles, Px-1 ¹ and Got-2 ¹, were found in fodder beet accessions. No significant differences of average allele frequencies of five loci between fodder beet and both sugar beets were recognized. Several unique alleles and different isozyme phenotypes were observed in the accessions of B. vulgaris ssp. macrocarpa and ssp. adanensis. Future utilization of cultivated beet gene pools for sugar beet breeding is discussed from the viewpoint of genetic resources.     

Continuous anaerobic conversion of sugar beet pulp to biogas

Summary A continuous two step anaerobic digestion of sugar beet pulp as carbon and energy source was carried out. The loading rates in the acidification reactor were varied from 5 g·1^–1·d^–1 to 15 g·1^–1·d^–1 while the hydraulic retention time was in the range of 10 hours to 30 hours; the corresponding values for the methane reactor varied from 2 days to nearly 6 days.With this reactor configuration a biogas yield of more than 85% of the theoretical value for total carbon conversion was achieved resulting in a corresponding COD reduction.     

Comparative effectiveness of sugar beet microsatellite markers isolated from genomic libraries and GenBank ESTs to map the sugar beet genome

Sugar beet (Beta vulgaris) is an important root crop for sucrose production. A study was conducted to find a new abundant source of microsatellite (SSR) markers in order to develop marker assistance for breeding. Different sources of existing microsatellites were used and new ones were developed to compare their efficiency to reveal diversity in mapping population and mapping coverage. Forty-one microsatellite markers were isolated from a B. vulgaris ssp maritima genomic library and 201 SSRs were extracted from a B. vulgaris ssp vulgaris library. Data mining was applied on GenBank B. vulgaris expressed sequence tags (ESTs), 803 EST-SSRs were identified over 19,709 ESTs. Characteristics, polymorphism and cross-species transferability of these microsatellites were compared. Based on these markers, a high density genetic map was constructed using 92 F₂ individuals from a cross between a sugar and a table beet. The map contains 284 markers, spans over 555 cM and covers the nine chromosomes of the species with an average markers density of one marker every 2.2 cM. A set of markers for assignation to the nine chromosomes of sugar beet is provided.     

Mapping sugar beet pectin acetylation pattern

Homogalacturonan-derived partly methylated and/or acetylated oligogalacturonates were recovered after enzymatic hydrolysis (endo-polygalacturonase+pectin methyl esterase+side-chain degrading enzymes) of sugar beet pectin followed by anion-exchange and size exclusion chromatography. Around 90% of the GalA and 75% of the acetyl groups present in the initial sugar beet pectin were recovered as homogalacturonan-derived oligogalacturonates, the remaining GalA and acetyl belonging to rhamnogalacturonic regions. Around 50% of the acetyl groups present in sugar beet homogalacturonans were recovered as partly methylated and/or acetylated oligogalacturonates of degree of polymerisation 5 whose structures were determined by electrospray ionization ion trap mass spectrometry (ESI-IT-MSn). 2-O-acetyl- and 3-O-acetyl-GalA were detected in roughly similar amounts but 2,3-di-O-acetylation was absent. Methyl-esterified GalA residues occurred mainly upstream 2-O-acetyl GalA. Oligogalacturonates containing GalA residues that are at once methyl- and acetyl-esterified were recovered in very limited amounts. A tentative mapping of the distribution of acetyl and methyl esters within sugar beet homogalacturonans is proposed. Unsubstituted GalA residues are likely to be present in limited amounts (approximately 10% of total GalA residues), due to the fact that methyl and acetyl groups are assumed to be most often not carried by the same residues.     

Enzymic saccharification of sugar beet pulp

Culture filtrates of Talaromyces emersonii UCG 208 grown on beet pulp can convert the polysaccharide components of this agricultural waste to soluble sugars. The saccharification process is facilitated if the pulp is milled or incubated with alkali or peracetic acid before addition of enzyme. However, treatment of unmilled pulp with commercial pectinase prior to incubation with Talaromyces filtrate is also very effective; under suitable conditions, complete hydrolysis of total polysaccharides has been achieved.     

Anaerobic digestion of sugar beet pulps

Summary Anaerobic digestion of sugar beet pulps was studied in a 70 l digestor with sequential feeding, after enzymatic hydrolysis by Trichoderma harzianum cellulases. During the 130 days feeding, 3.6 m³ of biogas were produced with an average content of 58% CH₄ from 270 l of hydrolysed pulps at 20 g VS/l. Average yield and production rate were respectively 0.67 m³/kg VS and 0.4 m³/ kg VS and 0.4 m³/m³ of digestor per day.     

Volatile components of sugar beet leaves

Extracts of both young and old sugar beet plants were obtained using a modified Likens and Nickerson apparatus. Constituents were identified by GC/MS, and using selected ion monitoring it was shown that the previously determined phenylacetonitrile was probably not of glucosinolate origin. Some unsaturated aldehydes, alcohols and derivatives (enzymic lipid degradation products) were formed to greater extents by the younger leaves, but otherwise such quantitative differences were relatively few and generally random. An interesting range of chlorinated compounds was obtained only from the older plants; a pesticide origin is suggested.     

Enzymatic hydrolysis of sugar beet pulp

Summary In order to prepare fermentable sugars from cellulosic raw materials, we have tested the effect of different pretreatments (heat, chemicals, pectinase) on enzymatic hydrolysis of sugar beet pulp. Best results (90% hydrolysis) have been obtained after heat treatment (30 mn at 120°C) with 16 IU.Fp.g^–1 of fresh pulp in 48 hours.     

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.     

Competitiveness of transgenic sugar beet resistant to beet necrotic yellow vein virus and potential impact on wild beet populations

Beets are a crop of particular concern regarding invasiveness questions because they commonly become feral due to unintentional hybridization with annual forms of wild beets. In this study the performance of transgenic beets resistant to Beet Necrotic Yellow Vein Virus (BNYVV) was compared to the performance of unmodified material from the same breeding line. Both transgenic and control genotypes were also compared to a conventionally bred variety carrying a similar phenotypic trait. Field tests were developed in a step by step fashion in order to study seed emergence and competitiveness in early life stages. The tests quantified the potential ecological advantage of virus resistance under virus and non-virus infestation conditions. In experimental field releases in 1993 and 1994 in Germany, a small but increasingly clear 'additive' ecological advantage of the genetically engineered trait was detected. In both years and all competition treatments, the conventional tolerant variety performed best. An impact of naturalization on natural, nonagricultural habitats may appear in wild beet populations in Italian seed beet production areas. However, a survey of coastal areas of North-Eastern Italy found no virus infestation in 1994, suggesting that an increase in wild beet fitness is unlikely to occur.     

Anaerobic biodegradation of sugar beet pulp

Sugar beet pulp is a by-product of sugar production and consists mainly of cellulose, hemicellulose and pectin. Its composition is suitable for biological degradation. A possible alternative for the utilization of this material (besides cattle feeding) can be anaerobic methanogenic degradation. It has an additional advantage – biogas production. Beet pulp was treated by a two-step anaerobic process. The first step consisted of hydrolysis andacidification. The second step was methanogenesis. In this paper, observation ofthe process of anaerobic degradation and determination of optimal parameters is discussed. A laboratory-scale model for sugar beet pulp anaerobic biodegradation was operated. Results of model performance have shown very good pulp digestion characteristics. In addition, high efficiency removal of organic matter was achieved. Methane yield was over 0.360 m³ kg^-1 dried pulp and excess sludge production was 0.094 g per gram COD added.     

Experiments with fungicides to control Aphanomyces cochlioides in sugar beet

Aphanomyces cochlioides attacking sugar-beet seedlings was controlled by fenaminosulf applied as seed treatment or to the seed furrow at sowing. In the absence of blackleg caused by A. cochlioides, fenaminosulf seed treatment at 0–75 % (of seed weight) and soil applications decreased seedling emergence, and soil applications of more than 2-2 kg a.i./ha significantly depressed sugar yield. Controlling moderate attacks of seedling blackleg caused by A. cochlioides did not increase yield. Dichlone, benomyl and maneb applied as seed or soil treatments, captafol seed treatment, and quintozene and thiram soil treatments did not control A. cochlioides.