Effects of beet cryptic virus infection on sugar beet in field trials

The effects of beet cryptic virus (BCV) infection on sugar beet crops were investigated in field trials in 1990. Two sugar beet breeding stock lines were screened for infection by BCV. Seed lots containing different proportions of seed infected with BCV1 & 2 were obtained by crossing the stock lines and used in field trials at five different sites. Five characteristics of the infected plants were assessed. BCV infection appeared to have no significant effects on the sugar beet crop at four locations which suffered from drought stress but significant effects were found at one site where the crop was grown on grade 1 land with good moisture retention properties. Root yield and sugar yield were reduced by up to 17% and 20%, respectively, by BCV infection.     

Different CMS sources found in Beta vulgaris ssp maritima: mitochondrial variability in wild populations revealed by a rapid screening procedure

Summary Mitochondrial DNA (mtDNA) variation in natural Beta maritima populations has been characterized by way of Southern blot hybridizations of total DNA using non-radioactive probes and chemiluminescent detection. It was found that the previously described N (normal) mitochondrial type could be subdivided into three subtypes. A new mitochondrial genotype (type R) was distinguished in addition to the previously described type S. Both are male-sterile cytoplasms and can produce a. segregation of sexual phenotypes in their progenies depending on the nuclear background. The populations contained at least two to four different mitochondrial genotypes.     

The effects of yellowing viruses on yield of sugar beet in field trials, 1985 and 1987

The separate effects of beet yellows virus (BYV) and beet mild yellowing virus (BMYV) on yield of sugar-beet cultivars inoculated at different growth stages were assessed in field trials in 1985 and 1987. Early or mid-season inoculation decreased sugar yield by up to 47% for BYV, and up to 29% for BMYV. Infections after the end of July had no significant effect on yield. Both viruses caused significant increases in the juice impurities sodium, potassium and amino-nitrogen after infecting plants early in the season. Yield losses associated with infection were determined by the causative virus, the time of infection, and susceptibility of the sugar-beet cultivars.     

The influence of size and duration of aphid infestation on host plant quality, and its effect on sugar beet yellowing virus epidemiology

This paper studies the influence of previous infestation on the host quality of sugar beet (Beta vulgaris L.) for aphids and the influence of previous infestation on sugar beet yellowing virus epidemiology. Sugar beet previously infested with Myzus persicae (Sulzer) or Aphis fabae Scopoli (Homoptera: Aphididae) had an improved host quality for subsequently infesting aphids of the same species. There was a significant negative relationship between the number of M. persicae infesting a plant and the proportion of those that died with a dark deposit in their stomachs, and a significant positive relationship between the number that settled on a plant and the number that infested it previously. Nymphs feeding on previously infested plants grew more rapidly than those on control plants. The beneficial effect of previous infestation persisted for at least 2 weeks and prolongation of the infestation beyond 2 weeks was of no further benefit to the aphids. Field grown sugar beet, previously colonised by M. persicae, was more susceptible to natural infestation by M. persicae up to 5 days after exposure. Previously infested plants were also more susceptible to infection with beet mild yellowing virus (BMYV) but not beet yellows virus (BYV), suggesting that the aphids on the previously infested sugar beet settled more readily and were more inclined to feed (and thus transmit BMYV) than aphids on the previously uninfested plants. The consequences for the control of sugar beet yellowing virus vectors are discussed.     

Development of simple sequence repeat (SSR) markers for the assessment of gene flow between sea beet (Beta vulgaris ssp. maritima) populations

Molecular markers can be used to estimate gene flow indirectly by monitoring the relative frequency of alleles in adjacent populations. Sea beet (Beta vulgaris ssp. maritima) is a wild plant species found along the coastlines of many European countries and is closely related to cultivated beets. A set of six simple sequence repeat (SSR) markers that are polymorphic in UK populations have been developed for sea beet to assess the problems of indirect measurement of gene flow in these populations.     

Backcrossing of nematode-resistant sugar beet: a second nematode resistance gene at the locus containing Hs1pro-1?

Beet cyst nematode-resistant sugar beet plants, containing the Hs1^pro-1 locus from Beta procumbens, show a female transmission frequency of the resistance of ca. 90%. Such plants often suffer from tumour formation on leaves and root systems, and from the occurrence of a so-called multi-top phenotype. With the aim of obtaining resistant sugar beet material lacking these negative traits, nematode-resistant plants with a reduced size of the chromosome segment of the wild beet that carries the Hs1^pro-1 gene were selected from backcrosses between the resistant stocks B883 or AN1-65-2 and susceptible sugar beet (Beta vulgaris). Analysis of such plants, referred to as Sat-minus plants, showed that the transmission frequency of the resistance to subsequent generations had dropped dramatically to ca. 0.5%. The multi-top phenotype was still present in the newly selected material, indicating that improvement of the resistant sugar beet material by further backcrossing will be hard to achieve. Two of the selected resistant offspring plants were analysed at the molecular level. With the aid of AFLP markers it was found that the size of the alien chromosome segment had decreased to 35% and 17% of the original size, respectively. Surprisingly, both plants had lost the Hs1^pro-1 nematode resistance gene that recently was isolated from the original introgression material. This shows that more than one gene conferring resistance must be present in the locus in B883 and AN1-65-2 carrying the resistance gene Hs1^pro-1.     

The effect of beet cyst nematode, Heterodera schachtii, on the yield of sugar beet in organic soils

In ten experiments on commercial sugar-beet crops grown on organic soils in 1984–86, a Genstat programme was used to examine the relationship between the initial population of Heterodera schachtii and sugar-beet root yield using the equation
Y = Ymin + (Ymax - Ymin) Z^pi-T
Fixing T = 200 eggs + juveniles 100 g^-1 soil and Z^T= 0.95, estimated values of Ymax varied from 49.2–67.1 t ha^-1 (129– 155% of the national average root yield for the years in which the experiments were carried out) and estimates of Ymin varied from 14.5–53.9 t ha^-1 (27–94% of Ymax). The estimated average root yield loss caused by the nematode was 6.95 t ha^-1.     

稀土元素对甜菜种子萌发,幼苗生长及块根产量的影响

本文研究了稀土元素对甜菜的生物效应。结果表明,稀土元素可显著地提高种子萌发率,促进幼苗生长,增加幼苗根系活力、叶片净光合速率与块根产量,并明显地降低了甜菜叶片细胞膜在低温下的透性,即提高了叶片的抗寒力。     

Some preliminary results on the action of rhamnogalacturonase on rhamnogalacturonan oligosaccharides from beet pulp

Sugar-beet pulp was saponified and then hydrolysed with 0.1 M HCI at 80°C for 72 h, and a rhamnogalacturonan fraction was isolated by ion-exchange chromatography on AG 1X8 resin. Four individual oligomers, and a mixture of oligomers with higher degrees of polymerization, were obtained by chromatography on BioGel P-4. They all presented the -d-GalAp-(1 [→2)--l-Rhap-(1 → 4)--d-GalAp-(1]_n→2)-l-Rhap structure (with n 2) The five fractions were submitted to hydrolysis with rhamnogalacturonase. The enzyme was active on oligomers with degrees of polymerization f10, and gave as main products -l-Rhap-(1 → 4)--d-GalAp-(1 → 2)--l-Rhap(1 → 4)-d-GalAp and -d-GalAp-(1 → 2)--l- Rhap- (1 → 4) --d- GalAp- (1 → 2) --l-Rhap-(1 → 4)-d-GalAp.     

Observations on Fertilization in Sugar Beet

The whole process of double fertilization in sugar beet has been observed, the main results are as follows: About 2 hours after pollination, the pollen grains germinate, the sperms in the pollen tube are long-oval. 15 hours after pollination, the pollen tube destroys a synergid and releases two sperms on one side or at the chalazal end of the egg cell. The sperms are spherical each having a cytoplasmic sheath. 17 hours after pollination, one sperm enters the egg cell, and the sperm nucleus fuses with the egg nucleus rapidly. 21 hours after pollination, the zygote is formed. In the meantime, the primary endosperm nucleus has divided into two free endosperm nuclei. 25 hours after pollination, the zygote begins to divide, forming a two-celled proembryo. The dormancy stage of the zygote is about 4 hours. In the meantime the endosperm is at the stage of four free nuclei. 17 hours after pollination, the sperm nucleus comes into contact and fuses with the secondary nucleus. The sperm nucleus fuses with the secondary nucleus, faster than the sperm with the egg. he first division of the primary endosperm nucleus is earlier than that of the zygote, it takes place about 20 hours after pollination, the dormancy stage of the primary endosperm is about 2 hours. The endosperm is free nuclear. The fertilization of sugar beet belongs to premitotic type of syngamy. From the stage of zygote to the two-celled proembryo, it can be seen that addition- al sperms enter the embryo sac, but polyspermy has not been observed yet.     

De novo genome assembly of Cercospora beticola for microsatellite marker development and validation

Cercospora leaf spot caused by Cercospora beticola is a significant threat to the production of sugar and table beet worldwide. A de novo genome assembly of C. beticola was used to develop eight polymorphic and reproducible microsatellite markers for population genetic analyses. These markers were used, along with five previously described microsatellite loci to genotype two C. beticola populations from table beet fields in New York, USA. High allelic and genotypic diversity and low population differentiation were found between fields. Linkage disequilibrium of loci after clone-correction of datasets was attributed to the presence of two distinct clonal lineages within the populations. Linkage equilibrium of loci in one of the clusters supported the presence of sexual reproduction. The draft de novo genome assembly will help elucidate the reproductive system of C. beticola through investigating evidence of recombination in the C. beticola genome.     

Comparaison des teneurs en saccharose et en nucléotides riches en énergie des graines en germination d'une betterave sucrière et d'une betterave fourragère

Comparison of a sugar beet with a forage beet variety shows that, during germination, the seedlings have the same nucleoside triphosphate content, but those of sugar beet contain more sucrose and less UDPG than those of forage beet.     

Bacterial Microflora on Disinfected Sugar Beet Seeds

Sugar beet seeds disinfected with the carbofuran-containing insecticide adifur and the fungicide tachygaren by seed-producing firms were found to be abundantly populated with bacterial microflora. The bacteria isolated from the seed surface were identified to a species level. The selection of bacteria with respect to pesticide resistance may lead to the obtaining of agronomically useful bacterial strains.     

Economic consequences for UK farmers of growing GM herbicide tolerant sugar beet

Weed control is important and one of the more expensive inputs to sugar beet production. The introduction of genetically modified herbicide tolerant (GMHT) sugar beet would result in a major saving in weed control costs in the crop for growers, including control of problem weeds such as perennial weeds and weed beet. However, there would be other economic consequences of growing GMHT beet, some of which would manifest themselves in other parts of the rotation, such as the previous crop, the cereal stubbles that proceed most beet crops, soil tillage and spray application. The average national saving for UK sugar beet growers if they could use the technology would be in excess of £150 ha^?1 yr^?1 or £23 million yr^?1, which includes reductions in agrochemical use of c. £80 ha,^?1 yr^?1 or £12 million yr^?1. However, for some growers, the gains would be much larger and for a few, less than these figures. The possible cost savings are sufficiently large that they could ensure that sugar beet production, with its regionally important environmental benefits as a spring crop, remains economically viable in the UK post reform of the EU sugar regime.     

植物内生菌在生物防治中的应用

从植物内生菌的抗病虫机理及生防作用方面综述了植物内生菌在生物防治中的研究进展,对植物内生菌的抗病虫机理进行了探讨,并展望了植物内生菌在植物保护中的应用前景.     

甜菜纤维的制备及其性质

甜菜纤维的制备及其性质樊志和周人纲王占武李晓芝韩炜（河北省农林科学院农业物理生理生化研究所,石家庄０５００５１）Ａｐｒａｃｔｉｃａｌｐｒｅｐａｒａｔｉｏｎａｎｄｃｈａｒａｃｔｅｒｉｚａｔｉｏｎｏｆｄｉｅｔａｒｙｆｉｂｅｒｆｒｏｍｓｕｇａｒ┐ｂｅｅｔｐ...     

Antagonistic potential of certain legumes to Meloidgyne incognita on sugar beet

Under greenhouse conditions, a pot experiment was conducted to clarify the potential of using some legumes as intercropped plants for reducing the root-knot nematode Meloidogyne incognita infecting sugar beet (Beta vulgaris L.) cv. DS-9004 compared to non-legume plant, garlic and non-intercropped plants. The obtained results revealed that all legumes including chickpea, Egyptian clover, faba bean, fenugreek, lentil and lupin significantly (p ≤ 0.05) reduced nematode criteria on the roots of sugar beet at different degrees. Chickpea and Egyptian clover reduced the number of galls on the roots of sugar beet as the percentage of reductions were 54 and 50%, respectively, followed by lupin and fenugreek, while garlic achieved 72% reduction compared to non-intercropped plants. Lupin reduced the number of egg masses by 59% followed by Egyptian clover and fenugreek (32%), three months after the treatment. On the other hand, six months after the treatment, chickpea reduced the number of galls by 55.7% followed by lupin (53.4%) and Egyptian clover (52.3%) and the percentage of reduction of egg masses behaved the same trend. Also, the treatments improved plant growth criteria of sugar beet, weight of roots (tubers) and the percentage of total soluble solids (TSS).     

Beet luteovirus coat protein sequence variation

The sequences of cDNA clones covering the coat protein genes of 29 isolates of beet mild yellowing virus from sugar beet and beet western yellows virus mainly from oilseed rape were compared. The sequences could be partitioned into seven distinct clusters falling into three main groups. Group 1 isolates were found both in oilseed rape and sugar beet mainly from north Europe; group 2 isolates were from hosts other than sugar beet in England and France; group 3 isolates were beet-specific and found from northern Italy and Iran. The factors affecting this variation and its significance in relation to coat protein-mediated protection are discussed.     

Les α-galactosides du saccharose au cours de la germination des graines de betteraves sucrières et fourragères

During the first three hours of beet seed germination, sucrose α-galactosides briefly appear while sucrose and UDPGal contents decrease. The ¹⁴C-sucrose penetration into 12-hour-old embryos is followed by a partial eclipse of this compound and its replacement by sucrose α-galactosides. These two processes are more important in sugar than in forage beet. The significance of these results in sugar metabolism is discussed.