Beta Procumbens Research Articles

Association of a nematode resistance bearing addition chromosome with a recurring leaf intumescence somaclonal variation in sugar beet

Intumescent leaf variants of sugar beet (Beta vulgaris L.) were obtained through callus culture of a monosomic addition that carried resistance to Heterodera schachtii Schm. The frothy pockmarked appearance of the leaf surface was due to hyperplastic growth of the mesophyll and epidermal cells. The epidermis had many malformed stomata. Veins were underdeveloped, but protrusions beneath were pronounced. Intumescence occurred in 20.3% of the regenerated plants and it was heritable to F1 and later progeny. Leaf intumescence is a new phenotype for Beta. About 73.5% of regenerants contained the donor somatic chromosome number, the remainder were doubled or mixoploids, with no chromosome losses apparent. The 38-chromosome intumescent plant represents a dual somaclonal variation, chromosome doubling and leaf intumescence. Progeny of the 19- and 38-chromosome intumescent plants intercrossed or pollinated by diploids or tetraploids had 9, 18, 19, 27, 28, 29, 36, 37, 38, or 39 chromosomes. All intumescent plants were aneuploids with the monosome addition. There were linkages for leaf intumescence (Li), resistance to H. schachtii (Hs), and hypocotyl color (Rpro) on the addition chromosome. The efficacy of Hs remained intact through the in vitro culture and succeeding crosses. The Li-bearing plants manifested depressed growth and markedly reduced seed set. Leaf intumescence was thought to be the alternative expression of galling potential of Beta procumbens Chr. Sm. germ plasm.Key words: somaclonal variation, leaf intumescence, nematode resistance, monosomic addition, Beta vulgaris L.

Assessment of the degree of genetic variation in beet based on RFLP analysis and the taxonomy of Beta

Clones derived from Beta vulgaris and Beta maritima were assayed for their ability to detect restriction fragment length polymorphisms (RFLPs) in different beet accessions. The clones able to detect polymorphism were used as genetic markers to assess the degree of genetic variation existing between and within different species of the genus Beta. The data support the current taxonomy of the Beta vulgaris section, while the great genetic similarity found between Beta webbiana and Beta procumbens indicates that they could belong to the same species.

Symptomatological and Morphological Study of the Resistance of Wild Beet Species of the Patellares Section to Cercospora beticola Sacc.

AbstractThe reactions of Beta procumbens C. Sm. and Beta webbiana Moq. were compared to those of Beta vulgaris L. with regard to an infection by Cercospora beticola Sacc. The fleck reaction obsrved in B. webbiana may be interpreted as hypersensitivity based on symptomatological, light microscopical, fluorescent microscopical and electron microscopical data. The B. procumbens clone was found to show resistance characteristics similar to those of B. webbiana and B. vulgaris, as it reacted both by flecks (B. webbiana) and leaf spots (B. vulgaris) to a C. beticola infection.

Analysis of DNA from a Beta procumbens chromosome fragment in sugar beet carrying a gene for nematode resistance

We have begun to apply techniques for the preparation and anaylsis of large DNA segments from sugar beet (Beta vulgaris) addition lines carrying a mitotically stable chromosome fragment from B. procumbens that confers monogenic resistance to the nematode Heterodera schachtii, with a view towards isolating the resistance gene. DNA probes specific for this chromosome fragment were selected, and various methods for cloning genome-specific fragments, including probes from megabase DNA separated in pulsed-field slab gels, are compared. Probes that display high homology to B. procumbens have been used for hybridization of a representative genomic library and for initial step in mapping the chromosome fragment via pulsed-field gel electrophoresis after restriction with infrequently cutting enzymes. Our data indicate that DNA molecules from the entire chomosome fragment can be separated from protoplast DNA lysates.

Are Beta procumbens Chr. Sm. and Beta webbiana Moq. Different Species?

AbstractDifferent Origins of Beta procumbens and B. webbiana, which are wild species of the section Procumbentes, were investigated by means of electrophoretical techniques. The isozyme patterns did not show any differences between the two species. Assignment of accessions to either one of the two species was not possible using the differences occurring in the banding patterns of some enzyme systems. One can raise the question, therefore if the classification of B. procumbens and B. Webbiana into two species is justified.

Investigation into chromosomal stability of in-vitro growing cells from a transformed monosomic addition plant of beet

Crown galls were obtained from a monosomic addition plant of beet, carrying an extra chromosome of Beta procumbens, after transformation with a wild-type Agrobacterium tumefaciens strain. Analysis of peroxidase and esterase patterns obtained after cellulose acetate gel electrophoresis and iso-electric focusing respectively, gave evidence that no preferential loss of the alien chromosome on repeated subculture in-vitro from the crown galls occurred.

Monosomic additions in beet (Beta vulgaris) carrying extra chromosomes of Beta procumbens

Eleven isozyme systems were used to identify the extra chromosomes, originating from Beta procumbens, in progenies of 33 monosomic additions in beet (B. vulgaris). Nine groups of monosomic additions could be distinguished, representing the nine different chromosome types of B. procumbens.

Sugar beets homozygous for resistance to beet cyst nematode (Heterodera schachtii Schm.), developed from monosomic additions of Beta procumbens to B. vulgaris

Monosomic additions of Beta vulgaris x B. procumbens with resistance to beet cyst nematode (Heterodera schachtii Schm.) were used for the production of resistant diploids through incorporation of the B. procumbens chromosome fragment bearing the resistance gene(s) into one of the sugar beet chromosomes. The heterozygotes obtained accordingly were selfed for producing homozygotes. These homozygotes differed morphologically from commercial sugar beet varieties, but produced reasonable amounts of pollen. Female transmission of resistance was 100%, whereas male transmission, apart from some exceptions, was more than 90%. The number of hypersensitivity reactions to penetrated larvae was related to the degree of susceptibility. Larval development was severely retarded in the resistant plants, preventing most of them to produce cysts. If cysts were formed, their content was considerably less as compared to those in the susceptible plants.

Alien chromosome fragments conditioning resistance to beet cyst nematode in diploid descendants from monosomic additions of Beta procumbens to B. vulgaris

A monosomic addition plant of Beta vulgaris, containing an extra chromosome of B. procumbens with a gene for resistance to the beet cyst nematode, gave rise to a diploid descendant with an additional chromosome fragment. This fragment was found to bear the gene for resistance. A study of its morphology and behaviour made it likely that it represents the short arm of the alien chromosome and may have originated by centric fission of the single addition chromosome at anaphase I or II. The fragment showed incomplete generative transmission. In part of the somatic cells the fragment was missing and occasionally more than one fragment per cell was observed. The transmission of resistance in the telosome addition material was about 10%, which is 2.5 times lower than that of the monosomic addition. The pattern of transmission can be explained by an incomplete centromere, otherwise disturbed centric activity, or chromatid cohesiveness. Comparison with other monosomic addition plants showed that the resistance gene is located on the short arm of the satellite chromosome of B. procumbens and thus is linked to the nucleoar organizer region. The long arm of this chromosome possesses genes influencing annuality and leaf shape.Key words: Beta vulgaris, Beta procumbens, beet cyst nematode, monosomic addition, centric chromosome fragment.

Invasion of non-host plant roots by larvae of the sugarbeet nematode, Heterodera schachtii

A study by Steele (8) showed that females of the sugarbeet nematode (Heterodera schachtii Schmidt 1871) developed to maturity and reproduced on 73 plant species . Of 17 species given an infection index rating of less than 1.0, only one or two fe­ males were observed on individual plants of these species . Reports indicate that larvae of the sugarbeet nematode in­ vade but do not develop to maturity in roots of Phaseolus vulgaTis L. (navy bean), Lactuca sativa L. (lettuce), HespeTis matTonalis L., Beta procumbens CHRSmidt., B. pate llaTis Moq. and B. webbiana Moq., (1 ,2,3) . However, Steele and Savitsky later reported that single females developed on two plants of B. pa­ tellaTis (7). These findings suggest that many other non-host plants may be invaded by sugarbeet nematode larvae. To test this hypothesis, several non-host plants were selected at random and tested to determine which , if any, were invaded by sugar­ beet nematode larvae.

Resistance of sugar beet to the cyst‐nematode Heterodera schachtii Schm.

SUMMARYLines exhibiting heritable resistance and susceptibility to beet cyst nematode were selected from a heterogeneous cultivated variety of beet but no major gene resistance was detected although many hundreds of lines of wild and cultivated varieties were tested. Recurrent selection improved the resistance of one line, selected originally for yield and non‐bolting qualities, when progenies in each generation were compared with susceptible controls and with the original ancestral lines. Resistance was inherited by progenies from selections crossed with susceptible plants, but evidence of some reduction in resistance was detectable where fewer eelworms were available to invade from the soil. There was no evidence of heritable cytoplasmic influence on the resistance. Resistance is probably controlled by a polygene system in sugar beet, although immunity in Beta procumbens and B. webbiana and near‐immunity in B. patellaris suggest that in other species of Beta major gene resistance may occur.

A sugarbect X Beta procumbens hybrid and its backcross derivative

A sugarbect X Beta procumbens hybrid and its backcross derivative

The course of the first meiotic prophase in Beta procumbens and in the F1 between B. vulgaris and B. procumbens

The succession of the stages of the first meiotic prophase in Beta procumbens has been ascertained by measurements of the nuclear volume and by other criteria. By this method it has been possible to relate the appearance of pairing gaps to the beginning separation of the chromosomes after pachytene. A zygotene-like stage of early diplotene has been found. Asynchronous condensation of the bivalents and reduction of the chiasma frequency have been observed in diplotene and diakinesis. - The lengths and arm ratios of the pachytene chromosomes of Beta procumbens were determined.Stages similar to those in B. procumbens have been recognized in the F 1 hybrid between Beta vulgaris and Beta procumbens. The pachytene chromosomes appeared to be paired to a great extent. However, only some of the cells showed bivalents in diakinesis, in the majority desynapsis occurred during diplotene or early diakinesis. In metaphase I, bivalents, univalents, cases of secondary association due to stickiness and cases of fragmentation have been observed.

Meiosis in an Fl hybrid between a Turkish wild beet (Beta Vulgaris, ssp. maritima) and Beta procumbens

Meiosis in an Fl hybrid between a Turkish wild beet (Beta Vulgaris, ssp. maritima) and Beta procumbens