Solanum Pimpinellifolium Research Articles

Fusarium oxysporum f.sp. lycopersici . [Descriptions of Fungi and Bacteria

Abstract A description is provided for Fusarium oxysporum f.sp. lycopersici . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Lycopersicon esculentum (tomato), L. pimpinellifolium (red currant tomato) and other species of Lycopersicon . DISEASE: Vascular wilt of tomato. GEOGRAPHICAL DISTRIBUTION: Africa, Asia, N. and S. America, Australasia, Europe, W. Indies and C. America. TRANSMISSION: Soil-borne and seed-borne. Long distance spread by infected seed and transplants. Local dissemination by transplants, wind-borne and water-borne infested soil, surface-drainage water.

Phänotypische Normalisierung der Mutante albina2 von Lycopersicon pimpinellifolium (Jusl.) Mill.

1. The homozygous recessive mutant albina 2 ( ala 2 ) of Lycopersicon pimpinellifolium has white cotyledons and is lethal in the seedlings stage. 2. Grafting of these white seedlings on normal green tomato stocks results in the compensation of the metabolic deficiency in the mutant scion: The grafted mutant becomes able to form a green shoot with typical chloroplast (Fig. 1 and 2). 3. Seeds from normalized green mutant shoots give typical white albina 2 seedlings. 4. Grafting of albina 2 on green stocks thus leads to the occurence of a practically complete phenotypic no rmalization. 5. Reciprocal grafting (green seedlings grafted on mutant stocks) also leads to phenotypic normalization of the side branches formed by the mutant stock. 6. Attempts to achieve normalization of mutant seedlings by various other treatments (organic and anorganic compounds, sterile culture) have been without success. 7. Branches of the normalized mutant scion have been cut off and caused to regenerate roots. These cuttings, which tend to die under usual conditions, are able to normal continuous growth under artificial light of 20 hours per day (Fig. 3). Decisive for the normalization is the length of daily exposure to light, and not the intensity or the quality of light or the temperature. All other treatments of the cuttings did not result in a continuous normalization (Table 1, Fig. 2). 8. The normalized mutant cuttings have an almost normal chlorophyll content (Table 2, 3); however, their rate of photosynthesis is clearly reduced in comparison with the control. 9. The relation between the reduced rate of photosynthesis in normalized leaves and the requirement of a very long daily light period is discussed.

Trehalase: a new pollen enzyme.

Pollen from 5 plant species (Lycopersicon pimpinellifolium Mill., Hermerocallis minor Mill., Galtonia condicans Decne., Camellia japonica L., and Lathyrus odoratus L.) representing 4 families germinated well in media containing trehalose as the sole carbon source. Data are presented indicating that pollen metabolized this disaccharide for germination and subsequent pollen-tube growth; the sugar was not merely an osmoregulator. An inhibitor of trehalase activity depressed germination in trehalose but not in sucrose. Phloridzin dihydrate, an inhibitor of glucose transport, depressed germination in both disaccharides. Biochemical tests demonstrated that a pollen extract was capable of hydrolyzing trehalose to its constituent glucose monomers. Heat inactivation experiments confirmed the presence of a distinct trehalase having a rigid specificity for its substrate. By this method, trehalase activity was completely distinguishable from the activities of other alpha- and beta-glucosidases and beta-galactosidases. Localization data indicated that the enzyme diffused from intact grains and was probably soluble. The presence of its substrate could not be demonstrated in pollen or in stigmatic or stylar tissues.

Incorporação de resistência ao mosaico Y em tomateiro

Sessenta tipos de tomateiros, entre selvagens e cultivados, foram testados por inoculação mecânica quanto à sua resistência a estirpes do vírus Y comuns em tomatais no Estado de São Paulo. Um nível satisfatório de resistência foi encontrado em L. pimpinellifolium NAV 1062 e numa variedade de tomate originária do Peru (P.I. 126410). Cruzamentos e retrocruzamentos entre L. pimpincllifolium NAV 1062 e P.I. 126410 com a variedade Santa Cruz e entre os dois primeiros tipos resistentes entre si indicaram que o caráter, alto nível de resistência ao vírus Y destes, é condicionado pelo mesmo par de gens recessivos. Progenies resultantes do cruzamento Santa Cruz x P. I. 126410 mostraram-se mais promissoras que as do cruzamento Santa Cruz x Lycopersicon pimpinellifolium NAV 1062. Seleções feitas em gerações avançadas do primeiro cruzamento, seguidas ou não de retrocruzamentos, deram origem a três grupos de linhagens que possuem características comerciais comparáveis às da variedade Santa Cruz e incorporam nível satisfatório de resistência a estirpes do grupo Y comuns em tomatais. Uma delas, denominada Angela, está sendo distribuída a lavradores, em caráter semi-experimental.

Biosynthesis of tomatidine from cholesterol in Lycopersicon pimpinellifolium

After administration of cholesterol-4- 14C (I) to the leaves and flowers of growing Lycopersicon pimpinellifolium plants, radioactive tomatidine (II) was isolated. The radiochemical purity of tomatidine was established by chromatography, crystallization, and oxidation to tomatidin-3-one.

Biosynthesis of neotigogenin and Δ 16-5α-pregnen-3β-ol-20-one from cholesterol in Lycopersicon pimpinellifolium

Radioactive neotigogenin and Δ 16-5α-pregnen-3β-ol-20-one were isolated from the flowers of Lycopersicon pimpinellifolium plants which had been treated with cholesterol-4- 14C. Both were purified to constant specific activity by chromatography and recrystallization of the acetates as well as the free sterols. Since radioactive tomatidine had previously been isolated from the same plants, the simultaneous biosynthesis of the structurally analogous steroidal sapogenins and alkaloids from cholesterol has now been demonstrated.

A diallel analysis of solids in tomatoes

A diallel analysis was used to estimate certain genetic parameters for soluble solids in tomatoes. All crosses of small- x small-fruited strains and some small- x large-fruited crosses showed heterosis in the F1 with the means exceeding the top parent. The genetic analysis indicated that epistasis or nonallelic gene interaction was primarily responsible for the heterosis. The experiment also demonstrated the existence of dominant genes for high solids. These genes were shown to have rather large effects. Evidence indicates that genes for high solids were contributed by the wild species Lycopersicon pimpinellifolium. A heritability estimate of .54±.07 was obtained for soluble solids.

Isolierung von nebenalkaloiden und 3β-hydroxy-5α-pregn-16-en-20-on aus Lycopersicon pimpinellifolium mill.

Acid hydrolysis of a crude tomatine preparation from leaves and stems of the wild tomato Lycopersicon pimpinellifolium Mil. yielded, in addition to tomatidine (I), a number of steroidal minor alkaloids. Two of them were shown to be identical with soladulcidine (III) and tomatida-3.5-diene (VI), certainly an artificial product obtained by the acid hydrolysis of naturally occurring tomatid-5-en-3β-ol glycosides. A third substance, representing a new steroidal alkaloid, possesses the empirical formula C 27H 45NO 3. Finally, a nitrogen-free compound also isolated has been identified as 3β-hydroxy-5α-pregn-16-en-20-one (VII), which is most probably a product of the biological degradation of tomatidine.

STUDIES ON THE NATURE OF RESISTANCE IN TOMATO TO CLADOSPORIUM FULVUM COOKE

The sugar and amino acid content of six tomato varieties were compared by paper chromatographic methods. These varieties reacted to race 1 of Cladosporium fulvum Cke. as follows: Potentate, susceptible; V-121 and Stirling Castle, resistant; Vetomold, Vinequeen, and Lycopersicon pimpinellifolium (Jusl.) Mill., immune. Potentate, Vetomold, and V-121 are closely related genetically, the last two having been developed by repeated backcrossing to Potentate of immune and resistant segregates from Potentate × L. pimpinellifolium crosses. The resistance of Stirling Castle is controlled by a gene different from the gene which conditions immunity in Vetomold and one that confers resistance on V-121, while the immunity of Vinequeen stems from L. hirsutum Humb. and Bonpl.Fructose, glucose, and sucrose occurred in all varieties, but, among the three closely related ones, the consistently low level of all three in V-121 and the low fructose in Red Currant were suggestive, while Potentate and Vetomold displayed reciprocal levels of fructose and sucrose. The two resistant varieties differed in sugar content and the three immune ones were not consistent.From four sets of extracts of all six varieties, grown under conditions optimal for disease expression, 15 amino acids were identified. The relative amounts of these differed significantly in different varieties without, however, any general causal relation to resistance being evident. The consistently lower levels of one or more of aspartic acid, serine, and glutamine in V-121 may be significant in limiting the development of the fungus in this resistant variety. The immunity of Vetomold did not seem to be conditioned by the presence or absence of specific amino acids nor did the immunity of Vinequeen. When extracts of this sort were compared with extracts from plants grown under a light experience reduced sufficiently to disturb the host–parasite relations, it was evident that this treatment significantly altered both the sugar and amino acid content of the varieties in characteristic varietal patterns. This may suggest that a suitable C/N ratio is prerequisite to compatibility. The desirability of further studies is indicated.

Inheritance of Spotted Wilt Resistance in the Tomato II. Five Genes Controlling Spotted Wilt Resistance in Four Tomato Types

The four spotted-wilt-resistant tomato types, Lycopersicon pimpinellifolium and L. esculentum varieties Rey de los Tempranos, Pearl Harbour, and Manzana, were each crossed with the susceptible variety Potentate, and also crossed with each other in all possible combinations. The F 1 and F 2 plants, when inoculated with 10 strains of tomato spotted wilt virus, were resistant to five groups of these strains.

APPARENT LOCALIZATION OF FUSARIUM WILT RESISTANCE IN THE PAN AMERICA TOMATO

THE HIGH degree of resistance to the wilt disease caused by Fusarium oxysporum f. lycopersici Snyder and Hansen, in the tomato variety Pan America introduced by Porte and Walker (1941), has been proved by many laboratory and field tests. The near immunity is equal to that of the most resistant lines of Lycopersicon pimpinellifolium (Jusl.) Mill., the wild host which was used as a parent of Pan America. Grafting has been used to study the nature of disease resistance in several plants (Bond, 1936; Leach, 1929; May, 1930; and Schmidt, 1933), but in the experiments dealing with wilt resistance in tomatoes the varieties used as resistant are now recognized as having a much lower degree of resistance than Pan America. In the experiments reported here Bonny Best, a variety long recognized as very susceptible to the tomato wilt fungus, and the resistant Pan America variety were used. L. pimpinellifolium plants were used in one experiment. MATERIALS AND METHODS.-The seeds were planted in flats of one-half composted soil and onehalf sand mixture. After the cotyledons were fully expanded the seedlings were transplanted to 2?/2inch pots. When the plants were about three weeks old they were used for grafting. Two types of grafts were used-stem approach grafts and stem splice grafts. The approach grafts were made by removing a thin section about one inch in length, between the cotyledons and the first leaf, from adjacent sides of the two stems. The cut surfaces were immediately placed against each other and securely wrapped with a rubberized paraffin tape known as Parafilm (fig. 1). The graft components were both left intact until the plants were examined for wilt. The splice grafts were made by severing the two plants with a smooth slant-

ON THE NOMENCLATURE OF THE CURRANT TOMATO, LYCOPERSICUM PIMPINELLIFOLIUM MILL.

Journal Article ON THE NOMENCLATURE OF THE CURRANT TOMATO, LYCOPERSICUM PIMPINELLIFOLIUM MILL Get access T. E. T. Bond, Ph.D. T. E. T. Bond, Ph.D. Search for other works by this author on: Oxford Academic Google Scholar Proceedings Linnean Society London, Volume 150, Issue 3, June 1938, Pages 181–187, https://doi.org/10.1111/j.1095-8312.1938.tb00179.x Published: 09 April 2009

INFECTION EXPERIMENTS WITH CLADOSPORIUM FULVUM COOKE AND RELATED SPECIES

SUMMARY1. Symptoms of infection on resistant and susceptible varieties of tomato (Lycopersicum esculentum Mill.) are briefly indicated, together with a numerical method of recording the progress of infection.2. The histology of infection on tomato varieties is described. Penetration is stomatal and no appressoria or other modifications are formed. The mycelium is intercellular and without haustoria, and develops normally only for so long as the host cells are alive.3. By the use of a controlled environment chamber, the frequency of penetration is shown to be far greater at a humidity fluctuating from saturation to 85 % than at constant saturation. The suggestion is made that penetration is controlled, in part at least, by a hydrotropic stimulus.4. The initial rate of spread of the mycelium within the host, immediately subsequent to penetration, is lower in the variety “Mainerop” than in “Giant Red” and is lower also in the basal region of the plant than in the middle. This behaviour runs parallel with the subsequent differences observed in the external symptoms of infection.5. Normal stomatal penetration occurs over a wide range of immune and “inappropriate” hosts.6. Symptoms of infection have been recorded only in the varieties of L. esculentum, in L. Humboldtii Dun., and in two strains received as L. racemigerum which, appear to be more closely related to the cultivated varieties than, to the true currant tomato.7. Confusion occurs as to the correct nomenclature of the currant tomato. The name Lycopersicum pimpinellifolium Mill, is preferred. L. racemigerum Lange (=Solanum racemigerum) and L. racemiforme Lange are synonyms.8. The extent and distribution of the mycelium in the currant tomato appears to be determined largely by the age and relative maturity of the leaf. The mycelium is intercellular and without haustoria, and can apparently remain alive in the leaf for a considerable period of time. No conidiophores are produced. No reaction of the host cells is observed except where, on account of structural considerations, host and parasite are brought into more immediate contact. Here, individual host cells are frequently necrotic.9. On many other Solanaceae, including species of Solatium, Hyos‐cyamus, Nicotiana, Schizanthus, and other genera, the course of events is essentially similar to that observed on the currant tomato.10. In other Solanaceae, and in plants belonging to the Scrophu‐lariaceae, Compositae, and Cucurbitaceae, an extensive mycelium is never developed, even under apparently favourable conditions.

THE PARASITISM OF CLADOSPORIUM FULVUM COOKE AND THE GENETICS OF RESISTANCE TO IT

Four physiologic forms of the imperfect fungus Cladosporium fulvum Cooke, causal agent of the leaf mold disease of tomatoes, have been differentiated by differences in pathogenicity. Cultural studies likewise have shown that this species is a composite of physiologic forms.Saltant strains of differing degrees of stability have been isolated repeatedly from cultures arising from single one-celled spores. Since each cell of a conidium contains a single nucleus, these saltant strains are considered to arise as a result of mutations, in the broad sense of the term.Four main classes of reaction to C. fulvum have been defined: complete susceptibility, two types of partial resistance, and immunity.The reaction between pure lines of host and parasite is plastic. Environmentally conditioned variations in each of the four reaction types have been described. Of such variations the seasonal fluctuations in the reaction of Lyco-persicum esculentum var. Stirling Castle to Form 1 are outstanding. It has been shown that the failure of the expression of the inherent resistance of this variety during midwinter at Toronto is due largely to the reduced light experience of plants grown at this time, while the failure of such plants to support sporulation is caused by the low relative humidity then prevalent in the greenhouses.The genetics of the three types of resistance was fully analyzed. The Red Currant tomato, L. pimpinellifolium, carries, in addition to the dominant factor for immunity, an independently segregating dominant factor which, in the absence of the immunity factor, governs resistance to all four forms of C. fulvum. The resistance of Stirling Castle to Forms 1 and 3 has been shown to be due to another dominant factor.Conspicuous among the genetic factors in the host which modify the main reaction types is the recessive lutescence factor in the homozygous condition. Its most striking effect is the production, on genetically immune individuals, of small inconspicuous infection spots whose increase in size is arrested very soon after symptoms appear.As a result of linkage studies the three resistance factors have been located in MacArthur's (12) chromosome maps of the tomato.The conflicting reports concerning the resistance of esculentum tomato varieties to C. fulvum are discussed in the light of physiologic specialization and of a plastic host reaction.

PHYTOPHTHORA INFESTANS (MONT.) DEBARY AND CLADOSPORIUM FULVUM COOKE ON VARIETIES OF TOMATO AND POTATO AND ON GRAFTED SOLANACEOUS PLANTS

SUMMARYExperiments are described which are concerned with the possibility of an increase or decrease in susceptibility to pathogenic fungi, induced or transmitted by grafting. Two diseases are investigated, namely, potato blight, caused by Phytophthora infestans (Mont.) dc By., and tomato leaf mould, caused by Cladosporium fulvum Cke.Preliminary inoculation experiments were carried out on eleven large‐fruited varieties of tomato, eight varieties of potato, various small‐fruited tomatoes, and other Solanaceous plants, with the following results: Phytophthora infestans. All the varieties of potato were equally susceptible, but certain varieties only of tomato, viz. Giant Red, Golden Queen. Detached leaves of the currant tomato were also infected. Cladosporium fulvum. Only tomato varieties and certain smail‐fruited tomatoes were susceptible. Giant Red and Golden Queen were particularly susceptible, Stirling Castle and Maincrop were relatively resistant. The currant tomato (Lycopersicum racemigerum Lange or L. pimpinellifolium Dun.) was immune. No support can be given to Schmidt's suggestion that immunity depended on the presence of a substance termed “prohibitin”, capable of inhibiting spore germination. It is suggested that the identity of Schmidt's cultures was mistaken.About fifty grafts were made involving various combinations of resistant and susceptible plants. The grafts were inoculated, in most cases, after new growth had developed from stock and scion. Without exception, the results of these experiments were the same as on the ungrafted material, both stock and scion retaining their characteristic reaction to infection unaltered. Although negative results cannot be conclusive in themselves, they indicate that resistance and susceptibility are either genotypic properties of the protoplasm or else are due to some factor that is not, as such, transmissible from stock to scion or vice versa.