Daniel-Navan: A white-skinned,medium-late potato cultivar suitable for regions with a hot climate

Daniel-Navan is a new potato cultivar suitable for the spring crop (between February and July) in the Negev region of Israel, and having a high yielding potential with excellent tuber appearance. The cultivar is resistant to heat stress, Verticillium wilt (V. dahliae) and early blight (Alternaria solani). Tubers of Daniel-Navan are oval, white-skinned, with creamy-white flesh, free of deformities, and growth cracks. It has a high dry matter content (22.7%) and boils and bakes well. The marketable yield of Daniel-Navan obtained at maturity consistently surpasses that of Desiree, the control. Daniel-Navan is a main crop cultivar bred and selected by the Horticultural and Plant Breeding Station, Northern Ireland, and the Agricultural Research Organization, Gilat Experiment Station, Israel. Owing to its high yielding performance and tuber quality, this cultivar could be suitable for use in regions with a hot climate.     

Laboratory testing of potato tubers for multigenic resistance to late blight

Resistance in the tubers of potato clones with various levels of foliar multigenic resistance toPhytophthora infestans was measured to detect possible correlations between tuber and foliar resistance. A highly significant correlation was found using wound-healed tuber tissues. High levels of tuber resistance were detected in most foliar-resistant clones when inoculations with race 1,2,3,4 were made after 24–48 hours of wound periderm formation at 20 C. The resistance of wound-healed tissues increased as the time between wounding and inoculation increased. This increase in resistance was significantly greater for clones with foliar resistance than for clones with susceptible foliage.     

Kinetin,thermotherapy, and tissue culture to eliminate potato virus (PVX) in potato

PVX infected plantlets from two potato cultivars grownin vitro with 0.3, 3, 30 or 300 ppm kinetin were exposed to temperatures of 28 or 35 C. After 3 wk, axillary buds were isolated and grown aseptically in organogenic media, followed by PVX testing by ELISA. The serological test was also run on whole plantlets at the end of the kinetin-temperature exposure. No donor plants exposed to 28 C nor the plantlets derived from their buds gave an ELISA (-) reaction, regardless of the kinetin content of the media or that of the cultivar. At 35 C the virus was suppressed to undetectable levels in several whole plantlets. In the cultivar Alpha, 2 out of 6 resulting plantlets after isolation of buds were virus-free in the presence of 3.0 mg/1 kinetin during the treatments. From Atzimba, about 15–40% of the regenerated plants were ELISA (-), without any relationship to the cytokinin content in the media. Heat had a stronger influence on virus elimination than kinetin and the results varied with the cultivar.     

Redsen: A new bright red-skinned potato cultivar

Redsen is a smooth, round, bright red-skinned potato cultivar with medium to high yield potential. It has resistance to race 0 of late blight (Phytophthora infestons) and is moderately resistant to some strains of silver scurf (Helminthosporium solanum) and common scab (Streptomyces scabies). The red color resists fading during storage and Redsen retains excellent marketability during storage.     

S-methyl-L-cysteine content of various legume meals

Total nitrogen, total sulphur and S-methyl-L-cysteine content of seed meals ofPhaseolus vulgaris, Vigna aureus, Vigna unguiculata, Phaseolus lunatus, Pisum sativum, Cajanus cajan, Vicia faba major,Vicia faba minor,Glycine max, Lupinus albus andSphenostylis stenocarpa, have been determined. The nutritional significance of the presence of S-methyl-L-cysteine is discussed, together with the role that this amino acid may play in interfering with the determination of methionine by cleavage with cyanogen bromide and subsequent gas-chromatographic identification of methyl thiocyanate.     

The effects of ‘Vicia faba L.’ polyphenols on absorption,growth and metabolism in the rat

Two varieties of ‘Vicia faba L.’equina andminor, were studied. Theequina variety had a higher polyphenolic content than theminor variety. Both varieties significantly inhibited rat growth rate and ‘in vivo’ intestinal glucose transport, theequina variety being a more powerful inhibitor than theminor variety. However the raw legume fed animals showed a normal urinary excretion rate of 3-Methylhistidine.     

Hybridization between Gp. Tuberosum Haploids and 1EBN wild potato species

Diploid wild potato species, classified as 1EBN (Endosperm Balance Number), do not cross with tetraploid or diploid forms ofS. tuberosum Gp. Tuberosum. The crossing of 2n pollen producing 1EBN clones as well as chromosome-doubled 1EBN clones with Gp. Tuberosum haploids was initiated to overcome this hybridization barrier. The screening of eleven 1EBN species,S. brachistotrichum, S. bulbocastanum, S. cardiophyllum, S. chancayense, S. commersonii, S. etuberosum, S. fernandezianum, S. jamesii, S. mochicense, S. pinnatisectum andS. trifidum, resulted in the identification of 2n pollen producers in eight of the species examined. Direct hybridization with Gp. Tuberosum haploids utilizing the above-mentioned crossing scheme was successful withS. chancayense andS. commersonii. The hybrids obtained, however, were male and female sterile. Abnormal microsporogenesis in the hybrids was postulated to be the result of an interaction between Gp. Tuberosum cytoplasm and nuclear genes contributed by the 1EBN male parent. Analyses of the growth of 1EBN species’ pollen tubes in the stigma/style of Gp. Tuberosum haploids were also conducted. Interspecific incompatibilities were observed with the most severe forms found with the use of species in the Series Etuberosa. The use of the Endosperm Balance Number theory can aid in designing crosses which overcome barriers to successful endosperm development. Sterilities in the hybrids obtained as well as interspecific incompatibilities will also need to be addressed, however, before 1EBN species germplasm can be successfully utilized for the improvement of the cultivated potato.     

Phenolic constituents of glandular trichomes onSolanum berthaultii andS. polyadenium

Phenolic compounds in Type A glandular trichomes of two insectresistant potato species were separated and identified using a combination of high pressure liquid chromatography (HPLC), UV-visible spectrometry, and¹H proton nuclear magnetic resonance (NMR) procedures. Type A trichomes ofSolanum berthaultii andS. polyadenium contained a phenolic compound tentatively identified as the glucose ester of p-hydroxyphenylpropionic acid. Its presence in trichomes of both species suggests that this compound may play a major role in formation of the brownish, insect entrapping exudate characteristic of trichome-mediated insect resistance in these species. Chlorogenic acid, a major phenolic constituent of Type A trichomes ofSolanum polyadenium was not detected in trichomes of 5.berthaultii. The exclusive presence of chlorogenic acid in trichome exudates ofS. polyadenium may be responsible, at least in part, for the greater levels of insect entrapment by this species, compared with that ofS. berthaultii.     

Tobique,a new chipping variety

Tobique is a chipping variety with good yield and table quality. It is resistant to Verticillium wilt,Fusarium sambucinum, Fusarium coeruleum, and virus Y. Tobique was originated at Fredericton, New Brunswick and is a product of the potato breeding program of Agriculture Canada. This variety has been under test in New Brunswick for fifteen years as seedling F61025. It has also been tested extensively in the Maritime Provinces and throughout Canada through the facilities of regional and national evaluation trials. Tobique was selected from a cross between the variety Cariboo and Fredericton seedling F45019. Cariboo was introduced in British Columbia as a maincrop variety of distinctive appearance and bruise resistance; also with resistance toVerticillium alboatrum andPhoma rot. F45019 is a late blight resistant seedling with high dry matter. Pedigree: {ie419-01}     

Coastal Russet: A mid-season Russet-skinned potato cultivar

Coastal Russet (tested as B9596-2) is a clone with mid-season maturity that produces russet skin tubers that are long and slightly flattened. Tuber yields in the eastern portions of the United States have been considerably greater than for BelRus. Tubers are well-shaped, have shallow eyes, and are attractive in appearance. Tuber appearance and size make this cultivar very well suited for the tablestock market. It is not suitable for processing. Coastal Russet is highly resistant to tuber net necrosis caused by late current season infection with leafroll and is tolerant to common scab.     

Mechanical and rheological properties of calcium carbonate-filled ethylene propylene diene elastomer reinforced by metallic acrylate salt

High performance ethylene propylene diene methylene elastomer (EPDM)/calcium carbonate (CaCO₃)/aluminum triacrylate (ALTA) hybrids have been prepared by a melt compounding process. The mechanical properties of the peroxide cured EPDM/CaCO₃/ALTA vulcanizates were investigated by tensile, hardness, resilience, abrasion and fatigue life tests. The results showed that the ALTA can greatly improve the modulus at 100 %, tensile strength, abrasion resistance and fatigue life of the EPDM/CaCO₃/ALTA vulcanizates, while retaining their high elongation at break. ALTA as a reactive filler had accelerating effect on the vulcanization reaction of and increased the crosslink density of the EPDM/CaCO₃ composites. This phenomenon is due to increasing the ionic bonds arise from both homo-polymerization of ALTA and graft co-polymerization of it onto the EPDM. Scanning electron microscopy (SEM) revealed the presence of ALTA causes to the roughness of the fracture surface of CaCO₃-filled EPDM compounds demonstrating high interaction between the fillers and EPDM improved by introduction of ALTA. Dynamic mechanical analysis revealed that the glass transition temperature (T _g ) and dissipation peak (tan δ) of EPDM composites decreases with increasing ALTA content. Decrease in tan δ value and inward shifting of T _g were related to improved interaction of filler and EPDM.     

Experimental host range of the potato spindle tuber ‘virus’

Two hundred thirty-two plant selections (species and varieties) were tested for susceptibility to the potato spindle tuber ‘virus’ (PSTV). One hundred thirty-eight selections were found to be susceptible to PSTV but no ‘virus’ was recovered from the remaining 94. Susceptible plants were found in the families Boraginaceae, Campanulaceae, Caryophyllaceae, Compositae, Convolvulaceae, Dipsaceae, Sapindaceae, Scrophulariaceae, Solanaceae, and Valerianaceae. Most of the susceptible selections were symptomless carriers of PSTV. Visible symptoms were produced by both mild and severe strains of PSTV inLycopersicon esculentum cv. Allerfruheste-frëiland,Scopolia anomala, S. corniolica, S. lurida, S. sinensis,S. stramonifolia, S. tangutica, Solanum aviculare, andS. avicular var.albiforme; and only by the severe strain inGynura aurantica, Petunia hybrida var. Burpee Blue, andSolanum depilatum. Temperature of 21.1-22.8 C (70-73 F) with a light intensity of about 400 ft-c favored local lesion development inScopolia sinensis. S. sinensis appeared to be more susceptible than otherScopolia species.     

The cause of deep-pitted scab of potatoes

By use of a tyrosine-casinate-nitrate medium,Streptomyces atroolivaceous, S. cinerochromogenes, S. corchorusii, S. diastatochromogenes, S. lydicus, S. malachiticus, and three unidentifiedStreptomyces spp. were isolated from deep-pitted scab lesions on potato cultivars Green Mountain, Red Pontiac, Russet Burbank, and Saco. Over 90% of the deep-pitted lesions contained one or more of theseStreptomyces spp., butS. scabies the cause of shallow scab was not isolated. Isolates ofStreptomyces spp. were also consistently isolated from aseptically excised non-necrotic tissue near the edge of lesions. TheseStreptomyces spp. appeared to be the primary colonizers of this tissue. Alternaria spp.,Fusarium spp.,Penicillium spp.,Rhizopus spp.,Trichoderma spp., and several unidentified non-sporulating fungi as well asBacillus spp.,Pseudomonas spp., andMicrococcus spp. were isolated from deep-pitted scab lesions. Fungal and bacterial isolates varied from one scab lesion to another and except for anAlternaria sp., were not pathogenic. Most of theStreptomyces spp. isolates used to infest heat pasteurized field soil caused deep and/or shallow scab on tubers of the potato cultivar Kennebec in greenhouse and outdoor plantings. Re-isolations from resulting scab lesions yieldedStreptomyces spp. similar in morphology to those used as inoculum. We concluded that a number ofStreptomyces spp. probably includingS. scabies (ATCC 3352 = S.griseus) may cause deep and shallow scab.     

Quantitative analysis of host resistance,fungicide and weather effects on potato early and late blight using computer simulation models

Models which simulate the development of potato early blight, potato late blight and fungicide dynamics were used to analyze the effects of host resistance, fungicide and weather on individual and combined epidemics of these diseases. Fungicide and host resistance effects were based on (and accurately reflected) products and cultivars available to commercial potato growers in northeastern USA. Moderate resistance to early blight had a 2-3 fold greater effect than did moderate resistance to late blight in suppressing early and late blight, respectively. Analysis of simulation experiments indicated that replacement of an early blight susceptible cultivar with a cultivar moderately resistant to the disease would permit a reduction in the fungicide application frequency from once every week to once every two weeks without loss of disease suppression. Fungicide effect in suppressing late blight was 2-3 fold greater than in suppressing early blight. Variation in seasonal weather (typical of northeastern USA) influenced late blight development more strongly than it affected early blight development, and it affected epidemics of individual diseases more than combined epidemics.     

Purple top roll disease of potato

A graft transmissible disease of potato termed purple top roll is prevalent in several potato varieties grown in the hilly tracts of India. The common symptoms are rolling of the basal parts of younger leaves, sometimes accompanied by pink or purple pigmentation. The plants are stunted with profuse growth of axillary branches and aerial tubers. The losses in yield varied from 40 to 70%. Five to 20% of the tubers from diseased plants developed hairy sprouts. Tuber transmission of the pathogen varied from 6 to 33%, depending on the variety.Datura, tomato and white clover are among susceptible plants.N. rustica was tolerant or a symptomless carrier. Sunnhemp, Petunia andSesamum were immune to the pathogen, which was transmitted by the leaf hopper,O. albicinctus Distant but not byCuscuta spp. or by sap inoculation. Application of Chloramphenicol, Tetracycline and Antiamoebin resulted in remission of symptoms and increased tuber yields, indicating possible association of a mycoplasma-like organism.     

Reniform nematode resistance in potato clones

SeveralSolatium tuberosum clones were tested for resistance to the reniform nematode,Rotylenchulus reniformis. Commercial cultivars La Rouge and possibly Red La Soda had high levels of resistance to the reniform nematode.R. reniformis resistance was found to exist independently of the H₁, H₂, or H₃ genes for resistance to races of potato cyst nematodes,Globodera rostochiensis andG. pallida. In addition to reniform nematode resistance, B7642-2, B7154-8 and B7680-6 contained the H₁ gene and breeding linePI 377741 contains the H₁ and H₂ gene for potato cyst nematode resistance. Over a three month period reniform nematode counts were significantly lower in pots where resistant varieties were grown.     

The nutritional quality of Lupinseed

Mature seeds of four Lupinus species,L. albus, L. angustifolius, L. luteus andL. mutabilis, have been analysed comprehensively to evaluate their potential for nutrition. Particular interest attaches to the comparison betweenlupinus species and soyabeans. All species are rich in high-quality protein, as judged from amino-acid profiles,In vitro studies indicate high levels of digestibility and imply the presence of few interfering factors. In contrast to many other legumes, lupinseeds are free of both protease inhibitors and haemagglutinins. Only one factor, a C-glycosyl poly-hydroxy flavone, which could conceivably interfere with protein absorption, has been identified. Lupinseed could possibly be developed as an oilseed crop, though oil contents are currently somewhat lower than those of soyabeans. The composition of lupinseed oil is similar to that of soyabean oil, both being limited in quality by the presence of linolenic acid. The bright yellow colour of the partially refined oil is due to the presence of the two carotenoids, β-carotene and zeaxanthin. Lupinseed is well-known to contain toxic alkaloids of the quinolizidine group. However, intensive breeding programmes involving all four named species have been in progress for many years. At least in the cases of the first three species, cultivars have been developed that are virtually alkaloid-free. Alkaloid profiles are of interest in being decisive chemotaxonomic indicators of species. The pyrimidine bases responsible for inducing favism through the consumption ofVicia faba are absent from lupinseed. Like soyabeans, lupinseed invariably contains a range of chemically complex saponins. Concentrations in the seed are of a similar order, but it is doubtful whether these should be considered significant anti-nutritional factors for Man. Lupinseeds contain a range of oligosaccharides—raffinose, stachyose and verbascose —which correspond with the flatus factors present in soyabeans and many other legumes. Levels, however, are no higher than those found in soyabeans.     

Association of viral,bacterial and fungal pathogens with vascular discoloration of Russet Burbank potato tubers

Russet Burbank potatoes from the 1979 and 1980 crop years, collected from Chicago, IL repack warehouses and retail markets, were sampled for vascular discoloration. The amount of discoloration varied among sampling months and states of origin and decreased from 7.7% in 1979 to 1.6% in 1980. Highest levels of vascular discoloration were detected in December and January samples. Vascular discolored and non-discolored (control) tubers were assayed for the presence of potato leafroll, potato virus X, and beet western yellows viruses by the enzyme-linked immunosorbent assay (ELISA). Tubers were also assayed for 2 subspecies ofErwinia carotovora and forVerticillium albo-atrum andV. dahliae. Potato leafroll virus was detected in 31 of 831 vascular discolored tubers.V. albo-atrum was detected in 1 of 180 discolored tubers. Beet western yellows virus was not detected in discolored or non-discolored tubers. Two subspecies ofE. carotovora and potato virus X were equally common in discolored and non-discolored tubers.