Regeneration of cybrid Lycopersicon peruvianum x (Solanum rickii) plants with genetically transformed chloroplasts

The hybrid plants with transformed plastids were regenerated after PEG fusion of chlorophyll-deficient Lycopersicon peruvianum leaf mesophyll protoplasts and leaf mesophyll protoplasts of Solanum rickii, which were previously genetically transformed and as the result were resistant to streptomycine and spectinomycine. The hybrid callus selection was based on the inability of the Lycopersicon peruvianum minicalli to have the green coloration and on the inability of gamma-preirradiated Solanum rickii protoplasts to divide. The hybrids were identified on the base of PCR analyses of nuclear and plastid DNA.     

瑞克纤孔菌在皂荚上的首次发现

报道皂荚树的一种新病原菌,对采集的标本及其培养物的形态特征进行观察,对其ITS序列进行测定。将其鉴定为瑞克纤孔菌Inonotus rickii,与其亲缘关系较近的是I. patouillardii和I. quercustris。     

Agroinfection-based high-throughput screening reveals specific recognition of INF elicitins in Solanum

We adapted and optimized the use of the Agrobacterium tumefaciens binary PVX expression system (PVX agroinfection) to screen Solanum plants for response to pathogen elicitors and applied the assay to identify a total of 11 clones of Solanum huancabambense and Solanum microdontum , out of 31 species tested, that respond to the elicitins INF1, INF2A and INF2B of Phytophthora infestans . Prior to this study, response to INF elicitins was only known in Nicotiana spp. within the Solanaceae. The identified S. huancabambense and S. microdontum clones also exhibited hypersensitivity-like cell death following infiltration with purified recombinant INF1, INF2A and INF2B, thereby validating the screening protocol. Comparison of INF elicitin activity revealed that Nicotiana plants responded to significantly lower concentrations than Solanum , suggesting variable levels of sensitivity to INF elicitins. We exploited natural variation in response to INF elicitins in the identified Solanum accessions to evaluate the relationship between INF recognition and late blight resistance. Interestingly, several INF-responsive Solanum plants were susceptible to P. infestans . Also, an S. microdontum  × Solanum tuberosum (potato) population that segregates for INF response was generated but failed to identify a measurable contribution of INF response to resistance. These results suggest that in Solanum , INF elicitins are recognized as general elicitors and do not have a measurable contribution to disease resistance.     

Protoplast culture and somaclonal variability of species of series Juglandifolia

Mesophyll protoplasts of species of series Juglandifolia (Solanum rickii, S. lycopersicoides, S. ochranthum and S. juglandifolium) were isolated and cultured in liquid nutrient media TM-2 or KM8P. The cell colonies formed were transferred onto agar-solidified media TM-3 or GM, and 10 to 15 days later onto TM-4, PRM, MS3ZG, KK or C regeneration media. Formation of the shoots for S. rickii and S. lycopersicoides was observed after 30 to 35 days on regeneration medium. The regenerated shoots were rooted on hormone-free MS medium. Morphological and cytogenetic analyses have shown that somaclonal variants might arise in the course of plant regeneration from protoplasts of these species.Abbreviations BAP 6-benzylaminopurine - 2, 4-D 2, 4 dichlorophenoxyacetic acid - NAA -naphthaleneacetic acid - GA₃ gibberellic acid - IAA indole-3-acetic acid - MS Murashige and Skoog medium - B5 Gamborg medium - TRIS tris(hydroxymethyl)aminomethane     

Age dependency of the meiotic process in an F<Subscript>1</Subscript> interspecific hybrid of <Emphasis Type="Italic">Solanum lnnaeum</Emphasis> L. × <Emphasis Type="Italic">Solanum incanum</Emphasis>

A study of the meiotic process in first- and second-year plants of an F₁ interspecific hybrid of Solanum linnaeum L. × Solanum incanum L. has been carried out. Fruits with seeds were obtained during the second year of vegetation. The numbers of univalents and tetravalents, as well as the percentage of basic impairments, decreased as the age of plants increased. The process of meiosis in the parental forms was normal. A conclusion was made regarding the connection between the regularity of meiosis in the F₁ heterozygotes of Solanum lynnaeum L. × Solanum incanum L., on the one hand, and the hybrid nature of the genotype and age and the influence of environmental factors, on the other hand.     

The structure of two CONSTANS-LIKE1 genes in potato and its wild relatives

Day length controls development in many plants. In Arabidopsis thaliana, the CONSTANS (CO) gene has been firmly established as a key component in the photoperiodic pathway of floral transition; less is known about CONSTANS-LIKE1 (COL1) orthologues of this gene in Arabidopsis and several other species. The CONSTANS protein comprises two B-box-type zinc fingers, CCT domain, and a variable middle region (MR) which corresponds to exon 2 in the COL1 genes of Solanum species. Solanum COL1 proteins are over 85% identical within the genus and about 50% similar to Arabidopsis CO. Comparative COL1 analysis in several cultivated and wild Solanum species discerned two gene variants, which differed in the structures of exon 2 and introns 1 and 2. In exon 2, two variants were primarily discerned by the numbers of AAC/AAT and CAA/CAG repeats coding for polyasparagine and polyglutamine tracts in MR; therefore two variants were dubbed short and long COL1 genes (sCOL1 and lCOL1). However, intron 1 in lCOL1 was shorter than in sCOL1 due to three indels, whereas intron 2 in available COL1 sequences was represented by three different variants. The temporal profiles of sCOL1 and lCOL1 expression in tuberosum potato dramatically differed under short and long day, and the level of sCOL1 expression exceeded that of lSOL1 by an order of magnitude. Both sCOL1 and lCOL1 were found in each Solanum genome under study and in each individual plant, and the ratio of their copy numbers was not related to plant ploidy and photoperiodic response. Evidently the evolution of two COL1 genes preceded Solanum speciation, and the day-length response of diverse Solanum genotypes does not stem from the primary COL1 structure.     

Somatic hybrid plants produced by electrofusion between Solanum melongena L. and Solanum torvum Sw

Summary Somatic hybrid plants between eggplant (Solanum melongena) and Solanum torvum have been produced by the electrofusion of mesophyll protoplasts in a movable multi-electrode fusion chamber. Using hair structure as a selection criteria, we identified a total of 19 somatic hybrids, which represented an overall average of 15.3% of the 124 regenerated plants obtained in the two fusion experiments. Several morphological traits were intermediate to those of the parents, including trichome density and structure, height, leaf form and inflorescence. Cytological analyses revealed that the chromosome numbers of the somatic hybrids approximated the expected tetraploid level (2n=4x=48). Fifteen hybrid plants were homogeneous and had relatively stable chromosome numbers (46–48), while four other hybrids had variable chromosome numbers (35–48) and exhibited greater morphological variation. The hybridity of these 19 somatic hybrid plants was confirmed by analyses of phosphoglucomutase (Pgm) and esterase zymograms.     

Stomatal Response of some Cultivated and Wild Tuber-bearing Potatoes in Warm Tropics as Influenced by Water Deficits

Leaf resistances of 14 cultivated potato genotypes (Solanumspp) and three tuber-bearing wild Solanum species were comparedwhen plants were grown under water stress at two tropical sitesFactors investigated were diurnal changes in leaf resistance,the effect of plant age, transient drought versus well-wateredconditions of potted and field-grown plants These measurementswere carried out in order to determine the stomatal behaviourof tuber-bearing genotypes and species Significant genotypic differences in leaf resistances were notedwithin the cultivated genotypes All genotypes had higher resistanceswhen water-stressed, but LT-7 appeared to have the lowest leafresistances Genetic differences in stomatal behaviour of tuber-bearingSolanum species were confirmed Abaxial stomatal resistancesof water-stressed plants of the species ranged between 1 74and 13 8 s cm^–1 Stomata of S chacoense were less affectedby drought (three-fold) than S tuberosum (four-fold) The greatesteffect was on S jungasense (five-fold) and on S raphanifoliumThese data show that stomata behaviour among tuber-bearing Solanumspecies is sufficiently different to warrant investigationsof drought-resistance in potato species under dry hot conditions Solanum tuberosum L., Solanum raphanifolium, Solanum chacoense, Solanum jungasense, leaf resistance     

Host plant choice experiments of Colorado potato beetle (Coleoptera: Chrysomelidae) in Virginia

Field and laboratory-choice experiments were conducted to understand aspects of host plant orientation by the Colorado potato beetle, Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae), in Virginia. In laboratory bioassays, L. decemlineata oriented to volatiles emitted by potato, Solanum tuberosum L., foliage over both tomato, Lycopersicon esculentum L., and eggplant, Solanum melongena L., foliage, and eggplant over tomato foliage, all of which had been mechanically damaged. Field choice tests revealed more L. decemlineata adults, larvae, and egg masses on eggplant than on tomato. In other experiments, counts of live L. decemlineata on untreated paired plants and counts of dead beetles on imidacloprid-treated plants did not differ between potato and eggplant. L. decemlineata was significantly attracted to eggplant over both tomato and pepper. To determine whether feeding adults affected orientation to host plants, an imidacloprid-treated eggplant or potato plant was paired with an untreated eggplant or potato plant covered in a mesh bag containing two adult male beetles. Significantly more adults were attracted to eggplant with feeding male beetles paired with another eggplant than any other treatment combination. These results indicate that the presence of male L. decemlineata on plants affects host plant orientation and suggests that the male-produced aggregation pheromone may be involved.     

Inbreeding depression in Solanum carolinense (Solanaceae) under field conditions and implications for mating system evolution

The clonal weed Solanum carolinense exhibits plasticity in the strength of its self-incompatibility (SI) system and suffers low levels of inbreeding depression (δ) in the greenhouse. We planted one inbred and one outbred plant from each of eight maternal plants in a ring (replicated twice) and monitored clonal growth, herbivory, and reproduction over two years. Per ramet δ was estimated to be 0.63 in year one and 0.79 in year two, and outbred plants produced 2.5 times more ramets than inbred plants in the spring of year two. Inbred plants also suffered more herbivore damage than outbred plants in both fields, suggesting that inbreeding compromises herbivore resistance. Total per genet δ was 0.85 over the two years, indicating that S. carolinense is unlikely to become completely self-compatible, and suggesting that plasticity in the SI system is part of a stable mixed-mating system permitting self-fertilization when cross pollen limits seed production.     

温度和寄主植物对瓢虫柄腹姬小蜂自身干扰反应的影响

研究了温度和寄主植物与寄生蜂密度对瓢虫柄腹姬小蜂PediobiusfoveolatusCrawford功能反应的影响。结果表明瓢虫柄腹姬小蜂对自身密度的干扰反应均符合Watt所提出的模型(A =aP-b)。在1 9～3 1℃5个温度下,以2 8℃下的干扰系数最小,其模型为A =4 0 4p-0 41。在4种寄主植物枝叶上,以酸酱枝叶上干扰系数最大,为0 . 5 0 ;而在西红柿枝叶、龙葵枝叶、茄枝叶上分别为0 . 2 8,0 .2 6,0 .2 4。可为合理地利用该蜂提供参考。     

Field assessment of dihaploid Solatium tuberosum and S. brevidens somatic hybrids

Summary Following both chemical and electrical fusion of protoplasts of a dihaploid line of potato (Solanum tuberosum), (PDH40), with those of the wild species, Solanum brevidens, 11 and 40 somatic hybrid plants, respectively were obtained. Fifteen of these somatic hybrid genotypes and the two parents were studied further in a small field trial to assess field performance and phenotypic variability. In the UK, somatic hybrid plants are classified as genetically engineered organisms, and the UK Advisory Committee on Genetic Manipulation have imposed various restrictions on field experiments. Examination of the somatic hybrids in the field showed extensive phenotypic variability, and no two genotypes were identical. Some of the variation reflected changes in chromosome numbers, but other factors were also involved. Half the somatic hybrid genotypes produced tubers in the field, although the tubers were smaller and differed morphologically from those of PDH40. The results of the study suggest that the extent of somaclonal variation manifested in somatic hybrids is greater than that found in protoplast-derived plants of potato. The implications of this observation and the current regulations concerning field experiments of somatic hybrid plants in the UK are discussed.     

Growth and alkaloid production along with expression profiles of biosynthetic pathway genes in two contrasting morphotypes of prickly and prickleless Solanum viarum Dunal

Protoplasma - Growth and production kinetics of three important glycoalkaloids viz. α-solanine, solanidine, and solasodine in two contrasting prickly and prickleless plants of Solanum viarum...     

Race nonspecific resistance for potato late blight

The late blight fungus (Phytophthora infestans) rots susceptible species of potato plants. None of the major varieties of potato (Solanum tuberosum) grown in the USA is resistant to US-8, the most prevalent genotype of the fungus. Now, Junqi Song, James Bradeen and colleagues have cloned the RB gene from the wild diploid potato species, Solanum bulbocastanum, using a map-based approach in combination with long-range PCR. Transgenic plants containing the gene, normally fully susceptible, displayed broad-spectrum late blight resistance.     

The chimærical structure of a somatic solanum mutant revealed by ionizing irradiation

The aim of the present study was to investigate whether it is possible to reveal the chimaerical structure of somatic mutants inSolanum tuberosum by means of ionizing irradiation. A somatic subdivided-leaf mutant of the variety Prosident was chosen as subject. This mutant was isolated in 1957 and has proved to keep permanent and stable during a five years' propagation. In spite of a two years' eye-excision experiment in which, totally, 50 tuber-halves were tested, it has been impossible to demonstrate the chimærical structure of this type. Im May 1961, 50 tuber-halves of the subdivided-leaf type were X-irradiated with a dose of 4,000 r. Five of the surviving 40 plants showed from one to three normal shoots. Furthermore, in one of these plants, a few leaves were observed one half of which was subdivided and the other normal. In the corresponding 50 tuber-halves, which served as a control, no morphological changes could be found. It is concluded that X-irradiation is an efficient and easy method for revealing the chimærical structure of somatic mutants inSolanum tuberosum.     

A Pressure-Volume Analysis of Solanum melongena Leaves

A pressure-volume analysis of aubergine (Solanum melongena)leaves following water stress was undertaken to determine apossible role of changes in cellular water relations in influencingstomatal conductance responses to water stress. A comparisonof two methods of rehydrating the leaves was also undertaken.It was shown that the rehydration of excised leaves did notreveal osmoregulation, whilst rehydration of intact plants didreveal osmoregulation following water stress. An increase inthe bulk volumetric elastic modulus and the bound water fractionalso occurred in response to water stress. These results arediscussed in relation to pressure-volume technique and stomatalconductance responses to drought. Key words: P-V analysis, water stress, Solanum melongena