Biological Control of Postharvest Diseases of Apple and Pear under Semi-commercial and Commercial Conditions Using Three Saprophytic Yeasts

The yeastsCryptococcus laurentii(strain HRA5),Cryptococcus infirmominiatus(strain YY6), andRhodotorula glutinis(strain HRB6) were tested as biocontrol agents of postharvest diseases of apple and pear in semi-commercial and commercial trials. The yeasts effectively controlled decay when applied in a drench or line spray. The yeasts were not adversely affected when treated fruits were stored in a controlled atmosphere consisting of 1% oxygen and 99% nitrogen. In a commercial trial, the most effective treatments for control of blue mold of pear were a combination ofC. laurentiiandC. infirmo-miniatus(91% control) and the commercially recommended high rate (528 μg/ml) of thiabendazole (88% control). In the commercial apple trial, the most effective treatments for blue mold wereC. infirmo-miniatuscombined with 264 μg/ml thiabendazole (91% control),C. infirmo-miniatuscombined withC. laurentii(84% control), and thiabendazole alone at 528 μg/ml (79% control). The combination ofC. laurentiiwith 264 μg/ml of thiabendazole was significantly more effective for control of blue mold on pear than thiabendazole at 528 μg/ml whenever any thiabendazole-resistant spores were present in the inoculum.     

Sclerotinia nivalis, sp. nov., the pathogen of snow mold of herbaceous dicots in Northern Japan

A newSclerotinia, previously reported asS. intermedia from Japan, is described asSclerotinia nivalis on the morphological basis of the sclerotial anamorph and teleomorph produced in culture. The characters assigning this species to the genusSclerotinia are the tuberoid sclerotia superficially produced on suscepts, the small sclerotia produced on aerial mycelium in culture, the interhyphal spaces in medullary tissue of sclerotia, and the globose cells constructing the ectal excipulum of apothecia. It is distinguishable fromS. sclerotiorum, S. minor, andS. trifoliorum by the intermediate sized sclerotia in culture, binucleate ascospores, the molecular mass of major proteins of sclerotia, and the patterns of esterase isozymes in sclerotial extracts. AlthoughS. nivalis causes snow mold of various dicots, it is a mesophile having an optimum temperature for mycelial growth of around 20°C. It attacks edible burdock(Arctium lappa), Chryhsanthemum morifolium, Ambrosia elatior, carrot(Daucus carota), Angelica acutiloba, Ajuga reptans, andPlantago lanceolata.     

Production of ROL gene transformed plants of Rosa hybrida L. and characterization of their rooting ability

Transgenic plants of the rootstock Rosa hybrida L. cv. Moneyway were produced via a two-step procedure. First, kanamycin-resistant roots were generated on stem slices from micropropagated shoots, which were cocultivated with Agrobacterium tumefaciens containing the neomycin phosphotransferase II (NPTII) gene for conferring kanamycin resistance, together with individual ROL genes from A. rhizogenes. Root formation was quite efficient and up to two kanamycin-resistant roots per stem slice were produced. In the second step, these roots were used to regenerate transgenic plants via somatic embryogenesis. Although regeneration lasted up to 12 months, production of several transformants was successfully accomplished. Untransformed escapes were not found, indicating that the initial selection on kanamycin resistance was reliable.The presence of a combination of ROLA, B and C genes enhanced adventitious root formation on micropropagated shoots and explants of stems and leaves. It appears that the auxin sensitivity was increased to such a degree that cells were able to respond even to endogenous auxins present in shoots and leaves. Rooting experiments in greenhouse demonstrated that adventitious root formation on cuttings was improved threefold upon introduction of these ROL genes. It is concluded that a method was developed for the production of ROL gene transformed roses with improved rooting characteristics.     

Induction of anthocyanin accumulation in rose suspension-cultured cells by conditioned medium of strawberry suspension cultures

A conditioned medium (CM) prepared from suspended cultures of strawberry, Fragaria ananassa, which stimulated anthocyanin accumulation in cultured strawberry cells, was applied to the suspension-cultured cells of rose, Rosa hybrida sp which did not normally produce anthocyanin. When the rose cells were transferred into the CM, it induced anthocyanin formation and accumulation in the rose cells. It is suggested that the CM may be effective for inducing anthocyanin accumulation in cultured cells of other species. This revised version was published online in June 2006 with corrections to the Cover Date.     

Anxiogenic effects of substance P and its 7–11 C terminal, but not the 1–7 N terminal, injected into the dorsal periaqueductal gray

The dorsal periaqueductal gray matter (DPAG) is one of the main output regions of the brainstem for the expression of defense reaction. Recent findings implicating neurokinins in the expression of fear or anxiety-like behaviors, have stimulated interest in the participation of these neuropeptides in the generation of aversive states in the dorsal periaqueductal gray matter. Analyses of traditional measures of the behavior of rats submitted to the elevated plus-maze test in this laboratory have shown that microinjections of substance P (SP) into the DPAG produce anxiogenic-like effects. The present study employs an ethological analysis of the behavior of animals in this test to investigate the involvement of substance P (SP) and its C- and N- fragments (7–11 and 1–7) in the expression of the different aspects of fear upon injection into the DPAG. To this end, rats were implanted with a cannula in the DPAG and injected one week later with 35 and 70 pmol of either substance P, or C- or N- SP fragments and tested immediately afterwards in the elevated plus-maze. The results show that SP and its C terminal fragment, produced increases in scanning, stretched attend posture, head dipping and flat–back approach, whereas the fragment N terminal produced only an increase in rearing. Therefore, the effects of SP and its C terminal fragment were associated to risk assessment behavior, whereas those of N terminal fragment were related to vertical exploratory activity. The results indicate that SP produces anxiogenic effects through activation of neural substrates of aversion in the DPAG and that this effect is probably related to its C terminal fragment.     

Neuronal types in the spinal dorsal gray of the turtle Chrysemys d'orbigny: a Golgi study

At thoracic and lumbar levels the spinal dorsal gray of young specimens of the turtle Chrysemys d'orbigny consists of a cell-free neuropil and an aggregation of perikarya termed here the lateral column of the dorsal horn (LCDH). Nerve cell clusters also occur in the dorsal commissure. The main neuropil area can be divided into a thin superficial layer containing some myelinated fibers (neuropil area Ib) and a compact core composed of unmyelinated axon terminals, dendritic branches, and thin glial processes (neuropil area II). A looser neuropil area is located at the horn base (neuropil area III). The so-called marginal zone of de Lange represents a fourth synaptic field termed here neuropil area Ia. The LCDH consists of neurons of different size and shape. Two peculiar nerve cell types have been recognized in the dorsal horn: giant and bitufted neurons. The former exhibits a large dendritic arbor, which after passing through neuropil areas II and Ib projects into neuropil area Ia and the adjacent white matter. Most frequently Golgi-stained giant neurons have perikarya and dendritic domains on the same side (ipsilateral giant neurons). There are also heterolateral giant neurons whose dendritic branches invade the opposite horn. Bitufted neurons are characterized by the presence of two main dendritic shafts connecting neuropil area II of both dorsal horns. At neuropil levels the major dendritic branches ramify profusely giving rise to short tortuous terminal processes. Perikarya of bitufted neurons occur in the dorsal commissure. The LCDH also contains many small and medium-sized neurons. These are oriented in two main directions: parallel or radial with respect to the dorsal horn surface. The population of horizontally oriented neurons comprises two subtypes termed here alpha and beta. Radially oriented neurons are pleomorphic, defying precise, unequivocal classification.     

The use of thidiazuron in tissue culture

Summary Thidiazuron (N-phenyl-N’-1,2,3-thiadiazol-5-ylurea) was first reported to have cytokinin activity in 1982. Since then, thidiazuron has been used successfully in vitro to induce adventitious shoot formation and to promote axillary shoot proliferation. Thidiazuron is especially effective with recalcitrant woody species. Shoot numbers produced on medium containing thidiazuron are equivalent to or greater than numbers initiated on medium with purine-type cytokinins. Low concentrations of thidiazuron (0.0022 to 0.088 mg/liter) are effective for micropropagation. Prolonged exposure to thidiazuron should be avoided, as this may cause hyperhydricity, abnormal shoot morphology, or problems in rooting. Presented in the Session-in-Depth Novel Plant Growth Regulators at the 1992 World Congress on Cell and Tissue Culture, Washington, D.C., June 20–25, 1992.     

Effect of hypoxia on the content and stoichiometry of cytochromes in muscle of the gray mullet Liza aurata

The maintenance of the gray mullet Liza aurata under conditions of hypoxia ( $ P_{O_2 } The maintenance of the gray mullet Liza aurata under conditions of hypoxia ( 55–82 GPa) for 1–2 days led to a decrease of oxygen tension in arterial blood by 47%, while in venous blood—by 28%. The mean muscle oxygen tension decreased by 19.2%. The number of hypoxic and anoxic zones in muscle tissue decreased significantly, in particular in red muscle. The maintenance of the fish in hypoxic waters for 15 days led to a rise of the content of cytochromes in muscle and a qualitative readjustment of the mitochondrial respiratory chain manifested in an increase of the content of cytochromes a and a3 and a decrease of cytochrome b. In discussion, literature data are presented which support the described regularity. Original Russian Text ? A. A. Soldatov, M. V. Savina, 2008, published in Zhurnal Evolyutsionnoi Biokhimii i Fiziologii, 2008, Vol. 44, No. 5, pp. 508–512.     

Dip listening and the cocktail party problem in grey treefrogs: Signal recognition in temporally fluctuating noise

Dip listening refers to our ability to catch brief "acoustic glimpses" of speech and other sounds when fluctuating background noise levels momentarily decrease. Exploiting dips in natural fluctuations of noise contributes to our ability to overcome the "cocktail party problem" of understanding speech in multi-talker social environments. We presently know little about how nonhuman animals solve analogous communication problems. Here, we asked whether female grey treefrogs (Hyla chrysoscelis) might benefit from dip listening in selecting a mate in the noisy social setting of a breeding chorus. Consistent with a dip listening hypothesis, subjects recognized conspecific calls at lower thresholds when the dips in a chorus-like noise masker were long enough to allow glimpses of nine or more consecutive pulses. No benefits of dip listening were observed when dips were shorter and included five or fewer pulses. Recognition thresholds were higher when the noise fluctuated at a rate similar to the pulse rate of the call. In a second experiment, advertisement calls comprising six to nine pulses were necessary to elicit responses under quiet conditions. Together, these results suggest that in frogs, the benefits of dip listening are constrained by neural mechanisms underlying temporal pattern recognition. These constraints have important implications for the evolution of male signalling strategies in noisy social environments.     

The vertebrate social behavior network: evolutionary themes and variations

Based on a wide variety of data, it is now clear that birds and teleost (bony) fish possess a core "social behavior network" within the basal forebrain and midbrain that is homologous to the social behavior network of mammals. The nodes of this network are reciprocally connected, contain receptors for sex steroid hormones, and are involved in multiple forms of social behavior. Other hodological features and neuropeptide distributions are likewise very similar across taxa. This evolutionary conservation represents a boon for experiments on phenotypic behavioral variation, as the extraordinary social diversity of teleost fish and songbirds can now be used to generate broadly relevant insights into issues of brain function that are not particularly tractable in other vertebrate groups. Two such lines of research are presented here, each of which addresses functional variation within the network as it relates to divergent patterns of social behavior. In the first set of experiments, we have used a sexually polymorphic fish to demonstrate that natural selection can operate independently on hypothalamic neuroendocrine functions that are relevant for (1) gonadal regulation and (2) sex-typical behavioral modulation. In the second set of experiments, we have exploited the diversity of avian social organizations and ecologies to isolate species-typical group size as a quasi-independent variable. These experiments have shown that specific areas and peptidergic components of the social behavior network possess functional properties that evolve in parallel with divergence and convergence in sociality.