Identification of the rice blast resistance gene Pib in the National Small Grains Collection.

The Pib gene in rice confers resistance to a wide range of races of the rice blast pathogen, Magnaporthe oryzae, including race IE1k that overcomes Pita, another broad-spectrum resistance gene. In this study, the presence of Pib was determined in 164 rice germplasm accessions from a core subset of the National Small Grains Collection utilizing DNA markers and pathogenicity assays. The presence of Pib was evaluated with two simple sequence repeat (SSR) markers and a dominant marker (Pib-dom) derived from the Pib gene sequence. Pathogenicity assays using two avirulent races (IE1k and IB1) and a virulent race (IB54) were performed to verify the resistance responses of accessions. Of the 164 accessions evaluated, 109 contained the Pib gene as determined using both SSR markers and pathogenicity assays, albeit different haplotypes were detected. The remaining 52 germplasm accessions were different in their responses to the blast races IB54, IE1k, and IB1, thus indicating the presence of R gene(s) other than Pib. The accessions characterized in this study could be used for marker-assisted breeding to improve blast resistance in indica and japonica cultivars worldwide.

First Report of Fruit Rot of Pumpkin Caused by Fusarium solani f. sp. cucurbitae in Arkansas.

During 2008, fruit rot of pumpkin (Cucurbita pepo L.) occurred on several cultivars in commercial fields in northeast and northwest Arkansas. Disease incidence ranged from 50 to 75% of the fruit, which were unmarketable. Symptoms included large (>10 cm), brown, corky lesions where the fruit was in contact with the soil. Initially, the lesions were water soaked. A cross section of the symptomatic fruit rind revealed a dry, brown, spongy rot with a light brown halo. Lesions finally became soft and wet, causing infected fruit to collapse. Masses of white mycelia surrounded advanced lesions. No rot symptoms were observed on the vines. Fusarium spp. were isolated from symptomatic fruit. Macroconidia obtained from field-infected fruit and pure potato dextrose agar (PDA) cultures of the predominant Fusarium sp. were morphologically similar. The straight, cylindrical, and robust macroconidia contained between five and seven septa. The apical cell was rounded and blunt and the basal cell was rounded. All three morphological types were tested for pathogenicity on mature fruit of cv. Sorcerer. Fruit were surface disinfected in 70% ethanol. Wounds were made (4 mm deep) in the fruit surface with a cork borer. Three wounds per isolate per fruit were inoculated with a PDA plug colonized with mycelium from a 3-day-old culture. Three replicated wounds were inoculated per isolate and four replicate fruit were used. After inoculation, the wounds were covered with saran wrap. The fruit were incubated at approximately 24°C and evaluated after 7 days. An uncolonized PDA plug was used as a negative control. After 7 days, only the predominant Fusarium sp. produced typical lesions, which were brown, water soaked, and approximately 3 cm in diameter. Fusarium spp. were recovered from the inoculated lesions. The colonies on PDA and macroconidia of the pathogenic Fusarium sp. were morphologically similar to the isolate inoculated and the ones recovered from field lesions. DNA was extracted from the same three isolates used in the pathogenicity test. A portion of the translation elongation factor 1α (TEF) gene was sequenced to verify the identity of the pathogenic isolates. On the basis of a comparison of the Fusarium-ID database at Pennsylvania State University (3), the pathogenic isolates had a 100% match with Fusarium solani f. sp. cucurbitae race 1, teleomorph Nectria haematococca mating population I, isolate NRRL 22098. F. solani f. sp cucurbitae was previously identified as the causal agent of crown and foot rot and a fruit rot of cucurbits and responsible for outbreaks on pumpkin fruit in Connecticut, Missouri, New York, and Ohio from 2001 to 2003 and again in Ohio in 2005 (2). In 2008, a higher average total of monthly precipitation was recorded late in the growing season in Arkansas, (13.7 cm in August and 23.7 cm in September). Although F. equiseti has previously been reported as a fruit rot pathogen of pumpkin in Arkansas (1), to our knowledge, this is the first report of F. solani f. sp cucurbitae as causal agent of pumpkin fruit rot in the state. Reference: (1) J. C. Correll et al. Plant Dis. 75:751, 1991. (2) W. H. Elmer et al. Plant Dis. 91:1142, 2007. (3) D. M. Geiser et al. Eur. J. Plant Pathol. 110:473, 2004.

Burkholderia glumae and B. gladioli Cause Bacterial Panicle Blight in Rice in the Southern United States.

Bacterial panicle blight (BPB) is among the three most limiting rice diseases in Louisiana and the southern United States. The identity and characterization of pathogens associated with this disease was unclear. This research details studies carried out on the pathogens causing BPB on rice in Louisiana and other rice producing southern states. Bacterial strains were isolated from BPB-infected sheath, panicle, or grain samples collected from rice fields in Louisiana, Arkansas, Texas, and Mississippi. In greenhouse inoculation tests, 292 of 364 strains were pathogenic on rice seedlings or panicles. Identification of strains in the pathogen complex by growth on S-PG medium, carbon source utilization profile (Biolog), cellular fatty acid analysis, and polymerase chain reaction (PCR) methods revealed that 76 and 5% of the strains were Burkholderia glumae and B. gladioli, respectively. The other strains have not been conclusively identified. Although strains of both species produced similar symptoms on rice, B. glumae strains were generally more aggressive and caused more severe symptoms on rice than B. gladioli. Virulent strains of both species produced toxoflavin in culture. The two species had similar growth responses to temperature, and optima ranged from 38 to 40°C for B. glumae and 35 to 37°C for B. gladioli. PCR was the most sensitive and accurate method tested for identifying the bacterial pathogens to the species level. The 16S rDNA gene and 16S-23S rDNA internal transcribed spacer (ITS) region sequences of the B. glumae and B. gladioli strains from rice showed more than 99% sequence homology with published sequences. A real-time PCR system was developed to detect and quantify this pathogen from infected seed lots. Our results clearly indicate that B. glumae and B. gladioli were the major pathogens causing BPB in the southern United States.

Rapid eye movement sleep characteristics during and after mood-disturbing events.

Twenty-nine women undergoing divorce were monitored for six nights to explore the relation of mood disturbance and rapid eye movement (REM) sleep. Follow-up evaluations were completed on 13 women one to two years later. The more traditional women were more depressed and had shortened REM latencies. Depression was also related to an irregular eye movement density sequence throughout the night. Although depression and REM latency were both significantly improved at follow-up, the REM latency of those initially most depressed remained at a lower than normal level and the eye movement density sequency remained irregular, suggesting some lag in the sleep response or a traitlike vulnerability to future depression.

Focusing on dreams. A preparation program for psychotherapy.

Forty-eight patients selected as potential early dropouts from insight-oriented psychotherapy were offered a two-week program to prepare them for treatment. Thirty-two were sleep-monitored for eight nights; half were given access to their dreams by awakening them from rapid eye movement (REM) sleep periods; the other half were awakened as often, but only from non-FEM (NREM) stages. A third group of 16 subjects went directly into treatment. All laboratory subjects were asked each morning to recall and discuss the reports they had given during the night. The effect of these discussions was measured on the drop-out rate during the first ten treatment hours and on the development of treatment-appropriate behaviors. Those who successfully retrieved and discussed dreams as opposed to other content stayed in therapy at a significantly higher rate and used the hours more productively.

REM latency and the recovery from depression: getting over divorce.

OBJECTIVE: The authors' goal was to address five questions: 1) What is the frequency of early REM sleep in subjects in the process of divorce who meet diagnostic criteria for major depressive disorder? 2) What is the frequency of this sign in subjects in the process of divorce who are not depressed? 3) How often does this sign persist following remission of depressive symptoms? 4) What is the predictive value of early REM sleep among depressed subjects for later adjustment to the process of divorce? and 5) What is the role of a family history of depression or alcoholism in the presence and persistence of early REM sleep? METHOD: Two hundred fourteen volunteers undergoing marital separation were recruited; 70 of these subjects were selected for a 3-night sleep study. Forty of the 70 subjects met criteria for depression and 30 did not; 61 (87%) returned for repeat studies 1 year later. RESULTS: Fifteen (38%) of the 40 depressed subjects had short REM latency. Seven of these continued to have short REM latency 1 year later, but none of these met the criteria for depression at that time. A higher proportion of these subjects had made a good adjustment to their new life than did depressed subjects whose initial and follow-up REM latencies fell within the normal range. CONCLUSIONS: These data suggest that depressed individuals with normal REM latency may need more aggressive treatment intervention.

Effect of sleep position on sleep apnea severity.

Thirty male patients evaluated sequentially for sleep apnea syndrome by all-night clinical polysomnography were compared for apnea plus hypopnea index (A + HI) during the time in the side versus time in the back sleep posture. For 24 subjects of this sample, who occupied both major body positions during the evaluation night, the apnea index was found to be twice as high during the time spent sleeping on their backs as it was when they slept in the side position. This difference is reliable and inversely related to obesity. Five patients meeting diagnostic criteria for sleep apnea on an all-night basis fell within normal limits while in the side sleep position. This suggests sleep position adjustment may be a viable treatment for some nonobese sleep apnea patients.

Silent partners: the wives of sleep apneic patients.

The wives of 10 male patients being treated for sleep apnea, obstructive type, were interviewed and given the Social Adjustment Scale (SAS) and Marital Satisfaction Inventory (MSI). The patients also completed an SAS and a Minnesota Multiphasic Personality Inventory (MMPI). These data were compared with those from a sample of divorced patients from the same pool. The married patients were significantly more depressed and socially isolated than were those divorced. Both marital partners showed poor adjustment in the Marital and Social/Leisure areas, and patients also showed poor adjustment in their Parental Role. Marriages do not necessarily represent social support but appear to be an added burden for sleep apneic patients.

The effects of sleep posture and sleep stage on apnea frequency.

The Apnea Plus Hypopnea Index (A + HI) of 60 male positional sleep apneics was analyzed by sleep stage to determine if positional differences are limited to NREM sleep. Differences in apnea severity by sleep position were found to persist in REM sleep and to be of equal extent to those differences found in NREM sleep, despite the fact that there is also a significant increase in the frequency of apneic events associated with REM sleep. The positional effect persists in REM sleep, making treatments to control sleep posture a viable option.

Sleep position training as treatment for sleep apnea syndrome: a preliminary study.

Ten male patients selected as having sleep apnea predominantly of the obstructive type associated with the supine sleep position on their evaluation night were trained for 1 additional night to avoid the back sleep position by wearing a gravity-activated position monitor/alarm on the chest. This device emitted an auditory signal if the patient remained supine for more than 15 s. The number of apneic events was significantly reduced, as were the number of episodes of significant O2 desaturation. While wearing the alarm, the apnea index of seven patients remained within or near normal limits. On a follow-up night, with only instructions to maintain the lateral decubitus posture, five patients remained significantly improved. Sleep position training may be appropriate as a single or interim treatment for a significant number of sleep apnea patients who have position-related obstruction.

Adjustment disorders of sleep: the sleep effects of a major stressful event and its resolution.

Seventy volunteers had 3 nights of sleep recordings during a period of marital separation, and 61 returned for repeat studies 1 year later. At that time, the divorce was final for 42. Forty of the volunteers were depressed when first screened, and 30 were not. Initially all those undergoing marital separation had less delta sleep than an age-matched married comparison sample. Delta increased at followup for those whose divorce was completed. Rapid eye movement (REM) latency was reduced and REM percent was elevated only in the depressed. Among the not depressed, those whose divorces remained incomplete at the followup had lower delta, higher REM percent, and shorter REM latency than did those whose divorces were finalized. This suggests that prolonged emotional stress may put these subjects at some risk for a mood disorder.

The contribution of dream masochism to the sex ratio difference in major depression.

Twenty-five women and twenty-one men undergoing divorce had three laboratory nights of sleep on two occasions 1 year apart. On the third night, dream reports were elicited from subjects for each period of rapid eye movement (REM) sleep. Three groups differing on dream "masochism" were compared on personality, sex role, and social adjustment. Women "masochistic" dreamers had significantly higher scores on a scale of negative aspects of traditional feminine sex role identity than men or women without such dreams. They also showed less improvement at followup and had more need for emotional support. Dream masochism may be a continuing cognitive characteristic that contributes to the vulnerability of women to major depression.

Comparison of MMPI profiles in medically and psychologically based insomnias.

The MMPI performance of two sub-groups of chronic insomniac patients was compared to determine if patients with psychologically based insomnia (Group 1) differed from those with medically based insomnia (Group 2). This was done to establish whether etiology of insomnia had an impact on the psychological picture. We postulated that Group 1 would show a higher overall incidence of psychopathology, particularly on scales suggesting internalization of distress. Surprisingly, the results revealed no significant differences between the groups with respect to these questions. When the two diagnostic groups were combined, the sample as a whole was characterized by a high overall prevalence of psychopathology. As many as 79.3% of the MMPI records contained one or more clinical scales in the pathological range. Depression was a prominent feature. Our findings emphasize the importance of not assuming that a patient with an organically-based insomnia (e.g. due to sleep apnea, etc.) is free of psychological disturbance. This, in turn, underscores the need for a psychological evaluation as a routine part of the diagnostic work-up of all insomniac patients, regardless of the etiology of their disorder.

Early REM sleep: a compensatory change in depression?

To test for a possible mood-regulatory function of dreaming, the dream reports of 61 subjects undergoing divorce were scored for their dream-like quality (DLQ), and a difference score (DLQd) was computed between the content of rapid eye movement (REM) period 1 and the mean of the subsequent dreams of the night. Subjects with reduced latency to the first REM period had enhanced first dream DLQ scores in relation to the mean of later dreams (DLQd+ score). Those with DLQd+ had significantly higher scores on the Beck Depression Inventory (BDI). Depressed subjects with DLQd+ showed significantly lower mean BDI scores at followup assessment. Implications for a psychological function of dreaming are discussed.

Dream dimension differences during a life change.

Dreams reported from laboratory awakening of stably married women differed from those of women undergoing divorce: The former dreamed of the experiment; the latter had more threat themes. Those coping well during the divorce had more positive motives in the last dream than those who were depressed. Dreams of the nondepressed divorcées increased in anxiety from first to last dream report, whereas those of the depressed increased in masochism. Affiliation motives were common in dreams of the married subjects, while harm avoidance predominated in the divorcées' dreams. Nurturance and abasement were also common needs in the dreams of the depressed sample.

Obstructive sleep apnea: variations in surgical management.

Forty patients with obstructive sleep apnea (OSA) were either treated by submucous resection, alone or by palatopharyngoplasty (PPP). Before surgery, each patient underwent a thorough sleep evaluation for the diagnosis of OSA. Of the 23 patients treated by submucous resection alone, eight had more than a 50% reduction in their apnea index and were considered successfully treated. Of the remaining 15, ten received a supplemental tongue retaining device (TRD). Five of the ten were markedly improved. The overall success rate in this group was 57%. Of the 17 patients treated by submucous resection and PPP, ten were treated successfully. Six of the remaining seven patients were subsequently treated with a TRD, which was successful in four. The overall success rate in this group was 82%.

Identification of Molecular Genetic Markers in Pyrenophora teres f. teres Associated with Low Virulence on 'Harbin' Barley.

ABSTRACT Two isolates of the barley net blotch pathogen (Pyrenophora teres f. teres), one possessing high virulence (0-1) and the other possessing low virulence (15A) on the barley cultivar Harbin, were crossed and the progeny of the mating were isolated. Conidia from cultures of the parent and progeny isolates were used as inoculum to determine the inheritance of virulence in the pathogen. Of the 82 progeny tested, 42 exhibited high virulence and 40 exhibited low virulence on 'Harbin' barley. The data support a model in which a single, major gene controls virulence in P. teres f. teres on this barley cultivar (1:1 ratio; chi(2) = 0.05, P = 0.83). Preparations of DNA were made from parental and progeny isolates, and the DNA was subjected to the random amplified polymorphic DNA (RAPD) technique in a search for molecular genetic markers associated with the virulence phenotype. Five RAPD markers were obtained that were associated in coupling with low virulence. The data indicate that the RAPD technique can be used to tag genetic determinants for virulence in P. teres f. teres.

Characterization of Pyricularia grisea in the United States Using Independent Genetic and Molecular Markers.

ABSTRACT A total of 540 isolates of Pyricularia grisea from rice in the United States were examined for vegetative compatibility, MGR586 DNA fingerprint diversity, and mating type based on hybridization with the mat1-1 and mat1-2 sexual mating type alleles. The collections contained both archived and contemporary field isolates representative of the known MGR586 lineages and races that occur throughout the United States. Complementary nitrate nonutilizing (nit) or sulfate nonutilizing (sul) mutants were used to assess vegetative compatibility in P. grisea. There was a complete correspondence between vegetative compatibility groups (VCGs), MGR586 lineage, and mating type among 527 contemporary isolates (collected between 1991 and 1997) from Arkansas, Louisiana, Missouri, Mississippi, and Texas; all isolates in MGR586 lineages A, B, C, and D belonged to VCGs US-01, US-02, US-03, and US-04, respectively. In addition, all isolates tested in VCGs US-01 and US-04 had the mat1-1 mating type allele whereas those in VCGs US-02 and US-03 had the mat1-2 allele. The strict association of independent markers during this sample period was consistent with a strictly asexual mode of reproduction. However, examination of archived isolates collected in the 1970s and 1980s and contemporary isolates revealed an incongruent relationship between the independent markers. MGR586 C and E isolates were vegetatively compatible which indicated that multiple robust MGR586 delineated lineages could be nested within certain VCGs. Although isolates in lineages C and E were vegetatively compatible, they were of opposite mating type. Several hypotheses, including recombination, could account for the incongruence between the various markers. Among the eight MGR586 lineages (A through H) that occur in the United States, all isolates in lineages A, D, E, G, and H had the mat1-1 allele, whereas isolates in lineages B, C, and F had the mat1-2 allele. Nit mutants can be recovered relatively easy from P. grisea and should allow large numbers of individuals within a population to be assessed for vegetative compatibility. VCGs may prove to be an effective multilocus marker in P. grisea. Thus, VCGs should be a useful means for characterizing genetic structure in populations of the rice blast fungus worldwide, provide a useful genetic framework to assist in interpreting molecular population data, and may provide insight into potential sexual or asexual recombination events.

Natural Occurrence of Fumonisins in Rice with Fusarium Sheath Rot Disease.

Twenty samples of rough rice (Oryza sativa) (unpolished kernels) collected during the 1995 harvest season from Arkansas (seven samples) and Texas (13 samples) were obtained from rice fields known to include plants with symptoms of Fusarium sheath rot putatively caused by Fusarium proliferatum. Samples were analyzed for fumonisin B1 (FB1) at three laboratories using three different extracting solvents by high-performance liquid chromatography (HPLC) or enzyme-linked immunosorbent assay (ELISA) methods. Forty percent of the samples were positive for FB1 at levels ≤4.3 µg/g by HPLC. The same samples contained FB1 at ≤3.6 µg/g when measured by an ELISA method. Most samples that were positive for FB1 were positive for fumonisin B2 (FB2) and fumonisin B3 (FB3) by HPLC at levels ≤1.2 µg/g. Very good agreement was obtained among the two laboratories using HPLC methods and the third using ELISA. Shelling of the unpolished rice results in hull and brown rice fractions. In a sample that contained 4.3 µg/g in whole kernels, the fumonisin level was very high in hulls (≤16.8 µg/g) and low in brown rice (≤0.9 µg/g). Milling of brown rice results in bran and white rice fractions. Fumonisins were found in bran at a level of ≤3.7 µg/g but were below the level of detection by HPLC in white rice. The presence of fumonisins (FB1, FB2, and FB3) was confirmed by fast atom bombardment/mass spectrometry. This is the first report of fumonisins in naturally contaminated rice in the United States.

Affect and cognition in dreams: a critique of the cognitive role in adaptive dream functioning and support for associative models.

Dream affect and cognition are examined in a 4-month longitudinal study of depressed, recently divorced subjects. Several measures of cognition in dream reports were used to determine whether remitting subjects were more likely to utilize certain cognitive strategies than nonremitters. No differences were found in the cognition between those who were remitting and nonremitting subjects. Levels of cognition in dreaming were directly related to the emotional intensity of the dreams across all subjects. In subjects with higher depression scores (Beck Depression Inventory > 20), depression levels were inversely related to both dream affect and cognition. It is argued that cognition plays a secondary role in dream production. A modification of David Foulkes's model of dreaming is proposed, in which emotional intensity drives associative processes, which in turn require more elaborate cognitive devices to relate diverse activated mnemonic units.