The mediating effects of parenting style on the relationship between parental stress and behavioral problems in girls with precocious puberty in Korea: a cross-sectional study.

BACKGROUND: This study aimed to examine the mediating effects of parenting style on the relationship between parental stress and behavioral problems of girls with precocious puberty. METHODS: This cross-sectional study analyzed a convenience sample of 200 mothers of girls with precocious puberty at a university hospital located in a metropolitan area. The Parental Stress measurement, Parents as Social Context Questionnaire, and Korean version Child Behavior Checklist (K-CBCL) 6-18 were measured via self-report questionnaires. Descriptive, t-test, Pearson correlation, and bootstrapping analyses were used to analyze the data. RESULTS: Negative parenting styles had a full mediating effect on the relationship between parental stress and internalizing and externalizing behavioral problems. CONCLUSIONS: Care plans for parents of girls with precocious puberty should be designed and applied in health care settings to reduce internalizing and externalizing behavioral problems by decreasing negative parenting styles.

Relationship between parental stress and post-traumatic stress disorder: The moderating effect of visitation restrictions in paediatric intensive care units during COVID-19.

BACKGROUND: Visitation restrictions due to COVID-19 kept parents from being with their children who were hospitalized in the PICU and from meeting with professional staff. AIM: This study examined the moderating effect of COVID-19-induced visitation restrictions on the relationship between stress and post-traumatic stress disorder in parents of children admitted to the paediatric intensive care unit. STUDY DESIGN: We conducted a descriptive, exploratory study involving 93 parents of children hospitalized in the paediatric intensive care unit using the Korean version of the Parental Stressor Scale: Paediatric Intensive Care Unit and the Revised Impact of Events Scale. Descriptive, Pearson's correlation, and logistic regression analyses were used to investigate the data. Self-reported survey questionnaires were provided for parents to complete in a separate area of the outpatient clinic when they visited for follow-up care after their children were discharged from the paediatric intensive care unit. RESULTS: Mothers showed significantly higher post-traumatic stress disorder scores than fathers. The relationship between all the sub-domains of perceived stress and post-traumatic stress disorder was statistically significant. Visitation restrictions because of the COVID-19 pandemic had significant moderating effects on the relationship between perceived parental stress and post-traumatic stress disorder. Moreover, the moderating effects of COVID-19 were exhibited when the two sub-domains-hyperarousal and intrusion-were investigated. CONCLUSIONS: Paediatric intensive care unit visitation may be an important intervention for parental post-traumatic stress disorder. Parental visitation should be enabled, and alternative interventions should be developed in situations where visitation is prohibited. RELEVANCE TO CLINICAL PRACTICE: It is necessary to develop and apply various and effective alternatives visitation that can prepare hospitals for visiting restrictions during pandemic situations which could emerge in the future.

Confirmatory factor analysis of the Child Oral Health Impact Profile (Korean version).

Empirical support for the factor structure of the Child Oral Health Impact Profile (COHIP) has not been fully established. The purposes of this study were to evaluate the factor structure of the Korean version of the COHIP (COHIP-K) empirically using confirmatory factor analysis (CFA) based on the theoretical framework and then to assess whether any of the factors in the structure could be grouped into a simpler single second-order factor. Data were collected through self-reported COHIP-K responses from a representative community sample of 2,236 Korean children, 8-15 yr of age. Because a large inter-factor correlation of 0.92 was estimated in the original five-factor structure, the two strongly correlated factors were combined into one factor, resulting in a four-factor structure. The revised four-factor model showed a reasonable fit with appropriate inter-factor correlations. Additionally, the second-order model with four sub-factors was reasonable with sufficient fit and showed equal fit to the revised four-factor model. A cross-validation procedure confirmed the appropriateness of the findings. Our analysis empirically supported a four-factor structure of COHIP-K, a summarized second-order model, and the use of an integrated summary COHIP score.

Longitudinal relationship between depression and antisocial behaviors in Korean adolescents.

Background: It is well known that depression and delinquency in adolescents are highly correlated, but longitudinal studies on the causal relationship between them are not active in East Asia compared to in Western culture. In addition, even the results of research on causal models and sex differences are inconsistent. Objectives: This study examines the longitudinal reciprocal effects between depression and delinquent behavior in Korean adolescents based on sex differences. Methods: We conducted multiple-group analysis by using an autoregressive cross-lagged model (ACLM). Longitudinal data from 2,075 individuals (2011-2013) were used for analysis. The longitudinal data are from the Korean Children and Youth Panel Survey (KCYPS), and data were used beginning with students at 14 years old (in the second grade of middle school) and tracked them until they were 16 (in the first grade of high school). Results: Boys' delinquent behaviors at 15 years (the third grade of middle school) affected their depression at 16 years (the first grade of high school). In contrast, girls' depression at 15 years (the third grade of middle school) influenced their delinquent behaviors at 16 years (the first grade of high school). Discussion: The findings support the failure model (FM) among adolescent boys and the acting-out model (ACM) among girls. The results imply that strategies to effectively prevent and treat delinquency and depression in adolescents must consider sex effects.

Testing multiple levels of influence in the intergenerational transmission of alcohol disorders from a developmental perspective: the example of alcohol use promoting peers and µ-opioid receptor M1 variation.

This study examined the interplay between the influence of peers who promote alcohol use and µ-opioid receptor M1 (OPRM1) genetic variation in the intergenerational transmission of alcohol use disorder (AUD) symptoms while separating the "traitlike" components of AUD symptoms from their age-specific manifestations at three ages from emerging adulthood (17-23 years) to adulthood (29-40 years). The results for males were consistent with genetically influenced peer selection mechanisms as mediators of parent alcoholism effects. Male children of alcoholics were less likely to be carriers of the G allele in single nucleotide polymorphism A118G (rs1799971), and those who were homozygous for the A allele were more likely to affiliate with alcohol use promoting peers who increased the risk for AUD symptoms at all ages. There was evidence for women of an interaction between OPRM1 variation and peer affiliations but only at the earliest age band. Peer influences had stronger effects among women who were G-carriers. These results illustrate the complex ways in which the interplay between influences at multiple levels of analysis can underlie the intergenerational transmission of alcohol disorders as well as the importance of considering age and gender differences in these pathways.

Preliminary Report of Validity for the Infant Comprehensive Evaluation for Neurodevelopmental Delay, a Newly Developed Inventory for Children Aged 12 to 71 Months.

OBJECTIVES: Early detection of developmental issues in infants and necessary intervention are important. To identify the comorbid conditions, a comprehensive evaluation is required. The study's objectives were to 1) generate scale items by identifying and eliciting concepts relevant to young children (12-71 months) with developmental delays, 2) develop a comprehensive screening tool for developmental delay and comorbid conditions, and 3) assess the tool's validity and cut-off. METHODS: Multidisciplinary experts devised the "Infant Comprehensive Evaluation for Neurodevelopmental Delay (ICEND)," an assessment method that comes in two versions depending on the age of the child: 12-36 months and 37-71 months, through monthly seminars and focused group interviews. The ICEND is composed of three parts: risk factors, resilience factors, and clinical scales. In parts 1 and 2, there were 41 caretakers responded to the questionnaires. Part 3 involved clinicians evaluating ten subscales using 98 and 114 questionnaires for younger and older versions, respectively. The Child Behavior Checklist, Strengths and Difficulties Questionnaire, Infant- Toddler Social Emotional Assessment, and Korean Developmental Screening Test for Infants and Children were employed to analyze concurrent validity with the ICEND. The analyses were performed on both typical and high-risk infants to identify concurrent validity, reliability, and cut-off scores. RESULTS: A total of 296 people participated in the study, with 57 of them being high-risk (19.2%). The Cronbach's alpha was positive (0.533-0.928). In the majority of domains, the ICEND demonstrated a fair discriminatory ability, with a sensitivity of 0.5-0.7 and specificity 0.7-0.9. CONCLUSION: The ICEND is reliable and valid, indicating its potential as an auxiliary tool for assessing neurodevelopmental delay and comorbid conditions in children aged 12-36 months and 37-71 months.

Shotgun proteomic analysis for detecting differentially expressed proteins in the reduced culm number rice.

To survey protein expression patterns in the reduced culm number (RCN) rice, a comparative shotgun proteomic analysis was conducted. For large-scale protein identification, multidimensional protein identification technology (MudPIT) coupled with pre-fractionation of plant shoot proteins led to the identification of 3004 non-redundant rice proteins. By statistically comparing relative amounts of 1353 reproducibly identified proteins between the RCN rice and the wild-type rice, 44 differentially expressed proteins were detected, where 42 proteins were increased and 2 proteins were decreased in the RCN rice. These proteins appear to have roles in glycolysis, trichloroacetic acid cycle, secondary metabolism, nutrient recycling, and nucleotide metabolism and repair. Consequently, we hypothesized that the RCN rice might fail to maintain sugar nutrient homeostasis. This was confirmed with the observation that the sucrose concentration was increased significantly in the RCN rice compared with the wild-type rice. Also, the RCN rice showed a hypersensitive response to exogenous sucrose treatment.

False memory for trauma-related Deese-Roediger-McDermott lists in adolescents and adults with histories of child sexual abuse.

The purpose of the present research was to examine Deese-Roediger-McDermott false memory for trauma-related and nontrauma-related lists in adolescents and adults with and without documented histories of child sexual abuse (CSA). Individual differences in psychopathology and adult attachment were also explored. Participants were administered free recall and recognition tests after hearing CSA, negative, neutral, and positive Deese-Roediger-McDermott lists. In free recall, CSA and negative lists produced the most false memory. In sharp contrast, for recognition, CSA lists enjoyed the highest d' scores. CSA-group adolescents who evinced greater posttraumatic stress disorder (PTSD) symptoms had higher rates of false memory compared to (a) non-CSA group adolescents with higher PTSD symptom scores (free recall), and (b) CSA-group adolescents with lower PTSD symptom scores (recognition). Regression analyses revealed that individuals with higher PTSD scores and greater fearful-avoidant attachment tendencies showed less proficient memory monitoring for CSA lists. Implications for trauma and memory development and for translational research are discussed.

Understanding the psychological processes of the racial match effect in Asian Americans.

Some studies on mental health outcomes research have found that when clients and therapists are ethnically or racially matched, this tends to be related to greater satisfaction and better outcomes. However, the precise underlying mechanism for the match effect has not been extensively examined. In this experimental study, we tested the effect of racial match on critical counseling processes (i.e., therapist credibility and the working alliance) using a sample of 171 Asian American respondents. We also examined Asian ethnic identification as a potential moderator of the racial match effect. Structural equation modeling analyses indicated that racially matched individuals perceived greater experiential similarity with the therapist than nonmatched individuals, and experiential similarity was positively associated with therapist credibility. Although racial match did not predict attitudinal similarity, attitudinal similarity was strongly related to the working alliance and therapist credibility. Counseling implications are discussed.

Sequence information on simple sequence repeats and single nucleotide polymorphisms through transcriptome analysis of mungbean.

Mungbean (Vigna radiata (L.) Wilczek) is a unique species in its ability to fix atmospheric nitrogen, with early maturity, and relatively good drought resistance. We used 454 sequencing technology for transcriptome sequencing. A total of 150 159 and 142 993 reads produced 5 254 and 6 374 large contigs (≥ 500 bp) with an average length of 833 and 853 for Sunhwa and Jangan, respectively. Functional annotation to known sequences yielded 41.34% and 41.74% unigenes for Jangan and Sunhwa. A higher number of simple sequence repeat (SSR) motifs was identified in Jangan (1 630) compared with that of Sunhwa (1 334). A similar SSR distribution pattern was observed in both varieties. A total of 8 249 single nucleotide polymorphisms (SNPs) and indels with 2 098 high-confidence candidates were identified in the two mungbean varieties. The average distance between individual SNPs was approximately 860 bp. Our report demonstrates the utility of transcriptomic data for implementing a functional annotation and development of genetic markers. We also provide large resource sequence data for mungbean improvement programs.

The Yin-Yang personality from biopsychological perspective using revised Sasang Personality Questionnaire.

BACKGROUND: The biopsychological, pathological and physical characteristics of Yin-Yang (Eum-Yang in Korean) have been suggested using Sasang Personality Questionnaire (SPQ), however, the revision of SPQ is required for escalating its clinical use and multidimensional study on Yin-Yang. METHODS: 274 university students were recruited to complete the SPQ, candidate items of revised SPQ (rSPQ) along with the Temperament and Character Inventory (TCI). After selecting rSPQ items using Item Analysis and Explorative Factor Analysis, its psychometric property was examined using Confirmatory Factor Analysis, Pearson's correlation and t-test. The biopsychological features of Yin and Yang personality groups based on rSPQ total score were illustrated with the TCI using ANOVA and Profile Analysis. RESULTS: The behavior, cognition and emotion subscales of 15-item rSPQ had robust psychometric construct and showed distinctive psychological characteristics of Yin-Yang. The rSPQ-total score was correlated positively with SPQ-total (r = 0.644, p < 0.01) and TCI Novelty-Seeking (r = 0.398, p < 0.01), and negatively with TCI Harm-Avoidance (r = -0.364, p < 0.01). And, the Yin personality group (34.45 ±â€¯10.36 and 46.82 ±â€¯12.27) has significantly different scores in Novelty-Seeking and Harm-Avoidance compared to Yang personality group (43.2 ±â€¯9.1 and 36.53 ±â€¯10.78). Yin and Yang personality groups showed distinctive TCI subscale profiles as shown in previous studies. CONCLUSION: The current study showed the organized subscale structure and clinical validity of rSPQ for Yin-Yang personality, and it would provide foundation for East-West cross-cultural psychology and integrative medicine.

Children's eyewitness memory: a comparison of two interviewing strategies as realized by forensic professionals.

A critical issue for developmental psychology is how to obtain accurate and complete eyewitness memory reports from preschoolers without offering suggestions that might result in false allegations. We examined effects of two interviewing strategies (police/verbal interviews and clinician/prop-assisted interviews) on young children's reports about a medical examination. A total of 58 4-year-olds participated in the study, which conformed to a 2 (Interview Type)x2 (Number of Interviews) factorial design. Analyses revealed that interviewers spent less time off topic and asked more free recall questions in the police/verbal interviews than in the clinician/prop-assisted interviews. Compared with police/verbal interviews, clinician/prop-assisted interviews resulted in significantly more correct rejections and commission errors in children's memory reports. However, on a final free recall test, error rates were comparable across conditions. Higher child verbal intelligence predicted memory accuracy in police/verbal interviews, and greater parental attachment anxiety predicted children being asked a higher number of misleading questions. The study provides new insights into interview techniques that promote preschoolers' accurate eyewitness reports.

Validity and Reliability of the Behavior Development Screening for Toddlers-Questionnaire/Parents(BeDevel-Q/P): A Korean Autism Screening Instrument for Infants aged 24-35 Months.

OBJECTIVE: This study tested the validity and reliability of the Behavior Development Screening for Toddlers-Questionnaire-Parents (BeDevel-Q/P), a new autism spectrum disorder (ASD) screening instrument being developed in South Korea. The parents of 24-35-month-old infants were recruited to complete the questionnaire. METHODS: The participants were 791 infants aged 24-35 months. There were 623 typically developing infants, 88 infants with ASD, and 80 developmentally delayed infants. For test-retest, the participants were surveyed every 1-4 weeks. Participants were recruited nationwide. Subjects' parents completed the BeDevel-Q/P and concurrent validity questionnaires. The data were used for statistical analysis. RESULTS: A total of 24 items consisting of 16 items from factor 1 (F1), 6 items from factor 2 (F2), and 2 items from factor 3 (F3), were selected for the final BeDevel-Q/P items. CONCLUSION: The factors of the screening instrument developed in this study were analyzed, and three factors were extracted, confirming the theoretical foundation of the BeDevel-Q for the parents of 24-35-month-old infants.

Development of 454 New Kompetitive Allele-Specific PCR (KASP) Markers for Temperate japonica Rice Varieties.

Temperate japonica rice varieties exhibit wide variation in the phenotypes of several important agronomic traits, including disease resistance, pre-harvest sprouting resistance, plant architecture, and grain quality, indicating the presence of genes contributing to favorable agronomic traits. However, gene mapping and molecular breeding has been hampered as a result of the low genetic diversity among cultivars and scarcity of polymorphic DNA markers. Single nucleotide polymorphism (SNP)-based kompetitive allele-specific PCR (KASP) markers allow high-throughput genotyping for marker-assisted selection and quantitative trait loci (QTL) mapping within closely related populations. Previously, we identified 740,566 SNPs and developed 771 KASP markers for Korean temperate japonica rice varieties. However, additional markers were needed to provide sufficient genome coverage to support breeding programs. In this study, the 740,566 SNPs were categorized according to their predicted impacts on gene function. The high-impact, moderate-impact, modifier, and low-impact groups contained 703 (0.1%), 20,179 (2.7%), 699,866 (94.5%), and 19,818 (2.7%) SNPs, respectively. A subset of 357 SNPs from the high-impact group was selected for initial KASP marker development, resulting in 283 polymorphic KASP markers. After incorporation of the 283 markers with the 771 existing markers in a physical map, additional markers were developed to fill genomic regions with large gaps between markers, and 171 polymorphic KASP markers were successfully developed from 284 SNPs. Overall, a set of 1225 KASP markers was produced. The markers were evenly distributed across the rice genome, with average marker density of 3.3 KASP markers per Mbp. The 1225 KASP markers will facilitate QTL/gene mapping and marker-assisted selection in temperate japonica rice breeding programs.

Middle cerebral artery fenestration in patients with cerebral ischemia.

BACKGROUND: We report five cases of middle cerebral artery (MCA) fenestration that might have caused cerebral infarction or ischemia. CASE REPORT: Unilateral fenestration of the MCA was observed in five patients with artery-relevant cerebral infarction or ischemia. Enhanced magnetic resonance imaging (MRI) and three-dimensional MR angiography (MRA) were performed in the patients, and a division of the lumen after fenestration was observed using virtual arterial endoscopy. In one patient, MRA and virtual endoscopy showed an obstruction in one limb of the fenestration. The MCA fenestrations were observed in the proximal portion in three cases and the intermediate portion in two cases, and there was no associated aneurysm near or far from the fenestration. METHODS: The five patients underwent both contrast-enhanced magnetic resonance imaging (MRI) and 3D MRA. Virtual arterial endoscopy was then performed to visualize the division of the lumen, a landmark of fenestration. CONCLUSIONS: The association between cerebral ischemia and MCA fenestration in the five cases suggests that the fenestration disturbing local flow hemodynamics seems to cause cerebral ischemia, even a direct causative relationship should be elucidated further.

Reliability and Validity of the Korean Version of the Infant-Toddler Social and Emotional Assessment.

OBJECTIVE: This article examined the psychometric properties of the Korean version of the Infant-Toddler Social and Emotional Assessment (K-ITSEA). METHODS: Translation and back-translation of the K-ITSEA were conducted after obtaining a permission. Two thousand two hundred thirty six Korean community infants (1,199 boys and 1,037 girls) between the ages of 12 and 36 months (M=34.23, SD=3.80) and 90 clinical infant samples (60 boys and 30 girls) between the ages of 12 and 36 months (M=26.84, SD=6.24) participated in the present study. RESULTS: Confirmatory factor analyses supported the Internalizing, Externalizing, Dysregulation, and Competence domains as well as the 17 individual scales that comprise the K-ITSEA. Young children's sex and age differences emerged for some problem and most competence scales. All domains showed adequate intrascale reliability and test-retest reliability. Scale intracorrelation analyses and associations between the K-ITSEA and Korean version of PSI, Korean version of CBCL1.5-5 supported the validity of the assessment. Comparisons of the K-ITSEA scores for the Autism Spectrum Disorder, Psychiatric Disorders and Matched control groups supported the discriminant validity of the K-ITSEA. CONCLUSION: This preliminary results indicate that the K-ITSEA would be a useful assessment for detecting the early childhood's behavior problems and competences in Korean population.

Measuring theory of mind in schizophrenia research: Cross-cultural validation.

Theory of mind (ToM) is the ability to understand mental states of others and it is crucial for building sensitivity to other persons or events. Measuring ToM is important for understanding and rehabilitating social cognitive impairments in persons with schizophrenia. The Social Attribution Task-Multiple Choice (SAT-MC) has been successfully employed to measure ToM between individuals with schizophrenia (SZ) and healthy controls (HC) in North America. Given that the SAT-MC uses geometric shapes, is nonverbal and less culturally loaded than other social cognition measures, it may serve for measuring ToM in schizophrenia across cultures. A total of 120 participants (30 per group; Korean SZ; Korean HC; North American SZ; North American HC) were selected from existing databases to examine the reliability and validity of the SAT-MC. Internal consistency, factor structure, measurement invariance, discriminant validity, and convergent/divergent validity were examined. The SAT-MC had good internal consistency regardless of the clinical and cultural group as evidence by Cronbach's α ≥ 0.78 in all groups. Confirmatory factor analysis confirmed the one-factor model with a good model fit (χ2 = 188.122, TLI = 0.958, CFI = 0.963, RMSEA = 0.045). The SAT-MC was sensitive to detect individual differences in ToM of SZ and HC, regardless of culture (p < 0.001), and significantly correlated with other social cognition tasks (Hinting and Reading the Mind in the Eyes Test) among Korean and North American patients. The SAT-MC is a reliable measure for evaluating ToM in both Koreans and North Americans with or without schizophrenia, supporting its potential utility in diverse language and cultures for schizophrenia research.

Characterization and mapping of a shattering mutant in rice that corresponds to a block of domestication genes.

Easy shattering reduces yield due to grain loss during harvest in cereals. Shattering is also a hindrance in breeding programs that use wild accessions because the shattering habit is often linked to desirable traits. We characterized a shattering mutant line of rice, Hsh, which was derived from a nonshattering japonica variety, Hwacheong, by N-methyl-N-nitrosourea (MNU) treatment. The breaking tensile strength (BTS) of the grain pedicel was measured using a digital force gauge to evaluate the degree of shattering of rice varieties at 5, 10, 15, 20, 25, 30, 35, and 40 days after heading (DAH). The BTS of Hwacheong did not decrease with increasing DAH, maintaining a level of 180-240 gf, while that of Hsh decreased greatly during 10-20 DAH and finally stabilized at 50 gf. Optical microscopy revealed that Hsh had a well-developed abscission layer similar to the wild rice Oryza nivara (accession IRGC105706), while Hwacheong did not produce an abscission layer, indicating that the shattering of Hsh was caused by differentiation of the abscission layer. On the basis of the BTS value and morphology of the abscission layer of F(1) plants and segregation data in F(2) populations, it was concluded that the easy shattering of Hsh was controlled by the single recessive gene sh-h. The gene sh-h was determined to be located on rice chromosome 7 by bulked segregant analysis. Using 14 SSR markers on rice chromosome 7, the gene sh-h was mapped between the flanking markers RM8262 and RM7161 at distances of 1.6 and 2.0 cM, respectively. An SSR marker Rc17 cosegregated with the gene sh-h. The locus sh-h for shattering was tightly linked to the Rc locus conferring red pericarp, as well as a QTL qSD(s)-7-1 for seed dormancy, implying that this region might represent a domestication block in the evolutionary pathway of rice.

Identification of QTLs associated with physiological nitrogen use efficiency in rice.

Demand for low-input sustainable crop cultivation is increasing to meet the need for environment-friendly agriculture. Consequently, developing genotypes with high nutrient use efficiency is one of the major objectives of crop breeding programs. This study was conducted to identify QTLs for traits associated with physiological nitrogen use efficiency (PNUE). A recombinant inbred population (DT-RILs) between Dasanbyeo (a tongil type rice, derived from an indica x japonica cross and similar to indica in its genetic make-up) and TR22183 (a Chinese japonica variety) consisting of 166 F8 lines was developed and used for mapping. A frame map of 1,409 cM containing 113 SSR and 103 STS markers with an average interval of 6.5 cM between adjacent marker loci was constructed using the DT-RILs. The RILs were cultivated in ordinary-N (N-P2O5-K2O = 100-80-80 kg/ha) and low-N (N-P2O5-K2O= 50-80-80 kg/ha) (100 kg/ha) conditions. PNUE was positively correlated with the harvest index and grain yield in both conditions. Twenty single QTLs (S-QTLs) and 58 pairs of epistatic loci (E-QTLs) were identified for the nitrogen concentration of grain, nitrogen concentration of straw, nitrogen content of shoot, harvest index, grain yield, straw yield and PNUE in both conditions. The phenotypic variance explained by these S-QTLs and E-QTLs ranged from 11.1 to 44.3% and from 16.0% to 63.6% , respectively. The total phenotypic variance explained by all the QTLs for each trait ranged from 35.8% to 71.3%, showing that the expression of PNUE and related characters depends significantly upon genetic factors. Both S-QTLs and E-QTLs may be useful for marker-assisted selection (MAS) to develop higher PNUE genotypes.

Identification of QTLs for some agronomic traits in rice using an introgression line from Oryza minuta.

Wild progenitor species provide potential gene sources for complex traits such as yield and multiple resistances to biotic and abiotic stresses, and thus are expected to contribute to sustainable food supplies. An introgression line 'IR71033-121-15' was derived from a wild species Oryza minuta (2n = 48, BBCC, Acc No. 101141) at IRRI. Introgression analysis using 530 SSR and STS markers revealed that at least 14 chromosomal segments distributed over 12 chromosomes had been introgressed from O. minuta. An F2:3 population from the cross between IR71033 and Junambyeo (a Korean japonica cultivar) consisting of 146 lines was used for quantitative trait loci (QTL) analysis of 16 agronomic traits. A total of 36 single-locus QTLs (S-QTLs) and 45 digenic epistasis (E-QTLs) were identified. In spite of it's inferiority of O. minuta for most of the traits studied, its alleles contributed positively to 57% of the QTLs. The other QTLs originated from either parent, IR71033 or Junambyeo. QTLs for phenotypically correlated traits were mostly detected on introgressed segments. Fourteen QTLs corresponded to QTLs reported earlier, indicating that these QTLs are stable across genetic backgrounds. Twenty-two QTLs controlling yield and its components had not been detected in previous QTL studies. Of these, thirteen consisted of potentially novel alleles from O. minuta. QTLs from O. minuta introgression could be new sources of natural variation for the genetic improvement of rice.