RESUMEN
Evaluation of a set of 10 F1 hybrids along with their female (27A and 7A) and male parents (C 43, RS 673, RS 627, CB 26, and CB 29) for grain yield and its component traits revealed that grain yield/plant followed by panicle weight, primary branches/panicle, and 100-seed weight exhibited high levels of heterosis. Eight hybrids exhibited 50% or more mid-parent heterosis for grain yield/plant, of which, one hybrid (27A × RS673) recorded heterobeltiosis above 50% (73.61%). Differential display analysis generated about 2995 reproducible transcripts, which were categorized as UPF1-expressed in any one of the parents and F1 (10.53-14.76%), BPnF1-expressed in both parents but not in F1 (4.56-11.44%), UPnF1-expressed in either of the parents and not in F1 (17.95-27.40%), F1nBP-expressed only in F1 but not in either of the parents (14.39-20.54%), and UET-expressed in both parents and F1 (34.52-42.43%). A comparison between high and low heterotic hybrids revealed that the proportions of UPF1 and F1nBP transcript patterns were much higher in the former (21.31% and 45.24%) as compared to the latter (16.67% and 32.14%) at the booting and flowering stage, respectively, indicating the role of over-dominance and dominance in the manifestation of grain yield heterosis. Significant positive correlations were observed for differential transcript patterns with mid-parent and better-parent heterosis for the components of grain yield such as primary branches (0.63 and 0.61 at p < 0.01) and 100-seed weight (0.64 and 0.52 at p < 0.01). Cloning and sequence analysis of 16 transcripts that were differentially expressed in hybrids and their parental lines revealed that they code for genes involved in basic cellular processes, cellulose biosynthesis, and assimilate partitioning between various organs and allocation between various pathways, pyrimidine, and polyamine biosynthesis, enhancing ATP production and regulation of plant growth and development.
RESUMEN
BACKGROUND: Human beings regularly walk over even and uneven surfaces during their daily activities. A human being with lower limb disability needs an exoskeleton to walk independently. However, walking surface irregularities increase the risk of falling of exoskeleton users. This falling tendency can be minimized by balancing the exoskeleton on irregular surface profiles against the gait cycle variation. Gait variation is studied using quality EMG signals obtained from the gastrocnemius and hamstring muscle activity during uneven surface walking. OBJECTIVE: The present study compares the activity of hamstring and gastrocnemius muscles during walking on a treadmill, utilizing both even and uneven planes. METHODS: Integrated electromyography signals from eight healthy male subjects are collected while walking on a treadmill, even and uneven planes. Muscle activity variation on these planes is studied using two-way ANOVA with replications. RESULTS: The results show that hamstring muscle activity registers a sound variation in swing phase but has no variation in stance phase over all three planes, whereas gastrocnemius muscle activity changes between swing and stance phases over even and uneven planes during forward walking. CONCLUSIONS: The results illustrate that the gait cycle variation depends on surface irregularities which indicates the importance of surface consideration.
Asunto(s)
Marcha , Músculos Isquiosurales/fisiología , Músculo Esquelético/fisiología , Adulto , Electromiografía , Humanos , Masculino , Propiedades de Superficie , CaminataRESUMEN
The cultivar Ajaya (IET 8585) exhibits durable broad-spectrum resistance to bacterial blight (BB) disease of rice and is widely used as a resistance donor. The present study was carried out to decipher the genetics of BB resistance in Ajaya and map the gene(s) conferring resistance. Genetic analysis in the F2 indicated a quantitative/additive nature of resistance governed by two loci with equal effects. Linked marker analysis and allelic tests revealed that one of the resistance genes is xa5. Sequence analysis of a 244 bp region of the second exon of the gene-encoding Transcription factor IIAγ (the candidate gene for xa5) confirmed the presence of xa5. Bulked-segregant analysis (BSA) revealed the putative location of the two quantitative trait loci (QTLs)/genes associated with resistance on chromosomes 5 and 8. Composite interval mapping located the first locus on Chr. 5S exactly in the genomic region spanned by xa5 and the second locus (qtl BBR 8.1) on Chr. 8L. Owing to its differential disease reaction with a set of seven hyper-virulent isolates of Xanthomonas oryzae, a map location on Chr. 8L, which was distinct from xa13 and data from allelism tests, the second resistance locus in Ajaya was determined to be novel and was designated as xaAj. A contig map spanning xaAj was constructed in silico and the genomic region was delimited to a 13.5 kb physical interval. In silico analysis of the genomic region spanning xaAj identified four putatively expressed candidate genes, one of which could be involved in imparting BB resistance in Ajaya along with xa5.