Genetic analysis for high temperature tolerance in bread wheat

Heat stress, characterised by a trend in average temperature increase during anthesis and grain filling, leads to forced maturity is one of the major constraints of wheat production in arid and, semiarid regions of the world. This study examined the nature and magnitude of gene action for yield and its contributing characters and some important heat tolerant parameters in bread wheat (Triticum aestivum l em. thell) to determine breeding strategies for future breeding programmes. Twelve lines and four testers were crossed in an L x T mating design. The 48 crosses and their parents were raised under normal (21, November 2002) and late sown (1, January 2003) seasons at the Experimental Farm of Rajasthan College of Agriculture, Udaipur in India. Lines K’sona, DWR 195, C 306 and K 9708 were found to be good combiners for different heat tolerant parameters along with grain yield. Combinations of Raj 3077 x Kailash under normal (E1) and late sown (E2), C 306 x PBN 51 (E1) and C 306 x HD 2189 (E2) for grain yield; had high sca effect. The crosses viz., K 9708 x PBN 51 for proline content and heat injury, DWR 195 with HD 2189, and C 306 with Kailash for heat injury had desirable significant sca effects. The other crosses, HD 2329 x Kailash for pollen viability, and Raj 3765 x Kailash for chlorophyll content, were the best specific combiners. Parents like C 306, K’sona, DWR 195, K 9708, Raj 3077, PBN 51 and Kailash could be utilised in multiple crossing programmes and further biparental matting for selection of high yielding progenies for heat tolerance

Validity and reliability of subjective methods to assess sedentary behaviour in adults: a systematic review and meta-analysis.

BACKGROUND: Subjective measures of sedentary behaviour (SB) (i.e. questionnaires and diaries/logs) are widely implemented, and can be useful for capturing type and context of SBs. However, little is known about comparative validity and reliability. The aim of this systematic review and meta-analysis was to: 1) identify subjective methods to assess overall, domain- and behaviour-specific SB, and 2) examine the validity and reliability of these methods. METHODS: The databases MEDLINE, EMBASE and SPORTDiscus were searched up to March 2020. Inclusion criteria were: 1) assessment of SB, 2) evaluation of subjective measurement tools, 3) being performed in healthy adults, 4) manuscript written in English, and 5) paper was peer-reviewed. Data of validity and/or reliability measurements was extracted from included studies and a meta-analysis using random effects was performed to assess the pooled correlation coefficients of the validity. RESULTS: The systematic search resulted in 2423 hits. After excluding duplicates and screening on title and abstract, 82 studies were included with 75 self-reported measurement tools. There was wide variability in the measurement properties and quality of the studies. The criterion validity varied between poor-to-excellent (correlation coefficient [R] range - 0.01- 0.90) with logs/diaries (R = 0.63 [95%CI 0.48-0.78]) showing higher criterion validity compared to questionnaires (R = 0.35 [95%CI 0.32-0.39]). Furthermore, correlation coefficients of single- and multiple-item questionnaires were comparable (1-item R = 0.34; 2-to-9-items R = 0.35; ≥10-items R = 0.37). The reliability of SB measures was moderate-to-good, with the quality of these studies being mostly fair-to-good. CONCLUSION: Logs and diaries are recommended to validly and reliably assess self-reported SB. However, due to time and resources constraints, 1-item questionnaires may be preferred to subjectively assess SB in large-scale observations when showing similar validity and reliability compared to longer questionnaires. REGISTRATION NUMBER: CRD42018105994