Combining Ability of Different Agronomic Traits and Yield Components in Hybrid Barley
Selection of parents based on their combining ability is an effective approach in hybrid breeding. In this study, eight maintainer lines and nine restorer lines were used to obtain 72 crosses for analyzing the general combining ability (GCA) and special combining ability (SCA) for seven agronomic and yield characters including plant height (PH), spike length excluding awns (SL), inter-node length (IL), spikes per plant (SP), thousand kernel weight (TKW), kernel weight per plant (KWP) and dry matter weight per plant (DWP). The results showed that GCA was significantly different among parents and SCA was also significantly different among crosses. The performance of hybrid was significantly correlated with the sum of female and male GCA (TGCA), SCA and heterosis. Hu1154 A, Mian684 A, 86F098 A, 8036 R and 8041 R were excellent parents with greater general combining ability. Five crosses, Hu1154 A×8032 R, Humai10 A×8040 R, Mian684 A×8037 R, Mian684 A×8041 R and 86F098 A×8037 R, showed superior heterosis for most characters.
Combining Ability Studies in Maize ( Zea Mays L.)
The present study was conducted to assess the general combining ability effects of parents and specific combining ability effects of hybrids for yield and yield related traits and explore their use in hybrid development. 170 F1s generated by crossing thirty four lines with five testers were evaluated. The ratio of sca / gca variance revealed that there was preponderance of non additive gene action in the expression of all the traits under study. Inbred lines viz., MAI 708, MAI 109, MAI 111, MAI 121, Cymt 3 and Cymt 30 were good general combiners for yield and yield attributing characters. Tester CM 500 was high combiner for grain yield. Among the hybrids, MAI 109 X MAI 105, MAI 109 X CM 202, Cymt 30 X NAI 137, Cymt 3 X SKV 50 and Cymt 3 X CM 202 exhibited highest significant sca effects and high heterosis over checks for yield and yield attributing traits.
Differences in the length of initial hospital stay in very preterm infants
Aim: To investigate the effect of maternal, infant and birth hospital district related factors on the length of initial hospital stay in very preterm infants. In addition, rehospitalization rate within the first year from the initial discharge was studied.