University of Guilan Cereal Research 2252-0163 7 1 2017 05 22 The selection of maize lines derived from CIMMYT germplasm through combining ability with temperate testers The selection of maize lines derived from CIMMYT germplasm through combining ability with temperate testers 101 114 2431 10.22124/c.2017.2431 FA Mohammadreza Shiri Research Assist., Seed and Plant Improvement Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran Laleh Ebrahimi Research Assist., Dept. of Plant Protection Research, Ardabil Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Moghan, Iran Journal Article 2015 12 08 To assess the combining ability of lines derived from tropical and subtropical CIMMYT germplasm with temperate region lines and to determine their heterotic groups, twenty eight crosses of four temperate maize testers (MO17, K18, K166B and A679) with seven lines originated from CIMMYT germplasm were evaluated along with two hybrid checks (SC704 and SC705) using randomized complete block design with three replications, in Moghan, Iran, in two years 2012-13. The results of line×tester analysis to estimate gene action showed that both additive and non-additive effects played an important role in controlling grain yield and other traits. The estimation of general combining ability showed that there was the possibility of direct improvement of grain yield via lines No. 3, 5 and 7. Also, positive significant specific combining ability were only found for L3×MO17 testcross. In order to learn more about lines derived from various sources of CIMMYT germplasm and to assign lines to heterotic groups, HSGCA effects were calculated. According to the HSGCA, the reaction of line 1 was similar to Lancaster-Sure-Crop’s heterotic group, lines 3 and 4 had similar reaction to Reid-Yellow-Dent’s heterotic group and line 6 had similar reaction to K166B’s heterotic group (a tester extracted from none-temperate CIMMYT originated materials in Iran) and the other lines showed no similar reaction to the heterotic groups of the studied testers. These results showed that using more testers as well as more than one tester from each heterotic group, is necessary to identify appropriate sources of the tropical and subtropical germplasm to facilitate the success in development of adapted maize germplasm. To assess the combining ability of lines derived from tropical and subtropical CIMMYT germplasm with temperate region lines and to determine their heterotic groups, twenty eight crosses of four temperate maize testers (MO17, K18, K166B and A679) with seven lines originated from CIMMYT germplasm were evaluated along with two hybrid checks (SC704 and SC705) using randomized complete block design with three replications, in Moghan, Iran, in two years 2012-13. The results of line×tester analysis to estimate gene action showed that both additive and non-additive effects played an important role in controlling grain yield and other traits. The estimation of general combining ability showed that there was the possibility of direct improvement of grain yield via lines No. 3, 5 and 7. Also, positive significant specific combining ability were only found for L3×MO17 testcross. In order to learn more about lines derived from various sources of CIMMYT germplasm and to assign lines to heterotic groups, HSGCA effects were calculated. According to the HSGCA, the reaction of line 1 was similar to Lancaster-Sure-Crop’s heterotic group, lines 3 and 4 had similar reaction to Reid-Yellow-Dent’s heterotic group and line 6 had similar reaction to K166B’s heterotic group (a tester extracted from none-temperate CIMMYT originated materials in Iran) and the other lines showed no similar reaction to the heterotic groups of the studied testers. These results showed that using more testers as well as more than one tester from each heterotic group, is necessary to identify appropriate sources of the tropical and subtropical germplasm to facilitate the success in development of adapted maize germplasm. https://cr.guilan.ac.ir/article_2431_397525de06285e9d49f249389aaaad2d.pdf