Combining Ability of Maize Lines from Tropical and Subtropical Germplasm using Temperate Testers

This study aimed to assess the combining ability of maize lines derived from tropical and subtropical CIMMYT germplasm with temperate region tester lines. Thirty six crosses of four well-known temprate maize testers including a line from Lancaster Sure Crop hetrotic group (Mo17), a specific line derived from it (K18), a tester from Reid Yellow Dent hetrotic group (B73) and a particular line originate from it (K47/3) with nine lines originated from CIMMYT germplasm were evaluated using a randomized complete block design with three replications in Karaj, Dezful, Shiraz and Kermanshah for one year. The results of the gene action by line×tester analysis showed the additive and non-additive gene action in the expression of grain yield and other traits. Comparison of means results indicated that hybrids No. 32 had 8.641, No. 7 had 8.430 and No. 9 had 8.382 tha-1 grain yield.These hybrids were resulted from crossing line No. .5 with K18 and lines No. 7 and 9 with MO17 testers. Obtained results from general combining ability studies revealed that lines No. 5 had potential to be used directly for grain yield improvement. Specific combining ability of grain yield crosses showed a positive and significant SCA in case of line No. 4 with MO17 tester as well.