Combining Ability and Heterosis of 12 Different Kinds of Tropic Maize Populations

The present experiment used Tuxpeno,Suwan1,Double M9(DM9) and Ye 478 to obtain 9 maize populations with 25 %-75 % tropic and subtropical germplasm.NCⅡ design was adopted in this experiment to study the combining ability and heterotic of the 12 maize population combined with testers of Dan340,Chang7-2,Mo17,Qi319,CML161,CI44 and Tafa2.The results showed that the general combining ability(GCA) of Tuxpeno,Suwan1,the populations with 50 %-75 % DM9 and 75 % Tuxpeno germplasm proportion were higher than the others,whereas the GCA of the populations with 25 %-50 % Tuxpeno,50 % Suwan1 and 25 % DM9 germplasm proportion were lower.In the mode of tropic germplasm combining with tropic germplasm,different combinations with tropic germplasm all obtained higher yield and the highest yield were observed in the combinations with 50 %-75 % tropic germplasm combined with CML 161 and CI44.In the mode of tropic germplasm combining with temperate germplasm,the heterosis between combinations with different proportional tropic germplasm combined with temperate testers showed significant differences.The combining ability of Tuxpeno and populations with 25 % other tropic germplasm combined with Dan340 was lower.The inbred lines CML161 and CI44 could effectively identify different materials and were good testers for local maize germplasm.