Analysis On Effect For 2 CIMMYT Maize Populations By Mass Selection

Maize population generally has broad genetic background, and carries specific and favorable alleles. Therefore, systemic evaluations on populations are important for broadening the genetic base of maize germplasm in China. In this study, a total of 10 improved populations derived from different cycles of two CIMMYT populations are crossed on 2 testers, Ye478, Huangzaosi. By measuring the grain yield, silking date, and plant height of the different populations and the populations in different cycles of the test crosses, an all-round evaluation is derived on the 25 populations .The results are as follows :The method of under biparental mass selection is a good way to improved the sensibility of photoperiod of the subtropical belt and tropical zone maize populations .By 5 cycles selection used this method , days to silking, plant height and ear height are all like the C4'short . Compared the plant height and silking date in different cycles'populations, they have the same maximum. This showed the tightening chain traits of the plant height and silking date are inherited stably.By compare with the populations of the C0, the high yield of plant of the two improved C4 populations is the highest., but they have the different improvement in the two the populations. The yield of Suwan1 is better than Pob43's, but the improvement effection has the obviously different between with the cross of Huangzaosi and Ye 478 . Suwan1 and Ye478 was stronger than that of Huangzao4.Heterotic patterns with furthest popularization potential were Pob43×478 and Suwan1×478 in Huanghuaihai summer maize region. It is an effective method to improve Sipingtou germplasm by Suwan1 and Pob43 and combinate hybrid with Reid germplasm.It is important to improve the sensibility of photoperiod for Suwan1 and Pob43 in the next step. To shorten days to silking for Suwan1 and plant height for Pob43 is the emphasis.