Abstract:

The aim is to provide a scientific basis for the improvement of excellent maize inbred lines, the breeding of hybrids and the innovation of maize germplasm. 11 maize inbred lines, such as ‘Huangzao 4’, ‘Chang 7-2’, ‘Xinong 672’ and so on, were chosen for making 30 hybrid combinations as experimental materials with NCⅡ incomplete dialed cross design, the randomized block design was conducted in field experiments, and field investigation and indoor identification were combined to study the characteristics. LNT-SPSS software program was used to analyze the test data. The results were as follows: (1) the general combining abilities of the characteristics of ‘Huangzao-4’ inbred lines were generally low, the negative effect was obviously greater than the positive effect, only plant height, ear height and leaf area coefficient were positive; (2) the general combining abilities of the characteristics of ‘Chang 7-2’ were higher than those of ‘Hangzhou 4’, plant height, ear height and leaf area coefficient, rows per ear, grains per row, grain ratio and yield were positive, but ear length, length of seed setting and 100-grain weight were negative; (3) the ear length, length of seed setting, rows per ear, grains per row and yield of ‘Xinong 672’ had high positive effect, but 100-grain weight and grain ratio showed negative effect, the plant height, ear height and leaf area coefficient of ‘Xinong 672 were negative, they were adverse to those of ‘Chang 7-2’ and ‘Hangzao 4’. In conclusion, high base point inbred line receptor, donor group, successive new excellent genes’ introduction, the additive genetic variance utilization, and cumulating frequency of excellent genes are the key techniques for breeding new and excellent maize inbred lines.

Key words: maize, Huangzao 4, hybrid combination, general combining ability, positive effect, negative effect