Abstract:

The performance and characteristics of the new corn hybrid ‘Zhongkeyu 505’ are reported here to provide theoretical and practical information needed for large-scale commercialization of this hybrid. ‘Zhongkeyu 505’ was developed by crossing CT1668 as female parent and CT3354 as male parent. The yield performance, agronomic traits, drought resistance, high temperature tolerance, density tolerance, grain quality, and silage forage quality were analyzed based on the multi-year and multi-location data from national and provincial trials. The results showed that the yield of this hybrid increased by 3.4% and 8% respectively on average compared with that of the two check hybrid ‘Xianyu 335’ and ‘Zhengdan 958’. The ear characters such as ear length, ear diameter, kernel number per row, grain weight per ear and grain yield were better than those of the check hybrid. The drought tolerance reached the extremely strong standard, and the high-temperature tolerance reached the medium level equivalent to that of the check ‘Zhengdan 958’. The grain test weight was 746 g/L, the crude protein, crude fatty acid, crude starch, and lysine content reached 10.1%, 3.36%, 74.26%, and 0.3% respectively. The relative stalk feed quality was better than that of ‘Xianyu 335’ and ‘Zhengdan 958’. This hybrid is an excellent one of significant commercial value. In the process of commercial breeding of maize, special attention should be paid to the factors of the market safety evaluation of new varieties, seed production yield, stem rot, ear rot, Southern and Northern leaf blight, Southern rust, suitable planting density and lodging control etc., thus establishing a breeding method combining limited backcrossing with large population adversity screening.

Key words: maize, ‘Zhongkeyu 505’, variety breeding, commercial breeding, safety evaluation