| Experiment was conducted in cultivating room of college of Agronomy, AUH during 2009-2010 with 12 hybrids and 14 inbred lines of maize. The growth and development of seedling (from sowing to 7 leaf stage) were studied, and the focus were on the growth and development of root system and its characteristics including root mass, volume, root length density, surface area and root angle. This study was of great meaning in both theory and practices in further explicit the root characteristics of different maize germplasm, the relationship between shoot and root, and the relations between root character and drought tolerant. The results are showed as follows.1. Growing bag culture method was first set up based on the inconvenient of pot culture method in root character study. Compared with the 2 culture methods it could be found easily that growing bag method was more practicable and advantageous than pot culture method in studying the relationship between shoot and root of maize seedlings, and it was also a good culture method for the study of root characteristics of different germplasm. Using growing bag culture method combined with peg board fixing and root washing the root characteristics could be studied easily, such as the measurement of second root layers, root number, root angles of different root layers, and so on. The growing bag could be made easily and cheap, took little room. This method can be used in massive screening of root character of maize germplasm, even in the root study of other crops.2. Effect of environment factors on the growth and development of maize seedlings were studied. The results showed that maize seedling grew well at 1.0g urea per growing bag; irrigated 100ml water per bag every 3 days was reasonable for good seedling growing; compared with the sandy soil maize seedling grew well on loam soil.3. The growth and development of maize varieties Zhengdan 958 and CN165 was compared and a significant different was showed both in shoot and root characters. Every item of Zhengdan 958 increased at a big extent with the leaf stage, while for CN165 the scale was much lower. CN165 is a drought tolerant variety, the short plant and less second root number might have something to do with its water-saving and drought tolerant.4. It could be found from the comparison of 12 hybrids and 12 inbred lines that hybrids grew well than inbred lines both in shoot and root, and there were significant difference in plant height, leaf area, shoot and root dry weight at 7 leaf stage, but the difference was not significant in root and shoot ratio. Though the root mass of drought tolerant variety CN165 was lower than other varieties, its root length and volume and root surface area took a higher proportion at 0-20 cm soil layer. Compared with inbred lines the hybrids had a much more proportion of roots within the shallow soil layer.5. The root angle of every maize germplasm at root layers was measured, and the average angle was different. The root angles were decreased with the increase of root layers. Root distribution of the 2nd root layer was checked, the results showed that the root angles were a little bigger in drought tolerant germplasm, such as CN165, Zhongdan 8578, Jiyu 10, and Xundan 20, causing more roots distributed in the shallow soil layer; while for other germplasm like Xianyu 335, Zhengdan 958, Liyu 18, and Yongyan 4 need much water and the root angles were smaller, caused the root mass concentrated in the inner plant axis other than the out range. Different maize germplasm had there proper root characters. The relationships between root angle and the ability of drought tolerant need further study.
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