Study On Selection And Ecological Adaptability Of New Corn Variety Nongle 988 Examined And Approved By The State

Nongle 988 is a new maize cultivar, which is approved by the second session of National Crop Cultivar Approval Committee, the validation code: guoshenyu 2008011. The cultivar was selected by the author when he worked at Xinxiang Seed Company. In this paper, the author reviewed the history of Chinese maize breeding, analyzed the breeding process, ecological adaptability and physiological characteristic of the hybrid Nongle988, put forward a set of corresponding integrated cultivation measures, and provided the foundation of theoretical and technical for production application of the cultivar.1. The history of maize breeding in China demonstrates that continuous innovation of germplasm is the basic for improving maize breeding level. Maize breeding in China from the elite selection of good varieties to intervarietal hybrid, double hybrid, triple hybrid, single-cross hybrid, taking full advantage of heterosis, and introducing new germplasm resources, improving and modifying germplasm gradually. Many elite hybrids have been bred which were applied in maize production, it made Chinese maize production development steadily.2. Maize growth and development and yield formation is decided by ecological factors. So the ecological adaption of a new cultivar and complementary cultural practice of it should be considered. The key factor of maize culture technology is proper destiny.3. Practices prove that the heterotic model of basic material from P group and Raid group crossed with Huangzaosi modified line is a successful breeding method. Maternal line NL278 for Nongle988 is derived from 3189(Raid group) and Dan 3130 (P group), male parent NL167 of the hybrid is derived from the Chang 7-2 and 5237 (Tangsipingtou modified lines). 4 Nongle 988 is a stay-green cultivar with dark green leaf, high growth vigor, prominent disease resistance character, large and uniform ear, high rate of seed and seed setting rate, and high yield traits. Its average yield is 9351.0 kg/ha in 2006 and 2007 in Huanghuaihai summer maize regional test, which is 5.63% higher than the control Zhengdan 958. In the production test, the average yield of Nongle 988 is 9283.5 kg/ha in 2007, which is 4.84% more than the control Zhengdan 958.5. According to the result of National Maize Variety Regional Trials in 2006 and 2007, compared with other cultivars, which participated in the trial, the yield of Nongle988 is more stable. By the yield difference significant analysis of 20 places in two years, this cultivar had significant differences in 20 places and different adaption character in different place.6. There has different yield of Nonele988 under different plant destiny. According to density experiment results, the proper plant density of Nonele988 is 52500-60000.7. Comparing with the main elite hybrid Zhengdan958 in China, Nongle988 had a higher dry matter accumulation at different period from jointing stage to maturity, which indicates that Nongle988 has a higher material production capacity. Although Nongle988 silks later than Zhengdan958, however Nongle 988 has a faster grain-filling rate at the beginning stage, and keeps a longer filling time. Furthermore Nongle988 has better stay-green traits at late period with bigger green leaf area and more green leaves.