Study On The Evolution Trend Of Maize Varieties In NanYang Basin

Based on maize production in Nanyang City in the replacement of lead in 1950--2006, maize production history will be divided into seven phases, through the various stages of the leading statistical data from the production performance ,agronomic traits, Variety sources and germplasm base four aspects of study to identify the evolution of the use of corn varieties trends, the findings show that:1,From the history of the use of corn varieties, single cross replaced the farm species, the diversity of species dominated by a single species of alternative absolutely dominant position .Among them, maize production is to decide the main factors of new strains,but its status is gradually declining.2,Nanyang unique geographic position, natural environment complex, its"ideal corn" agronomic performance shows that:(1) reproductive period :100 - 110 days, to make full use of local production in Nanyang season.(2)the height and ear coefficient: Breeding parents may not strict height requirements, but must pay attention to ear coefficient.The best ear coefficient is 40 per cent of the following.(3) Nanyang city is the main summer planting maize. Due to the summer heat, wet, damp, small spot disease occur from time to time. Therefore in the production must be used of anti-small spot disease species. In Breeding Breeding should also pay attention to small spot disease of the species, at the same time balancing the spot disease.(4) plant type: maize varieties in the choice of plant type, semi-compact plant type is almost certain period of the mainstream, but compact in the future direction of development. (5) spinning and shedding: Nanyang City often encountered high temperature, dry weather in the corn spinning phase, the first after shedding and silking to pollination, reducing bald missing tablets, but less and less difference between the number of days therefore. We must pay attention to the male and female flowering consistency in the breeding Parents.(6) ear traits : ear length: 20 cm around ;ear lines: 14 - 16 firms; grain weight:350g; panicle:cylinder.(7) tablets type, a half-tooth; grain color, yellow tablets. 3,Breeding in the future should pay attention to the application of local blood.