北京地区玉米就地加代技术的初步研究

1984—1986年在北京进行早熟、中早熟玉米一年两季加代试验.试验结果表明.第一季加代采用早春(3月上旬—下旬)温室育苗,3月末至4月上旬移栽到塑料薄膜复盖的阳畦、小棚或大棚;以及3月下旬直播于铺设电热线的阳畦,大棚等增温保温措施,早熟、中早熟玉米自交系和育种材料。可于5月下旬进入抽雄、吐丝、散粉期,7月上旬末以前收获授粉后25—30天果穗,种子发芽率可达到80%以上,第二季加代采用上季25—30天嫩粒,经2%H_2O_2浸种24小时,于7月上旬播种(气温偏高年份还可适当延迟播种),在大田条件下,8月下旬可进入抽雄、吐丝、散粉期,授粉工作可进行到9月上旬末,10月底以前收获的种子,发芽率一般达80%左右,高的达90%以上.H_2O_2处理玉米种子可明显加速种子发芽,促进幼苗生长.采用了短日照处理(8—10小时日照)生育后期叶面喷磷钾肥和乙烯利等促进早熟措施,对本试验成功实现一年两季加代,均取得了一定效果。

A PRELIMINARY STUDY ON TECHNIQUE OF ADDING GENERATION IN MAIZE BREEDING IN BEIJING

The experiment on the technique of adding generation of maize twice a yearwere carried out in Beijing during 1984-1986.The result of experiment showedthat temperature could be increased and kept optimum for maize in the firstseason by raising seedling in greenhouse from first decade to third decade inMarch, followed by transplanting seedling into the plastic-cove-red seedbedwith windbreaks,or into plastic greenhouse. It is also possible to plant the maizeseeds directly into electric heater seedbed with windbreaks, or in the plas-tic greenhouse. In both ways the early and medium-early inbred lines andbreeding materials of maize arrived at heading-silking-pollinating stage bythe third decade in May.The ears were collected at 25-30 days after pollin-ation with seeds of germination rate above 80%. Then the seeds of firstgeneration were treated with 2% H_2O_2 for 24 hours and planted in the fieldin the first decade of July, or a few days later under higher temperature.The maize of 2nd generation in the field conditions entered its heading-silking-pollinating stage at the third decade in August. Pollination could beeffective till the end of first decade of September. Seeds collected by theend of October with the germination rate above 80-90% or more.Germinatingenergy and seedling development could be improved by seed treatment with2% H_2O_2.Seed maturation were accelerated in the experiment by short-daytreatment (8 or 10 hr per day), application of P K and Ethral sprayingat late growth stage.