不同年代玉米品种苗期耐旱性的比较分析

Comparative Analysis of Seedling Drought Tolerance of Different Era Maize Varieties

我国北方地区时常发生春旱,严重影响玉米生产。因此苗期耐旱性是玉米育种中需要考虑的一个重要性状。本试验选用20世纪50年代以来玉米品种35个,包括50年代农家种4个,60年代双交种4个,70年代以后的单交种27个,在旱棚内鉴定苗期耐旱性,调查幼苗的生物量(鲜重和干重),计算各品种的耐旱系数,分析苗期耐旱系数随年代及年份变化的趋势,并根据耐旱指数对70年代以来的27个单交种进行聚类。结果表明,干旱处理对供试品种生物量的影响显著。我国玉米品种的苗期耐旱性50至60年代快速提高,60年代及70年代以后呈下降趋势,70年代以来的27个单交种可分为3类,耐旱性强杂交种有鲁单50、群单105、农大108、掖单13、掖单4号、郑单2号,耐旱性弱的杂交种有农大3138、农大60、沈单16,其余为中间类型。下一步育种工作的重点之一是在自交系选育中加大干旱压力,为进而培育耐旱的杂交种奠定基础。

Spring drought often occurs in northern region,which affects the production of maize.So seedling drought tolerance is an important factor to account for in maize breeding.Thirty-five varieties included four OPVs（open pollened varieties）（1950s）,four double hybrids（1960s） and twenty-seven single hybrids（1970s-2000s）.Seedling drought tolerance was evaluated in drought house.Biomass of seedling was investigated,including fresh weight and dry weight.Coefficient of seedling drought tolerance was calculated.The trend and response of the coefficient on era were analyzed.The hybrids were clustered based on the coefficient of seedling drought tolerance from 1970s.The result indicated that drought stress influenced biomass significantly.The seedling drought tolerance increased from 1950s to 1960s and declined from 1960s to 1970s and afterwards.The single hybrids after 1970s were clustered into three groups.Six hybrids were most tolerant to seedling drought including Ludan 50,Nongda 108,Qundan 105,Yedan 13,Yedan 4,and Zhengdan 2.Nongda 60,Nongda 3138,and Shendan 16 had the worst tolerance.Therefore,the next task of maize breeding is to strengthen drought stress pressure in selecting inbred lines,which will establish a foundation for breeding the hybrids tolerant to drought.