25份美国玉米自交系的利用潜力分析

采用NCII遗传交配设计，以优良玉米自交系CA193和CA749为测验种，与25份美国玉米自交系配制杂交组合，以吉单27和先玉335为对照，根据主要农艺性状表现、配合力和杂种优势分析，评价25份美国玉米自交系的育种利用潜力。结果表明，2MCDB、LH198、PHR63、LH184、PHHH9、MBWZ、PHJR5、LH186、PHT47、LH217、PHMK0、PHEG9和LH218自交系产量一般配合力较高，其中，5份自交系2MCDB、LH184、LH186、PHJR5和PHT47具有降低收获时含水量特点，PHT47和PHJR5具有增加穗行数、缩短生育期的优点，利用潜力最大。针对CA193和CA749产量低、穗行数少的缺点，遴选出2个组合CA193×PHT47和CA749×2MCDB，可作为基础群体用于自交系选育。3个组合CA193×PHT47、CA193×2MCDB和CA193×PHJR5产量显著高于吉单27，可用于杂交种选育。

Analysis on Utilization Potential of 25 Expired Proprietary (Ex-PVP) U.S. Corn Inbred Lines

Twenty five expired proprietary(ex-PVP) U.S. corn inbred lines were crossed to two elite tester inbred lines CA193 and CA749 by NCII genetic design. These crosses and two hybrid checks Jidan27 and Xianyu335 were evaluated for main agronomic traits in Gongzhuling of Jilin province and Harbin of Heilongjiang province to analyze the breeding potential of 25 ex-PVP U.S. inbred lines. The results showed that 13 inbred lines, including 2MCDB, LH198, PHR63, LH184, PHHH9, MBWZ, PHJR5, LH186, PHT47, LH217, PHMK0, PHEG9 and LH218, had high general combining abilities(GCA) effects for grain yield. Four of the 13 elite lines, 2MCDB, LH184, LH186, PHJR5 and PHT47, also showed the potential of reducing moisture content in harvest time. The inbred line PHT47 and PHJR5 had the best breeding potential for increasing ear row number and shortening growth period. The two cross, CA193×PHT47 and CA749×2MCDB, could be used to develop new lines targeting to the two lines CA193 and CA749, since they showed moderate yield and more row number per ear. The three high-yielding crosses comparing to Jidan27 hybrid, CA193×PHT47, CA193×2MCDB and CA193×PHJR5, could be tested to develop new hybrids.