Genetics and Plant Breeding, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India.
Genetics and Plant breeding, AICRP on Maize, MARS, Dharwad, University of Agricultural Sciences, Dharwad, Dharwad, Karnataka, India.
PeerJ. 2024 Jun 25;12:e17600. doi: 10.7717/peerj.17600. eCollection 2024.
Combining ability status of the inbred lines is crucial information for hybrid breeding program. Diallel or line × tester mating designs are frequently used to evaluate the combining ability. In the current study a modified diallel model was used, wherein the Griffing's combining ability effects were further partitioned to understand the effects due to maternal and reciprocal. To do this, eight parental lines of maize were crossed in full diallel method and the generated hybrids along with parents were phenotyped. The field data on the quantitative traits was analyzed using both Griffing's and the modified model to determine how well the parents' and the F hybrids combined. For each of the traits, a sizable reciprocal and maternal variance was observed. The number of kernel rows per cob variable had a ratio of additive variance to dominance variance greater than one. All other traits including grain yield had a ratio close to zero, suggesting that non-additive gene action was primarily responsible for the genetic control of most of the traits. The narrow sense heritability was low to moderate for majority of the variables, except for number of kernel rows per cob. With the help of the improved model, it was possible to choose superior parents and cross-parent pairings with accuracy. Based on the modified general combining ability effects and maternal effects, the parental line P5 was recognized as a potential female parent and P7 as a good male parent for grain yield and yield-attributing characteristics. The cross combination of P8×P1 had the highest specific combining ability effect on grain yield. P5×P6 cross had the highest reciprocal effect. The correlation analysis implies that the Griffing's general combining ability effects and specific combining ability effects were found to be less efficient in predicting F performance as compared to the modified model.
自交系的配合力状况是杂交育种计划的关键信息。通常使用完全双列杂交或系×测验种交配设计来评估配合力。在本研究中,使用了一种改良的双列模型,其中格里芬的配合力效应进一步分为母本和反交效应,以了解母本和反交的效应。为此,将 8 个玉米亲本系按完全双列杂交法杂交,杂种及其亲本进行表型鉴定。使用格里芬模型和改良模型分析了数量性状的田间数据,以确定亲本和 F1 杂种的组合情况。对于每个性状,都观察到相当大的反交和母本方差。每穗粒行数变量的加性方差与显性方差之比大于 1。包括籽粒产量在内的所有其他性状的比值接近零,表明非加性基因作用主要负责大多数性状的遗传控制。除每穗粒行数外,大多数变量的狭义遗传力均为低到中等。借助改良模型,可以准确地选择优良的亲本和杂交亲本组合。根据改良的一般配合力效应和母本效应,发现 P5 系是一个有潜力的雌性亲本,P7 系是一个良好的雄性亲本,可用于提高籽粒产量和产量性状。P8×P1 的杂交组合对籽粒产量具有最高的特殊配合力效应。P5×P6 杂交具有最高的反交效应。相关分析表明,与改良模型相比,格里芬的一般配合力效应和特殊配合力效应在预测 F1 表现方面效率较低。