Vieira R A, Scapim C A, Moterle L M, Tessmann D J, Conrado T V, Amaral Júnior A T
Departamento de Agronomia, Universidade Estadual de Maringá, Maringá, PR, Brasil.
Genet Mol Res. 2009 Dec 1;8(4):1427-36. doi: 10.4238/vol8-4gmr655.
We estimated general and specific combining abilities and examined resistance to northern leaf blight (Exserohilum turcicum) and to gray leaf spot (Cercospora zeae-maydis) in a set of nine inbred popcorn lines. These inbreds were crossed in a complete diallel scheme without reciprocals, which produced 36 F(1) hybrids. Two experiments with a square lattice design and three replications were conducted during the 2008/2009 crop season, in Maringá, PR, Brazil. The severity of northern leaf blight and gray leaf spot was assessed under natural infestation conditions. Data were examined by individual and joint analysis of variance. Individual and joint Griffing's diallel analyses were carried out for adjusted means. General combining ability and specific combining ability were significant (P < 0.10) by the F-test for northern leaf blight and gray leaf spot infestation levels. This denotes that additive and non-additive gene effects both contributed to resistance to these diseases, but that the additive gene effects were more important. Among the inbred lines, P(8) and P(9) gave the highest resistance to northern leaf blight, and P(3) and P(4.3) gave the highest resistance to gray leaf spot. The hybrids P(7.4) x P(8) and P(4.3) x P(9) could be exploited by reciprocal recurrent selection to provide genotypes with both northern leaf blight and gray leaf spot resistance. Significant interaction between general combining ability and crop season (P < 0.10) denotes the importance of environment, even though the disease levels in the hybrids were quite consistent.
我们评估了9个自交爆裂玉米品系的一般配合力和特殊配合力，并检测了它们对玉米大斑病（凸脐蠕孢菌）和玉米灰斑病（玉米尾孢菌）的抗性。这些自交系采用完全双列杂交设计进行杂交，不进行正反交，共产生36个F1杂种。2008/2009作物季在巴西巴拉那州马林加市进行了两项试验，采用方形格子设计，重复3次。在自然侵染条件下评估玉米大斑病和玉米灰斑病的严重程度。通过个体和联合方差分析对数据进行检验。对校正均值进行个体和联合格里芬双列分析。对于玉米大斑病和玉米灰斑病的侵染水平，通过F检验，一般配合力和特殊配合力均显著（P < 0.10）。这表明加性和非加性基因效应均对抗病性有贡献，但加性基因效应更为重要。在自交系中，P(8)和P(9)对玉米大斑病的抗性最高，P(3)和P(4.3)对玉米灰斑病的抗性最高。杂种P(7.4)×P(8)和P(4.3)×P(9)可通过互交轮回选择加以利用，以获得兼具玉米大斑病和玉米灰斑病抗性的基因型。一般配合力与作物季之间存在显著互作（P < 0.10），这表明环境的重要性，尽管杂种中的病害水平相当一致。
