Vittorazzi C, Amaral Junior A T, Guimarães A G, Viana A P, Silva F H L, Pena G F, Daher R F, Gerhardt I F S, Oliveira G H F, Pereira M G
Laboratorio de Melhoramento Genetico Vegetal, Centro de Ciencias e Tecnologia Agropecuária, , , Brasil.
Laboratorio de Melhoramento Genetico Vegetal, Centro de Ciencias e Tecnologia Agropecuária, , , Brasil
Genet Mol Res. 2017 Sep 27;16(3):gmr-16-03-gmr.16039769. doi: 10.4238/gmr16039769.
Selection indices commonly utilize economic weights, which become arbitrary genetic gains. In popcorn, this is even more evident due to the negative correlation between the main characteristics of economic importance - grain yield and popping expansion. As an option in the use of classical biometrics as a selection index, the optimal procedure restricted maximum likelihood/best linear unbiased predictor (REML/BLUP) allows the simultaneous estimation of genetic parameters and the prediction of genotypic values. Based on the mixed model methodology, the objective of this study was to investigate the comparative efficiency of eight selection indices estimated by REML/BLUP for the effective selection of superior popcorn families in the eighth intrapopulation recurrent selection cycle. We also investigated the efficiency of the inclusion of the variable "expanded popcorn volume per hectare" in the most advantageous selection of superior progenies. In total, 200 full-sib families were evaluated in two different areas in the North and Northwest regions of the State of Rio de Janeiro, Brazil. The REML/BLUP procedure resulted in higher estimated gains than those obtained with classical biometric selection index methodologies and should be incorporated into the selection of progenies. The following indices resulted in higher gains in the characteristics of greatest economic importance: the classical selection index/values attributed by trial, via REML/BLUP, and the greatest genotypic values/expanded popcorn volume per hectare, via REML. The expanded popcorn volume per hectare characteristic enabled satisfactory gains in grain yield and popping expansion; this characteristic should be considered super-trait in popcorn breeding programs.
选择指数通常使用经济权重，这会变成任意的遗传增益。在爆米花中，由于具有经济重要性的主要特征——籽粒产量和爆花膨胀率之间存在负相关，这种情况更为明显。作为将经典生物统计学用作选择指数的一种选择，最优程序限制最大似然法/最佳线性无偏预测法（REML/BLUP）允许同时估计遗传参数和预测基因型值。基于混合模型方法，本研究的目的是调查通过REML/BLUP估计的八个选择指数在第八个群体内轮回选择周期中有效选择优良爆米花家系的比较效率。我们还研究了在最有利地选择优良后代时纳入“每公顷爆花玉米体积”变量的效率。总共在巴西里约热内卢州北部和西北部的两个不同地区对200个全同胞家系进行了评估。与经典生物统计学选择指数方法相比，REML/BLUP程序产生了更高的估计增益，应将其纳入后代选择中。以下指数在具有最大经济重要性的特征方面产生了更高的增益：通过REML/BLUP的经典选择指数/试验赋予的值，以及通过REML的最大基因型值/每公顷爆花玉米体积。每公顷爆花玉米体积这一特征在籽粒产量和爆花膨胀率方面实现了令人满意的增益；在爆米花育种计划中应将这一特征视为超级性状。
