Selection of Jatropha genotypes for bioenergy purpose: an approach with multitrait, multiharvest and effective population size

ABSTRACT Jatropha curcas L. is a perennial plant with great potential for biodiesel production. Thus, the aim of this study was to select J. curcas genotypes for bioenergy purpose considering multitrait, multiharvest and effective population size. To this end, a data set with 70 J. curcas families, obtained through controlled crosses, evaluated in a randomized block design, with six replications, three plants per plot, spaced at 4 × 2 m was used. The following traits were evaluated: plant height in the 2014 and 2015 crop seasons; canopy projection in the row (2015 crop season); canopy projection between rows (2015 crop season); and grain yield (2015, 2016, and 2017 harvests). The mixed model methodology was used to estimate the variance components and to predict the genetic values. Superior genotypes were selected through Multitrait index based on factor analysis and genotype-ideotype distance (FAI-BLUP index), considering the effective population size. According to this index, 98% of all additive genetic variability were summarized in three factors. By adopting the selection intensity that allows maintaining the effective population size equal to 30 (i.e., selection of 214 individuals), the predicted gains were 15.56, 21.75, 4.16, and 5.37% for the traits grain yield in the 2015 and 2016 harvests, canopy projection in the row, and canopy projection between rows in the 2015 crop season, respectively. Thus, the results suggest that the FAI-BLUP index can be successfully used in J. curcas breeding.

摘要 麻疯树（Jatropha curcas L.）是一种极具生物柴油生产潜力的多年生植物。本研究旨在结合多性状、多收获次数与有效群体大小，筛选适用于生物能源用途的麻疯树基因型。本研究使用的数据集包含70个通过控制性杂交获得的麻疯树家系，试验采用随机区组设计，设置6次重复，每小区定植3株植株，株行距为4 m × 2 m。本研究评估的性状包括：2014与2015季的株高；2015季的行内冠幅投影、行间冠幅投影，以及2015、2016、2017收获季的籽粒产量。本研究采用混合模型分析法估计方差组分并预测遗传值，并结合有效群体大小，通过基于因子分析与基因型-理想型距离的多性状指数（FAI-BLUP指数）筛选优良基因型。结果显示，该指数可将总加性遗传变异的98%概括为3个因子。当采用可维持有效群体大小为30的选择强度（即筛选214个个体）时，2015与2016季籽粒产量、2015季行内冠幅投影以及行间冠幅投影的预测遗传增益分别为15.56%、21.75%、4.16%和5.37%。综上，研究结果表明FAI-BLUP指数可成功应用于麻疯树的遗传育种工作。