DIFFERENT STABILITY METHODS FOR CULTIVAR RECOMMENDATION IN ELEPHANT-GRASS FOR ENERGY PURPOSES IN BRAZIL

ABSTRACT The elephant-grass undergoes successive cutting and periodical evaluations that it possible to identify clones with high stability for dry matter production, which can be used for energy production. The present study was carried out to evaluate stability dry matter yield for different parametric and non-parametric methods in elephant grass genotypes for biomass production undergoes successive cutting in the agroclimatic conditions of the Norte Fluminense (RJ, Brazil). The variable measured in the 40 genotypes was dry matter yield (DMY) at 2009, 2010 and 2011 in a field study designed as randomized block design with two replicates. Each sample was grown in different environment condition. The stability methods tested were the Yates and Cochran’s, Plaisted and Peterson’s, Wricke’s ecovalence, Annicchiarico’s, Lin and Binns’ and Kang and Phan’s. Results indicated that cutting (E) and genotypes (G) influenced significantly on the performance of dry matter yield. The non-parametric stability methods were effective for the evaluation of stability in dry matter yield. Genotypes Mercker, Pinda-México, Mercker 86-México, Guaçu/IZ, Mercker Pinda, P-241-Piracicaba and Cubano Pinda were stable stability dry matter yield. Hence, there are genotypes may be exploited in future breeding programmes in order to improve productivity of upland elephant grass over environment.

摘要 本研究针对象草开展连续刈割与定期评价，以期筛选出干物质产量稳定性优异的克隆株系，用于能源生产。本试验旨在巴西北弗鲁米嫩塞地区（里约热内卢州）的农业气候条件下，针对经连续刈割的象草基因型，采用多种参数法与非参数法评估其干物质产量的稳定性。本试验共纳入40个象草基因型，于2009年、2010年及2011年测定其干物质产量（dry matter yield, DMY），田间试验采用随机区组设计，设置2次重复，每个供试样本种植于不同环境条件下。本次测试的稳定性分析方法包括：耶茨-科克伦法（Yates and Cochran’s）、普莱斯特-彼得森法（Plaisted and Peterson’s）、里克生态价法（Wricke’s ecovalence）、安尼基亚里科法（Annicchiarico’s）、林-宾斯法（Lin and Binns’）以及康-潘法（Kang and Phan’s）。结果表明，刈割环境（E）与基因型（G）对干物质产量表现具有显著影响。非参数稳定性分析方法可有效用于干物质产量的稳定性评价。基因型Mercker、Pinda-México、Mercker 86-México、Guaçu/IZ、Mercker Pinda、P-241-Piracicaba以及Cubano Pinda的干物质产量稳定性优异。综上，可在后续育种项目中利用上述基因型，以提升不同环境下旱地象草的生产性能。