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：象草经连续刈割与定期评价，可筛选出干物质生产稳定性优异的无性系，这类无性系可用于能源生产。本研究旨在针对巴西里约热内卢州北弗鲁米嫩塞地区农业气候条件下、用于生物质生产且经连续刈割的象草基因型，评估不同参数与非参数方法在干物质产量稳定性评价中的应用效果。本田间试验采用随机区组设计，设置2次重复，对40个象草基因型在2009、2010、2011年的干物质产量（dry matter yield, DMY）进行测定。所有供试样本均种植于不同环境条件下。供试的稳定性分析方法包括Yates与Cochran法、Plaisted与Peterson法、Wricke生态价法、Annicchiarico法、Lin与Binns法以及Kang与Phan法。结果显示，刈割环境（E）与基因型（G）对干物质产量表现存在显著影响。非参数稳定性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及Cubano Pinda具备稳定的干物质产量表现。综上，可在未来的育种项目中利用这些基因型，以提升不同环境下旱地象草的生产性能。