PDF(Pubmed)
Abstract：
Drought has become more recurrent and causes a substantial decline in forage yields leading to strain on feed resources for livestock production. This has intensified the search for drought-tolerant forages to promote sustainable livestock production. The objective of this study was to identify drought-tolerant Urochloa grasses and to discern their morpho-physiological and yield traits to water stress as well as the relationship between these traits and indices of drought resistance. The results showed that the ecotypes, water regimes and their interaction significantly influenced all the studied morpho-physiological and yield traits. There was a significant decrease in plant height, number of leaves and tillers, dry matter yield, relative water content, photosystem II and efficiency of photosystem II with an increase in non-photochemical quenching. The principal component analysis revealed that the performance of Urochloa grass ecotypes was different under water sufficient (WS) and water deficit conditions. Drought tolerance indicators (mean productivity, geometric mean productivity, tolerance index and stress tolerance index) were most effective in identifying Urochloa ecotypes with high biomass production under both water deficient and WS conditions. Ecotypes K17, K7, Kisii, Busia and Kakamega were the most drought tolerant, Basilisk, K6, K10, K19 and Toledo were moderately tolerant whereas, CIAT6385, CIAT16449, K13, K5 and K9 were drought sensitive. The five drought-tolerant Urochloa ecotypes should be tested for sustainable biomass production under field conditions and used in breeding programmes to develop high-yielding drought-tolerant varieties.
摘要：
干旱变得更加反复，并导致牧草产量大幅下降，导致畜牧业生产的饲料资源紧张。这加强了对耐旱牧草的寻找，以促进可持续的畜牧业生产。这项研究的目的是鉴定耐旱的乌克洛拉草，并辨别它们对水分胁迫的形态生理和产量性状，以及这些性状与抗旱指标之间的关系。结果表明，生态型，水分状况及其相互作用显着影响了所有研究的形态生理和产量性状。株高明显下降,叶子和分till的数量，干物质产量，相对含水量,光系统II和光系统II的效率随着非光化学猝灭的增加。主成分分析显示，在水分充足（WS）和水分亏缺条件下，乌罗克洛草生态型的表现不同。耐旱性指标(平均生产力，几何平均生产率，耐受性指数和胁迫耐受性指数）在缺水和WS条件下最有效地鉴定高生物量生产的Urochloa生态型。生态型K17，K7，Kisii，Busia和Kakamega是最耐旱性的，Basilisk,K6、K10、K19和托莱多具有中等耐受性，而CIAT6385、CIAT16449、K13、K5和K9对干旱敏感。应在田间条件下对五种耐旱的乌罗克洛瓦生态型进行可持续生物量生产测试，并将其用于育种计划，以开发高产的耐旱品种。
