Ochola Celestine Anyango, Ngugi Mathew Pierro, Nyaboga Evans N, Njarui Donald M G
Department of Biochemistry, Microbiology and Biotechnology, Kenyatta University, P.O Box 43844-00100, Nairobi, Kenya.
Department of Biochemistry, University of Nairobi, P.O Box 30197-00100, Nairobi, Kenya.
AoB Plants. 2024 Jun 6;16(3):plae034. doi: 10.1093/aobpla/plae034. eCollection 2024 Jun.
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 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 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 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 ecotypes should be tested for sustainable biomass production under field conditions and used in breeding programmes to develop high-yielding drought-tolerant varieties.
干旱发生得越来越频繁，导致牧草产量大幅下降，给畜牧生产的饲料资源带来压力。这加剧了人们对耐旱牧草的寻找，以促进可持续畜牧生产。本研究的目的是鉴定耐旱草种，识别它们在水分胁迫下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对所有研究的形态生理和产量性状均有显著影响。随着非光化学猝灭的增加，株高、叶片数、分蘖数、干物质产量、相对含水量、光系统II和光系统II效率均显著下降。主成分分析表明，在水分充足（WS）和水分亏缺条件下，草种生态型的表现不同。耐旱指标（平均生产力、几何平均生产力、耐性指数和胁迫耐性指数）在识别水分亏缺和WS条件下具有高生物量产量的生态型时最为有效。生态型K17、K7、基苏木、布西亚和卡卡梅加最耐旱，巴西利斯克、K6、K10、K19和托莱多为中度耐旱，而CIAT6385、CIAT16449、K13、K5和K9对干旱敏感。这五个耐旱生态型应在田间条件下进行可持续生物量生产测试，并用于育种计划，以培育高产耐旱品种。
