The use of periodical water stress and potassium fertilization may enhance rice tolerance to drought stress and improve the crop’s instantaneous water use efficiency without much yield reduction. This study was conducted to assess the effects of different periodical water stress combined with potassium fertilization regimes on growth, yield, leaf gas exchanges and biochemical changes in rice grown in pots and compare them with standard local rice grower practices. Five treatments including (1) standard local grower’s practice (control, 80CF = 80 kg K2O/ha + control flooding); (2) 120PW15 = 120 kg K2O/ha + periodical water stress for 15 days; (3) 120DS15V = 120 kg K2O/ha + drought stress for 15 days during the vegetative stage; (4) 120DS25V = 120 kg K2O/ha + drought stress for 25 days and (5) 120DS15R = 120 kg K2O/ha + drought stress for 15 days during the reproductive stage, were evaluated in this experiment. Control and 120PW15 treatments were stopped at 100 DAS, and continuously saturated conditions were applied until harvest. It was found that rice under 120PW15 treatment showed tolerance to drought stress evidenced by increased water use efficiency, peroxidase (POX), catalase (CAT) and proline levels, maximum efficiency of photosystem II (fv/fm) and lower minimal fluorescence (fo), compared to other treatments. Path coefficient analysis revealed that most of parameters contribute directly rather than indirectly to rice yield. In this experiment, there were four factors that are directly involved with rice yield: grain soluble sugar, photosynthesis, water use efficiency and total chlorophyll content. The residual factors affecting rice yield are observed to be quite low in the experiment (0.350), confirming that rice yield was mostly influenced by the parameters measured during the study.
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机译:定期水分胁迫和钾肥的使用可能会提高水稻对干旱胁迫的耐受性,并提高作物的瞬时水分利用效率,而不会大幅降低产量。这项研究旨在评估不同时期的水分胁迫结合钾肥施用方式对盆栽水稻的生长,产量,叶片气体交换和生化变化的影响,并将其与当地标准的水稻种植者做法进行比较。五种处理方法包括(1)标准的当地种植者的做法(对照,80CF = 80 kg K2O / ha +对照洪水); (2)120PW15 = 120千克K2O /公顷+持续15天的定期水分胁迫; (3)120DS15V = 120 kg K2O / ha +营养期15天的干旱胁迫;在该实验中评估了(4)生殖阶段的120DS25V = 120千克K2O / ha +干旱胁迫25天和(5)生殖阶段的120DS15R = 120千克K2O / ha +干旱胁迫15天。在100 DAS停止对照和120PW15处理,并施加连续饱和条件直至收获。研究发现,经过120PW15处理的水稻表现出对干旱胁迫的耐受性,其表现为水分利用效率,过氧化物酶(POX),过氧化氢酶(CAT)和脯氨酸水平提高,光系统II的最高效率(fv / fm)和最低荧光(fo)降低。 ,相比其他治疗方法。路径系数分析表明,大多数参数直接而不是间接影响水稻产量。在该实验中,有四个与水稻产量直接相关的因素:谷粒可溶性糖,光合作用,水分利用效率和总叶绿素含量。在实验中观察到影响水稻产量的残留因子非常低(0.350),这证实了水稻产量主要受研究过程中测得的参数影响。
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