旱涝急转对玉米叶片衰老特性和产量的影响

    Effects of drought-flood abrupt alternation on the characteristics of leaf senescence and grain yield of maize

    • 摘要: 为研究旱涝急转对玉米叶片衰老特性和产量的影响,以春玉米“宜丹629”为供试材料,2021年在测坑条件下,设置拔节期旱(drought,D)、涝(waterlogging,W)、旱急转轻涝(drought-light waterlogging,D-LW)、旱急转中涝(drought-moderate waterlogging,D-MW)、旱急转重涝(drought-heave waterlogging,D-HW)、和正常供水(control,CK)6个处理。测定不同处理组合下玉米大喇叭口期、抽雄期和灌浆期叶片叶绿素仪(soil and plant analyzer development,SPAD)值、过氧化物歧化酶(superoxide dismutase,SOD)、过氧化物酶(peroxidase,POD)、过氧化氢酶(catalase,CAT)活性、丙二醛(malondialdehyde,MDA)、可溶性蛋白含量和净光合速率(net photosynthetic rate,Pn),成熟期籽粒产量及其构成。结果表明,与CK相比,D-LW处理抽雄期和灌浆期玉米叶片的SPAD值、SOD、POD、CAT活性、可溶性蛋白含量、Pn和成熟期穗数、穗粒数和千粒质量差异不显著,其籽粒产量维持在较高水平(7810.3 kg/hm2),说明旱急转轻涝不会加速玉米叶片的衰老,从而稳定籽粒产量。而其他水分胁迫处理显著降低各监测时期玉米叶片SPAD值、SOD、POD、CAT活性、可溶性蛋白含量和Pn,明显提高MDA含量,使穗数、穗粒数和千粒质量减少,最终显著降低产量(较CK下降13.3%~72.7%)。整体上,D-MW和D-HW处理明显加速玉米叶片衰老,严重抑制籽粒产量。综上,拔节期旱后急转轻涝对玉米叶片SPAD值、抗氧化酶活性、可溶性蛋白含量和Pn有补偿作用,从而获得较高的籽粒产量。研究结果为玉米应对旱涝急转灾害和灌排管理提供理论依据。

       

      Abstract: Drought and waterlogging have been two of the most important abiotic stresses on plant growth and development. Furthermore, plants can suffer from the dual stresses of drought and waterlogging in some cases, including drought-flood abrupt alternation (DFAA) stress. The occurrence of DFAA is ever increasing in the middle and lower reaches of the Yangtze River, China, in recent years, due mainly to the global climate. There is a severe threat to the sustainable crop production. However, it remains unknown about the DFAA impact on the leaf senescence and grain yield of maize, together with the underlying mechanisms. The purpose of this study was to investigate the effects of different water stress treatments at the jointing stage on the net photosynthetic rate (Pn), leaf SPAD values, activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), soluble protein and malondialdehyde (MDA) contents at the key growth stages, ear number per plant, kernels number per ear, and one-thousand weight of maize. Taking the spring maize "Yidan 629" as the research object, a leaching-pond experiment was carried out in Jingzhou City, Hubei Province, China in 2021. The treatments included the moderate drought (with 55%-60% field capacity as irrigation low limit for 18 d, D), waterlogging for 6 d (W), moderate drought immediately followed by waterlogging for 3 d (D-LW), moderate drought immediately followed by waterlogging for 6 d (D-MW), moderate drought immediately followed by waterlogging for 9 d (D-HW) at the jointing stage, and well-water during the whole grown season (CK) of maize. Leaf senescence traits were characterized to determine the grain yield and its components at the bell, tasselling and filling stages. The results showed that there were comparable SPAD values, SOD, CAT, and POD activities, soluble protein content, Pn at the tasselling and filling stages, and ear number per plant, kernels number per ear, and one-thousand weight in the D-LW treatment, compared with the CK. Thus, a relatively high grain yield was obtained in the D-LW treatment. This indicated that the moderate drought immediately followed by waterlogging for 3 d at the jointing stage reduced the leaf senescence, thus stabilizing the grain yield of maize. Compared with the CK, the treatments D, W, D-MW, and D-HW significantly reduced Pn, SPAD values, activities of SOD, CAT, and POD, and soluble protein content, whereas, there was a significant increase in the MDA content of maize leaves at the bell, tasselling, and filling stages, resulting in the low ear number per plant, kernels number per ear, and one-thousand weight, and correspondingly smaller grain yield of maize. Consequently, the treatments D, W, D-MW, and D-HW significantly reduced the grain yield of maize by 13.3%-72.7%. Overall, the adverse effects of water stress treatments on the leaf senescence and grain yield were ranked in the descending order of D-HW, D-MW, W, D, D-LW treatment. Therefore, the moderate drought immediately followed by waterlogging for 3 d at the jointing stage shared the compensatory on the SPAD value, antioxidant enzyme activities, soluble protein content and Pn of maize leaves, leading to a relatively high grain yield of maize. The finding can also provide a theoretical reference to cope with the drought-flood abrupt alternation disaster, and then manage the irrigation and drainage for maize.

       

    /

    返回文章
    返回