College of Horticulture, Henan Agricultural University, Zhengzhou, 450002, PR China.
College of Horticulture, Henan Agricultural University, Zhengzhou, 450002, PR China.
Environ Pollut. 2023 Jan 1;316(Pt 1):120521. doi: 10.1016/j.envpol.2022.120521. Epub 2022 Oct 26.
Soil salinity severely limits crop yield and quality. Grafting onto tolerant rootstocks is known as an effective means to alleviate salt stress. The present study was planned to find out the potential roles, mechanisms and applications of luffa rootstock to improve salt tolerance of grafted cucumber plants. Here, we screened a highly salt-tolerant luffa rootstock by evaluating the growth, photosynthetic performance, antioxidant defense and the accumulation of Na and K under salt stress. Reciprocal grafting between cucumber and luffa showed that luffa rootstock significantly improved the salt tolerance of cucumber plants, as evidenced by higher fresh weight, photochemical efficiency (Fv/Fm), and lower relative electrical conductivity (REC), which was closely associated with the decreased accumulation of Na and increased the accumulation of K in shoots of luffa grafted cucumber seedlings, leading to a lower Na:K ratio in shoot when compared with self-grafted cucumber. Furthermore, grafting with intermediate stock of luffa also sufficiently alleviated cucumber salt stress by reducing Na accumulation in shoot and the whole plant but increasing Na accumulation in interstock and root under salt stress, fully proving the salt tolerance depending on the capacity of luffa interstock to limit the transport of Na from the root to the shoot. More importantly, luffa rootstock improved the growth, yield and quality of grafted cucumber plants grown in pots in solar greenhouse as revealed by increased net photosynthetic rate, plant height, leaf number, yield, Vitamin C and soluble sugar but decreased titratable acid under both salinity and normal conditions. Together, these results, for the first time, clearly demonstrated that luffa,a new highly salt-tolerant rootstock, enhances salt tolerance and improves yield and quality of grafted cucumber plants by reducing sodium transport to the shoot.
土壤盐度严重限制了作物的产量和品质。将接穗嫁接到耐盐砧木上被认为是缓解盐胁迫的有效手段。本研究旨在探讨丝瓜砧木提高嫁接黄瓜植株耐盐性的潜在作用、机制和应用。本研究通过评价生长、光合性能、抗氧化防御和盐胁迫下 Na 和 K 的积累，筛选出一种高度耐盐的丝瓜砧木。黄瓜和丝瓜的正反嫁接表明，丝瓜砧木显著提高了黄瓜植株的耐盐性，表现在嫁接黄瓜幼苗的鲜重、光化学效率（Fv/Fm）较高，相对电导率（REC）较低，这与嫁接黄瓜幼苗中 Na 的积累减少和 K 的积累增加密切相关，导致嫁接黄瓜幼苗的 shoot 中 Na:K 比值降低。此外，中间砧木的嫁接也通过减少 shoot 和整株植物中 Na 的积累，增加 interstock 和根中 Na 的积累，充分缓解了黄瓜的盐胁迫，充分证明了耐盐性取决于丝瓜 interstock 限制 Na 从根向 shoot 运输的能力。更重要的是，丝瓜砧木通过提高净光合速率、株高、叶片数、产量、维生素 C 和可溶性糖，降低可滴定酸度，在温室大棚中显著提高了嫁接黄瓜的生长、产量和品质，在盐胁迫和正常条件下均如此。总之，这些结果首次清楚地表明，丝瓜作为一种新的高度耐盐砧木，通过减少 Na 向 shoot 的运输，增强了嫁接黄瓜的耐盐性，提高了产量和品质。
