Messina (Melilotus siculus) is a new annual pasture legume with better combined waterlogging and salt tolerance than other annual legumes. Messina cv. Neptune and a new salt-tolerant rhizobial symbiont (Sinorhizobium medicae SRDI-554) were made available to Australian growers in 2017. Messina is related to the annual medics (Medicago spp.) that are nodulated by the same genus of rhizobia and regarded as sensitive to soil acidity. Because some saltland soils are acidic, it is important to understand the sensitivity of messina to soil acidity in order to avoid failures during early adoption.

Acidity tolerance of the messina–Sinorhizobium symbiosis was investigated in a hydroponic experiment (inoculation with SRDI-554, or the salt-intolerant strain WSM-1115 recommended for medics), and in three acidic soils (pH_Ca 4.3–5.5) (inoculation with SRDI-554 ± lime pelleting of seed), in the greenhouse.

In the hydroponic experiment, the percentage of messina plants (with SRDI-554) that formed nodules declined at pH levels between 5.7 (43%) and 5.5 (4%). Strain SRDI-554 was slightly more sensitive to acidity than strain WSM-1115. In the acidic soils, more plants formed nodules than in the hydroponic experiment at similar pH levels; however, without lime pelleting, nodule number was inadequate at soil pH_Ca <5.5. Addition of lime to seed was beneficial to messina nodulation. Nodule number per plant increased from 4.0 to 9.6 with the addition of lime.

The messina–Sinorhizobium symbiosis was confirmed as sensitive to low pH. At pH_Ca 5.5, which is the level recommended as the lower limit for growing messina, nodule number was constrained in both hydroponics and soil. The risk of suboptimal nodulation would be reduced if the recommended lower soil pH limit for growing messina is increased to pH_Ca 5.8, in line with most annual medics. Efforts to improve the acidity tolerance of the messina symbiosis would be best focused on the rhizobial symbiont, rather than the plant.

墨西拿（Milolosus siculus）是一种新的一年生牧草豆科植物，与其他一年生豆科植物相比，具有更好的抗涝和耐盐性。墨西拿简历 海王星和一种新的耐盐根瘤菌共生菌（中华根瘤菌SRDI-554）于2017年向澳大利亚种植者提供。墨西拿与由同一根瘤菌属支配并被认为是敏感的一年生医学家（Medicago spp。）有关。对土壤酸度。由于某些盐碱地土壤是酸性的，因此了解麦地那对土壤酸度的敏感性很重要，这样可以避免在早期采用时发生破坏。

的messina-酸度公差中华根瘤菌共生在水培试验进行了研究（接种SRDI-554，或该盐不耐受菌株WSM-1115建议用于医务人员），以及在三个酸性土壤（pH为_钙4.3-5.5）（接种SRDI-554±种子的石灰沉淀），在温室中。

在水培试验中，在5.7（43％）和5.5（4％）的pH值下，形成结节的麦地那植物（带有SRDI-554）的百分比下降。SRDI-554菌株对酸度的敏感性比WSM-1115菌株略高。在类似的pH值条件下，在酸性土壤中，比水培试验中形成结节的植物更多。但是，如果不进行石灰沉淀，则在土壤pH _Ca <5.5时结节数不足。在种子中添加石灰有利于麦穗结瘤。添加石灰使每株植物的根瘤数从4.0增加到9.6。

梅西纳-中华根瘤菌共生被证实对低pH敏感。在pH_的Ca 5.5，这是推荐为用于生长墨西下限水平，根瘤数在这两个水栽和土壤限制。如果与大多数年度医务人员保持一致，如果建议将用于种植麦穗的较低土壤pH限制下限提高至pH _Ca 5.8，则会降低次佳结瘤的风险。改善麦地那共生的耐酸性的努力最好集中在根瘤菌共生体上，而不是植物上。