Sagers Joseph K, Waldron Blair L, Creech Joseph Earl, Mott Ivan W, Bugbee Bruce
Plants, Soils, and Climate Department Utah State University Logan UT USA.
Forage and Range Research Laboratory USDA Agricultural Research Service Logan UT USA.
Ecol Evol. 2017 Nov 12;7(24):10916-10929. doi: 10.1002/ece3.3607. eCollection 2017 Dec.
Halogeton () is an invasive species that displaces Gardner's saltbush () on saline rangelands, whereas, forage kochia () potentially can rehabilitate these ecosystems. Salinity tolerance has been hypothesized as the predominant factor affecting frequency of these species. This study compared relative salinity tolerance of these species, and tall wheatgrass () and alfalfa (). Plants were evaluated in hydroponics, eliminating the confounding effects of drought, for 28 days at 0, 150, 200, 300, 400, 600, and 800 mmol/L NaCl. Survival, growth, and ion accumulation were determined. Alfalfa and tall wheatgrass shoot mass were reduced to 32% of the control at 150 mmol/L. Forage kochia survived to 600 mmol/L, but mass was reduced at all salinity levels. Halogeton and Gardner's saltbush increased or maintained shoot mass up to 400 mmol/L. Furthermore, both actively accumulated sodium in shoots, indicating that Na was the principle ion in osmotic adjustment, whereas, forage kochia exhibited passive (linear) Na accumulation as salinity increased. This study confirmed the halophytic nature of these three species, but, moreover, discovered that Gardner's saltbush was as saline tolerant as halogeton, whereas, forage kochia was less tolerant. Therefore, factors other than salinity tolerance drive these species' differential persistence in saline-desert ecosystems.
盐生草（Halogeton）是一种入侵物种，它会在盐碱草地上取代加德纳滨藜（Gardner's saltbush），而饲料地肤（forage kochia）则有可能恢复这些生态系统。耐盐性被认为是影响这些物种分布频率的主要因素。本研究比较了这些物种以及高羊茅（tall wheatgrass）和苜蓿（alfalfa）的相对耐盐性。在水培条件下对植物进行评估，消除干旱的混杂影响，在0、150、200、300、400、600和800 mmol/L的氯化钠溶液中培养28天。测定了植物的存活率、生长情况和离子积累。在150 mmol/L时，苜蓿和高羊茅的地上部生物量降至对照的32%。饲料地肤在600 mmol/L时仍能存活，但在所有盐度水平下生物量均有所下降。盐生草和加德纳滨藜在高达400 mmol/L时地上部生物量增加或保持不变。此外，两者地上部都积极积累钠，表明钠是渗透调节中的主要离子，而随着盐度增加，饲料地肤表现出被动（线性）钠积累。本研究证实了这三个物种的盐生植物特性，但此外还发现加德纳滨藜与盐生草的耐盐性相当，而饲料地肤的耐盐性较差。因此，除耐盐性外的其他因素驱动了这些物种在盐碱荒漠生态系统中的不同持久性。
