Salinity Effects on Germination and Plant Growth of Prairie Cordgrass and Switchgrass

Abstract

duced successfully on marginal lands, such as those affected by salinity, reduces the pressure to produce energy crops on land that would otherwise be used to produce food crops. In this paper, the degree of salinity tolerance of "Red River" prairie cordgrass (Spartina pectinata Link) and "Cave-in-Rock" switchgrass (Panicum virgatum L.) was determined by evaluating seed germination, plant growth, ion uptake, and leaf anatomical feature responses in saline conditions. Red River seeds retained 50% of germination potential under high salinity up to 300 mM NaCl, whereas Cave-in-Rock seed germination was reduced by 80% at 300 mM NaCl. Red River seedlings survived up to 500 mM NaCl, while more than 30% of Cave-in-Rock did not survive above 100 mM NaCl in greenhouse experiments. Red River produced more biomass and second-generation tillers and had a greater root and shoot biomass ratio than Cave-in-Rock under all salinity ranges. Sodium accumulation in shoots of Cave-in-Rock increased with increasing salinity, whereas Red River maintained a low level of sodium in biomass through salt-gland exclusion. The increasing rate of selectivity coefficient for potassium over sodium in Red River was higher than in Cave-in-Rock with increasing salinity. Although seed germination and plant growth decreased as salinity increased, Red River retained its potential of seed germination and to produce new tillers and biomass under salinity stress.

Stress-Tolerant Feedstocks for Sustainable Bioenergy Production on Marginal Land

“…Panicum virgatum is moderately tolerant of saline conditions, and cultivar "PV-1777" had the highest salinity tolerance for upland ecotypes in one study [151], but in others, "Blackwell" [164,165] and "Trailblazer" [166] performed well in highsalinity conditions. Compared with Spartina pectinata, Panicum virgatum "Cave-in-Rock" had low germination (down 80 %) in high (300 mM) salinity levels, and less than 70 % of seedlings survived in even moderate salinity (100 mM) treatments [167].…”

“…In contrast, Pennisetum purpureum showed major reductions in shoot biomass in saline conditions [146], and M. × giganteus was only moderately salt tolerant [160]. Upland ecotypes of Panicum virgatum (e.g., "Blackwell," "Trailblazer," and "PV-1777") were among the more salt-tolerant cultivars [151,164,166,184], although the upland ecotype, "Cave-in-Rock," was not tolerant at the seedling stage [167].…”

“…Spartina pectinata C4 High Spartina pectinata seeds germinated and seedlings survived in high salinity conditions (up to 500 mM NaCl). Under all salinity treatments, cordgrass produced more tillers and greater biomass than switchgrass, by exuding salt through salt glands [167]. Spartina pectinata has a level of tolerance to soil salinity that is higher than that of other tall warm-season grasses [106], and that is similar to halophytes [179], with an ability to maintain growth in salinity levels ranging from 2-20 dS/m [180].…”

Analysis of Active Nucleolus Organizing Regions in Polyploid Prairie Cordgrass (<i>Spartina pectinata</i> Link) by Silver Staining

“…This species has recently gained attention as an important biotic component for soil and water conservation practice on agricultural landscapes along with biomass production (Long 1975, Potter et al 1995, Boe and Lee 2007, Montemayor et al 2008, Skinner et al 2009, Boe et al 2009, Kim et al 2012a). Due to its massive rhizome and deep root system (Weaver 1968), prairie cordgrass is able to survive and even thrive under abiotic stress conditions such as waterlogging (Jensen 2006), soil salinity (Montemayor et al 2008, Kim et al 2012a) and drought (Boe et al 2009). In addition, the combination of genomic changes and increased genetic diversity induced by polyploidization (Parisod et al 2010) may be a key factor in growth, performance, adaptability of polyploid prairie cordgrass in such marginal environments.…”

“…Their cytotypes and geographic distribution were already given by Kim et al (2010Kim et al ( , 2012a. The objectives of this study were to estimate the number of AgNORs, their locations, and their activities on metaphase chromosomes and to determine the heteromorphic variation in size and number of nucleoli at interphase cells for different ploidy levels in prairie cordgrass populations.…”